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1
Keller, J�rg, et Maurice Krafft. « Effusive natrocarbonatite activity of Oldoinyo Lengai, June 1988 ». Bulletin of Volcanology 52, no 8 (novembre 1990) : 629–45. http://dx.doi.org/10.1007/bf00301213.
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Wadsworth, Fabian B., Edward W. Llewellin, Jérémie Vasseur, James E. Gardner et Hugh Tuffen. « Explosive-effusive volcanic eruption transitions caused by sintering ». Science Advances 6, no 39 (septembre 2020) : eaba7940. http://dx.doi.org/10.1126/sciadv.aba7940.
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Silicic volcanic activity has long been framed as either violently explosive or gently effusive. However, recent observations demonstrate that explosive and effusive behavior can occur simultaneously. Here, we propose that rhyolitic magma feeding subaerial eruptions generally fragments during ascent through the upper crust and that effusive eruptions result from conduit blockage and sintering of the pyroclastic products of deeper cryptic fragmentation. Our proposal is supported by (i) rhyolitic lavas are volatile depleted; (ii) textural evidence supports a pyroclastic origin for effusive products; (iii) numerical models show that small ash particles ≲10−5 m can diffusively degas, stick, and sinter to low porosity, in the time available between fragmentation and the surface; and (iv) inferred ascent rates from both explosive and apparently effusive eruptions can overlap. Our model reconciles previously paradoxical observations and offers a new framework in which to evaluate physical, numerical, and geochemical models of Earth’s most violent volcanic eruptions.
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Waythomas, Christopher. « Simultaneous effusive and explosive cinder cone eruptions at Veniaminof Volcano, Alaska ». Volcanica 4, no 2 (1 décembre 2021) : 295–307. http://dx.doi.org/10.30909/vol.04.02.295307.
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Historical eruptions of Veniaminof Volcano, Alaska have all occurred at a 300-m-high cinder cone within the icefilled caldera that characterizes the volcano. At least six of nineteen historical eruptions involved simultaneous explosive and effusive activity from separate vents. Eruptions in 1944, 1983–1984, 1993–1994, 2013, 2018 and 2021 included periods of explosive ash-producing Strombolian activity from summit vents and simultaneous nonexplosive effusion of lava from flank vents on either the southern or northeast sides of the cone. A T-junction conduit network is proposed to explain the simultaneous eruptive styles and as a mechanism for gas-magma segregation that must occur to produce the observed activity. Historical eruptions with simultaneous summit and flank activity produced slightly higher rising ash clouds compared to historical eruptions where simultaneous activity did not occur. This could be a consequence of the partitioning of more gas-charged magma into the vertical conduit of a T-junction conduit system.
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Zakšek, Klemen, Leonie Pick, Manoochehr Shirzaei et Matthias Hort. « Thermal monitoring of volcanic effusive activity : the uncertainties and outlier detection ». Geological Society, London, Special Publications 426, no 1 (21 mai 2015) : 93–113. http://dx.doi.org/10.1144/sp426.2.
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Katayama, Masato, et Yukina Uemura. « Prognostic Prediction for Therapeutic Effects of Mutian on 324 Client-Owned Cats with Feline Infectious Peritonitis Based on Clinical Laboratory Indicators and Physical Signs ». Veterinary Sciences 10, no 2 (9 février 2023) : 136. http://dx.doi.org/10.3390/vetsci10020136.
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Feline infectious peritonitis (FIP) is a fatal disease classified as either effusive, non-effusive (‘dry’), or a mixture (‘mixed’) of the forms of FIP, with mixed showing signs of both effusive and dry. To determine whether the therapeutic effect of Mutian on dry and mixed FIP can be predicted using clinical indicators before starting treatment, we entered 161 cats with mixed FIP and 163 cats with dry FIP into this study. Physical assessments, the reverse transcriptase-PCR detection of viral genes, and clinical laboratory tests (hematocrit, albumin/globulin ratio, serum amyloid A, α1-acid glycoprotein, and total bilirubin) were performed before Mutian was administered. These indicators were compared between the FIP groups that survived after receiving Mutian for 84 days and those that died before the completion of treatment. Significant differences in body temperature, appetite, and activity scores were confirmed between the surviving and non-surviving groups. The therapeutic effect was insufficient when total bilirubin levels increased in cats with the mixed form. In both of the FIP types, therapeutic effects were difficult to obtain when neurological clinical signs were observed. The therapeutic effects of Mutian on the cats with dry and mixed FIP can be predicted based on pre-treatment body temperature, appetite scores, and activity scores, as well as the presence of neurological signs.
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Sayyadi, Sara, Magnús Tumi Gudmundsson et Páll Einarsson. « Volcanic tremor associated with the Surtsey eruption of 1963–1967 ». Jokull 72, no 1 (2022) : 21–34. http://dx.doi.org/10.33799/jokull2022.72.021.
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The formation of the island of Surtsey over 3.5 years, remains one of the best-documented volcanic, island-forming eruptions to date. The basaltic submarine volcanic activity was detected on November 14, 1963, where ocean depth was 130 m prior to the eruption at the southern end of the Vestmannaeyjar archipelago. The eruptions occurred in several phases involving explosive and effusive activity, including the initial submarine phase on November 12–13, 1963. Separate phases of subaerial volcanic activity occurred during November 14, 1963–January 1964, January–April 1964, April 1964–May 1965, May–October 1965, December 1965–August 1966, and August 1966–June 1967. Seismic data quality from this period is inferior compared to that of modern monitoring systems. Four permanent seismic stations were operated in Iceland at the time, whereof only two, located at 115 and 140 km distance, had the sensitivity to record tremor from Surtsey. Nevertheless, the scanned analog seismograms (http://seismis.hi.is/) show that the eruptive activity was accompanied by considerable seismic activity, both earthquakes, and volcanic tremor. Earthquakes were primarily associated with changes in vent location. Both spasmodic and harmonic tremor was identified, both with low (<3 Hz) and higher (3–5 Hz) characteristic frequencies. The results indicate a complicated relationship between tremor and magma flow rate or style of activity. During the explosive eruption, the highest magma flow rates occurred in the first 10–20 days, a period with little observed tremor. The highest tremor is observed in December 1963–March 1964, after the discharge rates had dropped substantially, and on a timescale of hours-to-days, no clear relationship between tremor and eruption style is observed. The same applies to the effusive activity, where no seismic tremor was observed during most of the effusive eruption of Surtungur, despite the fact that magma flow rates were ~3 times higher than during later phases where some tremor was observed. Keywords: Submarine volcanism, eruption precursors, volcanic tremor, precursory tremor, continuous uprush eruptions
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Lebedeva, E. V. « Impact of volcanic and post volcanic activity on fluvial relief ». Geomorphology RAS, no 4 (8 novembre 2019) : 49–66. http://dx.doi.org/10.31857/s0435-42812019449-66.
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The characteristic features of the river network, the structure and functioning of the valleys affected by effusive and explosive volcanism, volcano-tectonic phenomena, gas hydrothermal activity and mud volcanism are revealed. It has been established that within flows and covers of effusives, the formation of new streams channels can occur not only due to backward erosion, but also as a result of the collapse of the roof of the near-surface lava tubes, which are actively used by underground runoff. A high erosion rate, a large volume of solid runoff, and a significant role of deflation in the transformation of the fluvial relief are characteristic for regions of domination of explosive activity. There valleys become zones of accumulation of volcanic material, which is gradually processed by mudflow, alluvial, aeolian and other processes. Volcanic-tectonic activity changes the rivers position, direction of streams and morphology of the valleys, leading to numerous reorganizations of the river network, as a result of which the valleys of modern watercourses often consist of uneven-age fragments. Valleys of hydrothermal zones are characterized by the active development of slope processes, which leads to the formation in them not only of sinter terraces, but also numerous landslide ones. Mud volcanic processes periodically lead to the filling and blocking of the valleys with mud breccia flows, which affects both the composition of the alluvium of watercourses and the morphology of the valleys.
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Boudal, Christian, et Claude Robin. « Relations entre dynamismes éruptifs et réalimentations magmatiques d'origine profonde au Popocatépetl ». Canadian Journal of Earth Sciences 25, no 7 (1 juillet 1988) : 955–71. http://dx.doi.org/10.1139/e88-096.
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The modern volcano Popocatépetl is 30 000 – 50 000 years old. Until 5000 years BP, its volcanic activity led to the construction of a 2000 m high cone, the El Fraile volcano. This edifice was later topped by the Popocatépetl summit. The volcanic activity was characterized by long-term construction by lava flows, alternating with periods of 1000–2000 years of mixed explosive and effusive activity. The El Fraile volcano experienced three periods of this type, marked by back-falling pyroclastic flows with heterogeneous magma products and thick air-fall deposits (ash and scoria). The first one occurred more than 10 000 years BP; the second, between 10 000 and 8000 years BP; the third, from 5000 to 3800 years BP. Each of these periods showed violent explosive episodes alternating with lava flows in cycles of 100 to several hundreds of years in duration. Whenever the explosive activity occurred, it destroyed the upper part of the volcano, opening large craters. After a ~ 2500 year period of lava-flow construction (from ~ 3800 to 1200 years BP), the Popocatépetl summit began a similar activity. The last event, producing pyroclastic flows, occurred just before me Hispanic Conquest, and since that time the activity has been effusive and Plinian.Heterogeneous to subhomogeneous pyroclastic flow products exhibit a complex mineralogy: Fe clinopyroxene, Mg clinopyroxene, Fe orthopyroxene, Mg orthopyroxene, plagioclase in equilibrium or disequilibrium, and scarce olivine. All lava flows show a similar paragenesis, suggesting magma-mixing processes. A model in which a basaltic magma is periodically injected in a differentiated chamber at the beginning of each explosive period (or each cycle?) is proposed to explain the heterogeneous products. However, calculations of mixing models do not agree with the high Mg and Ni values observed in some hybrid lavas. This excess is probably due to the remobilization of cumulative olivine by basic magma supplies in the lower part of the reservoir. On the other hand, lava flows emitted during the long phases of effusive activity correspond to evolution in a closed and zoned chamber, partly affected by convective movements. The convection explains the complex mineralogy of these lavas, which result from differentiation of a previously homogenized magma rather than directly from magma mixing.
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Harris, Andrew, Jon Dehn, Matt Patrick, Sonia Calvari, Maurizio Ripepe et Luigi Lodato. « Lava effusion rates from hand-held thermal infrared imagery : an example from the June 2003 effusive activity at Stromboli ». Bulletin of Volcanology 68, no 2 (24 juin 2005) : 107–17. http://dx.doi.org/10.1007/s00445-005-0425-7.
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Nandaka, I. Gusti Made Agung, Sulistiyani, Yosef Suharna et Raditya Putra. « Overview of Merapi Volcanic Activities from Monitoring Data 1992–2011 Periods ». Journal of Disaster Research 14, no 1 (1 février 2019) : 18–26. http://dx.doi.org/10.20965/jdr.2019.p0018.
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Merapi, the dangerous active volcano in Indonesia, has been monitored since the 1920s by applying several methods and tools. The monitoring data from earlier times are stored well and can be used as reference for any precursors and signs before each eruption. This article evaluates the long-term activity of Merapi from the monitoring data for 1992–2011 to obtain the trends and patterns before the eruption period by combining the seismicity, deformation, volcanic gas, and temperature data in the same time span. Several characteristics are exhibited before effusive and explosive eruptions, i.e., a significant level up in volcano-tectonic energy and increased CO2gas concentration indicating an explosive eruption. Effusive eruption is characterized by a significant multiphase earthquake with less occurrence of deep and shallow volcano-tectonic events. Deformation data from a tiltmeter and electronic distance measurement are important in understanding the dynamics of the lava dome and the eruption direction.
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Cannata, A., A. Catania, S. Alparone et S. Gresta. « Volcanic tremor at Mt. Etna : Inferences on magma dynamics during effusive and explosive activity ». Journal of Volcanology and Geothermal Research 178, no 1 (novembre 2008) : 19–31. http://dx.doi.org/10.1016/j.jvolgeores.2007.11.027.
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Plank, Marchese, Filizzola, Pergola, Neri, Nolde et Martinis. « The July/August 2019 Lava Flows at the Sciara del Fuoco, Stromboli–Analysis from Multi-Sensor Infrared Satellite Imagery ». Remote Sensing 11, no 23 (3 décembre 2019) : 2879. http://dx.doi.org/10.3390/rs11232879.
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On 3 July 2019 a rapid sequence of paroxysmal explosions at the summit craters of Stromboli (Aeolian-Islands, Italy) occurred, followed by a period of intense Strombolian and effusive activity in July, and continuing until the end of August 2019. We present a joint analysis of multi-sensor infrared satellite imagery to investigate this eruption episode. Data from the Spinning-Enhanced-Visible-and-InfraRed-Imager (SEVIRI) was used in combination with those from the Multispectral-Instrument (MSI), the Operational-Land-Imager (OLI), the Advanced-Very High-Resolution-Radiometer (AVHRR), and the Visible-Infrared-Imaging-Radiometer-Suite (VIIRS). The analysis of infrared SEVIRI-data allowed us to detect eruption onset and to investigate short-term variations of thermal volcanic activity, providing information in agreement with that inferred by nighttime-AVHRR-observations. By using Sentinel-2-MSI and Landsat-8-OLI imagery, we better localized the active lava-flows. The latter were quantitatively characterized using infrared VIIRS-data, estimating an erupted lava volume of 6.33×106±3.17×106 m3 and a mean output rate of 1.26 ± 0.63 m3/s for the July/August 2019 eruption period. The estimated mean-output-rate was higher than the ones in the 2002–2003 and 2014 Stromboli effusive eruptions, but was lower than in the 2007-eruption. These results confirmed that a multi-sensor-approach might provide a relevant contribution to investigate, monitor and characterize thermal volcanic activity in high-risk areas.
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Trubelja, Fabijan, Klaus Peter Burgath et Vesna Marchig. « Triassic Magmatism in the Area of the Central Dinarides (Bosnia and Herzegovina) : Geochemical Resolving of Tectonic Setting ». Geologia Croatica 57, no 2 (2004) : 159–70. http://dx.doi.org/10.4154/gc.2004.13.
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Triassic magmatic rocks in the Central Dinarides in Bosnia and Herze-govina are known from two separate geotectonic units: (1) the AdriaticCarbonate Platform (Outer Dinarides) and (2) the Palaeozoic–Triassicallochthonous complex. They are assigned to the same regional, genetic and geochemical unit. Their emplacement age is inferred from contacts with the surrounding marble and sedimentary rocks (post-Anisian for intrusives and Ladinian for effusives).The magmatic rocks display different levels of emplacement and crystallization (intrusive, effusive and dyke rocks). They represent different stages of magmatic differentiation, from gabbro/basalt via diorite/andesite to granodiorite/dacite and granites. The most frequent dyke rock is diabase. Pillow basalts indicate eruption under subaquaticconditions. Pyroclastic rocks within the volcano-sedimentary unit point to the temporary explosive character of orogenic magmatic activity. Most rocks are affected and modified by post-magmatic alteration and hydrothermal fluids. This led to the formation of spilite, keratophyre, quartz keratophyre and rarely K spilite.New geochemical data support the opinion that subduction was the main process which triggered the Triassic magmatic activity in the Central Dinarides. Although some of the investigated rocks reveal MORB characteristics (in the selected geochemical discriminations), most samples are enriched in all elements which are reported as characteristicfor arc magmatism at convergent margins including incorporationof sediments.
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Gambino, Salvatore, Marco Aloisi, Giuseppe Di Grazia, Giuseppe Falzone, Angelo Ferro et Giuseppe Laudani. « Ground Deformation Detected by Permanent Tiltmeters on Mt. Etna Summit : The August 23-26, 2018, Strombolian and Effusive Activity Case ». International Journal of Geophysics 2019 (1 avril 2019) : 1–10. http://dx.doi.org/10.1155/2019/1909087.
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Over the last few years, three tilt deep stations (27-30 meters) have been set up in the summit area of Mount Etna volcano. The aim of this challenging project is to record the ground deformations of the summit craters activity with high precision. We considered data related to the August 23-26, 2018, Strombolian and effusive activity. In this case, tiltmeters recorded variations in the order of 10−7 radians, not observed at the other stations. These changes suggest a shallow contraction source just south of the Southeast Crater. This result, related to the volcanic tremor source, points to the presence of a gas/magma reservoir feeding the Strombolian activity at 1200 m above sea level.
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Degterev, A. V., M. V. Chibisova et R. V. Zharkov. « Activity of Chirinkotan and Sarychev Peak volcanoes in 2021 (Kuril Islands) ». Geosystems of Transition Zones 5, no 4 (2021) : 354–60. http://dx.doi.org/10.30730/gtrz.2021.5.4.354-360.
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This communication, based on satellite data and the results of visual observations, considers the main features of the activity of Chirinkotan and Sarychev Peak volcanoes in 2021. In the period from August 8 to 23, 2021, a moderate explosive eruption of Chirinkotan volcano took place. During this time, 11 volcanic explosions were recorded at an altitude of 1.5 to 4.5 km a.s.l. The parameters of the 2021 eruption were similar to previous eruptions in 2013–2015, 2016, 2017. At Sarychev Peak volcano on June 29, July 1, August 6 and November 26 of 2021 single relatively weak ejections to an altitude of about 2.2–3 km a.s.l. were recorded. Current activity of the volcano is associated with a recent effusive eruption that has taken place from December 2020 to February 2021, in which result a crater and mouth of the volcano turned out to be sealed with lava.
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Adhikary, Dipal Krishna, Md Nazmul Hasan, Md Abu Siddique, Sajal Krishna Banerjee, ATM Iqbal, Md Nazmul Hasan et Md Rasul Amin. « Acute myopericarditis presenting as effusive-constrictive pericarditis a case report ». Bangladesh Medical Journal 44, no 3 (17 avril 2016) : 165–67. http://dx.doi.org/10.3329/bmj.v44i3.27378.
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Myopericarditis is primarily a pericardial inflammatory syndrome occurring when clinical diagnostic criteria for pericarditis are satisfied and concurrent mild myocardial involvement is documented by elevation of biomarkers of myocardial damage (i.e. increased troponins). Limited clinical data on the causes of myopericarditis suggest that viral infections are among the most common causes in developed countries. Cardiotropic viruses can cause pericardial and myocardial in!ammation via direct cytolytic or cytotoxic effects and/or subsequent immune-mediated mechanisms. Many cases of myopericarditis are subclinical. In other patients, cardiac symptoms and signs are over shadowed by systemic manifestations of infection or inflammation. The increased sensitivity of troponin assay and contemporary widespread use of troponins has greatly increased the reported number of cases. Management is similar to that reported for pericarditis, generally with a empiric anti-inflammatory drugs mainly aimed to control symptoms. Rest and avoidance of physical activity beyond normal sedentary activities has been recommended for 6 months is recommended as for myocarditis. At present, there is no evidence that troponin elevation confers worse prognosis (i.e. a greater risk of recurrence, death or transplantation) in patients with preserved left ventricular function. Usually complete remission is seen in 3 to 6 months. We report here a case of a 18 year young man with acute myopericarditis who presented with transient effusive-constrictive pericarditis.Bangladesh Med J. 2015 Sep; 44 (3): 165-167
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Kyselevych, L. « Lithofacial composition and distribution of middle albian strata within the Crimean Plains ». Visnyk of Taras Shevchenko National University of Kyiv. Geology, no 1 (64) (2014) : 6–11. http://dx.doi.org/10.17721/1728-2713.64.01.6-11.
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The Middle Albian sedimentary complex is deposited on Middle Albian rocks, commonly with no evident unconformity, and includes, along with sedimentary rocks, volcanic activity products. Middlle Albian sediments are distributed almost everywhere within the North Crimean paleodepression. They occur at a depth of 2-5 km and are represented by sedimentary-volcanogenic formations whose generation was caused by intense activity of 6 stratovolcanoes and 3 shield volcanoes. Such formations fail to occur only on a few local sites of the paleodepression and in its northern nearside zone. Sediments are characterized by wide development in their section, along with sedimentary rocks, of pyroclastic and effusive formations whose generation was caused by volcanic activity. The volcanic activity was at its highest during the Middle Albian, which resulted in accumulations of facies-variable volcanogenic-sedimentary strata. Volcanogenic and volcanogeno-clastic Middle Albian sediments occur among marine clay formations as lens-shaped bodies, sheets and flows sometimes stretching over dozens of kilometers, their thickness ranging from a few metres to hundreds. Structural features of volcanogenic-sedimentary strata of different regions depend on their proximity to the centers of volcanic activity and are determined by the nature and characteristics of paleovolcanic eruptions. A closer proximity to paleovolcanoes accounts for an increase in volcanic rocks in the section, with effusive rocks being mostly abundant among them. At a longer distance from the centers of volcanic activity, pyroclastic, volcanogenic-sedimentary and sedimentary deposits become more abundant in the section. Synthesis and analysis of the lithological and petrographic characteristics of Middle Albian sediments, which were based on analyzing deep parametrical and exploration drilling data, made it possible to define 10 main Middle Albian types of lithofacies. These differ in their composition and the share of volcanic activity products found in marine clay sediments. Lithological-facies types of the Middle Albian sediment sections have been defined, as well as the limits of their lateral distribution within the North Crimean paleodepression of the Crimean plains.
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Laiolo, Marco, Maurizio Ripepe, Corrado Cigolini, Diego Coppola, Massimo Della Schiava, Riccardo Genco, Lorenzo Innocenti et al. « Space- and Ground-Based Geophysical Data Tracking of Magma Migration in Shallow Feeding System of Mount Etna Volcano ». Remote Sensing 11, no 10 (18 mai 2019) : 1182. http://dx.doi.org/10.3390/rs11101182.
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After a month-long increase in activity at the summit craters, on 24 December 2018, the Etna volcano experienced a short-lived lateral effusive event followed by a rapid resumption of low-level explosive and degassing activity at the summit vents. By combining space (Moderate Resolution Imaging Spectroradiometer; MODIS and SENTINEL-2 images) and ground-based geophysical data, we track, in near real-time, the thermal, seismic and infrasonic changes associated with Etna’s activity during the September–December 2018 period. Satellite thermal data reveal that the fissural eruption was preceded by a persistent increase of summit activity, as reflected by overflow episodes in New SouthEast Crater (NSE) sector. This behavior is supported by infrasonic data, which recorded a constant increase both in the occurrence and in the energy of the strombolian activity at the same crater sectors mapped by satellite. The explosive activity trend is poorly constrained by the seismic tremor, which shows instead a sudden increase only since the 08:24 GMT on the 24 December 2018, almost concurrently with the end of the infrasonic detections occurred at 06:00 GMT. The arrays detected the resumption of infrasonic activity at 11:13 GMT of 24 December, when tremors almost reached the maximum amplitude. Infrasound indicates that the explosive activity was shifting from the summit crater along the flank of the Etna volcano, reflecting, with the seismic tremor, the intrusion of a gas-rich magma batch along a ~2.0 km long dyke, which reached the surface generating an intense explosive phase. The dyke propagation lasted for almost 3 h, during which magma migrated from the central conduit system to the lateral vent, at a mean speed of 0.15–0.20 m s−1. Based on MODIS and SENTINEL 2 images, we estimated that the summit outflows erupted a volume of lava of 1.4 Mm3 (±0.5 Mm3), and that the lateral effusive episode erupted a minimum volume of 0.85 Mm3 (±0.3 Mm3). The results presented here outline the support of satellite data on tracking the evolution of volcanic activity and the importance to integrate satellite with ground-based geophysical data in improving assessments of volcanic hazard during eruptive crises.
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Turner, Michael B., Shane J. Cronin, Mark S. Bebbington, Ian E. M. Smith et Robert B. Stewart. « Integrating records of explosive and effusive activity from proximal and distal sequences : Mt. Taranaki, New Zealand ». Quaternary International 246, no 1-2 (décembre 2011) : 364–73. http://dx.doi.org/10.1016/j.quaint.2011.07.006.
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Di Traglia, Federico, Sonia Calvari, Luca D'Auria, Teresa Nolesini, Alessandro Bonaccorso, Alessandro Fornaciai, Antonietta Esposito, Antonio Cristaldi, Massimiliano Favalli et Nicola Casagli. « The 2014 Effusive Eruption at Stromboli : New Insights from In Situ and Remote-Sensing Measurements ». Remote Sensing 10, no 12 (14 décembre 2018) : 2035. http://dx.doi.org/10.3390/rs10122035.
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In situ and remote-sensing measurements have been used to characterize the run-up phase and the phenomena that occurred during the August–November 2014 flank eruption at Stromboli. Data comprise videos recorded by the visible and infrared camera network, ground displacement recorded by the permanent-sited Ku-band, Ground-Based Interferometric Synthetic Aperture Radar (GBInSAR) device, seismic signals (band 0.02–10 Hz), and high-resolution Digital Elevation Models (DEMs) reconstructed based on Light Detection and Ranging (LiDAR) data and tri-stereo PLEIADES-1 imagery. This work highlights the importance of considering data from in situ sensors and remote-sensing platforms in monitoring active volcanoes. Comparison of data from live-cams, tremor amplitude, localization of Very-Long-Period (VLP) source and amplitude of explosion quakes, and ground displacements recorded by GBInSAR in the crater terrace provide information about the eruptive activity, nowcasting the shift in eruptive style of explosive to effusive. At the same time, the landslide activity during the run-up and onset phases could be forecasted and tracked using the integration of data from the GBInSAR and the seismic landslide index. Finally, the use of airborne and space-borne DEMs permitted the detection of topographic changes induced by the eruptive activity, allowing for the estimation of a total volume of 3.07 ± 0.37 × 106 m3 of the 2014 lava flow field emplaced on the steep Sciara del Fuoco slope.
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Niasari, Sintia Windhi, Lusia Rita Nugraheni et Puspita Dian Maghfira. « The b-value of the Kelud Volcano in the Last Three Decades ». E3S Web of Conferences 325 (2021) : 01019. http://dx.doi.org/10.1051/e3sconf/202132501019.
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Kelud volcano is located in the Kediri sub-district, East Java Province, Indonesia. This volcano is still active, with total population, in the radius of 10 km, is around 10 thousand people. Kelud volcano is a popular tourist destination. On the weekend, total visitor can reach 5,000 people per-day. These people are at high risk when the Kelud volcano erupts. The last eruption of the Kelud volcano occurred in 2014 and was explosive eruption. Previously, there was an effusive eruption in 2007. These two types of eruption have its own geo hazard risk. Thus, predict the eruption type could help hazard mitigation. In this study, two data sets of earthquakes, 1990-2007 and 2008-2020, were analysed to determine the b-value and its relationship to the eruption type of the Kelud volcano. The calculation of the b-value uses the Gutenberg-Richter relationship. Calculation of the b-value in 2007, when there was an effusive eruption, showed a value of 2.27, while in 2014 (when there was an explosive eruption) was 1.85. After 2009, the curve of the b-value against time shows decrease. As a long term precursor of the Kelud activity, this b-value curve should be analysed continuously, besides volcano tectonic seismicity monitoring.
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Verkhoturov, Alexey A. « ANALYSIS OF CHANGES IN THE STATE OF ECOSYSTEMS ON ATLASOVA ISLAND (KURIL ISLANDS) ». Vestnik SSUGT (Siberian State University of Geosystems and Technologies) 25, no 3 (2020) : 139–50. http://dx.doi.org/10.33764/2411-1759-2020-25-3-139-150.
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The territory of the Kuril Islands is a chain of volcanic structures and is subject, to certain extent, to volcanic hazards. Atlasova Island is composed of products of the Alaid volcano, which is characterized by effusive and explosive activity. The article analyzes the changes in ecosystems on Atlasov island, which are periodically caused by the Alaid volcano eruption. Large amount of pyroclastic material are brought to the surface during explosive eruptions: blocks, bombs, tephra, lapilli and volcanic ash, which is transported in the atmosphere over very long distances. Ecosystems are affected by pyroclastic deposition over a large area of island land. The purpose of this study was to identify the nature and extent of changes in the state of ecosystems affected by volcanic eruptions from multi-zone satellite images of medium resolution. Analysis of data obtained from space systems Landsat and Sentinel for the period 1972 to 2020, in GIS environment allowed us to trace the dynamics and character of the successions to the affected areas on the calculated values of the vegetation index NDVI. Techniques developed in the process of studying this issue can further facili-tate rapid assessment of impacts on ecosystems at the effusive-explosive eruptions and forecast volcanic hazard for surrounding areas.
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Owen, Jacqueline, Hugh Tuffen et Dave McGarvie. « Magma degassing in the effusive-explosive subglacial rhyolitic eruption of Dalakvísl, Torfajökull, Iceland : insights into quenching pressures, palaeo-ice thickness, and edifice erosion ». Jökull 68, no 1 (15 décembre 2018) : 67–94. http://dx.doi.org/10.33799/jokull2018.68.067.
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Dissolved volatile contents preserved in the matrix glass of subglacially erupted rocks offer important insights into quenching pressures. With careful interpretation, these data may yield information on eruption conditions. In this paper we present detailed edifice and glacier reconstructions for explosive and effusive subglacial rhyolitic deposits at Dalakvísl, Torfajökull, Iceland. When grouped by lithofacies, Dalakvísl glasses display trends of decreasing H2O with elevation, consistent with a subglacial setting. A number of solubility pressure curves (SPCs) have been used to model these quenching pressure–elevation trends in order to reconstruct the loading conditions. Effusively erupted glasses (e.g. lava lobes) have higher dissolved water contents than the more explosively produced material (e.g. obsidian sheets), indicating a systematic difference in subglacial pressure and/or degassing behaviour. Best model fits to data are achieved when loading is by a combination of erupted deposits (with a flat-topped morphology) and ice/meltwater. Our best estimate for the original edifice summit elevation is ∼810 m a.s.l., similar to its current elevation; however, as the edifice is now more conical this indicates significant post-eruptive erosion around the margins of the edifice. We propose that during the initial stages of the eruption, meltwater could not escape, thus maintaining high subglacial pressure under which effusive lava bodies were produced intrusively. Our best estimate is that the original palaeo-ice surface was ∼1,020 m a.s.l., suggesting a syn-eruptive glacier thickness of ∼350 m, assuming a similar base level to today (∼670 m a.s.l.). A sudden release of meltwater then led to a pressure drop, driving a transition to more explosive activity with an ice surface over the vent closer to 880 m a.s.l. This study demonstrates the uses of dissolved volatile contents in reconstructing past environments and shows how eruption dynamics can be tracked over the timeline of a pre-historic eruption, offering valuable insight into the complex coupling between pressure and the mechanisms of subglacial eruptions.
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Madonia, Paolo, Marianna Cangemi et Salvatore Inguaggiato. « Possible Micrometeorological Anomalies Induced by Volcanic Activity Recorded at Stromboli Island (Aeolian Archipelago, Italy) ». Advances in Meteorology 2015 (2015) : 1–7. http://dx.doi.org/10.1155/2015/434090.
Texte intégralRésumé :
Hourly values of atmospheric pressure and air temperature have been acquired at the top of two volcanic islands, Stromboli and Salina in the Aeolian Archipelago (Italy), very similar in height and morphology but completely different with regard to their volcanic activity state: the former is permanently active, whereas the latter is extinguished. During the last four years Stromboli experienced normal activity, volcanic unrests, and an effusive eruption (August–November 2014). The comparative analysis of the recorded data, both in the time and frequency domains, evidenced a peculiar micrometeorological regime at Stromboli, more turbulent during unrests with respect to the quieter periods, but showing an apparent paradox during eruptions, characterized by a lower atmospheric turbulence. These observations suggest that the studied volcanic-micrometeorological system is chaotic, due to contemporary opposite transients generated in the atmosphere by volcanic activity changes, and that micrometeorological conditions in volcanic areas are controlled both by exogenous processes and volcanic activity.
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Mangler, Martin, Julie Prytulak, Guillem Gisbert, Hugo Delgado-Granados et Chiara Maria Petrone. « Interplinian effusive activity at Popocatépetl volcano, Mexico : New insights into evolution and dynamics of the plumbing system ». Volcanica 2, no 1 (6 mai 2019) : 45–72. http://dx.doi.org/10.30909/vol.02.01.4572.
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Mattsson, Hannes B., et Ármann Höskuldsson. « Contemporaneous phreatomagmatic and effusive activity along the Hverfjall eruptive fissure, north Iceland : Eruption chronology and resulting deposits ». Journal of Volcanology and Geothermal Research 201, no 1-4 (avril 2011) : 241–52. http://dx.doi.org/10.1016/j.jvolgeores.2010.05.015.
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Andronico, Daniele, et Luigi Lodato. « Effusive Activity at Mount Etna Volcano (Italy) During the 20th Century : A Contribution to Volcanic Hazard Assessment ». Natural Hazards 36, no 3 (novembre 2005) : 407–43. http://dx.doi.org/10.1007/s11069-005-1938-2.
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Marsella, Maria, P. Baldi, M. Coltelli et M. Fabris. « The morphological evolution of the Sciara del Fuoco since 1868 : reconstructing the effusive activity at Stromboli volcano ». Bulletin of Volcanology 74, no 1 (7 août 2011) : 231–48. http://dx.doi.org/10.1007/s00445-011-0516-6.
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Filipovich, Ruben, Walter Báez, Emilce Bustos, Agustina Villagrán, Agostina Chiodi et Jose Viramonte. « Estilos eruptivos asociados al volcanismo monogenético máfico de la región de Pasto Ventura, Puna Austral, Argentina ». Andean Geology 46, no 2 (31 mai 2019) : 300. http://dx.doi.org/10.5027/andgeov46n2-3091.
Texte intégralRésumé :
One of the most outstanding features of the Southern Puna is the occurrence of a widespread monogenetic mafic volcanism during Neogene-Quaternary. Despite a number of published papers focusing on the petrogenesis of this back-arc volcanism, works aimed on its physical volcanology are scarce. This paper presents the characterization of the monogenetic mafic volcanism in the Pasto Ventura region, located in the southeast edge of the Southern Puna. The results show that in the Pasto Ventura region there is a low density of small-volume eruptive centers aligned with regional tectonic structures and a significant variability in eruptive styles (effusive, strombolian, hawaiian, violent strombolian and phreatomagmatic) and typology of volcanic structures (domes, scoria cones, maars and tuff rings). The first of these features is explained by a limited magma flow rate from the deep source and the use of favorable tectonic structures (oriented obliquely to the regional maximum compression direction) for the ascent of small volumes of magma through the upper crust. The variability of eruptive styles responds to the complex interaction of different endogenous and exogenous factors. The occurrence of effusive or explosive eruptions depends on the differences in magma ascent rates including periods of stagnation in the upper crust, which in turn control the efficiency of degassing and ultimately the occurrence of fragmentation. On the other hand, the more humid local climatic conditions (~150 mm/year), which are related to the geographical position of the Pasto Ventura region in the eastern edge of the Puna, favor the occurrence of phreatomagmatic activity. Phreatomagmatic activity also varies according to the topography, substrate typology and depth at which water-magma interaction occurs.
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Ardian, D. N., H. Darmawan, Wahyudi, B. W. Mutaqin, Suratman, N. Haerani et Wikanti. « Grain size, mineralogical, and geochemistry of the 1996-2018 Volcanic Products of Anak Krakatau Volcano, Indonesia ». IOP Conference Series : Earth and Environmental Science 1071, no 1 (1 août 2022) : 012017. http://dx.doi.org/10.1088/1755-1315/1071/1/012017.
Texte intégralRésumé :
Abstract Anak Krakatau Volcano is the only active volcano on Krakatau Volcanic Complex. It is located in the Sunda Strait as part of the Quaternary volcanic arc as a result of the Indo-Australian plate subduction under the Eurasian plate. The volcanic activity of the Anak Krakatau volcano since 1927 is considered to be very active with a combination of explosive and effusive eruptions. Lava flow tends to be concentrated in the southwestern part, except for the 1996 lava flow (north) and 1993 lava flow (northeast). In 2018 there was an eruption accompanied by flank collapse on the southwestern side, caused by the accumulation of the instability volcanic body due to volcanic and tectonic activity. The volcanic activity will be reflected in the resulting deposits. This study was conducted to determine the characteristics of the deposits, especially on the northern part for post-1996. The analysis carried out included the stratigraphic columns, granulometric, petrography, and geochemistry analysis.
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Marchese, Francesco, Diego Coppola, Alfredo Falconieri, Nicola Genzano et Nicola Pergola. « Investigating Phases of Thermal Unrest at Ambrym (Vanuatu) Volcano through the Normalized Hot Spot Indices Tool and the Integration with the MIROVA System ». Remote Sensing 14, no 13 (29 juin 2022) : 3136. http://dx.doi.org/10.3390/rs14133136.
Texte intégralRésumé :
Ambrym is an active volcanic island, located in the Vanuatu archipelago, consisting of a 12 km-wide summit caldera. This open vent volcano is characterized by an almost persistent degassing activity which occurs in the Benbow and Marum craters, which were also the site of recent lava lakes. On 15 December 2018, about three years after an intense lava effusion, the first recorded since 1989, a small-scale intra-caldera fissure eruption occurred. On 16 December, the eruption stopped, and the lava lakes at the Benbow and Marum craters were drained. In this work, we investigated the thermal activity of the Ambrym volcano, before, during, and after the 15 December 2018 eruption, using daytime Sentinel-2 (S2) Multispectral Instruments (MSI) and Landsat-8 (L8) Operational Land Imager (OLI) data, at a mid-high spatial resolution. The results were integrated with Moderate Resolution Imaging Spectroradiometer (MODIS) observations. Outputs of the Normalized Hotspot Indices (NHI) tool, retrieved from S2-MSI and L8-OLI data, show that the thermal activity at the Ambrym craters increased about three weeks before the 15 December 2018 lava effusion. This information is consistent with the estimates of volcanic radiative power (VRP), which were performed by the Middle Infrared Observation of Volcanic Activity (MIROVA) system, by analyzing the nighttime MODIS data. The latter revealed a significant increase of VRP, with values above 700 MW at the end of the October–November 2018 period. Moreover, the drastic reduction of thermal emissions at the craters, marked by the NHI tool since the day of the fissure eruption, is consistent with the drop in the lava lake level that was independently suggested in a previous study. These results demonstrate that the S2-MSI and L8-OLI time series, combined with infrared MODIS observations, may contribute to detecting increasing trends in lava lake activity, which may precede effusive eruptions at the open vent volcanoes. This study addresses some challenging scenarios regarding the definition of possible threshold levels (e.g., in terms of VRP and total Short Wave Infrared radiance) from the NHI and MIROVA datasets, which could require special attention from local authorities in terms of the occurrence of possible future eruptions.
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Carniel, Roberto, Ramon Ortiz et Mauro Di Cecca. « Spectral and dynamical hints on the time scale of preparation of the 5 April 2003 explosion at Stromboli volcano ». Canadian Journal of Earth Sciences 43, no 1 (1 janvier 2006) : 41–55. http://dx.doi.org/10.1139/e05-093.
Texte intégralRésumé :
Stromboli volcano is well known for its continuous strombolian activity. Moreover, the volcano occasionally shows effusive phases, the latest in 19851986. On 28 December 2002 Stromboli entered a new effusive phase, accompanied by different paroxysmal events that led to considerable hazards for inhabitants and tourists on the island of Stromboli. On 30 December 2002 a major sector collapse affected the Sciara del Fuoco slope and initiated a tsunami. On 5 April 2003 a powerful explosion, which can be compared in size with the most recent explosion in 1930, covered a large part of the normally tourist accessible summit area with bombs. As this explosion was not forecasted, although the island was by then effectively monitored by a dense deployment of instruments, in this paper, we tackle the problem of highlighting the time scale of preparation of this event and conduct a search for possible precursors. For this purpose, we analyze the seismic data preceding the paroxysm with spectral and dynamical methods, highlighting that this paroxysmal event can be seen as the final result of a dynamical phase that started at least 2.5 h before the event. Therefore, this is the time scale during which the search can and should be made for possible precursors. Moreover, the application of the "material failure forecast" method suggests that this final dynamical phase may be just the final acceleration of a process that was building up for at least several days prior to the event.
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Konstantinou, K. I., C. A. Perwita, S. Maryanto, A. Budianto et M. Hendrasto. « Maximal Lyapunov exponent variations of volcanic tremor recorded during explosive and effusive activity at Mt Semeru volcano, Indonesia ». Nonlinear Processes in Geophysics 20, no 6 (23 décembre 2013) : 1137–45. http://dx.doi.org/10.5194/npg-20-1137-2013.
Texte intégralRésumé :
Abstract. We analyze 25 episodes of volcanic tremor recorded from 22 November until 31 December 2009 at Mt Semeru volcano in order to investigate their spectral and dynamical properties. The overtone frequencies for most of the tremor events indicate a pattern of period-doubling, which is one possible route that can lead a system to chaotic behavior. Exponential divergence of the phase space orbits is a strong indicator of chaos and was quantified by estimating the maximal Lyapunov exponent (MLE) for all tremor events. MLEs were found to vary linearly with the number of frequency overtones present in the tremor signals. This implies that the tremor source at Semeru fluctuates between a quasi-periodic state with few overtone frequencies (2–3) and small MLEs (~0.013), and a chaotic one with more overtones (up to 8) and larger MLEs (up to 0.039). These results agree well with the tremor generation model suggested previously by Julian (1994), which describes wall oscillations of a crack excited by unsteady fluid flow. In this model, as fluid pressure increases, a period-doubling cascade leads to numerous new frequencies and a chaotic tremor signal. The temporal variation of MLEs exhibited significant fluctuations from 23 until 31 December when the eruptive activity shifted from explosive to effusive. Such a situation may reflect variable fluid pressure conditions inside the conduit, where at first magma is accumulated and subsequently is erupted, releasing the buildup of pressure. Our results give further evidence for the role of nonlinear deterministic processes in generating volcanic tremor and call for similar investigations to be conducted in other volcanoes.
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Nugraheni, Lusia Rita, Agung Harijoko, Wiwit Suryanto et Hetty Triastuty. « Permutation entropy variation for 2007 effusive dome-forming eruption period of Kelud Volcano, Indonesia ». E3S Web of Conferences 325 (2021) : 01010. http://dx.doi.org/10.1051/e3sconf/202132501010.
Texte intégralRésumé :
The complexity of a system recorded in time series data can be measured statistically using permutation entropy (PE). The state of a system (e.g. regular, chaotic, random, etc.) that underlies the appearance of variations in time series can be determined with PE. Since volcanoes are considered as the complex dynamical system controlled by interactions of many processes. Permutation entropy can be applied to study the system mechanism of volcano. We utilized PE to study system mechanism of Kelud volcano in 2007 dome-forming eruption period, from 3 (KWH; KLD; UMBK) seismic stations with different distances from the crater lake. Then, we want to compare the results. The result of study shows that the PE pattern for each station is different. The unique PE pattern that can be used as an eruption precursor is only shown at KWH and KLD stations. This pattern began to appear 2.7 days before the eruption on 3 November 2007. Data from UMBK station doesn’t show unique PE pattern. The factors such as sensor distance from magmatic activity center, size, and type of eruption probably influenced the final PE result. Using PE as the addition to volcano monitoring can maximize efforts in mitigation activities.
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Cole, Paul D., Annamaria Perrotta et Claudio Scarpati. « The volcanic history of the southwestern part of the city of Naples ». Geological Magazine 131, no 6 (novembre 1994) : 785–99. http://dx.doi.org/10.1017/s0016756800012863.
Texte intégralRésumé :
AbstractThe southwestern part of Naples was the site of small volume volcanic activity prior to 12000 y B.P. Lava domes and possibly a lava flow were erupted during the earliest period. Explosive activity followed and produced pyroclastic sequences that are the proximal deposits of tuff cones within the city and at its southwestern extreme. The explosive activity was complex but predominantly phreatomagmatic. As the volcanic activity more than 12000 y B.P. in western Campi Flegrei shows a similar evolution from effusive to explosive, it is suggested that a large volcanic field ‘Paleoflegrei’, encompassing the western part of the city of Naples, existed prior to emplacement of the Neapolitan Yellow Tuff. The Neapolitan Yellow Tuff eruption about 12000 y B.P., from a vent in Campi Flegrei, produced widespread deposits up to 150 m thick that blanketed the area of the city of Naples, although the present day topography is strongly influenced by the pre-Neapolitan Yellow Tuff centres. Following the Neapolitan Yellow Tuff a small explosive eruption occurred in the bay of Chiaia, immediately south of the city, and results in the possibility of future eruptions within the city of Naples, outside the confines of Campi Flegrei and Vesuvius.
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Mangler, Martin F., Chiara Maria Petrone et Julie Prytulak. « Magma recharge patterns control eruption styles and magnitudes at Popocatépetl volcano (Mexico) ». Geology 50, no 3 (5 janvier 2022) : 366–70. http://dx.doi.org/10.1130/g49365.1.
Texte intégralRésumé :
Abstract Diffusion chronometry has produced petrological evidence that magma recharge in mafic to intermediate systems can trigger volcanic eruptions within weeks to months. However, less is known about longer-term recharge frequencies and durations priming magma reservoirs for eruptions. We use Fe-Mg diffusion modeling in orthopyroxene to show that the duration, frequency, and timing of pre-eruptive recharge at Popocatépetl volcano (Mexico) vary systematically with eruption style and magnitude. Effusive eruptions are preceded by 9–13 yr of increased recharge activity, compared to 15–100 yr for explosive eruptions. Explosive eruptions also record a higher number of individual recharge episodes priming the plumbing system. The largest explosive eruptions are further distinguished by an ~1 yr recharge hiatus directly prior to eruption. Our results offer valuable context for the interpretation of ongoing activity at Popocatépetl, and seeking similar correlations at other arc volcanoes may advance eruption forecasting by including constraints on potential eruption size and style.
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Lombardo, Valerio, Stefano Corradini, Massimo Musacchio, Malvina Silvestri et Jacopo Taddeucci. « Eruptive Styles Recognition Using High Temporal Resolution Geostationary Infrared Satellite Data ». Remote Sensing 11, no 6 (19 mars 2019) : 669. http://dx.doi.org/10.3390/rs11060669.
Texte intégralRésumé :
The high temporal resolution of the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) instrument aboard Meteosat Second Generation (MSG) provides the opportunity to investigate eruptive processes and discriminate different styles of volcanic activity. To this goal, a new detection method based on the wavelet transform of SEVIRI infrared data is proposed. A statistical analysis is performed on wavelet smoothed data derived from SEVIRI Mid-Infrared( MIR) radiances collected from 2011 to 2017 on Mt Etna (Italy) volcano. Time-series analysis of the kurtosis of the radiance distribution allows for reliable hot-spot detection and precise timing of the start and end of eruptive events. Combined kurtosis and gradient trends allow for discrimination of the different activity styles of the volcano, from effusive lava flow, through Strombolian explosions, to paroxysmal fountaining. The same data also allow for the prediction, at the onset of an eruption, of what will be its dominant eruptive style at later stages. The results obtained have been validated against ground-based and literature data.
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Suhendro, Indranova, Muhammad Nadafa Isnain et Rizky Wahyudi. « Rock characteristics of post-caldera volcanoes in Dieng volcanic complex (DVC), Central Java, Indonesia ». Journal of Geoscience, Engineering, Environment, and Technology 7, no 4 (15 décembre 2022) : 151–57. http://dx.doi.org/10.25299/jgeet.2022.7.4.10015.
Texte intégralRésumé :
The Dieng volcanic complex (DVC) has one of the densest post-caldera volcanisms activity presents in Indonesia, yet its population density is considerably high. Therefore, it is important to identify the rock characteristics produced by the DVC post-caldera volcanoes to understand the risks and future hazards (i.e., eruption style). Based on lithology, we have classified DVC post-caldera volcanoes as (1) pyroclastic domain (PD; including Pagerkandang, Merdada, and Pangonan), and (2) lava domain (LD; including Prambanan, Kendil, Pakuwaja, Sikunir, Sikarim, and Seroja). PD is characterized by the domination of pyroclastic materials (mostly ash and lapilli) with oxidized scoria and volcanic lithics (fresh and/or altered) as the main components. The oxidized scoria clasts are moderately vesicular (27–41 % vesicularity; ) and phenocryst poor (<5 % phenocryst crystallinity, ), with plagioclase, pyroxene, and oxides as the main phenocryst phases. The LD is composed predominantly of lava. The observed lavas are typically dense (mostly <1 % , phenocryst rich (21–47 % ), and include plagioclase, pyroxene, biotite, amphibole, and oxides as the main phenocryst phases. Such differences in mineralogy and textures (i.e., vesicularity and crystallinity) suggest that PD and LD were likely sourced from different magmatic sources with different eruption styles (explosive and effusive styles, respectively). We have suggested that civilization settlements near PD are facing major threats from explosive magmatic, phreatomagmatic, and phreatic eruptions that could produce significant fallouts, ballistic materials, and highly destructive pyroclastic density currents. LDs pose a threat in the form of effusive magmatic eruptions such as lava flows and/or domes.
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Gutmann, J. T. « Strombolian and effusive activity as precursors to phreatomagmatism : eruptive sequence at maars of the Pinacate volcanic field, Sonora, Mexico ». Journal of Volcanology and Geothermal Research 113, no 1-2 (mars 2002) : 345–56. http://dx.doi.org/10.1016/s0377-0273(01)00265-7.
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Arámbula-Mendoza, R., P. Lesage, C. Valdés-González, N. R. Varley, G. Reyes-Dávila et C. Navarro. « Seismic activity that accompanied the effusive and explosive eruptions during the 2004–2005 period at Volcán de Colima, Mexico ». Journal of Volcanology and Geothermal Research 205, no 1-2 (août 2011) : 30–46. http://dx.doi.org/10.1016/j.jvolgeores.2011.02.009.
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Arámbula-Mendoza, Raúl, Gabriel Reyes-Dávila, M. Vargas-Bracamontes Dulce, Miguel González-Amezcua, Carlos Navarro-Ochoa, Alejandro Martínez-Fierros et Ariel Ramírez-Vázquez. « Seismic monitoring of effusive-explosive activity and large lava dome collapses during 2013–2015 at Volcán de Colima, Mexico ». Journal of Volcanology and Geothermal Research 351 (février 2018) : 75–88. http://dx.doi.org/10.1016/j.jvolgeores.2017.12.017.
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Lebedeva, E. V. « Present sedimentation in the volcanic lakes of the Kurile-Kamchatka region (Russia) as a basis for paleoreconstructions ». Limnology and Freshwater Biology, no 4 (2022) : 1464–66. http://dx.doi.org/10.31951/2658-3518-2022-a-4-1464.
Texte intégralRésumé :
Abstract. The results of modern processes observations of the sedimentation in the volcanic lakes of the region are summarized with the use of material from other regions of the world. The available data on the drained volcanic lakes deposits, Uzon-Geysernaya caldera as example, was analysed. The main sources of material (volcanic and post-volcanic activity, gravitational displacements on slopes, and erosion-denudation processes) and the mechanisms of its entry into volcanic lakes, as well as the features of the subsequent deposits transformation as a result of hydrothermal, seismic, and volcano-tectonic activity, are identified. The results of the studies carried out allow us to conclude that the volcanic lakes deposits are complexly constructed polyfacial complexes with alternating fine-grained lacustrine and lacustrine-swamp deposits with pyroclastic horizons and interlayers of untreated or poorly processed coarse clastic material coming as a result of volcano-tectonic activity, gravitational and erosion processes. The irregularity of horizons along strike is typical; and is characterized by the large-scale sediments deformation under the influence of seismic activity, growth of effusive and extrusive domes, phreatic explosions, etc. Hydrothermal activity contributes to the weathering and cementation of the lake sediments. Lava outpourings and the high-temperature pyroclastic flows provokes sintering of contacting horizons sediments.
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Patrick, Matthew R., et John L. Smellie. « Synthesis A spaceborne inventory of volcanic activity in Antarctica and southern oceans, 2000–10 ». Antarctic Science 25, no 4 (12 juin 2013) : 475–500. http://dx.doi.org/10.1017/s0954102013000436.
Texte intégralRésumé :
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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Degterev, A. V., et M. V. Chibisova. « Volcanic activity of the Kuril Islands in 2020–2021 ». Geosystems of Transition Zones 6, no 3 (2022) : 195–205. http://dx.doi.org/10.30730/gtrz.2022.6.3.195-205.
Texte intégralRésumé :
The data on volcanic activity in the Kuril Islands during 2020–2021 are presented. The activity of Ebeko (Paramushir Island), Chirinkotan (Chirinkotan Island) and Sarychev Peak (Matua Island) volcanoes is characterized on the basis of satellite data and results of visual observations. In 2020–2021 a weak (to moderate) explosive eruption (VEI 1-2), which has begun in autumn 2016, continued on Ebeko volcano. During the period under review, at least 1169 emissions were recorded at a height of 1.5–3 (up to 5) km a.s.l. In the interval from May till July, a sharp increase in the explosive activity of the volcano was noted, during this time more than half of the total number of explosions occurred: 2020 – 298 out of 558, 2021 – 344 out of 611. The ashfalls of varying intensity were periodically observed in Severo-Kurilsk. The active phase of the eruption has ended in December 2021, only 2 weak explosions occurred. A moderate (VEI 2) explosive eruption took place on Chirinkotan volcano from August 8 to August 23, 2021. At least 12 volcanic explosions were recorded at a height of 1.5 to 4.5 km a.s.l. An effusive eruption was observed on the Sarychev Peak volcano from December 2020 till February 2021: the crater was filled with lava, after which it erupted along the northeastern slope of the edifice. In 2021, the activity of the volcano was characterized by manifestations of several episodes of an explosive nature: on June 29, July 1, August 6, and November 26, single, relatively weak ejections to a height of about 2.2–3 km a.s.l. were recorded (VEI 2).
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Seniukov, S., et I. Nuzhdina. « SEISMISITY of THE VOLCANIC AREAS of KAMCHATKA in 2015 ». Earthquakes in Northern Eurasia, no 24 (14 décembre 2021) : 349–61. http://dx.doi.org/10.35540/1818-6254.2021.24.33.
Texte intégralRésumé :
The results of near real-time monitoring of the active Kamchatka volcanoes are described. Continuous monitoring was carried out using three remote methods: 1) seismic monitoring according to automatic telemetric seismic stations; 2) visual and video observation; 3) satellite observation of the thermal anomalies and the ash clouds. Annual results of seismic activity of the Northern (Shiveluch, Kluchevskoy, Bezymianny, Krestovsky, and Ushkovsky), the Avacha (Avachinsky, and Koryaksky), the Mutnovsky-Gorely volcano groups and the Kizimen volcano are presented. 5464 earthquakes with КS=1.8–8.1 were located for the Northern volcano group, 302 earthquakes with КS=1.7–5.7 – for the Avacha volcano group, 295 earthquakes with КS=2.1–6.8 for the Mutnovsky-Gorely volcano group, 462 earthquakes with КS=2.2–8.3 for Kizimen volcano, and 165 earthquakes with КS=2.5–8.4 for Zhupanovsky volcano in 2015. Maps of epicenters, quantities of seismic energy and earthquake distribution by energy classes are given. All periods of activity were fixed and investigated by remote methods in 2015: intensive volcanic activity of the Sheveluch volcano associated with a new cone; the summit explosive-effusive eruption of the Kluchevskoy volcano in January–April; and a continuation of seismic and volcanic activity of the Zhupanovsky volcano after 56-year quite period.
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Seniukov, S., et I. Nuzhdina. « VOLCANOES OF KAMCHATKA ». Earthquakes in Northern Eurasia, no 23 (15 décembre 2020) : 375–87. http://dx.doi.org/10.35540/1818-6254.2020.23.38.
Texte intégralRésumé :
The results of near real-time monitoring of the active Kamchatka volcanoes are described. Continuous monitoring was carried out using three remote methods: 1) seismic monitoring according to automatic telemetric seismic stations; 2) visual and video observation; 3) satellite observation of the thermal anomalies and the ash clouds. Daily information about volcanic activity is published in the Internet (http://www.emsd.ru/~ssl/ monitoring/main.htm) since February 2000. Annual results of seismic activity of the Northern (Shiveluch, Klu-chevskoy, Bezymianny, Krestovsky and Ushkovsky), Avacha (Avachinsky and Koryaksky), Mutnovsky-Gorely volcano group and Kizimen volcano are presented. 4983 earthquakes with КS=2.1–8.7 were located for Northern volcano group, 469 earthquakes with КS=1.6–6.1 – for Avacha volcano group, 459 earthquakes with КS=1.9–6.1 – Mutnovsky-Gorely volcano group, 220 earthquakes with КS=2.4–8.5 for Kizimen volcano and 238 earthquakes with КS=2.5–8.4 for Zhupanovsky volcano in 2014. Maps of epicenters, quantities of seismic energy and earth-quake distribution according to class are given. All periods of activity were fixed and investigated by remote me-thods in 2014: intensive volcanic activity of Shiveluch volcano associated with new cone, a con-tinuation of the seismic and volcanic activity of Zhupanovsky volcano after 56-year quite period and the ending of the summit explosive-effusive eruption of Kluchevskoy volcano in January-February.
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Girina, O. A., A. G. Manevich, D. V. Melnikov, A. A. Nuzhdaev et E. G. Petrova. « 2016 volcano eruptions in Kamchatka and the Northern Kuriles and their danger to aviation ». Вулканология и сейсмология, no 3 (14 mai 2019) : 34–48. http://dx.doi.org/10.31857/s0203-03062019334-48.
Texte intégralRésumé :
Strong explosive volcanic eruptions are extremely dangerous to the modern jet aircraft as they can produce several cubic kilometers of volcanic ash and aerosols that can be sent to the atmosphere and the stratosphere in several hours to several days during the eruption. In 2016, five from thirty active volcanoes erupted in Kamchatka (Sheveluch, Klyuchevskoy, Bezymianny, Karymsky, and Zhupanovsky) and three from six active volcanoes in the Northern Kuriles (Alaid, Ebeko, and Chikurachki). Effusive volcanic activity was noted at Sheveluch, Klyuchevskoy, Bezymianny and Alaid. All the volcanoes produced explosive activity. Strong explosive events occurred at Sheveluch mainly from September till December. Moderate ash emission had accompanied of Klyuchevskoy’s eruption through March till November. Explosive activity at Karymsky, Zhupanovsky, Alaid, and Chikurachki volcanoes was observed mainly in the first half of the year. The total area covered by ash in 2016 was estimated 600,000 km2, from which 460,000 km2 were related to the eruptions of Kamchatka volcanoes and 140,000 km2 were attributed to the eruption of the North Kuriles volcanoes. The activity at Sheveluch, Klyuchevskoy, and Zhupanovsky was dangerous to international and local airlines as explosions produced ash up to 10-12 km above sea level. The activity at Bezymianny, Karymsky, Alaid, Ebeko, and Chikurachki posed a threat to local aircrafts when explosions sent ash up to 5 km above sea level.
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Girina, O. A., A. G. Manevich, D. V. Melnikov, A. A. Nuzhdaev et E. G. Petrova. « 2016 volcano eruptions in Kamchatka and the Northern Kuriles and their danger to aviation ». Вулканология и сейсмология, no 3 (14 mai 2019) : 34–48. http://dx.doi.org/10.31857/s0205-96142019334-48.
Texte intégralRésumé :
Strong explosive volcanic eruptions are extremely dangerous to the modern jet aircraft as they can produce several cubic kilometers of volcanic ash and aerosols that can be sent to the atmosphere and the stratosphere in several hours to several days during the eruption. In 2016, five from thirty active volcanoes erupted in Kamchatka (Sheveluch, Klyuchevskoy, Bezymianny, Karymsky, and Zhupanovsky) and three from six active volcanoes in the Northern Kuriles (Alaid, Ebeko, and Chikurachki). Effusive volcanic activity was noted at Sheveluch, Klyuchevskoy, Bezymianny and Alaid. All the volcanoes produced explosive activity. Strong explosive events occurred at Sheveluch mainly from September till December. Moderate ash emission had accompanied of Klyuchevskoy’s eruption through March till November. Explosive activity at Karymsky, Zhupanovsky, Alaid, and Chikurachki volcanoes was observed mainly in the first half of the year. The total area covered by ash in 2016 was estimated 600,000 km2, from which 460,000 km2 were related to the eruptions of Kamchatka volcanoes and 140,000 km2 were attributed to the eruption of the North Kuriles volcanoes. The activity at Sheveluch, Klyuchevskoy, and Zhupanovsky was dangerous to international and local airlines as explosions produced ash up to 10-12 km above sea level. The activity at Bezymianny, Karymsky, Alaid, Ebeko, and Chikurachki posed a threat to local aircrafts when explosions sent ash up to 5 km above sea level.
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BRYAN, S. E., J. MARTÍ et R. A. F. CAS. « Stratigraphy of the Bandas del Sur Formation : an extracaldera record of Quaternary phonolitic explosive eruptions from the Las Cañadas edifice, Tenerife (Canary Islands) ». Geological Magazine 135, no 5 (septembre 1998) : 605–36. http://dx.doi.org/10.1017/s0016756897001258.
Texte intégralRésumé :
Explosive volcanism has dominated the large phonolitic shield volcano of Tenerife, the Las Cañadas edifice, for the last 1.5 m.y. Pyroclastic deposits of the Bandas del Sur Formation are exposed along the southern flanks, and record the last two of at least three long-term cycles of caldera-forming explosive eruptions. Each cycle began with flank fissure eruptions of alkali basalt lava, followed by minor eruptions of basanite to phonotephrite lavas. Minor phonotephritic to phonolitic lava effusions also occurred on the flanks of the edifice during the latter stages of the second explosive cycle. Non-welded plinian fall deposits and ignimbrites are the dominant explosive products preserved on the southern flanks. Of these, a significant volume has been dispersed offshore. Many pyroclastic units of the second explosive cycle exhibit compositional zonation. Banded pumice occurs in most units of the third (youngest) explosive cycle, and ignimbrites typically contain mixed phenocryst assemblages, indicating the role of magma mixing/mingling prior to eruption. At least four major eruptions of the third cycle began with phreatomagmatic activity, producing lithic-poor, accretionary lapilli-bearing fallout and/or surge deposits. The repeated, brief phase of phreatomagmatism at the onset of these eruptions is interpreted as reflecting an exhaustive water supply, probably a small caldera lake that was periodically established during the third cycle. Accidental syenite becomes an increasingly important lithic clast type in ignimbrites up-sequence, and is interpreted as recording the progressive development of a plutonic complex beneath the summit caldera.Successive eruptions during each explosive cycle increased in volume, with the largest eruption occurring at the end of the cycle. More than ten major explosive eruptions vented moderately large volumes (1−[ges ]10 km3) of phonolitic magma during the last two cycles. Culminating each explosive cycle was the emplacement of relatively large volume (>5−10 km3) ignimbrites with coarse, vent-derived lithic breccias, interpreted to record a major phase of caldera collapse. In the extracaldera record, explosive cycles are separated by ∼0.2 m.y. periods of non-explosive activity. Repose periods were characterized by erosion, remobilization of pyroclastic deposits by discharge events, and pedogenesis. The current period of non-explosive activity is characterized by the construction of the Teide-Pico Viejo stratovolcanic complex within the summit caldera. This suggests that eruptive hiatuses in the extracaldera record may reflect effusive activity and stratovolcano or shield-building phases within the summit caldera. Alternating effusive and explosive cycles have thus been important in the volcanic evolution of the Las Cañadas edifice.
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Dunbar, N. W., N. A. Iverson, J. L. Smellie, W. C. McIntosh, M. J. Zimmerer et P. R. Kyle. « Chapter 7.4 Active volcanoes in Marie Byrd Land ». Geological Society, London, Memoirs 55, no 1 (2021) : 759–83. http://dx.doi.org/10.1144/m55-2019-29.
Texte intégralRésumé :
AbstractTwo volcanoes in Marie Byrd Land, Mount Berlin and Mount Takahe, can be considered active, and a third, Mount Waesche, may be as well; although the chronology of activity is less well constrained. The records of explosive activity of these three volcanoes is well represented through deposits on the volcano flanks and tephra layers found in blue ice areas, as well as by the presence of cryptotephra layers found in West and East Antarctic ice cores. Records of effusive volcanism are found on the volcano flanks but some deposits may be obscured by pervasive glacerization of the edifices. Based on a compilation of tephra depths–ages in ice cores, the activity patterns of Mount Takahe and Mount Berlin are dramatically different. Mount Takahe has erupted infrequently over the past 100 kyr. Mount Berlin, by contrast, has erupted episodically during this time interval, with the number of eruptions being dramatically higher in the time interval betweenc.32 and 18 ka. Integration of the Mount Berlin tephra record from ice cores and blue ice areas over a 500 kyr time span reveals a pattern of geochemical evolution related to small batches of partial melt being progressively removed from a single source underlying Mount Berlin.