Academic literature on the topic 'Volcanis islands'
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Journal articles on the topic "Volcanis islands":
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Smellie, John L. "Chapter 3.2a Bransfield Strait and James Ross Island: volcanology." Geological Society, London, Memoirs 55, no. 1 (2021): 227–84. http://dx.doi.org/10.1144/m55-2018-58.
Abstract:
AbstractFollowing more than 25 years of exploration and research since the last regional appraisal, the number of known subaerially exposed volcanoes in the northern Antarctic Peninsula region has more than trebled, from less than 15 to more than 50, and that total must be increased at least three-fold if seamounts in Bransfield Strait are included. Several volcanoes remain unvisited and there are relatively few detailed studies. The region includes Deception Island, the most prolific active volcano in Antarctica, and Mount Haddington, the largest volcano in Antarctica. The tectonic environment of the volcanism is more variable than elsewhere in Antarctica. Most of the volcanism is related to subduction. It includes very young ensialic marginal basin volcanism (Bransfield Strait), back-arc alkaline volcanism (James Ross Island Volcanic Group) and slab-window-related volcanism (seamount offshore of Anvers Island), as well as volcanism of uncertain origin (Anvers and Brabant islands; small volcanic centres on Livingston and Greenwich islands). Only ‘normal’ arc volcanism is not clearly represented, possibly because active subduction virtually ceased atc.4 Ma. The eruptive environment for the volcanism varied between subglacial, marine and subaerial but a subglacial setting is prominent, particularly in the James Ross Island Volcanic Group.
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McDOUGALL, IAN. "Age of volcanism and its migration in the Samoa Islands." Geological Magazine 147, no. 5 (February 10, 2010): 705–17. http://dx.doi.org/10.1017/s0016756810000038.
Abstract:
AbstractPotassium–argon (K–Ar) ages on whole rock samples have been measured on lavas from the subaerial Samoa Islands, which form a broadly linear volcanic chain that extends from the ESE to the WNW for about 360 km. The Manu'a Islands near the southeast limit of the chain exhibit youthful ages, with most <0.4 Ma, in keeping with the geological observations. Tutuila consists of several volcanoes, and previous work yielded a mean K–Ar age of 1.26 ± 0.15 Ma for the shield-building volcanism. Upolu, to the WNW of Tutuila, gives a mean age of 2.15 ± 0.35 Ma for the shield-building phase, represented by the Fagaloa Volcanics, with much of the island covered by significantly younger volcanic rocks. Savai'i, further to the WNW, is dominated by youthful volcanism, extending into historic times. In a restricted area, adjacent to the NE coast of Savai'i, previously thought to have volcanic rocks correlating with the Fagaloa Volcanics of Upolu, the ages are much younger than those on Upolu, lying between 0.32 and 0.42 Ma. Considering only the subaerial volcanism from Ta'u to Upolu, but also including Vailulu'u, the volcanism has migrated in a systematic ESE direction at 130 ± 8 mm a−1 over 300 km in the last 2.2 Ma. This rate is nearly twice that obtained from GPS measurements of Pacific Plate motion of 72 mm a−1 at N64°W in this area. However, if the much older age of shield-building volcanism from the submarine foundations of Savai'i is included, the regression yields a volcanic migration rate of 72 ± 14 mm a−1, in keeping with the measured GPS rate and consistent with a hotspot origin for the island chain. This suggests that the volcanic migration rates determined from the age of subaerial volcanism can be considerably overestimated, and this is now evident in other Pacific Ocean island chains. Clearly, the ages of the main shield-building volcanism from subaerial volcanism are minima, and if the older submarine lavas can be measured, these may yield a migration rate more in keeping with current plate motions.
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Simurda, Christine, Lori A. Magruder, Jonathan Markel, James B. Garvin, and Daniel A. Slayback. "ICESat-2 Applications for Investigating Emerging Volcanoes." Geosciences 12, no. 1 (January 14, 2022): 40. http://dx.doi.org/10.3390/geosciences12010040.
Abstract:
Submarine volcanism in shallow waters (<100 m), particularly in remote settings, is difficult to monitor quantitatively and, in the rare formation of islands, it is challenging to understand the rapid-paced erosion. However, these newly erupted volcanic islands become observable to airborne and/or satellite remote sensing instruments. NASA’s ICESat-2 satellite laser altimeter, combined with visible imagery (optical and microwave), provide a novel method of evaluating the elevation characteristics of newly emerged volcanoes and their subaerial eruption products. Niijima Fukutoku-Okanoba (NFO) is a submarine volcano 1300 km south of Tokyo (Ogasawara Archipelago of Japan) that periodically breaches the ocean surface to create new islands that are subsequently eroded. The recent eruption in August 2021 is a rare opportunity to investigate this island evolution using high-resolution satellite datasets with geodetic-quality ICESat-2 altimetry. Lansdat-8 and Planet imagery provide a qualitative analysis of the exposed volcanic deposits, while ICESat-2 products provide elevation profiles necessary to quantify the physical surface structures. This investigation determines an innovative application for ICESat-2 data in evaluating newly emerged islands and how the combination of satellite remote sensing (visible and lidar) to investigate these short-lived volcanic features can improve our understanding of the volcanic island system in ways not previously possible.
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Leat, Philip T., and Teal R. Riley. "Chapter 3.1a Antarctic Peninsula and South Shetland Islands: volcanology." Geological Society, London, Memoirs 55, no. 1 (2021): 185–212. http://dx.doi.org/10.1144/m55-2018-52.
Abstract:
AbstractThe voluminous continental margin volcanic arc of the Antarctic Peninsula is one of the major tectonic features of West Antarctica. It extends from the Trinity Peninsula and the South Shetland Islands in the north to Alexander Island and Palmer Land in the south, a distance ofc.1300 km, and was related to east-directed subduction beneath the continental margin. Thicknesses of exposed volcanic rocks are up toc.1.5 km, and the terrain is highly dissected by erosion and heavily glacierized. The arc was active from Late Jurassic or Early Cretaceous times until the Early Miocene, a period of climate cooling from subtropical to glacial. The migration of the volcanic axis was towards the trench over time along most of the length of the arc. Early volcanism was commonly submarine but most of the volcanism was subaerial. Basaltic–andesitic stratocones and large silicic composite volcanoes with calderas can be identified. Other rock associations include volcaniclastic fans, distal tuff accumulations, coastal wetlands and glacio-marine eruptions.Other groups of volcanic rocks of Jurassic age in Alexander Island comprise accreted oceanic basalts within an accretionary complex and volcanic rocks erupted within a rift basin along the continental margin that apparently predate subduction.
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Griffiths, Chris J., and Richard D. J. Oglethorpe. "The stratigraphy and geochronology of Adelaide Island." Antarctic Science 10, no. 4 (December 1998): 462–75. http://dx.doi.org/10.1017/s095410209800056x.
Abstract:
The Mesozoic-Cenozoic volcanic arc of the Antarctic Peninsula is represented on Adelaide Island by a sedimentary and volcanic succession intruded by plutons. 40Ar-39 Ar step-heating age spectra have been obtained from volcanic rocks and hornblende separates from sedimentary clasts of plutonic origin. These spectra show evidence for some argon loss, but, in general, have plateau ages which are consistent with the mapped stratigraphy and with other geochronological controls, suggesting that they approximate to original ages. As a result the following events in the evolution of Adelaide Island can be recognized:1) mostly marine Mesozoic sedimentation, 2) Early Cretaceous (c. 141 Ma) plutonism (recorded in clasts from conglomerates), 3) Cretaceous volcanism, 4) Late Cretaceous (possibly Tertiary) sedimentation, 5) Early Tertiary volcanism, which was acidic in eastern outcrops and intermediate elsewhere, and 6) Eocene intermediate volcanism and deposition of arc-derived conglomerates. Volcanism was possibly coeval with known Palaeocene-Eocene plutonic activity on Adelaide Island (part of the Antarctic Peninsula Batholith) and with volcanism of similar age in northern Alexander Island and the South Shetland Islands. The volcanism on Adelaide Island and the South Shetland Islands, at least, was associated with a westward migration of the Antarctic Peninsula arc.
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Geyer, A., D. Pedrazzi, J. Almendros, M. Berrocoso, J. López-Martínez, A. Maestro, E. Carmona, A. M. Álvarez-Valero, and A. de Gil. "Chapter 7.1 Deception Island." Geological Society, London, Memoirs 55, no. 1 (2021): 667–93. http://dx.doi.org/10.1144/m55-2018-56.
Abstract:
AbstractDeception Island (South Shetland Islands) is one of the most active volcanoes in Antarctica, with more than 15 explosive eruptive events registered over the past two centuries. Recent eruptions (1967, 1969 and 1970) and volcanic unrest episodes in 1992, 1999 and 2014–15 demonstrate that the occurrence of future volcanic activity is a valid and pressing concern for scientists, logistic personnel and tourists that are visiting or are working on or near the island. Over the last few decades, intense research activity has been carried out on Deception Island to decipher the origin and evolution of this very complex volcano. To that end, a solid integration of related scientific disciplines, such as tectonics, petrology, geochemistry, geophysics, geomorphology, remote sensing, glaciology, is required. A proper understanding of the island's evolution in the past, and its present state, is essential for improving the efficiency in interpreting monitoring data recorded during volcanic unrest periods and, hence, for future eruption forecasting. In this chapter, we briefly present Deception Island's most relevant tectonic, geomorphological, volcanological and magmatic features, as well as the results obtained from decades of monitoring the island's seismic activity and ground deformation.
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Dimitrov, Dimitar, and Banush Banushev. "Geological-geomorphological characteristics and petrographical composition of the St. Anastasia Island." Acta Scientifica Naturalis 8, no. 1 (March 1, 2021): 118–25. http://dx.doi.org/10.2478/asn-2021-0010.
Abstract:
Abstract St. Anastasia Island is one of the symbols of the cultural and historical heritage of the Republic of Bulgaria. This raises the need for the study of risky oceanographic factors, climatic phenomena, risky geological processes as well as detailed petrographical characteristics of the Upper Cretaceous volcanic rocks forming the islands. The results of the petrographical study show that the island was built by Alkali feldspar trachytes. The volcanics from St. Anastasia Island shows a close petrochemical similarity to the volcanics from Alatepenski paleovolcano belonging to the “Peripheral Volcanic Centers” in the region.
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Mutaqin, Bachtiar W., Muh Aris Marfai, Danang Sri Hadmoko, Franck Lavigne, Audrey Faral, Helvetia Wijayanti, and Widiyana Riasasi. "Geomorphology of the small island of Tidore and Hiri (North Maluku, Indonesia)." E3S Web of Conferences 325 (2021): 03012. http://dx.doi.org/10.1051/e3sconf/202132503012.
Abstract:
Tidore and Hiri Islands in North Maluku Province is the result of a complex tectonic setting. In contrast with Ternate Island and its well-known volcano, Gamalama volcano, there is still a lack of research about volcanic information or volcanic landform in Tidore and Hiri Islands. Even though the two islands also have volcanoes, i.e., Hiri and Tidore/Kiematubu volcano. This study aims to provide geomorphological information, especially in Tidore and Hiri Islands, since this information is hard to find whereas it is very important to disaster mitigation and landuse planning. We used remote sensing images, digital elevation models (DEM), and geological maps to classify geomorphological information of the small island of Tidore and Hiri in the North Maluku based on geomorphological aspects, i.e., morphology, morphogenesis, morpho-chronology, and morpho-arrangement. As a volcanic island, the slope in Tidore and Hiri Island is dominated by a slightly steep (8°-16°) and a steep slope (16°-35°), while the relief is dominated by hills and mountainous. Volcanic landforms on Tidore and Hiri Islands are characterized by relatively symmetrical cone-shaped volcanic cones, which are accumulations of falling pyroclastic material and lava ejected from magma vents. Volcanic islands include the case of Tidore and Hiri Island have radial centrifugal river flow patterns. The material on Tidore and Hiri Islands is dominated by Holocene volcanic rocks. In Tidore, there is alluvial material on the west and east coasts of the island. This study result also can be developed into more detailed geomorphological maps, or landscape evolution in a volcanic island, or spatial planning.
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Patrick, Matthew R., and John L. Smellie. "Synthesis A spaceborne inventory of volcanic activity in Antarctica and southern oceans, 2000–10." Antarctic Science 25, no. 4 (June 12, 2013): 475–500. http://dx.doi.org/10.1017/s0954102013000436.
Abstract:
AbstractOf the more than twenty historically active volcanoes in Antarctica and the sub-Antarctic region only two, to our knowledge, host any ground-based monitoring instruments. Moreover, because of their remoteness, most of the volcanoes are seldom visited, thus relegating the monitoring of volcanism in this region almost entirely to satellites. In this study, high temporal resolution satellite data from the Hawaii Institute of Geophysics and Planetology's MODVOLC system using MODIS (Moderate Resolution Imaging Spectroradiometer) are complemented with high spatial resolution data (ASTER, or Advanced Spaceborne Thermal Emission and Reflection Radiometer, and similar sensors) to document volcanic activity throughout the region during the period 2000–10. Five volcanoes were observed in eruption (Mount Erebus, Mount Belinda, Mount Michael, Heard Island and McDonald Island), which were predominantly low-level and effusive in nature. Mount Belinda produced tephra, building a cinder cone in addition to an extensive lava field. Five volcanoes exhibited detectable thermal, and presumed fumarolic, activity (Deception, Zavodovski, Candlemas, Bristol, and Bellingshausen islands). A minor eruption reported at Marion Island was not detected in our survey due to its small size. This study also discovered a new active vent on Mount Michael, tracked dramatic vent enlargement on Heard Island, and provides an improved picture of the morphology of some of the volcanoes.
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Monjoie, Philippe, Henriette Lapierre, Artan Tashko, Georges H. Mascle, Aline Dechamp, Bardhyl Muceku, and Pierre Brunet. "Nature and origin of the Triassic volcanism in Albania and Othrys: a key to understanding the Neotethys opening?" Bulletin de la Société Géologique de France 179, no. 4 (July 1, 2008): 411–25. http://dx.doi.org/10.2113/gssgfbull.179.4.411.
Abstract:
AbstractTriassic volcanic rocks, stratigraphically associated with pelagic or reef limestones, are tectonically juxtaposed with Mesozoic ophiolites in the Tethyan realm. From the central (Dinarides, Hellenides) and eastern Mediterranean (Antalya, Troodos, Baër Bassit) to the Semail nappes (Oman), they occur either associated to the tectonic sole of the ophiolitic nappes or as a distinct tectonic pile intercalated between the ophiolites and other underthrust units. In the Dinaro-Hellenic belt, the Pelagonian units represent the lower plate, which is underthrust beneath the ophiolites. Middle to Late Triassic volcanic sequences are interpreted as the eastern flank of the Pelagonian platform and are therefore considered as a distal, deep-water part of the Pelagonian margin.The Triassic volcanics from Albania and Othrys are made up of basaltic pillowed and massive flows, associated locally with dolerites and trachytes. New elemental, Nd and Pb isotopic data allow to recognize four types of volcanic suites: (1) intra-oceanic alkaline and tholeiitic basalts, (2) intra-oceanic arc-tholeiites, (3) back-arc basin basalts, (4) calc-alkaline mafic to felsic rocks. Nd and Pb isotopic initial ratios suggest that the within-plate volcanic rocks were derived from an enriched oceanic island basalt type mantle source, devoid of any continental crustal component. The lower εNd value of the trachyte could be due to assimilation of oceanic altered crust or sediments in a shallow magma chamber. Island arc tholeiites and back-arc basin basalts have a similar wide range of εNd. The absence of Nb negative anomalies in the back-arc basin basalts suggests that the basin floored by these basalts was wide and mature. The high Th contents of the island arc tholeiites suggest that the arc volcanoes were located not far away from the continental margin.Albania and Othrys volcanics contrast with the Late Triassic volcanism from eastern Mediterranean (SW Cyprus, SW Turkey), which displays solely features of oceanic within plate suites. The presence of back-arc basin basalts associated with arc-related volcanics in Central Mediterranean indicates that they were close to a still active subduction during the Upper Triassic, while back-arc basins developed, associated with within-plate volcanism, leading to the NeoTethys opening.
Dissertations / Theses on the topic "Volcanis islands":
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García, Pérez Olaya. "The explosive volcanism of Teide-Pico Viejo volcanic complex, Canary Island." Doctoral thesis, Universitat de Barcelona, 2013. http://hdl.handle.net/10803/130923.
Abstract:
The explosive events in Teide Pico Viejo (TPV) complex in Tenerife Island (Spain) have traditionally been restricted to the subplinian eruption of Montaña Blanca, which occurred about 2000 years ago. A recent revision of the stratigraphy of TPV shows that phonolitic explosive activity has been significant during the Holocene, with several distinct episodes related to eruptions ranging from Strombolian to sub-plinian. Using field, mineralogical and geochemical stratigraphic correlations, we have identified 11 phonolitic explosive eruptions related to the satellite domes present all around TPV complex. One of the most representative eruptions is that of El Boqueron (5,660 yBP), a dome that generated an explosive event of VEI 3 with a minimum volume of 4-6x107 m3 and produced a plume with a height of up to 9km above sea level (MER 6.9-8.2x105 kg/s, during 9-15 h). The occurrence of these explosive events in the recent eruptive record of TPV is of major importance in evaluating the risk imposed by the volcanic complex on Tenerife. These eruptions have generated a wide range of direct hazards, such as fallout, emplacement of pyroclastic density currents, debris flows, lahars, and rock avalanches, which could occur again in case of a renewal of volcanic activity. The results obtained in our study are relevant to define realistic and precise eruptive scenarios for TPV and to assess its associated hazard, a necessary step in the evaluation and mitigations of volcanic risk in TenerifeEl complejo volcánico Teide Pico Viejo (TPV) es un stratovolcano situado en la isla de Tenerife, Islas Canarias, y ha sido considerado por la UNESCO el sistema volcánico activo más peligroso en Europa. Los eventos explosivos en el complejo TPV se han limitado tradicionalmente a la erupción subplinian de Montaña Blanca, que ocurrió hace unos 2000 años. Una reciente revisión de la estratigrafía muestra que la actividad explosiva fonolítica asociada a TPV ha sido significativa durante el Holoceno, presentado distintos episodios relacionados con erupciones que varían en tamaño de estromboliano a sub-pliniano. A través de las correlaciones estratigráficas obtenidas mediante observaciones de campo y datos de mineralógicos y geoquímicos, se han identificado 11 erupciones explosivas fonolítica relacionados con los domos satélite presentes en todo complejo TPV. Una de las erupciones más representativa es El Boquerón (5660 YBP), un domo que generó un evento explosivo de VEI 3 con un volumen mínimo de 4-6x107 m3 y produjo una columna con una altura de hasta 9 kilometros sobre el nivel del mar ( MER 6.9-8.2x105 kg / s, durante 9-15 h). La ocurrencia de estos eventos explosivos en el reciente registro eruptivo del complejo TPV es de gran importancia para evaluar el riesgo impuesto por el complejo volcánico en Tenerife. Estas erupciones han generado una amplia gama de amenazas directas, como los depósitos de caida, emplazamiento de las corrientes piroclásticas densidad, flujo de derrubios, lahares y avalanchas de roca, lo que podría ocurrir de nuevo en caso de renovación de la actividad volcánica. Los resultados obtenidos en nuestro estudio son relevantes para definir escenarios eruptivos realista y precisos para el complejo TPV y para evaluar su riesgo asociado, un paso necesario en la evaluación y mitigación del riesgo volcánico en Tenerife
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Maund, J. G. "The volcanic geology, petrology and geochemistry of Caldeira volcano, Graciosa, Azores, and its bearing on contemporaneous felsic-mafic oceanic island volcanism." Thesis, University of Reading, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370121.
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Letham-Brake, Mark. "Geological constraints on fluid flow at Whakaari volcano (White Island)." Thesis, University of Canterbury. Department of Geological Sciences, 2013. http://hdl.handle.net/10092/8728.
Abstract:
This study assesses the geological constraints on fluid flow within the main crater of Whakaari volcano (White Island) which is located in the Bay of Plenty, New Zealand. A review of the volcanological and morphological history, field mapping, and permeability experiments were used to propose a model for single-state (gas or liquid water) fluid flow in the volcano. Three structural scales were of most importance: (a) the elongate main crater (1.2 km by 0.5 km); which contains (b) three subcraters (~300-500 m in diameter); and (c) >14 historic eruption craters and crater complexes (30-300 m in diameter).
A large (2.1x10⁸ m³) sector collapse formed the basic morphology and structure of the amphitheatre-like main crater ≤3.4 ka. Hot fluids are released from magma at ~1–2 km depth and circulated within a conduit-hosted volcano-hydrothermal system. The collapse event was likely to have removed low permeability cone lavas, significantly increasing meteoric water collection and lateral seawater infiltration within high permeability main crater fill above the magma conduit. It is proposed that this caused a susceptibility to ‘wet’ (i.e. phreatic and phreatomagmatic) eruptions which possibly formed three prehistoric subcraters and has been demonstrated in the last ~200 years of available historic record. The permeability of the remaining in-situ cone lavas is controlled by micro- (<1 mm) and macro- (>1 mm) cracks but despite these cracks, the cone lavas’ permeability is still sufficiently low to focus rising magmatic fluid flow through main crater fill. Low-to-high permeability lithified tuffs are inferred to fill the main crater at depth. Low permeability fine ash tuffs generally restrict vertical fluid flow put permit it when vertical trains of vesicles are present. Atmospheric steam and gas pluming is accommodated by a permeable zone of repeated and overlapping historic eruption crater-related discontinuities that extend to >250 m depth through highly permeable unlithified main crater fill in the west. It is likely to be this material into which the seawater infiltrates from the east. Throughout the main crater, fluid flow is focussed at subcrater margins due to steeply-dipping discontinuities between low permeability lava and low-to-high permeability crater fill deposits. The variable permeabilities of crater fill deposits are due to age-related factors of hydrothermal alteration, reworking/sorting, consolidation, and pore mineralisation. At shallow levels (<100 m depth), vertical fluid flow is diverted to historic eruption crater margins by very low permeability clay (reworked and altered tephra). High permeability coarse ash tuffs, Fe-rich lapilli tuffs, and surficial solfatara deposits do not appear to have much effect on the overall fluid flow system.
The results of this study show that, within active volcanic craters, the spatial distributions of variably permeable lithologies are often related to discontinuous cratering structures. Together, these are significant geological constraints on fluid flow. Morphological changes to crater structure can directly impact the groundwater regime above the magma conduit and may strongly influence the occurrence of wet versus dry eruptions. This process is possibly a significant control on eruptive behaviour at volcanoes with similar fluid flow systems worldwide.
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Sigmarsson, Olgeir. "Geochimie isotopique du thorium des iles oceaniques (islande, canaries) et des zones de subduction (indonesie et chili)." Clermont-Ferrand 2, 1990. http://www.theses.fr/1990CLF21284.
Abstract:
La geochimie isotopique du thorium, associee a celle de l'o, du sr et du nd et a des mesures precises des teneurs en u et th dans les roches volcaniques actuelles, permet d'etudier la genese et l'evolution des magmas dans plusieurs contextes geodynamiques. Les resultats essentiels de ce travail sont les suivants: 1) la mise en evidence, en islande, de l'importance des phenomenes de contamination crustale: l'assimilation de croute profonde se produit aussi bien dans les zones de rift (produisant des tholeiites a quartz normatif a partir de tholeiites a olivine), que dans la zone laterale sud de l'islande ou l'extension est quasi inexistante et ou les basaltes primaires sont des basaltes alcalins donnant apres contamination crustale des basaltes riches en fe, ti; 2) l'origine des roches acides en islande est a rechercher dans la fusion de la croute metabasique, parfois prealablement alteree par l'hydrothermalisme. Ce modele pourrait s'appliquer a la formation de la croute continentale primitive; 3) le volcan hekla, etudie en detail, montre les roles respectifs de la fusion crustale et de la cristallisation fractionnee dans la formation des laves, allant des andesites basiques aux rhyolites; 4) dans l'archipel des canaries, les magmas primaires derivent d'un melange de magmas venant d'une source appauvrie et d'une source de type tristan de cunha; 5) l'importance d'un composant sedimentaire dans les sources des magmas de zones de subduction a ete mise en evidence dans l'arc de la sonde, en indonesie et au chili. Dans ce dernier cas, une correlation entre l'enrichissement des magmas en u et #1#0be montre que ces deux elements sont apportes dans les magmas par des fluides issus de la deshydration des sediments subductes, quelques 20000 ans avant leur eruption a la surface
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Belien, Isolde L. M. B. (Leo Maria Beatrijs) 1985. "Gas Migration Through Crystal-Rich Mafic Volcanic Systems and Application to Stromboli Volcano, Aeolian Islands, Italy." Thesis, University of Oregon, 2011. http://hdl.handle.net/1794/12107.
Abstract:
xvii, 171 p. : ill. (some col.)Crystals influence the migration of gas through magma. At low concentrations, they increase the bulk fluid properties, especially viscosity. At concentrations close to maximum packing, crystals form a rigid framework and magma cannot erupt. However, erupted pyroclasts with crystal contents close to the packing concentration are common at mafic volcanoes that exhibit Strombolian behavior. In this dissertation, I study the influence of solid particles on gas migration. I apply my results to Stromboli volcano, Italy, type locality of the normal Strombolian eruptive style, where gas moves through an essentially stagnant magma with crystallinity ∼50%. Specifically, I investigate the effect of crystals on flow regime, gas content (Chapter II), bubble concentration (number densities), bubble shapes, bubble sizes (Chapter III), and bubble rise velocities (gas flux) (Chapter IV). I find that gas-liquid flow regimes are not applicable at high particle concentrations and should be replaced by new, three-phase (gas-liquid-solid) regimes and that degassing efficiency increases with particle concentration (Chapter II). In Chapter III, I show that crystals modify bubble populations by trapping small bubbles and causing large bubbles to split into smaller ones and by modifying bubble shapes. In Chapter IV, I model Stromboli's crystal-rich magma as a network of capillary tubes and show that bubble rise velocities are significantly slower than free rise velocities in the absence of particles. In each chapter, I use analogue experiments to study the effect of different liquid and solid properties on gas migration in viscous liquids. I then apply my analogue results to magmatic conditions using simple parameterizations and/or numerical modeling or by comparing the results directly to observations made on crystal-rich volcanic rocks. Chapter V proposes a mechanism for Strombolian eruptions and gas migration through the crystalrich magma in which the effect of crystals is included. This model replaces the current twophase "slug" model, which cannot account for the high crystallinity observed at Stromboli. There are three appendices in this dissertation: a preliminary study of the influence of particles on gas expansion, image analysis methods, and the numerical code developed in Chapter IV. This dissertation includes previously published and unpublished co-authored material.
Committee in charge: Katharine Cashman, Chairperson; Alan Rempel, Member; Mark Reed, Member; Raghuveer Parthasarathy, Outside Member
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Dávila, Harris Pablo. "Explosive ocean-island volcanism : the 1.8–0.7 Ma explosive eruption history of Cañadas volcano recorded by the pyroclastic successions around Adeje and Abona, southern Tenerife, Canary Islands." Thesis, University of Leicester, 2009. http://hdl.handle.net/2381/9931.
Abstract:
The 1.8 to 0.7 Ma explosive eruption history of Las Cañadas volcano is recorded by the pyroclastic stratigraphy of southern Tenerife. A large pyroclastic apron is well exposed in the Bandas del Sur. It is divided into two regions, Adeje (southwest) and Abona (southeast). The lower stratigraphy of both successions is described here for the first time, and is divided into soil-bound eruption-units. The lithofacies record repeated phonolite explosive eruptions involving Plinian eruption columns and ignimbrite emplacement, with sedimentary reworking and soilification during repose intervals. The southwestern pyroclastic apron of Cañadas, around Adeje, includes eleven eruption-units, with one explosive eruption every 24,300–31,200 years. Two major unconformities are identified in this region, each representing ~0.6 myr hiatuses. The southeastern pyroclastic apron, around Abona, reveals nine newly discovered phonolitic eruption-units, eight of which are dated by 40Ar/39Ar. The eruptions span 1.6 Ma, and occurred with frequencies averaging one per 21,000 years to one per 79,556 years. The deposits include welded and non-welded ignimbrites and numerous fallout layers. Documentation of the ‘lower’ Bandas del Sur Group allows the entire pyroclastic record of southeast Tenerife to be constrained for the first time: over 18 explosive eruptions occurred during the past 1.6 myr, of which 7 may have been caldera-forming. Eruption frequencies cluster and are separated by unconformities that span from 184,000–563,000 years. A debris-avalanche deposit was discovered on the southeast flank of Cañadas. It records a catastrophic landslide, the Abona landslide, triggered by a phonolite explosive eruption 735 ± 5 ka ago. The Abona debris-avalanche deposit is enclosed between pyroclastic units of the Helecho Formation, and represents a single eruptionunit. Debris avalanche block and mixed facies, and a hummocky topography that dammed small ephemeral perched lakes, are exceptionally well-preserved. Limited disruption and mixing, and a general absence of clast segregation within the deposit, indicate that the landslide did not move as a rapid granular flow. The debris-block characteristics indicate that pervasive shattering and microbrecciation occurred progressively during transport, and were accompanied by limited shear, mixing and substrate erosion during predominantly laminar emplacement of a dilated, but essentially solid, shearing mass. The deposit is the only precisely dated giant landslide on Tenerife and provides the first unequivocal evidence of an eruption trigger on an ocean-island volcano.
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Grunewald, Uwe. "Measuring and modelling of volcanic pollutants from White Island and Ruapehu volcanoes assessment of related hazard in the North Island /." Thesis, University of Canterbury. Geological Sciences, 2007. http://hdl.handle.net/10092/1428.
Abstract:
White Island and Ruapehu are currently the most active volcanoes in New Zealand. During non-eruptive periods, intense quiescent degassing through fumaroles can occur. The current project studies the quiescent degassing plumes, including aerosol sampling on White Island and dispersion modelling of SO₂ and PM₁₀ from White Island and Ruapehu volcanoes. Aerosol sampling from fumaroles at the crater floor on White Island volcano was carried out on 9 February and 6 April 2005. The exposed filters were analysed for various anions and cations and the particle mass concentration and molar concentration determined. Major elemental constituents were sodium and chlorine (Na⁺: 413 µg m⁻³, Cl⁻: 1520 µg m⁻³), which show best correlation at both sampling sessions. Other ions detected, with little correlation, are Ca²⁺, PO₄³⁻ and to a certain extent Mg²⁺. Other constituents found, which cannot correlate explicitly to other ions, are K⁺, NH₄⁺, NO₃⁻, and SO₄²⁻. SEM study of one exposed filter was performed and mainly NaCl particles could be distinguished due to their well-defined cubic shape. The Air Pollution Model (TAPM) was used for dispersion modelling of SO₂ (models 1-4) and PM₁₀ (models 5 and 6) from White Island and Ruapehu volcanoes. Annual modelling was performed using different parameters of emission rate, exit temperature and exit velocity. The resulting plume dispersions show relatively low concentrations at ground level ≤10 m), particularly for the models of PM₁₀ dispersion. TAPM calculated the highest SO₂ ground level concentrations with model 4, where the NES values of 350 and 570 µg m⁻³ were exceeded several times. The data was then used for detailed hazard assessment of urban population in the North Island. The meteorological data from annual modelling was used for model evaluation and compared with observation data from different weather stations by statistical calculations. Overall, TAPM performed well with most good and very good results. To evaluate SO₂ dispersion modelling, airborne plume measurements were carried out on 22 November 2006 by plume traverses at 3, 10 and 20 km. Although there is some variation, the calculated correlation coefficients indicate good model results for two plume traverses at 3 and 20 km and one plume traverse at 10 km. The meteorological data was also used for model evaluation, and the results indicate good model performance. TAPM is therefore suggested for future studies when more observation data are available to verify the calculated model data.
8
Hevia, Cruz Francisco. "Climatic and landscape evolution of the Azores over the past million years." Electronic Thesis or Diss., université Paris-Saclay, 2023. http://www.theses.fr/2023UPASJ035.
Abstract:
L'évolution des îles volcaniques résulte d'interactions complexes entre croissance des volcans et processus de destruction (éruptions explosives, glissements de terrain, érosion fluviale, altération). Les changements climatiques peuvent influencer ces processus sur des échelles variées. A l’échelle événementielle, des précipitations intenses peuvent engendrer des épisodes érosifs extrêmes. Sur le long-terme, des variations des taux d'altération, sensibles aux précipitations et à la température, peuvent impacter la fertilité des sols et le cycle global du carbone.Les îles volcaniques des Açores offrent un cadre idéal pour étudier ces interactions, avec une grande importance scientifique et sociétal, en particulier dans le contexte actuel du réchauffement climatique. Au centre de l'Atlantique Nord, elles sont influencées par des facteurs climatiques majeurs. Ces îles ont eu des pulses d'activité volcanique au cours du dernier million d'années (Ma), une période marquée par d’importants changements climatiques liés aux cycles glaciaires-interglaciaires. Si les variations des conditions globales ont été bien documentées sur cette période, la reconstruction paléoclimatique aux échelles locales/régionales reste un défi. Les paléosols (PSs) sont des anciens sols inclus dans le registre géologique. Leur géochimie fournit des informations précieuses sur les conditions paléo-environnementales, et la géochronologie des produits volcaniques les encadrant permet leur contrainte temporelle.Dans ce travail, nous avons reconstruit les conditions moyennes annuelles de précipitation (MAP) et de température de l’air (MAAT) aux Açores au cours du dernier Ma. Deux proxies basés sur la composition en éléments majeurs des PSs ont été utilisés : l’indice d'altération CIA-K et l’argilosité, tous deux validés dans d'autres milieux volcaniques. La datation précise des unités volcaniques par K-Ar sur mésostase séparée (laves) et par ⁴⁰Ar/³⁹Ar sur monocristaux de feldspath potassique (dépôts pyroclastiques), révèle des «pulses» d‘altération sur quelques milliers d’années, notamment après les terminaisons glaciaires (MIS 21, 19, 11, 9e, 5e et 1). La géochimie des PSs montre des changements environnementaux rapides et des MAATs (12-28 ᵒC) en accord avec les données de température marine de surface établies à partir d’archives océaniques. Cette concordance indique une étroite relation océan-atmosphère. Ces «pulses» suggèrent en outre des phases d'affaiblissement de l'anticyclone des Açores, permettant aux courants d'air humides d'atteindre des secteurs plus au sud.Les taux moyens de formation des sols (3-180 mm/kyr) ont été influencés par la structure et la texture du substrat rocheux. Des PSs se sont formés lors de MAPs plus faibles dans les dépôts pyroclastiques que dans les coulées de lave (seuils de ~500 et ~800 mm/an). Cette différence supporte une cinétique favorisée par la fragmentation et une surface spécifique élevée. L’altération accrue en surface et le long des discontinuités géologiques de sub-surface peut avoir favorisé l'érosion par glissements de terrain. Des MAPs élevées (jusqu'à 1500 mm/an) sont notamment obtenues autour du stade interglaciaire de l’Eemien, qui coïncide avec l’initiation d’un glissement complexe sur le flanc Sud de Pico. Des MAPs intenses ont pu accélérer l’infiltration des eaux et favoriser les interactions hydromagmatiques. L’augmentation associée de pression interstitielle a ainsi pu déclencher la mise en mouvement du flanc le long de failles listriques toujours actives. Les conditions actuelles aux Açores sont plus humides et légèrement plus chaudes qu’au cours du dernier Ma, ce que pourrait favoriser le détachement du flanc externe de Pico, avec des conséquences potentiellement drastiques.Plus généralement, l’altération accrue favorise l’évolution rapide du paysage sur de telles îles et engendre des flux élémentaires et une absorption de CO₂ atmosphérique croissantes, ce qui a impacts locaux, régionaux et globauxLandscape evolution on volcanic islands is driven by complex interactions between volcano growth and destruction by a variety of processes (explosive eruptions, landslides, riverine erosion, weathering). Major climate changes, may impact the dynamics of degradation processes at different spatial and temporal scales. For example, extreme rain can produce an immediate hydrological response causing important destruction. Changes in weathering rates, sensitive to precipitation and temperature, can trigger changes in soil fertility but also modify global carbon cycling.The Azores volcanic islands provide an ideal setting to study these interactions, with both scientific and societal significance, especially in the context of ongoing global warming. Located in the Central North Atlantic, they are under the influence of major climatic drivers. Most of them had pulses of volcanic activity over the past 1 Myr, a period characterized by high-amplitude glacial-interglacial transitions with major climatic changes. While global climatic variations have been relatively well-studied for this period, reconstructing the atmospheric paleoclimate and its effects at local/regional scales remains challenging. Paleosols (PSs) are fossil soils formed by weathering at surface, and later incorporated into the geological record. Their geochemistry provides valuable insights into past environmental conditions, while the geochronology of volcanic products “bracketing” PSs allows their temporal constraint.In this work, we reconstructed mean annual precipitations (MAP) and air temperature (MAAT) over the last 1 Myr in the Azores region through a combined geochemical-geochronological study of PSs. Two proxies based on PSs’ major element were used: the weathering index (CIA-K) and the Clayeyness, both validated in other volcanic settings. The precise dating of volcanic units by either unspiked K-Ar on lava flow groundmass separates or ⁴⁰Ar/³⁹Ar on single K-feldspar of trachytic fallout evidence “pulses” of soil-formation within only a few kyr. This occurred especially after glacial terminations (MIS 21, 19, 11, 9e, 5e and 1), under wet and warm conditions. Fast paleoenvironmental changes were recorded in PSs’ geochemistry, and MAAT reconstructions (12-28 ᵒC) agree with previously published Sea Surface Temperatures, pointing to a tight ocean-atmosphere teleconnection. Those “pulses” suggest sustained weakening phases for the Azores High, allowing humid air currents (Westerlies) to reach further to the south.Our data also show contrasted rates of vertical soil development (3-180 mm/kyr). Weathering was favored by the structure and texture of parental materials, as PSs formed under lower MAP in pyroclastic deposits than in lava flows (~500 and ~800 mm/yr thresholds). This highlights the influence of fragmentation on weathering’s kinetics due to higher specific surface area. Enhanced weathering at surface and along geological discontinuities may have promoted mechanical weakening, favoring erosion and landslides. Notably, high MAPs (up to 1500 mm/yr) obtained around the Eemian interglacial stage are coincident in time with the initiation of a large slide complex on the southern flank of Pico. Intense precipitation may have led to increased water infiltration favoring enhanced hydromagmatic interactions. Drastic increase in pore pressure may then have triggered the initiation of the flank movement along listric faults that are still active. Current conditions in the Azores are wetter and slightly warmer than during the last Myr. Increased infiltration along faults could partly control subsequent movement and yield to detachment of the outer flank of Pico, with potentially dramatic consequences.More generally, present temperature and humidity increase on volcanic islands points to intense weathering, resulting in fast landscape evolution, increased lixiviation and elementary export and high atmospheric CO₂ uptaking, with local, regional and global impacts
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Meletlidis, Tsiogalos Stavros. "Eruptive dynamics and petrological evolution of recent volcanism on the El Hierro Island : Implications for volcanic hazard assessment." Doctoral thesis, Universitat de Barcelona, 2017. http://hdl.handle.net/10803/461582.
Abstract:
The Canarian archipelago, extends over approximately 500 km in total along the passive continental margin off NW Africa, comprises seven major and four minor islands, and it is part of the so called Macaronesia region, together with the archipelagos of Azores, Madeira, Salvajes and Cape Verde.
Within the oceanic geodynamic context, the Canary archipelago is located on oceanic crust of the big African plate, specifically upon the passive continental margin, with thickness exceeding 20 km. It is a good example of oceanic intraplate alkaline volcanism.
According the radioisotopic data available (Carracedo et al., 1998) the archipelago has been formed during the last 60 Ma and is still volcanically active. Multiple periods of volcanic activity accompanied with extreme range in magma compositions and eruptive styles have been exhibited during the evolution.
A wide variety of models have been proposed for the origin of the Canary Islands, such as, hot spot, decompressing fusion, Atlas generated propagating fracture, or the "block" model based on regional fractures that helped elevate the islands.
Holocene sub-aerial activity has occurred on all islands, except La Gomera, with 18 eruptions in the last 520 years (historic activity) on Tenerife, La Palma, Lanzarote and El Hierro. All these eruptive events consist of monogenetic basaltic eruptions along structures or zones identified as rifts (only the 1798 of Montaña Chahorra in Tenerife, expulsed intermediate composition magma and was located at the base of the Teide-Pico Viejo volcanic complex).
Although monogenetic volcanism is the most extended type of volcanic activity on the planet (Walker 2000) and is characterized by a large diversity of eruptive styles and products, it is generally associated to low level volcanic hazard and many times it is underestimated in the hazard assessment.
The main structures generated by these type of eruptions (concentrated as volcanic fields or long rift zones) are cinder cones, formed by the pyroclastic products and lava flows, that can reach several kilometres length. Eventually, can generate phreatomagmatic deposits, when an interaction between magma and water occurs (shallow submarine volcanism or littoral cones).
These eruptions, traditionally, are associated with a single batch and pulse of magma and are greatly influenced by local and regional stress fields. Other parameters that can be important in the evolution
of the activity, as in any other volcanic activity, are magma composition, volume, and rheological contrast beneath the surface.
Recent studies have revealed that, even in a monogenetic eruption, an internal geochemical evolution could be possible, mainly because of the multiple batches involved and the importance of the local stress controls in the migration and finally eruption of magma.
Complexity, derived from these internal and external conditions in combination with the depth where magmas are stored and transported, is reflected in the difficulty to anticipate and forecast these types of eruptions and their evolution, especially, for areas with long quiescent periods and a variety of magmas as in the Canary Islands, where a new volcano could come up in any location.
The reconstruction of the structure, geometry, composition and plumbing system conditions of pre- existed monogenetic eruptions on the Canary Islands along with the data obtained (petrological, seismological, geodetical, etc.) of an eruption in course such was the 2011 El Hierro eruption will help us obtain a significant progress in understanding the processes that take place, improve our knowledge on monogenetic eruptions and as a consequence enhance hazard assessment and reduce the risk to human lives.a última erupción en la isla de El Hierro (2011-12) representa una excelente oportunidad para estudiar el volcanismo monogenético basáltico. La comparación de los productos emitidos durante esa erupción con los emitidos en erupciones anteriores y la interpretación de los resultados petrológicos junto con los datos obtenidos por la red multiparamétrica de vigilancia volcánica del IGN de vigilancia (estaciones sísmicas, GNSS, gravimétricas,…) nos ha permitido lograr un conocimiento integral de los procesos que ocurren antes y durante este tipo de erupciones basáticas monogenéticas, que son las más probables a corto y medio plazo en Canarias. Este enfoque multidisciplinar nos ha proporcionado nueva información sobre el ascenso del magma, las condiciones y procesos internos, los mecanismos de las erupciones basálticas, los mecanismos de deposición y los escenarios de interacción. La interpretación conjunta de todos los datos obtenidos permitirá una mejor evaluación del riesgo volcánico, no solo para la isla de El Hierro, sino para todo el archipiélago canario. En esta tesis, junto con el estudio de la erupción de 2011-12, se han estudiado dos más erupciones; la que ha dado el depósito de productos evolucionados en el centro de la isla (área del Malpaso) donde la dinámica y evolución de ella se ha ligado en la interacción magma/agua y la erupción de Chinyero (1909, Tenerife) que con rasgos similares a la de El Hierro (basáltica) pero con menor volumen de magma involucrado, ha tenido una dinámica más explosiva de lo que se había creído hasta hoy. Por lo tanto, las evaluaciones de riesgo volcánico a largo y corto plazo para el conjunto de las islas Canarias deben tener en cuenta posibles escenarios que no solo incluyen la erupciones basálticas submarinas, como es el caso de 2011-2012, sino también las erupciones sub-aéreas de corta vida como la del Chinyero o las erupciones como la del Malpaso, donde la intrusión basáltica y la interacción con el agua son procesos que aumentan la explosividad de una erupción y como consecuencia, al área afectado de sus productos.
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Palmiotto, Camilla <1985>. "Transform Tectonics and Non-Volcanic Oceanic Islands." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6472/1/Palmiotto_Camilla_Tesi.pdf.
Abstract:
Oceanic islands can be divided, according to their origin, in volcanic and tectonic. Volcanic islands are due to excess volcanism. Tectonic islands are mainly formed due to vertical tectonic motions of blocks of oceanic lithosphere along transverse ridges flanking transform faults at slow and ultraslow mid-ocean ridges. Vertical tectonic motions are due to a reorganization of the geometry of the transform plate boundary, with the transition from a transcurrent tectonics to a transtensive and/or transpressive tectonics, with the formation of the transverse ridges. Tectonic islands can be located also at the ridge–transform intersection: in this case the uplift is due by the movement of the long-lived detachment faults located along the flanks of the mid-ocean ridges.
The "Vema" paleoisland (equatorial Atlantic) is at the summit of the southern transverse ridge of the Vema transform. It is now 450 m bsl and it is capped by a carbonate platform 500 m-thick, dated by 87Sr/86Sr at 10 Ma. Three tectonic paleoislands are on the summit of the transverse ridge flanking the Romanche megatrasform (equatorial Atlantic). They are now about 1,000 m bsl and they are formed by 300 m-thick carbonate platforms dated by 87Sr/86Sr, between 11 and 6 Ma. The tectonic paleoisland “Atlantis Bank" is located in the South-Western Indian Ridge, along the Atlantis II transform, and it is today 700 m bsl. The only modern example of oceanic tectonics island is the St. Paul Rocks (equatorial Atlantic), located along the St. Paul transform. This archipelago is the top of a peridotitic massif that it is now a left overstep undergoing transpression.
Oceanic volcanic islands are characterized by rapid growth and subsequent thermal subsidence and drowning; in contrast, oceanic tectonic islands may have one or more stages of emersion related to vertical tectonic events along the large oceanic fracture zones.
Books on the topic "Volcanis islands":
1
Greensmith, J. T. Lanzarote, Canary Islands. London: Geologists' Association, 2000.
2
Luigina, Vezzoli, ed. Island of Ischia. Roma: Consiglio nazionale delle ricerche, 1988.
3
Tagliaferro, Linda. How does a volcano become an island? London: Raintree, 2010.
4
Tagliaferro, Linda. How does a volcano become an island? Chicago, Ill: Raintree, 2008.
5
K, Sako Maurice, Geological Survey (U.S.), and Northern Mariana Islands. Disaster Control Office, eds. Volcanic investigations in the Commonwealth of the Northern Mariana Islands, April to May 1994. [Denver, CO]: U.S. Geological Survey, 1995.
6
Sigurjónsson, Sigurgeir. Volcano island. Reykjavík: Forlagið, 2010.
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D, Ayres L., and Geological Association of Canada, eds. Pyroclastic volcanism and deposits of cenozoic intermediate to felsicvolcanic islands: With implications for precambrian greenstone-belt volcanoes. Ann Arbor: U.M.I., 1987.
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Gill, Robin. Tenerife Canary Islands. 2nd ed. London: The Geologists' Association, 2003.
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Tait, Peter. White Island: New Zealand's most active volcano. Auckland, N.Z: Godwit, 2001.
10
Greensmith, J. T. Lanzarote, Canary Islands. [London]: The Geologists' Association, 2000.
Book chapters on the topic "Volcanis islands":
1
Hernández Ramos, William, Victor Ortega, Monika Przeor, Nemesio M. Pérez, and Pedro A. Hernández. "Submarine Eruption of El Hierro, Geotourism and Geoparks." In Geoheritage, Geoparks and Geotourism, 115–23. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-07289-5_11.
Abstract:
AbstractThe year 2011 remained in the memory of the residents of the island of El Hierro (Canary Island, Spain) because of the volcanic episode that originated in its vicinity. From the beginning of the first precursory signs in July 2011, the island’s inhabitants reminded that the islands’ geological origin is volcanic and, what are the consequent threats of living on them. The eruption, however, has occurred in the marine realm leaving the only threats to the population, strong earthquakes, and diffuse emission of volcanic gases. The Tagoro eruption has not caused any loss of human life, however, its major impact indirectly affected the economy of the residents of the village of La Restinga, in whose vicinity the volcano originated. From a scientific point of view, the eruption has provided an enormous field of observation of the volcanic phenomenon. With the information obtained during the monitoring of the volcano, there is more insight into possible future eruptions. A volcanic product that has never been seen before (Restringolites) was found thanks to this eruption, which is why this volcano was so particular from a petrological point of view. The eruption affected the island's economy, and it also had negative consequences on Herreño tourism. The inhabitants of the island, wanting to recover the pre-eruptive economic levels and attract tourists, who, due to the false catastrophic descriptions about the eruption, stopped coming, have taken decisive steps. El Hierro, having peculiar geomorphological and geological characteristics, was the perfect candidate to obtain the Geopark status. In this way, the island of El Hierro, being the Biosphere Reserve since 2000, became also the Geopark since 2014.
2
Dóniz-Páez, Javier, and Rafael Becerra-Ramírez. "Geomorphosites of El Hierro UNESCO Global Geopark (Canary Islands, Spain): Promotion of Georoutes for Volcanic Tourism." In Geoheritage, Geoparks and Geotourism, 87–93. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-07289-5_8.
Abstract:
AbstractGeotourism is a relatively recent concept and a novel kind of tourism, which has acquired a significant boom in the last decades, associated with the creation and consolidation of the UNESCO global geoparks network. There are two approaches to geotourism, one geological and the other geographical, much more global and inclusive of the elements of the natural and cultural heritage. In this chapter, we have chosen to use the geographical approach of geotourism, to apply it to the El Hierro global geopark and diversify the island's tourism, traditionally focused on diving and hiking, through geoforms (volcanic and non-volcanic), and its link with cultural heritage. For this, the most representative, preserved and accessible geomorphosites in the geopark have been identified, inventoried and selected, which can be visited through volcano tourism georoutes. To do this, a route is proposed in the El Faro-Orchilla geozone (GZH-07) of the geopark, since it is one of the best examples of recent monogenetic basaltic volcanism in the Canary Islands. This geozone has a high geodiversity and richness in its natural and cultural heritage, it is easily accessible and different geoforms and views of the island landscape can be seen along a 9.5 km route and 8 stops.
3
Guillén-Martín, Cayetano, and Carmen Romero. "Volcanic Geomorphology in El Hierro Global Geopark." In Geoheritage, Geoparks and Geotourism, 33–42. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-07289-5_3.
Abstract:
AbstractFew oceanic islands express their geomorphological history in such a marked way as the island of El Hierro. Indeed, on El Hierro, its geomorphology goes hand in hand with the evolution of its insular geology. In fact, seventy percent of places of geological interest in El Hierro’s Geopark have geomorphological features as their main or secondary interest, which is indicative of the importance of geomorphology in the configuration of the island’s relief. However, there are few studies that have addressed the processes or features of the island’s geomorphology. In this study, the first geomorphological characterization is carried out in which the island is considered as a whole unit.
4
Gill, Jim. "Island Arc Volcanism, Volcanic Arcs." In Encyclopedia of Marine Geosciences, 1–7. Dordrecht: Springer Netherlands, 2015. http://dx.doi.org/10.1007/978-94-007-6644-0_20-2.
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Gill, Jim. "Island Arc Volcanism, Volcanic Arcs." In Encyclopedia of Marine Geosciences, 379–83. Dordrecht: Springer Netherlands, 2016. http://dx.doi.org/10.1007/978-94-007-6238-1_20.
6
De la Cruz-Modino, Raquel, Cristina Piñeiro-Corbeira, Shankar Aswani, Carla González-Cruz, David Domínguez, Paula Ordóñez García, Agustín Santana-Talavera, and José Pascual-Fernández. "Cultural Seascapes in the ‘Sea of Calms’ and La Restinga Coast." In Geoheritage, Geoparks and Geotourism, 105–13. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-07289-5_10.
Abstract:
AbstractEl Hierro has been characterized by the balance between human development and environmental sustainability. The island was historically far from the mass tourism developments dominant on the other Canary Islands. Tourism accommodations in El Hierro are few compared to more developed coastal areas in the Archipelago, and recreational activities are mainly linked to cultural and natural sites and resources. This chapter focuses on La Restinga fishing village and its coasts, where the ‘Sea of Calms’ and one multiple-use Marine Reserve (MR) are located, both of which became popular over the last decade. The tourist development experience has promoted a new way of looking at the sea and conceptualizing its habitats and populations. In 2014, after the submarine volcano eruption occurred in 2011, we estimated that at least 25,391 dives had been carried out in the diving spots established by the MR and other diving sites close to La Restinga. Despite the difficulties experienced after the volcano eruption, a unique imaginaire has been consolidated, thanks to the image of the island's exclusive nature and iconic elements. In addition, the rapid recovery of the destination is an excellent example of how the tourism system can adapt and incorporate unexpected events such as volcanic eruptions.
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Schmincke, Hans-Ulrich. "Seamounts and Volcanic Islands." In Volcanism, 71–96. Berlin, Heidelberg: Springer Berlin Heidelberg, 2004. http://dx.doi.org/10.1007/978-3-642-18952-4_6.
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Schmieder, Robert William. "Volcanic features." In Heard Island, 299–314. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-20343-5_12.
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Casillas Ruiz, Ramón, Yurena Pérez Candelario, and Cristina Ferro Fernández. "Geoheritage Inventory of the El Hierro UNESCO Global Geopark." In Geoheritage, Geoparks and Geotourism, 43–51. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-07289-5_4.
Abstract:
AbstractIn 2014 the Island of El Hierro (Canary Islands) was declared a Geopark of the Unesco network, thus becoming the first UNESCO geopark of the Canary Islands. The geological history of the Island of El Hierro can be understood through the visit of 61 geosites, which are representative of the growth and destruction of an oceanic Island in an intraplate environment. The geological heritage represented by these geosites has as foremost exponents those related to the formation of mega-landslides and the formation of extensive fields of pahoehoe lava-flows related to the historical or prehistoric fissure volcanism concerning the activity of its three rifts. This chapter describes the methodology used in establishing the geosite inventory carried out in 2019, as well as the description of the established geosites.
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Beltrán-Yanes, Esther, and Isabel Esquivel-Sigut. "The Vegetation Landscapes of a Oceanic Recent Volcanic Island." In Geoheritage, Geoparks and Geotourism, 53–63. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-07289-5_5.
Abstract:
AbstractThe aim of this chapter is to characterise the vegetation landscapes of El Hierro’s Geopark, highlighting the important role played by the island’s volcanic morphology in the richness and diversity of its landscapes. To this end, some of its most representative vegetation landscapes have been selected at various spatial scales, recognising their main discontinuities and internal organisation, and identifying the integrated combinations of the geographical factors that determine them have been identified, with special interest in the volcanic morphostructural conditioning factors. This work has required photointerpretation of aerial images and consultation of the WMS (Web Map Service) of IdeCanarias, as well as field work for the preparation of vegetation profiles and floristic-physiognomic inventories. Active volcanic areas are distinguished by being some of the most dynamic types of landscape on the planet. In this sense, the study of the vegetation landscapes of the small island of El Hierro allows us to discover how volcanic morphogenesis can extraordinarily diversify island landscapes.
Conference papers on the topic "Volcanis islands":
1
Waibel, Al, and Adam Jones. "Near-Offshore Oceanic Geothermal Resources Developed from On-Shore Directional Drilling." In Offshore Technology Conference. OTC, 2024. http://dx.doi.org/10.4043/35417-ms.
Abstract:
New opportunities have emerged for the application of oilfield technologies transfer, such as directional drilling, to utilize base-load renewable energy. Development of geothermal resources have largely been restricted to on-shore sites, yet a major category of untapped geothermal development prospects are near-shore resources. Development of near-shore geothermal resources can provide renewable base-load electrical power options to areas that are now served by non-renewable power generation which can supply domestic, commercial, or industrial land-based and marine use. It may also support emerging technologies such as battery charging and green hydrogen generation for land-based and marine transportation or commercial applications. Additionally, the need for reliable and renewable base-load electrical power to support U.S. Naval operations has increased markedly in recent years, particularly in the western Pacific. The advantages of geothermal over other advanced renewable power sources is its base-load reliability, a relatively small footprint in terms of land use and the long-term durability of the equipment. Additionally, this generally untapped energy field provides an opportunity for oil and gas development companies to expand the application of their technology, experienced staff, and knowledge. However, as exploration and development of these geothermal resources may have substantial effects on their near-shore locations, it is important that this development recognize the commercial and environmental value of the near-shore marine environment and mitigate any effects from these activities. Many of the potential near-shore and shallow marine geothermal plays are associated with volcanic activity. However, non-volcanic structural plays also hold significant potential (figure 1). Perhaps the most dramatic and well-documented volcanic hydrothermal sites are the spectacular deep marine "black-smoker" vents associated with oceanic spreading centers. Yet, other than a few notable exceptions, such as Iceland (Atkins & Audunsson, 2013), these systems are usually located far from shore in deep marine environments (Hiriart et al., 2010) and have currently limited potential for widespread development. Other volcanic geothermal resources occurring near-shore are like structurally controlled settings observed on land. Examples include: Lihir Island, Papua-New Guinea (Peterson et.al., 2002; White, et.al., 2010); in the Mediterranean Sea (Fytikas et.al., 2005; Meteoboy, 2013) and the shores of Mexico’s Baja Peninsula (Vidal, et.al., 1978; Prol-Ledesma et.al., 2002). The western Pacific area is rife with volcanic islands. Yet only a few of these volcanoes have had geothermal resources developed for electrical production. One of the limiting features for geothermal evaluation of these volcanic islands is that, while they are often massive volcanoes, only the central top of the volcano is exposed above the water, while the bulk of the flanks are submerged beneath the sea. These volcanoes would have the same geothermal resource potential as their terrestrial counterpart but due to their partially submerged setting, they have been out of view and out of mind for the geothermal development community. With advances in directional drilling technologies over the past decades, it is now possible to develop near-shore (1~1.5 km) geothermal resources from on-shore locations, increasing the economic viability of these prospects while minimizing seafloor disturbance.
2
Septama, E. "Java Volcanic Arc, what lies beneath?" In Indonesian Petroleum Association 44th Annual Convention and Exhibition. Indonesian Petroleum Association, 2021. http://dx.doi.org/10.29118/ipa21-g-257.
Abstract:
Java Island is an active volcanic arc that resides in the southwestern - southern boundary of Sundaland edges. The volcanic arc consists of several volcanism episodes, with a relatively younging trend northward (Late Oligocene to Pleistocene), following the Indo-Australian plates inward migration. In contrast to the prolific neighboring Northwest and Northeast Java Basins in the Northern edges of Java Island; the basin reconstruction and development in the East-West trending depression in median ranges of Java (from Bogor to Kendeng Troughs) are overlooked and lays bare the challenge to the seismic imaging due to the structural complexity of the overthrusted Neogene unit as well as immense Quaternary volcanic eruption covers. On the other hand, oil and gas seepages around the northern and central parts of the Island confirmed the active petroleum generation. Five focused window areas are selected for this study. A total of 1,893 Km sections, 584 rock samples, 1569 gravity, and magnetic data, and 29 geochemical samples (rocks, oil, and gas samples) were acquired during the study. Geological fieldwork was focused on the stratigraphic unit composition and the observable features of deformation products from the outcrops. Due to the scarcity of the Paleogene deposit exposure in the Central-East Java area, the rock samples were also collected from the mud volcano ejected materials in the Sangiran Dome. Both Bogor and Kendeng Troughs are active petroleum systems that generate type II /III Kerogen typical to the reduction organic material derived from transition to the shallow marine environment. The result suggests that these basins are secular from the neighboring basins, The Northwest and Northeast Java Basins, characterized by oxidized terrigenous type III Kerogen. The contrasting subsurface configuration between Bogor and Kendeng Troughs mainly concerns the fold-thrust belt basement involvement and the tectonic shortening effect on the formerly rift basin.
3
Иванов, А. Н. "TO THE QUESTION OF POLYSTRUCTURAL ORGANISATION OF LANDSCAPE SPACE." In Геосистемы Северо-Восточной Азии. Crossref, 2021. http://dx.doi.org/10.35735/tig.2021.61.88.005.
Abstract:
Обсуждается понятие полиструктурности ландшафтного пространства. Объект исследований – остров Матуа с активным вулканом, отсутствием поверхностного стока и широким развитием селевых и лавинных комплексов. Разработана ландшафтная карта, основанная на структурно-генетических принципах, внутри островного ландшафта выделены три географические местности. Предложена модель нуклеарной системы с ядром в виде кратера вулкана, по степени влияния вулкана на природные комплексы выделены три зоны. В составе парадинамических геосистем, связанных однонаправленными потоками вещества и энергии, выделены и проанализированы селевые и лавинные геосистемы. Количественно оценены вещественные потоки, генерируемые вулканом, лавинами и селями. Установлено, что в современный период именно вулкан является основным системообразующим фактором для большинства природных комплексов острова. Сделан вывод о том, что полиструктурность ландшафтного пространства отчетливо проявляется в пределах острова и связана с формированием на одной территории разных типов геосистем, выделение которых основано на разных физических принципах. The concept of polystructurality of landscape space is discussed. The object of research is the island of Matua with an active volcano, lack of surface run-off and widespread development of debris-flow and avalanche complexes. A landscape map of the island's territory is presented, based on structural and genetic principles; three geographic areas are identified within the island landscape. A model of a nuclear system with a core in the form of a volcano crater has been developed; three zones have been identified according to the degree of the volcano's influence on natural complexes. Debris-flow and avalanche geosystems have been identified and analyzed as part of paradynamic geosystems connected by unidirectional flows of matter and energy. It has been established that in the modern period it is the volcano that is the main system-forming factor for most of the natural complexes of the island. It is concluded that the polystructural nature of the landscape space is clearly manifested within the island and is associated with the formation of different types of geosystems on the same territory, the identification of which is based on different physical principles.
4
Asgary, Ali. "Holovulcano: Augmented Reality simulation of volcanic eruptions." In The 8th International Defence and Homeland Security Simulation Workshop. CAL-TEK srl, 2018. http://dx.doi.org/10.46354/i3m.2018.dhss.007.
Abstract:
"This paper describes an interactive holographic simulation of volcanic eruption. The aim of the project is to use Augmented Reality (AR) technology to visualize different volcanic eruptions for public education, emergency training, and preparedness planning purposes. To achieve this goal, a 3D model of the entire Vulcano Island in Italy has been created using real elevation data. Unity game engine and Microsoft Visual Studio have been used to develop HoloVulcano augmented/virtual reality simulation application. The current version of HoloVulcano simulates normal and unrest situations, single and long lasting Vulcanian, Plinian, and Strombolian eruptions. HoloVulcano has been developed for Microsoft HoloLens AR device. Wearing the HoloLens, users can interact with the volcano through voice, gazing, and gestures and view different eruptions from different points in the island. HoloVulcano will be used for training emergency exercises and public education."
5
Yanis, Muhammad, Zaini Nasrullah, Muhammad Isa, Ananda Riski, Muzakir Zainal, and Andri Yadi Paembonan. "Optimizing the Gravity Data and Geological Observation for Mapping the Local Fault around the Jaboi Volcano." In The 5th International Conference on Science and Technology Applications. Switzerland: Trans Tech Publications Ltd, 2024. http://dx.doi.org/10.4028/p-mezta6.
Abstract:
Geothermal is a very expensive investment industry. Therefore, it is necessary to map a geological structure in the sub-surface, i.e., faults, and rock formations that control volcanic hydrothermal systems to reduce investment risk in the exploitation of geothermal. On the other hand, the hydrothermal system aims for flow paths connecting reservoir wells for fluid production. The Jaboi Volcano, with an estimated 80 MWe located on Weh Island, Indonesia, has been planned by the government to develop electrical energy, where the excess energy will be exported to Banda Aceh via undersea cables. We use global gravity model plus (GGM+) in a resolution of ~230m/px for mapping the geological structure of Jaboi volcano. Based on GGM+ data analysis, the Bouguer anomaly data shows low gravity values in volcanic areas, namely 46 – 69 mGal. These data only represent rock density values with low density in geothermal areas. We also calculate the residual anomaly from the Bouguer data using the high-pass-filtering technique, wherein the volcanic area, several high-gravity anomalies (1 – 1.4 mGal) correspond to the Leumomate fault in the direction of NW-SE. The same pattern is also obtained in the area with a suspected Ceunohot fault in the SW – NE direction. This research demonstrates the optimization of gravity satellite that free access to be used in mapping geological structures in geothermal Jaboi. Finally, we conclude that GGM+ data is a very efficient and cost-effective technique to detect geological structures around the Jaboi volcano, which developing countries can use as a preliminary study for evaluating and exploring geothermal energy
6
Hanamuro, Takahiro, Ken-Ichi Yasue, Yoko Saito-Kokubu, Koichi Asamori, Tsuneari Ishimaru, and Koji Umeda. "Current R & D Activities in the Study on Geosphere Stability." In ASME 2010 13th International Conference on Environmental Remediation and Radioactive Waste Management. ASMEDC, 2010. http://dx.doi.org/10.1115/icem2010-40018.
Abstract:
The Japanese islands are located in a tectonically active zone. The scientific base is required for assessing the geosphere stability for long-term isolation of radioactive waste in Japan. JAEA is promoting the establishment of investigation method for geotectonic events affecting geosphere stability and prediction model for the future changes of geological environments, that is necessary for site selection and safety assessment of the HLW geological disposal. For seismicity and faulting, detection techniques for active faults without topographic surface expression, such as using helium isotope ratios in hot spring gases or detection of hydrogen gas, and studies on the assessment of fault evolution have been developed. For volcanism and geothermal activity, heat sources for anomalous geothermal activity in non-volcanic regions are considered. Detection techniques for high-temperature fluids and magma deep underground, using geophysical and geochemical approaches, were constructed. For uplift, denudation and climatic/sea-level changes, a methodology to predict the future topographic change was developed. Also, for dating techniques as an essential part to proceed on these studies, C-14 and Be-10 dating using AMS and (U-Th)/He dating using QMS and ICP-MS have been developed. We are planning the establishment of assessment methods for geosphere stability including assessment of the activity of faults encountered in underground excavations, development of long-term prediction model of volcanism and hydrothermal activities, and hydrogeological analyses considering topographic change.
7
Naidu, Som, Dhiraj Bhartu, and Tony Mays. "Access to ICT Infrastructure and Devices in the South Pacific." In Tenth Pan-Commonwealth Forum on Open Learning. Commonwealth of Learning, 2022. http://dx.doi.org/10.56059/pcf10.3503.
Abstract:
The South Pacific region spreads over more than 30 million square kilometres of the Pacific Ocean. The region comprises more than a dozen island nations ranging from small volcanic islands to even smaller coral atolls. Population masses in the island nations vary from around 2,000 in Tokelau to a little more than 800,000 in the Republic of Fiji. Access to information and communications technologies and internet connectivity in the region is varied. This project involves the design and conduct of a desktop study into access to ICT infrastructure, connectivity and devices and their use by students and teachers in the Pacific. Outcomes of this study will enable COL to make informed decisions about what access and delivery technologies to employ in the Partnership for Open Distance and Flexible Learning project in the Pacific. The study will address issues of access to hardware, software, connectivity and skills, as well as examples of ways in which teachers, institutions or Ministries have found ways to address the challenges in low bandwidth/limited access environments, especially in the nine developing countries of the Commonwealth in the region.
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Godsey, Nick, Nichole Grau, and Jenna Cookson. "Session 2.1 Jeju volcanic island and lava tubes." In The 4th Global Virtual Conference of the Youth Environmental Alliance in Higher Education. Michigan Technological University, 2022. http://dx.doi.org/10.37099/mtu.dc.yeah-conference/dec2021/all-events/4.
Abstract:
"Jeju volcanic island and lava tubes is a National Park on an island off the southern coast of South Korea. Formed through volcanic activity hundreds of thousands of years ago, the island is now a tourist destination with the park being the centerpiece but also boasting great beaches for surfing, 3 World Heritage sites, and many museums. Bringing in tourism is essential to this island with only 2 cities but also comes along with some difficult challenges such as increased pollution, energy needs, and public transportation on this island. Type: Short talk (e.g. PowerPoint, Google Slides)"
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Vindas Umaña, Andrea, Jonathan Godinez, Jason Navarro Ulate, Cornelia Van Hazinga, Sara Mana, and Paulo Ruiz. "LACK OF VOLCANIC LINEAMENTS AND ANISOTROPY IN VOLCANISM RELATED TO RIFTING IN EL HIERRO, CANARY ISLANDS - SPAIN." In Northeastern Section-56th Annual Meeting-2021. Geological Society of America, 2021. http://dx.doi.org/10.1130/abs/2021ne-361606.
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Secrétan, Alexia, and Olivier Reubi. "Linking the sub-volcanic plutonic complex and the magmatic evolution at La Gomera volcano, Canary Islands." In Goldschmidt2023. France: European Association of Geochemistry, 2023. http://dx.doi.org/10.7185/gold2023.17912.
Reports on the topic "Volcanis islands":
1
Tweet, Justin S., Vincent L. Santucci, Kenneth Convery, Jonathan Hoffman, and Laura Kirn. Channel Islands National Park: Paleontological resource inventory (public version). National Park Service, September 2020. http://dx.doi.org/10.36967/nrr-2278664.
Abstract:
Channel Island National Park (CHIS), incorporating five islands off the coast of southern California (Anacapa Island, San Miguel Island, Santa Barbara Island, Santa Cruz Island, and Santa Rosa Island), has an outstanding paleontological record. The park has significant fossils dating from the Late Cretaceous to the Holocene, representing organisms of the sea, the land, and the air. Highlights include: the famous pygmy mammoths that inhabited the conjoined northern islands during the late Pleistocene; the best fossil avifauna of any National Park Service (NPS) unit; intertwined paleontological and cultural records extending into the latest Pleistocene, including Arlington Man, the oldest well-dated human known from North America; calichified “fossil forests”; records of Miocene desmostylians and sirenians, unusual sea mammals; abundant Pleistocene mollusks illustrating changes in sea level and ocean temperature; one of the most thoroughly studied records of microfossils in the NPS; and type specimens for 23 fossil taxa. Paleontological research on the islands of CHIS began in the second half of the 19th century. The first discovery of a mammoth specimen was reported in 1873. Research can be divided into four periods: 1) the few early reports from the 19th century; 2) a sustained burst of activity in the 1920s and 1930s; 3) a second burst from the 1950s into the 1970s; and 4) the modern period of activity, symbolically opened with the 1994 discovery of a nearly complete pygmy mammoth skeleton on Santa Rosa Island. The work associated with this paleontological resource inventory may be considered the beginning of a fifth period. Fossils were specifically mentioned in the 1938 proclamation establishing what was then Channel Islands National Monument, making CHIS one of 18 NPS areas for which paleontological resources are referenced in the enabling legislation. Each of the five islands of CHIS has distinct paleontological and geological records, each has some kind of fossil resources, and almost all of the sedimentary formations on the islands are fossiliferous within CHIS. Anacapa Island and Santa Barbara Island, the two smallest islands, are primarily composed of Miocene volcanic rocks interfingered with small quantities of sedimentary rock and covered with a veneer of Quaternary sediments. Santa Barbara stands apart from Anacapa because it was never part of Santarosae, the landmass that existed at times in the Pleistocene when sea level was low enough that the four northern islands were connected. San Miguel Island, Santa Cruz Island, and Santa Rosa Island have more complex geologic histories. Of these three islands, San Miguel Island has relatively simple geologic structure and few formations. Santa Cruz Island has the most varied geology of the islands, as well as the longest rock record exposed at the surface, beginning with Jurassic metamorphic and intrusive igneous rocks. The Channel Islands have been uplifted and faulted in a complex 20-million-year-long geologic episode tied to the collision of the North American and Pacific Places, the initiation of the San Andreas fault system, and the 90° clockwise rotation of the Transverse Ranges, of which the northern Channel Islands are the westernmost part. Widespread volcanic activity from about 19 to 14 million years ago is evidenced by the igneous rocks found on each island.
2
Haggart, J. W., L. T. Dafoe, K. M. Bell, G L Williams, E. T. Burden, L. D. Currie, R. A. Fensome, and A. R. Sweet. Historical development of a litho- and biostratigraphic framework for onshore Cretaceous-Paleocene deposits along western Baffin Bay. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/321828.
Abstract:
Cretaceous-Paleogene strata along the eastern coast of Baffin Island, on Bylot Island, and on associated islands north of Cape Dyer, have been known since the early days of exploration of Baffin Bay in the mid-nineteenth century. Studies of these strata in the 1970s-1990s established their clastic nature and revealed details of their stratigraphy, ages, and depositional settings. Onshore strata in the Cape Dyer area accumulated in close association with volcanic deposits related to late-stage rifting in the Late Cretaceous to Early Paleocene that eventually formed Baffin Bay. In contrast, deposits in more northerly areas, such as the Eclipse and North Bylot troughs on Bylot Island, exhibit similar clastic rocks, but lack conspicuous volcanic strata, and have been associated with either the Sverdrup Basin or the Baffin Bay rift. The litho- and biostratigraphy of these deposits are summarized and discussed in terms of differing and contrasting stratigraphic interpretations, age assignments, and depositional environments.
3
Peterson, T. D., N. Wodicka, S J Pehrsson, P. Acosta-Gongora, V. Tschirhart, C. J. Jefferson, H. Steenkamp, E. Martel, J. Percival, and D. Corrigan. The Rae Province at 2.6 Ga: a sanukitoid storm on the Canadian Shield, Nunavut. Natural Resources Canada/CMSS/Information Management, 2024. http://dx.doi.org/10.4095/332505.
Abstract:
Between 2.62 and 2.58 Ga, Rae Province was intruded from Lake Athabasca to Melville Peninsula (more than 1700 km) by mafic to felsic plutons (Snow Island Suite), and overlain by volcanic rocks that are now mostly preserved beneath Paleoproterozoic basins. The Snow Island Suite was preceded by offshore arc volcanism and possible back-arc basin activity, with a U-Pb age peak at 2.635 Ga (Marjorie peak). About 50% of the Snow Island Suite is an infracrustal granitoid with K-enriched and tonalitic subtypes; the remainder lies on a sanukitoid spectrum. The sanukitoidal rocks are dominantly orthopyroxene-bearing magnesian diorite and monzodiorite with Mesoarchean Nd model ages. Some isotopically juvenile Snow Island Suite and Marjorie peak mafic rocks also have strong sanukitoid or adakite trace-element signatures. Four important features in the data are: 1) Marjorie peak mafic assemblages are prominent on the southeastern edge of Rae Province. Related nickel showings are present in south Rae Province Marjorie peak and early Snow Island Suite rocks; 2) U-Pb ages in the Snow Island Suite young toward the west edge of the province; 3) the Committee Bay Block (north-central Rae Province) is distinctively rich in infracrustal Snow Island Suite migmatite and poor in Snow Island Suite sanukitoid rocks and in tonalite of any age; and 4) there is a marked shift from tonalite-rich infracrustal sources in south Rae Province to more tonalite-poor sources in central Rae Province. The data are consistent with the Snow Island Suite, representing a continental magmatic arc segment, verging westward, with ponding of mafic magmas, inducing melting in the lower lithosphere to generate intermediate melts that ascended and induced additional melting in the middle to upper crust to generate granite.
4
Narvaez, Liliana, Joerg Szarzynski, and Zita Sebesvari. Technical Report: Tonga volcano eruption. United Nations University - Institute for Environment and Human Security (UNU-EHS), August 2022. http://dx.doi.org/10.53324/ysxa5862.
Abstract:
On 15 January 2022, the Hunga-Tonga-Hunga-Ha'apai volcano eruption was felt across the Pacific Ocean and beyond, releasing energy equivalent to hundreds of Hiroshima nuclear explosions and creating supersonic air pressure waves that were observed from space. In the archipelago Kingdom of Tonga, the ashfall, tsunami and shock waves caused widespread devastation on several islands. The only fibre-optic cable that connects the islands with the rest of the world was severely damaged, leaving the entire country offline for more than three weeks. The case the Hunga Tonga-Hunga Ha’apai volcano eruption showed that the inability to “be online” becomes a vulnerability in the context of extreme events. This technical background report for the 2021/2022 edition of the Interconnected Disaster Risks report analyses the root causes, drivers, impacts and potential solutions for the Tonga volcano eruption through a forensic analysis of academic literature, media articles and expert interviews.
5
Berndt, Christian. RV SONNE Fahrtbericht / Cruise Report SO277 OMAX: Offshore Malta Aquifer Exploration, Emden (Germany) – Emden (Germany), 14.08. – 03.10.2020. GEOMAR Helmholtz Centre for Ocean Research Kiel, January 2021. http://dx.doi.org/10.3289/geomar_rep_ns_57_20.
Abstract:
SO277 OMAX served two scientific projects. The objectives of the first project, SMART, were to develop multi-disciplinary methodologies to detect, quantify, and model offshore groundwater reservoirs in regions dominated by carbonate geology such as the Mediterranean Sea. To this end we acquired controlled-source electromagnetic, seismic, hydroacoustic, geochemical, seafloor imagery data off Malta. Preliminary evaluation of the geophysical data show that there are resisitivity anomalies that may represent offshore freshwater aquifers. The absence of evidence for offshore springs means that these aquifers would be confined and that it will be difficult to use them in a sustainable manner. The objective of the second project, MAPACT-ETNA, is to monitor the flank of Etna volcano on Sicily which is slowly deforming seaward. Here, we deployed six seafloor geodesy stations and six ocean bottom seismometers for long-term observation (1-3 years). In addition, we mapped the seafloor off Mt. Etna and off the island of Stromboli to constrain the geological processes that control volcanic flank stability.
6
Nye, C. J., W. E. Scott, O. K. Neill, C. F. Waythomas, C. E. Cameron, and A. T. Calvert. Geology of Kasatochi volcano, Aleutian Islands, Alaska. Alaska Division of Geological & Geophysical Surveys, July 2017. http://dx.doi.org/10.14509/29718.
7
Saumur, B. M., M. C. Williamson, and C. A. Evenchick. Volcanic-intrusive complexes of western Axel Heiberg Island. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 2015. http://dx.doi.org/10.4095/297374.
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Williamson, M. C., B. M. Saumur, and C. A. Evenchick. HALIP volcanic-intrusive complexes, Axel Heiberg Island, Nunavut. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 2016. http://dx.doi.org/10.4095/297491.
9
Williamson, M. C., B. M. Saumur, and C. A. Evenchick. HALIP volcanic-intrusive complexes, Axel Heiberg Island, Nunavut. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 2016. http://dx.doi.org/10.4095/297784.
10
Robbins, S. D. Active volcanoes of Kamchatka and northern Kurile Islands. Alaska Division of Geological & Geophysical Surveys, December 2010. http://dx.doi.org/10.14509/21141.