Journal articles: 'Wedge Island'

1

Mackay, J. Ross. "The frequency of ice-wedge cracking (1967–1987) at Garry Island, western Arctic coast, Canada." Canadian Journal of Earth Sciences 29, no. 2 (February 1, 1992): 236–48. http://dx.doi.org/10.1139/e92-022.

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The frequency of ice-wedge cracking has been studied at Garry Island, Northwest Territories, for the 1967–1987 period. Sites have included low-centre polygons, intermediate-centre polygons, and polygons that do not fit any classification system. Analyses of crack frequency have included trough characteristics, polygon characteristics, and ice-wedge types. The results show that crack frequencies are highly variable within one site and also between two adjacent sites. The correlation between crack frequency and a low air temperature is poor. Crack frequencies for a site with 59 wedges ranged from 8 to 42% between 1967 and 1979 and for a nearby site with 32 wedges from 22 to 75% between 1967 and 1987. In view of the wide range in crack frequencies at a given site, the use of mean ice-wedge growth rates for estimating ages of ice wedges and their casts in environmental reconstruction may be hazardous. The data show that the common twofold classification into active and inactive wedges is difficult to apply because crack frequencies are gradational and dependent on such factors as the number of ice wedges being monitored, the size of the area, the types of ice wedges, and the length of the observation period. A system for classifying crack frequency is proposed.

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Vasil’Chuk, Yu K., and A. C. Vasil’Chuk. "Oxygen isotope composition of the ice wedges of Ayon Island and Late Pleistocene and Holocene palaeotemperature reconstruction of the Northern Chukotka." Moscow University Bulletin. Series 4. Geology, no. 6 (December 28, 2017): 92–104. http://dx.doi.org/10.33623/0579-9406-2017-6-92-104.

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Syngenetic ice wedges have been investigated in the Ayon Island. Their isotopic composition, geochemical characteristics of both ice wedges and enclosing sediment have been obtained; four ice-wedges stages have been distinguished. Paleo temperature reconstructions for Ayon Island and adjacent territories of northern Chukotka have been yielded at the basis of these results. It is observed almost identical trends in the distribution of ice-wedge isotopic characteristics in the island and in the lower reaches of the Kolyma River, as well as differences in the magnitude of isotopic oscillations during the transition from Late Pleistocene to the Holocene as compared to ice-wedges of the Lower Kolyma region.

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Savoskul, Oksana S. "Ion Content of polygonal wedge ice on Bolshoi Lyakhov: a source of palaeoenvironmental information." Annals of Glaciology 21 (1995): 394–98. http://dx.doi.org/10.1017/s0260305500016128.

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Bolshoi Lyakhov is one of the group of the New Siberian Islands in the Laptev Sea. The permafrost of the island is of an extremely low temperature regime, polygonal wedge ice being the most specific feature. The geomorphological level considered is a so-called edoma, presumably of late-Quaternary origin: polygonal ice wedges are more than 10 m wide and up to 25 m deep on this level, and about 1 m × 1.5 m on the peat bogs of Holocene age. Sixty-six samples of underground ice were taken on both surfaces. The macro-ion content was analyzed, i.e. Ca, Mg, Na, K, HCO3, Cl, SO4. A significant difference in ion content was found between the older and the younger ice. The late-Quaternary wedge ice is characterized by the predominance of Ca and HCO3, while the Holocene ice contains considerably higher proportions of Na and Cl. This may be attributed to different environmental conditions during wedge-ice growth: more continental in the late Quaternary and more maritime in the Holocene.

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Savoskul, Oksana S. "Ion Content of polygonal wedge ice on Bolshoi Lyakhov: a source of palaeoenvironmental information." Annals of Glaciology 21 (1995): 394–98. http://dx.doi.org/10.3189/s0260305500016128.

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Bolshoi Lyakhov is one of the group of the New Siberian Islands in the Laptev Sea. The permafrost of the island is of an extremely low temperature regime, polygonal wedge ice being the most specific feature. The geomorphological level considered is a so-called edoma, presumably of late-Quaternary origin: polygonal ice wedges are more than 10 m wide and up to 25 m deep on this level, and about 1 m × 1.5 m on the peat bogs of Holocene age. Sixty-six samples of underground ice were taken on both surfaces. The macro-ion content was analyzed, i.e. Ca, Mg, Na, K, HCO3, Cl, SO4. A significant difference in ion content was found between the older and the younger ice. The late-Quaternary wedge ice is characterized by the predominance of Ca and HCO3, while the Holocene ice contains considerably higher proportions of Na and Cl. This may be attributed to different environmental conditions during wedge-ice growth: more continental in the late Quaternary and more maritime in the Holocene.

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5

Lewkowicz, Antoni G. "Ice-wedge rejuvenation, fosheim peninsula, ellesmere Island, Canada." Permafrost and Periglacial Processes 5, no. 4 (October 1994): 251–68. http://dx.doi.org/10.1002/ppp.3430050405.

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Bird, Jeremy P., Sialesi Risalto, Elenoa Seniloli, and Tuverea Tuamoto. "A pre-eradication survey of Wedge-tailed Shearwater Puffinus pacificus on Monuriki, Mamanuca Group, Fiji." South Pacific Journal of Natural and Applied Sciences 31, no. 1 (2013): 45. http://dx.doi.org/10.1071/sp13004.

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A brief visit to Monuriki, an island in Fiji’s Mamanuca group was completed in March-April 2011 to gather baseline data on the island’s population of Wedge-tailed Shearwaters Puffinus pacificus prior to the eradication of alien invasive Polynesian Rat Rattus exulans and feral goats Capra hircus from the island in December 2011. We estimated an island-wide population of 2,000-5,500 pairs of Wedge-tailed Shearwaters, the largest population recorded in Fiji. Productivity was estimated to be 40%. It is anticipated these baseline figures will be used to assess the impacts that the removal of invasive mammals has on the population.

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Fortier, Daniel, and Michel Allard. "Late Holocene syngenetic ice-wedge polygons development, Bylot Island, Canadian Arctic Archipelago." Canadian Journal of Earth Sciences 41, no. 8 (August 1, 2004): 997–1012. http://dx.doi.org/10.1139/e04-031.

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The initial configuration of the syngenetic ice-wedge polygons that developed in the outwash plain of glacier C-79 after 6000 BP was modified by the accumulation of wind-blown and organic sediments that began after 3670 ± 110 BP. The late Holocene sedimentation led to an increase in the thermal contraction coefficient of the soil and the formation of third- and fourth-order contraction cracks, partially explaining the current configuration of the polygonal network. The upturning of the sedimentary strata bordering the ice wedges was associated with the summer thermal expansion and resulting internal creep of the soil. The mean annual soil displacement coefficient was in the order of 2.52.7 × 105 /°C at the thousand-year scale. The late Holocene sedimentary strata under the centre of the polygons were undisturbed, which will make it possible to use this sedimentary record in further studies to attempt paleoenvironmental reconstructions from cores.

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Opel, Thomas, Sebastian Wetterich, Hanno Meyer, Alexander Y. Dereviagin, Margret C. Fuchs, and Lutz Schirrmeister. "Ground-ice stable isotopes and cryostratigraphy reflect late Quaternary palaeoclimate in the Northeast Siberian Arctic (Oyogos Yar coast, Dmitry Laptev Strait)." Climate of the Past 13, no. 6 (June 6, 2017): 587–611. http://dx.doi.org/10.5194/cp-13-587-2017.

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Abstract. To reconstruct palaeoclimate and palaeoenvironmental conditions in the northeast Siberian Arctic, we studied late Quaternary permafrost at the Oyogos Yar coast (Dmitry Laptev Strait). New infrared-stimulated luminescence ages for distinctive floodplain deposits of the Kuchchugui Suite (112.5 ± 9.6 kyr) and thermokarst-lake deposits of the Krest Yuryakh Suite (102.4 ± 9.7 kyr), respectively, provide new substantial geochronological data and shed light on the landscape history of the Dmitry Laptev Strait region during Marine Isotope Stage (MIS) 5. Ground-ice stable-isotope data are presented together with cryolithological information for eight cryostratigraphic units and are complemented by data from nearby Bol'shoy Lyakhovsky Island. Our combined record of ice-wedge stable isotopes as a proxy for past winter climate conditions covers about 200 000 years and is supplemented by stable isotopes of pore and segregated ice which reflect annual climate conditions overprinted by freezing processes. Our ice-wedge stable-isotope data indicate substantial variations in northeast Siberian Arctic winter climate conditions during the late Quaternary, in particular between glacial and interglacial times but also over the last millennia to centuries. Stable isotope values of ice complex ice wedges indicate cold to very cold winter temperatures about 200 kyr ago (MIS7), very cold winter conditions about 100 kyr ago (MIS5), very cold to moderate winter conditions between about 60 and 30 kyr ago, and extremely cold winter temperatures during the Last Glacial Maximum (MIS2). Much warmer winter conditions are reflected by extensive thermokarst development during MIS5c and by Holocene ice-wedge stable isotopes. Modern ice-wedge stable isotopes are most enriched and testify to the recent winter warming in the Arctic. Hence, ice-wedge-based reconstructions of changes in winter climate conditions add substantial information to those derived from paleoecological proxies stored in permafrost and allow a distinction between seasonal trends of past climate dynamics. Future progress in ice-wedge dating and an improved temporal resolution of ice-wedge-derived climate information may help to fully explore the palaeoclimatic potential of ice wedges.

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Wetterich, Sebastian, Natalia Rudaya, Vladislav Kuznetsov, Fedor Maksimov, Thomas Opel, Hanno Meyer, Frank Günther, et al. "Ice Complex formation on Bol'shoy Lyakhovsky Island (New Siberian Archipelago, East Siberian Arctic) since about 200 ka." Quaternary Research 92, no. 2 (April 17, 2019): 530–48. http://dx.doi.org/10.1017/qua.2019.6.

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AbstractLate Quaternary landscapes of unglaciated Beringia were largely shaped by ice-wedge polygon tundra. Ice Complex (IC) strata preserve such ancient polygon formations. Here we report on the Yukagir IC from Bol'shoy Lyakhovsky Island in northeastern Siberia and suggest that new radioisotope disequilibria (230Th/U) dates of the Yukagir IC peat confirm its formation during the Marine Oxygen Isotope Stage (MIS) 7a–c interglacial period. The preservation of the ice-rich Yukagir IC proves its resilience to last interglacial and late glacial–Holocene warming. This study compares the Yukagir IC to IC strata of MIS 5, MIS 3, and MIS 2 ages exposed on Bol'shoy Lyakhovsky Island. Besides high intrasedimental ice content and syngenetic ice wedges intersecting silts, sandy silts, the Yukagir IC is characterized by high organic matter (OM) accumulation and low OM decomposition of a distinctive Drepanocladus moss-peat. The Yukagir IC pollen data reveal grass-shrub-moss tundra indicating rather wet summer conditions similar to modern ones. The stable isotope composition of Yukagir IC wedge ice is similar to those of the MIS 5 and MIS 3 ICs pointing to similar atmospheric moisture generation and transport patterns in winter. IC data from glacial and interglacial periods provide insights into permafrost and climate dynamics since about 200 ka.

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10

Nitzbon, Jan, Moritz Langer, Sebastian Westermann, Léo Martin, Kjetil Schanke Aas, and Julia Boike. "Pathways of ice-wedge degradation in polygonal tundra under different hydrological conditions." Cryosphere 13, no. 4 (April 4, 2019): 1089–123. http://dx.doi.org/10.5194/tc-13-1089-2019.

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Abstract. Ice-wedge polygons are common features of lowland tundra in the continuous permafrost zone and prone to rapid degradation through melting of ground ice. There are many interrelated processes involved in ice-wedge thermokarst and it is a major challenge to quantify their influence on the stability of the permafrost underlying the landscape. In this study we used a numerical modelling approach to investigate the degradation of ice wedges with a focus on the influence of hydrological conditions. Our study area was Samoylov Island in the Lena River delta of northern Siberia, for which we had in situ measurements to evaluate the model. The tailored version of the CryoGrid 3 land surface model was capable of simulating the changing microtopography of polygonal tundra and also regarded lateral fluxes of heat, water, and snow. We demonstrated that the approach is capable of simulating ice-wedge degradation and the associated transition from a low-centred to a high-centred polygonal microtopography. The model simulations showed ice-wedge degradation under recent climatic conditions of the study area, irrespective of hydrological conditions. However, we found that wetter conditions lead to an earlier onset of degradation and cause more rapid ground subsidence. We set our findings in correspondence to observed types of ice-wedge polygons in the study area and hypothesized on remaining discrepancies between modelled and observed ice-wedge thermokarst activity. Our quantitative approach provides a valuable complement to previous, more qualitative and conceptual, descriptions of the possible pathways of ice-wedge polygon evolution. We concluded that our study is a blueprint for investigating thermokarst landforms and marks a step forward in understanding the complex interrelationships between various processes shaping ice-rich permafrost landscapes.

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11

Ellis, Susan, Francesca Ghisetti, Philip M. Barnes, Carolyn Boulton, Åke Fagereng, and Susanne Buiter. "The contemporary force balance in a wide accretionary wedge: numerical models of the southcentral Hikurangi margin of New Zealand." Geophysical Journal International 219, no. 2 (July 16, 2019): 776–95. http://dx.doi.org/10.1093/gji/ggz317.

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SUMMARY The southcentral Hikurangi subduction margin (North Island, New Zealand) has a wide, low-taper accretionary wedge that is frontally accreting a >3-km-thick layer of sediments, with deformation currently focused near the toe of the wedge. We use a geological model based on a depth-converted seismic section, together with physically realistic parameters for fluid pressure, and sediment and décollement friction based on laboratory experiments, to investigate the present-day force balance in the wedge. Numerical models are used to establish the range of physical parameters compatible with the present-day wedge geometry and mechanics. Our analysis shows that the accretionary wedge stability and taper angle require either high to moderate fluid pressure on the plate interface, and/or weak frictional strength along the décollement. The décollement beneath the outer wedge requires a relatively weaker effective strength than beneath the inner (consolidated) wedge. Increasing density and cohesion with depth make it easier to attain a stable taper within the inner wedge, while anything that weakens the wedge—such as high fluid pressures and weak faults—make it harder. Our results allow a near-hydrostatic wedge fluid pressure, sublithostatic fluid overpressure at the subduction interface, and friction coefficients compatible with measurements from laboratory experiments on weak clay minerals.

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Jones Lennon, Michelle, David A. Taggart, Peter D. Temple-Smith, and Mark D. B. Eldridge. "The impact of isolation and bottlenecks on genetic diversity in the Pearson Island population of the black-footed rock-wallaby (Petrogale lateralis pearsoni; Marsupialia:Macropodidae)." Australian Mammalogy 33, no. 2 (2011): 152. http://dx.doi.org/10.1071/am11011.

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A morphologically distinct subspecies of black-footed rock-wallaby (Petrogale lateralis pearsoni), is naturally found only on North Pearson Island (~160 ha) in the Investigator Group, SA, where it was isolated by rising sea levels ~10 500 years ago. Subsequent translocations have seen additional populations established on Middle-South Pearson Island (~53 ha) in 1960 and Wedge Island (96 ha) in 1975. We have used 10 hypervariable microsatellite loci to examine the levels of genetic diversity in the endemic (n = 38) and translocated (n = 45–77) P. l. pearsoni populations compared with mainland P. lateralis populations (n = 19–52). Results show that all sampled P. l. pearsoni populations have very low levels of genetic diversity (A = 1.5–1.9; HE = 0.02–0.13) compared with mainland populations (A = 3.5–12.7; HE = 0.54–0.87). Intriguingly, more diversity was detected in the translocated Middle-South Pearson population than in its source population from North Pearson Island. In contrast, the Wedge Island population was almost monomorphic. Overall, the severe loss of genetic diversity (up to 98%) in P. l. pearsoni populations appears to result from random genetic drift on a small isolated population, exacerbated by some subsequent one-off translocation events. Although additional supplementary translocations are recommended to enhance genetic diversity, populations of P. l. pearsoni are likely to remain inherently vulnerable to extinction and therefore of special conservation concern.

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13

JOLLY, WAYNE T., EDWARD G. LIDIAK, ALAN P. DICKIN, and TSAI-WAY WU. "Recycling in the Puerto Rican mantle wedge, Greater Antilles Island Arc." Island Arc 11, no. 1 (March 2002): 10–24. http://dx.doi.org/10.1046/j.1440-1738.2002.00355.x.

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14

Kushiro, Ikuo. "Partial melting of mantle wedge and evolution of island arc crust." Journal of Geophysical Research 95, B10 (1990): 15929. http://dx.doi.org/10.1029/jb095ib10p15929.

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Dallimore, Scott R., Stephen A. Wolfe, and Steven M. Solomon. "Influence of ground ice and permafrost on coastal evolution, Richards Island, Beaufort Sea coast, N.W.T." Canadian Journal of Earth Sciences 33, no. 5 (May 1, 1996): 664–75. http://dx.doi.org/10.1139/e96-050.

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A long-term sediment budget (1947−1985) for northern Richards Island shows that, when ground ice and offshore erosion are accounted for, there is a near balance between headland erosion and coastal deposition. Excess ice constitutes about 20% of the total volume of eroded material from the headlands, with massive ground ice contributing nearly 9% and segregated ice lenses and ice wedges making up the remainder. Coastal response to major storms in 1987 and 1993 suggests that erosion is episodic, with short periods of intense disruption followed by readjustment of cliff profiles. Processes characteristic of this environment include mechanical erosion of ice-bonded sediments creating unstable erosional niches, mechanical failure of niches along ice-wedge planes, and longer term thermal erosion of ice-bonded sediments. Where ice contents are high, localized thaw slumps initiated by coastal erosion may retreat at rates substantially higher than those observed at other sections of the coast. Cliff-top retreat rates may be out of phase with storm-event chronology.

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Hyndman, R. D., C. J. Yorath, R. M. Clowes, and E. E. Davis. "The northern Cascadia subduction zone at Vancouver Island: seismic structure and tectonic history." Canadian Journal of Earth Sciences 27, no. 3 (March 1, 1990): 313–29. http://dx.doi.org/10.1139/e90-030.

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The structure and Tertiary tectonic history of the northern Cascadia subduction zone have been delineated by a series of new multichannel seismic lines acquired across the continental shelf to the deep sea, combined with adjacent land multichannel seismic data and results from a wide range of other geophysical and geological studies. The top of the downgoing oceanic crust is imaged for a remarkable distance downdip from the deep ocean basin to a depth of 40 km beneath Vancouver Island. The reflection depths are in good agreement with seismic refraction models and Benioff–Wadati seismicity. Two broad reflective bands imaged as dipping gently landward at depths of about 15 and 30 km on the land lines merge to a single reflector band offshore. They may represent underplated oceanic material or, alternatively, they may not be structural but may be zones of contrasting physical properties, perhaps representing trapped fluid. Two narrow terranes, the Mesozoic marine sedimentary Pacific Rim Terrane and the Eocene marine volcanic Crescent Terrane, have been thrust beneath, and accreted to, the margin in the Eocene, about 42 Ma, near the start of the present phase of subduction. They provide a landward-dipping backstop to the large sediment wedge accreted since that time. The deformation front is characterized by mainly landward-dipping thrust faults that cut close to basement. This result and the mass balance of the incoming sediment compared with that present in the accreted wedge suggest that there is little subduction of sediment into the mantle. The Tofino Basin sediments, up to 4 km in thickness, have been deposited on the continental shelf over the accreted terranes and the developing accretionary wedge.

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Carter, J. L., G. J. E. Hill, and P. K. Dyer. "Breeding Cycle of Wedge-tailed ShearwatersPuffinus pacificusat Heron Island, Great Barrier Reef." Emu - Austral Ornithology 96, no. 3 (September 1996): 195–98. http://dx.doi.org/10.1071/mu9960195.

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Robinson, S., and L. Gadd. "Unviable feral cat population results in eradication success on Wedge Island, Tasmania." Papers and Proceedings of The Royal Society of Tasmania 154 (2020): 47–50. http://dx.doi.org/10.26749/rstpp.154.47.

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19

Kartoziia, Andrei. "Assessment of the Ice Wedge Polygon Current State by Means of UAV Imagery Analysis (Samoylov Island, the Lena Delta)." Remote Sensing 11, no. 13 (July 9, 2019): 1627. http://dx.doi.org/10.3390/rs11131627.

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Modern degradation of Arctic permafrost promotes changes in tundra landscapes and leads to degradation of ice wedge polygons, which are the most widespread landforms of Arctic wetlands. Status assessment of polygon degradation is important for various environmental studies. We have applied the geographic information systems’ (GIS) analysis of data from unmanned aerial vehicles (UAV) to accurately assess the status of ice wedge polygon degradation on Samoylov Island. We used several modern models of polygon degradation for revealing polygon types, which obviously correspond to different stages of degradation. Manual methods of mapping and a high spatial resolution of used UAV data allowed for a high degree of accuracy in the identification of all land units. The study revealed the following: 41.79% of the first terrace surface was composed of non-degraded polygonal tundra; 18.37% was composed of polygons, which had signs of thermokarst activity and corresponded to various stages of degradation in the models; and 39.84% was composed of collapsed polygons, slopes, valleys, and water bodies, excluding ponds of individual polygons. This study characterizes the current status of polygonal tundra degradation of the first terrace surface on Samoylov Island. Our assessment reflects the landscape condition of the first terrace surface of Samoylov Island, which is the typical island of the southern part of the Lena Delta. Moreover, the study illustrates the potential of UAV data GIS analysis for highly accurate investigations of Arctic landscape changes.

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Ostendorf, Bertram, Wayne S. J. Boardman, and David A. Taggart. "Islands as refuges for threatened species: multispecies translocation and evidence of species interactions four decades on." Australian Mammalogy 38, no. 2 (2016): 204. http://dx.doi.org/10.1071/am15018.

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Australia has one of the worst mammal extinction rates in the world, with translocations to refuge locations increasingly being advocated to help address problems of species decline. Offshore islands can function as these refuges, removing species from threatening processes and providing a source of animals for reintroduction. Historically, the focus of many island translocations in Australia has been the conservation of a single species, with data on long-term translocation success and population dynamics after release generally lacking. Here we examine the results of a multispecies translocation onto Wedge Island, off the South Australian coast 30–40 years ago. Fewer than a dozen individuals of three species – southern hairy-nosed wombat (Lasiorhinus latifrons), black-footed rock-wallaby (Petrogale lateralis pearsonii), and brush-tailed bettong (Bettongia penicillata) – were released. All three species have shown substantial population increase and wombat activity across the island has increased exponentially with >700 burrows detected. Substantial levels of co-use of wombat burrows by rock-wallabies and bettongs were observed, providing clear evidence for interspecies interactions. Rock-wallabies showed a significant preference for wombat-active burrows (45% co-used), whereas bettongs showed a significant preference for wombat-inactive burrows (10% used). This study suggests that islands have significant potential for long-term threatened species conservation and that translocation of an ecosystem engineer may increase habitat complexity and help improve habitat suitability for multiple species and thus increase the overall conservation benefit.

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Jackson, H. Ruth, Kate Dickie, and François Marillier. "A seismic reflection study of northern Baffin Bay: implication for tectonic evolution." Canadian Journal of Earth Sciences 29, no. 11 (November 1, 1992): 2353–69. http://dx.doi.org/10.1139/e92-184.

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Reflection profiles offshore of Baffin Island, south of Lancaster Sound, reveal coast-parallel half-grabens containing flat-lying sedimentary sections typical of a rifted margin. In northernmost Baffin Bay, adjacent to Devon and southern Ellesmere islands, four sedimentary basins are identified. In these basins the sedimentary sections are faulted, folded, and laterally discontinuous. The basement shows linear trends, steep faults, and abrupt variations in depth. In one basin a 50 km long and 10 km wide "flower structure" is observed. A transpressive tectonic regime is suggested to explain the uplifted sedimentary and basement section and the change in depth to basement across it. A 150 km long paleoshelf, buried by a thickening sedimentary wedge, is present offshore of Devon Island. Because strike-slip and compressional features are observed on seismic profiles north of Lancaster Sound and extensional features are observed to the south, differences in the plate tectonic development are inferred. The interpretations of the seismic reflection records are shown to be compatible with plate motions determined by matching magnetic anomalies in the North Atlantic, the Labrador Sea, the Norwegian and Greenland seas, and the Eurasia Basin. In addition, the onshore geology of Baffin Island, Labrador, and Greenland is consistent with the predrift position of the plates.

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Kepezhinskas, Pavel, Nikita Kepezhinskas, and Nikolai Berdnikov. "Gold, platinum and palladium enrichments in arcs: role of mantle wedge, arc crust and halogen-rich slab fluids." E3S Web of Conferences 98 (2019): 08010. http://dx.doi.org/10.1051/e3sconf/20199808010.

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Arc-related magmas are frequently enriched in Au, Pt and Pd in respect to MORB and OIB igneous suites. Magmatic arcs commonly host large-scale hydrothermal Au and Au-Cu and PGE mineralization related to young volcanic systems and zoned ultramafic complexes respectively. Island-arc mantle xenoliths show Au, Pt, Pd enrichments related to mantle wedge metasomatism by slab-derived fluids. Long-lived plumbing systems in arc crust (arc magma chambers) show further enhancement of Au, Pt and Pd enrichments through subduction-related metamorphic and metasomatic processes in the presence of halogen-rich, aqueous fluids. We propose that Au-Pt-Pd enrichments in arcs are caused by mantle wedge-slab interactions followed by differentiation and metamorphism of magmatic conduits in arc crust.

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Olsen, Ingrid Leirvik, Tom Arne Rydningen, Matthias Forwick, Jan Sverre Laberg, and Katrine Husum. "Last glacial ice sheet dynamics offshore NE Greenland – a case study from Store Koldewey Trough." Cryosphere 14, no. 12 (December 4, 2020): 4475–94. http://dx.doi.org/10.5194/tc-14-4475-2020.

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Abstract. The presence of a grounded Greenland Ice Sheet on the northeastern part of the Greenland continental shelf during the Last Glacial Maximum is supported by new swath bathymetry and high-resolution seismic data, supplemented with multi-proxy analyses of sediment gravity cores from Store Koldewey Trough. Subglacial till fills the trough, with an overlying drape of maximum 2.5 m thick glacier-proximal and glacier-distal sediment. The presence of mega-scale glacial lineations and a grounding zone wedge in the outer part of the trough, comprising subglacial till, provides evidence of the expansion of fast-flowing, grounded ice, probably originating from the area presently covered with the Storstrømmen ice stream and thereby previously flowing across Store Koldewey Island and Germania Land. Grounding zone wedges and recessional moraines provide evidence that multiple halts and/or readvances interrupted the deglaciation. The formation of the grounding zone wedges is estimated to be at least 130 years, while distances between the recessional moraines indicate that the grounding line locally retreated between 80 and 400 m yr−1 during the deglaciation, assuming that the moraines formed annually. The complex geomorphology in Store Koldewey Trough is attributed to the trough shallowing and narrowing towards the coast. At a late stage of the deglaciation, the ice stream flowed around the topography on Store Koldewey Island and Germania Land, terminating the sediment input from this sector of the Greenland Ice Sheet to Store Koldewey Trough.

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Godin, Etienne, Daniel Fortier, and Esther Lévesque. "Nonlinear thermal and moisture response of ice-wedge polygons to permafrost disturbance increases heterogeneity of high Arctic wetland." Biogeosciences 13, no. 5 (March 8, 2016): 1439–52. http://dx.doi.org/10.5194/bg-13-1439-2016.

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Abstract. Low-center polygonal terrains with gentle sloping surfaces and lowlands in the high Arctic have a potential to retain water in the lower central portion of ice-wedge polygons and are considered high-latitude wetlands. Such wetlands in the continuous permafrost regions have an important ecological role in an otherwise generally arid region. In the valley of the glacier C-79 on Bylot Island (Nunavut, Canada), thermal erosion gullies were rapidly eroding the permafrost along ice wedges affecting the integrity of the polygons by breaching and collapsing the surrounding rims. Intact polygons were characterized by a relative homogeneity in terms of topography, snow cover, maximum active layer thaw depth, ground moisture content and vegetation cover (where eroded polygons responded nonlinearly to perturbations, which resulted in differing conditions in the latter elements). The heterogeneous nature of disturbed terrains impacted active layer thickness, ground ice aggradation in the upper portion of permafrost, soil moisture, vegetation dynamics and carbon storage.

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Tsibizov, L. V., E. I. Esin, A. V. Grigorevskaya, and K. A. Sosnovtsev. "Magnetometry and ground penetrating radar in application to mapping of polygonal wedge ice of yedoma complex." Arctic and Antarctic Research 64, no. 4 (December 26, 2018): 427–38. http://dx.doi.org/10.30758/0555-2648-2018-64-4-427-438.

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Paper is dedicated to geophysical mapping of polygonal wedge ice. Magnetometric and ground penetrating radar surveys were implemented on a small area of Yedoma ice complex on Kurungnakh island in Lena river delta. Such deposits are widely spread on a huge areas of Siberia and Alaska. The study was conducted near the thermoerosional gully, which propagates along the most thick ice wedges. Polygonal pattern is observable on high-resolution aerial imagery and digital elevation model - this data was used during the interpreting of obtained results. Study area (40×50 m) was covered with highresolution magnetic survey at the elevation of 2 m with 2×2 m step and with ground penetrating radar survey along profiles with 1 m distance between the profiles. Map of total magnetic field anomalies allow to determine the ice wedges of Yedoma ice complex distinctly. Difference between maximum positive (polygons centers) and negative (ice wedges) anomalies reaches 6 nT (error of the survey is 0,3 nT). Beyond that smaller ice wedges which penetrate the ice wedges of Yedoma complex are also observable in magnetic field. Basing on ground penetrating radar data an amplitude slice of at 3,5 m depth was built. Yedoma ice wedges are observable at depth of 3–4 m. Ground penetrating radar data is quite noisy due to surface inhomogeneity (puddles, knolls, etc.). Results of the surveys were compared in the light of practical application of the methods for above mentioned goal. Magnetometric method appears as more efficient than ground penetrating radar survey: it does not require a contact with the surface and more rapid, it is more sensitive as the case stands. Ground penetrating radar method may have advantages in the case of natural (magnetic storm, high-magnetized overlaying deposits) and anthropogenic (metal constructions — pipelines, ETL) noise.

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Thornett, Elizabeth, Bertram Ostendorf, and David A. Taggart. "Interspecies co-use of southern hairy-nosed wombat (Lasiorhinus latifrons) burrows." Australian Mammalogy 39, no. 2 (2017): 205. http://dx.doi.org/10.1071/am15052.

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Burrows can provide refuge for both burrowing and non-burrowing species within harsh environments through protection from climatic extremes, water loss and predation. In Australia, however, despite having a rich diversity of burrowing mammals, little is known about the use of burrows by non-burrowing species. This study aimed to identify the extent of co-use of southern hairy-nosed wombat (Lasiorhinus latifrons) burrows on Wedge Island off the coast of South Australia. Burrow use was monitored using 34 motion-activated cameras placed outside wombat burrows between March and September 2015. Eleven species were found to use burrows, with six commensal species observed using burrows on numerous occasions. These included two mammal species (black-footed rock-wallaby, Petrogale lateralis pearsoni; brush-tailed bettong, Bettongia penicillata), three reptile species (peninsula dragon, Ctenophorus fionni; southern sand-skink, Liopholis multiscutata; White’s skink, Liopholis whitii), and one avian species (little penguin, Eudyptula minor). The most common species observed using burrows was the black-footed rock-wallaby, which was recorded using burrows 1795 times. Observations of wombats using burrows were made 1674 times. The prevalent use of burrows on Wedge Island by species other than wombats is an observation with potentially important and broad ecological, conservation, and management implications across Australia’s arid and semiarid zones.

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Garkaklis, M. J., C. V. Sims, J. S. Bradley, and R. D. Wooller. "The Breeding Phenology of Wedge-tailed Shearwaters Puffinus pacificus on Rottnest Island, Western Australia." Emu - Austral Ornithology 98, no. 4 (December 1998): 317–19. http://dx.doi.org/10.1071/mu98043.

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Calvert, A. J. "Seismic reflection constraints on imbrication and underplating of the northern Cascadia convergent margin." Canadian Journal of Earth Sciences 33, no. 9 (September 1, 1996): 1294–307. http://dx.doi.org/10.1139/e96-098.

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An interpretation of the deep structure of the continental shelf offshore southern Vancouver Island, subject to constraints from other geophysical data, is derived by combining seismic reflection profiles shot in 1989 with those from an earlier 1985 survey. Accretionary wedge sediments, which extend landward beneath the volcanic Crescent terrane, comprise two primary units, both of which have shortened through duplex formation. The maximum thickness of the Crescent terrane, 6–8 km, occurs just seaward of its contact with the inboard, largely metasedimentary Pacific Rim terrane. The E region of reflectivity, first detected dipping landward beneath Vancouver Island, is regionally extensive, being observed on all the seismic profiles. The E reflectivity thins seaward and splits into two or more strands that probably link into major faults within the accreted sedimentary wedge. Reflections from the interplate décollement beneath the outer continental shelf separate from the downgoing plate, continue into the deepest level of the E reflectivity, and are interpreted to represent a single décollement surface above which imbrication of accreted units occurred. It is proposed that at the southern end of Vancouver Island the E reflections represent mainly underthrust sediments above a former subduction décollement, both of which were incorporated into the overlying continent when the subduction thrust stepped down into the descending oceanic plate. This change in depth of the subduction thrust underplated one or more mafic units to the continent. The reflection from the top of the subducting Juan de Fuca plate appears to be around 5 km shallower farther north along the margin, indicating that the underplated region could be confined to the embayment in the Cascadia subduction zone.

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Tsuji, Takashi. "AN ETHNOGRAPHY ON THE WEDGE SEA HARE IN MACTAN ISLAND, THE PHILIPPINES (ETNOGRAFI TENTANG KELINCI LAUT DI PULAU MACTAN, FILIPINA)." Naditira Widya 13, no. 2 (December 31, 2019): 135–50. http://dx.doi.org/10.24832/nw.v13i2.395.

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The wedge sea hare (Dolabella auricularia) is a mollusk species found in tidal flats and is consumed as food around the Philippines. The practice of consuming its internal organs is probably found only on the Mactan Island. The Problem of this study is to clarify why people collect the internal organs of wedge sea hare. The objective is a gleaner who have special skills to identify the sea hare burrows. Participatory observation and measurement method were employed for this research. As a result, it found that the gleaners precisely identify occupied sea hare burrows using unique skills, and to remove the edible internal organs from the disposable body. Local people regard the internal organs as a nutrition. As a conclusion, this practice must be an adaptation to an environment where vegetable protein is scarce due to a limestone-based soil unsuitable for agriculture. Thus, the role of the wedge sea hare in a unique culture was also developed.Kelinci laut (Dolabella auricularia) adalah spesies moluska yang ditemukan di dataran pasang surut dan dikonsumsi sebagai makanan di sekitar Filipina. Praktik mengkonsumsi organ internalnya mungkin hanya ditemukan di Pulau Mactan. Masalah penelitian ini adalah untuk menjelaskan mengapa orang mengumpulkan organ internal kelinci laut. Tujuannya adalah seorang pengumpul yang memiliki keterampilan khusus untuk mengidentifikasi lubang kelinci laut. Metode pengamatan dan pengukuran partisipatif digunakan untuk penelitian ini. Sebagai hasilnya, ditemukan bahwa para pengumpul secara tepat mengidentifikasi lubang yang didiami kelinci laut dengan menggunakan keterampilan unik, dan mengeluarkan organ internal yang dapat dimakan dari tubuh yang bisa dibuang. Masyarakat lokal menganggap organ dalam sebagai nutrisi. Sebagai kesimpulan, praktik ini harus merupakan adaptasi terhadap lingkungan di mana protein nabati langka karena tanah berbahan dasar batugamping yang tidak cocok untuk pertanian. Dengan demikian, peran kelinci laut dalam budaya unik juga dikembangkan.

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Karakitsios, V., M. Roveri, S. Lugli, V. Manzi, R. Gennari, A. Antonarakou, M. Triantaphyllou, K. Agiadi, and G. Kontakiotis. "Remarks on the Messinian evaporites of Zakynthos Island (Io- nian Sea, Eastern Mediterranean)." Bulletin of the Geological Society of Greece 47, no. 1 (December 21, 2016): 146. http://dx.doi.org/10.12681/bgsg.10915.

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Detailed mapping of the Neogene deposits on Zakynthos Island shows that the Messinian primary evaporite basins, formed over Ionian basement, are delimited by the westernmost outcrop of the Triassic evaporitic diapirs, located west of the Kalamaki-Argasi Messinian gypsum unit. The post-Miocene external Ionian thrust is emplaced west of the Triassic diapirs. Planktonic foraminifera biostratigraphy indicates that primary evaporite accumulation took place probably during the first stage of the Messinian salinity crisis (5.96-5.60 Ma), in shallower parts of a foreland basin, formed over the Pre-Apulian and the Ionian zone basement. Establishment of these depositional environments, before the Ionian thrust emplacement, was probably due to the particularities of the foreland basin, which extended from the external Ionian to the internal Pre-Apulian zone. Field observations, borehole data and an onshore seismic profile show that the Neogene sediments over the Pre-Apulian basement correspond to the foredeep through forebulge domain of the foreland basin, as it is documented from their spatial thickness distribution. In contrast, the Neogene sediments over the Ionian basement correspond to the wedge top of the foreland basin, which was less subsiding, as it is deduced by their reduced thickness. This lower subsidence rate was the result of the concurrent diapiric movements of the Ionian Triassic evaporites. In Agios Sostis area, located over Pre-Apulian basement, the Neogene sequence is intercalated by decametre-thick resedimented blocks consisting of shallow water selenite. To the southeast, this mass-wasting Messinian gypsum passes to mainly gypsum turbidite. In Kalamaki-Argasi area, located over Ionian basement, the shallow water environment led to the deposition of the observed primary gypsum. Erosion of the primary gypsum of both forebulge and wedge top supplied the foreland basin’s depocenter with gypsum turbidites.

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TROUW, R. A. J., C. W. PASSCHIER, L. S. A. SIMÕES, R. R. ANDREIS, and C. M. VALERIANO. "Mesozoic tectonic evolution of the South Orkney Microcontinent, Scotia arc, Antarctica." Geological Magazine 134, no. 3 (May 1997): 383–401. http://dx.doi.org/10.1017/s0016756897007036.

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The South Orkney Islands are the exposed part of a continental fragment on the southern limb of the Scotia arc. The islands are to a large extent composed of metapelites and metagreywackes of probable Triassic sedimentary age. Deformation related to an accretionary wedge setting, with associated metamorphism from anchizone to the greenschist facies, are of Jurassic age (176–200 Ma). On Powell Island, in the centre of the archipelago, five phases of deformation are recognized. The first three, associated with the main metamorphism, are tentatively correlated with early Jurassic subduction along the Pacific margin of Gondwana. D4 is a phase of middle to late Jurassic crustal extension associated with uplift. This extension phase may be related to opening of the Rocas Verdes basin in southern Chile, associated with the breakup of Gondwanaland. Upper Jurassic conglomerates cover the metamorphic rocks unconformably. D5 is a phase of brittle extensional faulting probably associated with Cenozoic opening of the Powell basin west of the archipelago, and with development of the Scotia arc.

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PARK, Jin-Oh. "Pictorial 2 : Structure Crossing the Nankai Trough Accretionary Wedge off Cape Ashizuri of Shikoku Island." Journal of Geography (Chigaku Zasshi) 110, no. 4 (2001): Plate4. http://dx.doi.org/10.5026/jgeography.110.4_plate4.

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Ceres, Robert L., Chris E. Forest, and Klaus Keller. "Optimization of multiple storm surge risk mitigation strategies for an island City On a Wedge." Environmental Modelling & Software 119 (September 2019): 341–53. http://dx.doi.org/10.1016/j.envsoft.2019.06.011.

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Hill, G. J. E., and A. Barnes. "Census and Distribution of Wedge-tailed Shearwater Puffinus pacificus Burrows on Heron Island, November 1985." Emu - Austral Ornithology 89, no. 3 (September 1989): 135–39. http://dx.doi.org/10.1071/mu9890135.

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Nielsen, Jan Kresten, Masakazu Nara, and Aase Roland Jacobsen. "Bowl-shaped structures in a Pleistocene clastic carbonate wedge on the Island of Rhodes, Greece." Ichnos 27, no. 3 (April 10, 2020): 326–33. http://dx.doi.org/10.1080/10420940.2020.1744582.

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36

Carter, Jenny. "Nest-site Selection and Breeding Success of Wedge-tailed Shearwaters Puffinus pacificus at Heron Island." Australian Geographical Studies 35, no. 2 (July 1997): 153–67. http://dx.doi.org/10.1111/1467-8470.00016.

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Kusakabe, Minoru, Keisuke Nagao, Takeshi Ohba, Jung Hun Seo, Sung-Hyun Park, Jong Ik Lee, and Byong-Kwon Park. "Noble gas and stable isotope geochemistry of thermal fluids from Deception Island, Antarctica." Antarctic Science 21, no. 3 (February 11, 2009): 255–67. http://dx.doi.org/10.1017/s0954102009001783.

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AbstractNew stable isotope and noble gas data obtained from fumarolic and bubbling gases and hot spring waters sampled from Deception Island, Antarctica, were analysed to constrain the geochemical features of the island's active hydrothermal system and magmatism in the Bransfield back-arc basin. The 3He/4He ratios of the gases (< 9.8 × 10-6), which are slightly lower than typical MORB values, suggest that the Deception Island magma was generated in the mantle wedge of a MORB-type source but the signature was influenced by the addition of radiogenic 4He derived from subducted components in the former Phoenix Plate. The N2/He ratios of fumarolic gas are higher than those of typical mantle-derived gases suggesting that N2 was added during decomposition of sediments in the subducting slab. The δ13C values of -5 to -6‰ for CO2 also indicate degassing from a MORB-type mantle source. The H2/Ar- and SiO2 geothermometers indicate that the temperatures in the hydrothermal system below Deception Island range from ~150°C to ~300°C. The δD and δ18O values measured from fumarolic gas and hot spring waters do not indicate any contribution of magmatic water to the samples. The major ionic components and δD-δ18O-δ34S values indicate that hot spring waters are a mixture of local meteoric water and seawater. Mn and SiO2 in spring waters were enriched relative to seawater reflecting water-rock interaction at depth.

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Payot, Betchaida, Shoji Arai, Masako Yoshikawa, Akihiro Tamura, Mitsuru Okuno, and Danikko Rivera. "Mantle Evolution from Ocean to Arc: The Record in Spinel Peridotite Xenoliths in Mt. Pinatubo, Philippines." Minerals 8, no. 11 (November 8, 2018): 515. http://dx.doi.org/10.3390/min8110515.

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A suite of peridotite xenoliths were collected from lahar flow deposits located close to the summit of Mt. Pinatubo. Spinel harzburgite is the most dominant lithology among dunites, pyroxenites and websterites. A rare spinel lherzolite xenolith (P12-7) is also present in this suite. The spinel lherzolite has well-preserved protogranular texture with very minimal presence of secondary amphibole, low Cr# in the chromian spinel, and depleted and hump shaped patterns of chondrite-normalized rare earth element (REE) patterns for the clinopyroxenes. In contrast, the spinel harzburgites contain abundant secondary amphiboles and orthopyroxenes, higher Cr# in the spinel, and slightly elevated patterns for the chondrite-normalized REE patterns for the amphiboles. The spinel lherzolite also exhibits higher olivine Fo content for a given spinel Cr# compared to the spinel harzburgites. The spinel lherzolite is interpreted as a typical residue from partial melting of abyssal peridotites whereas the spinel harzburgites may have formed via partial melting with subsequent modification during the influx of fluids in the mantle wedge. Our results suggest that fragments of MOR-derived lithosphere exist in the mantle wedge beneath the Philippine island arc. This work provides evidence for the conversion of abyssal to arc peridotites in the mantle wedge.

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Whitney, Michael M., David S. Ullman, and Daniel L. Codiga. "Subtidal Exchange in Eastern Long Island Sound." Journal of Physical Oceanography 46, no. 8 (August 2016): 2351–71. http://dx.doi.org/10.1175/jpo-d-15-0107.1.

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AbstractLong Island Sound (LIS) is a large and wide macrotidal estuary with distributed river inputs, including the Connecticut River (the largest freshwater source) that flows into the eastern LIS near the mouth. In 2010, shipboard surveys of salinity, temperature, and currents were collected along an across-estuary transect in eastern LIS. Numerical model results are compared to these observations and used to study the spatial and temporal variability of salinity, velocity, and freshwater and salt fluxes over a 4-yr period. For all low wind conditions, observations and model results indicate an outward-flowing, low-salinity wedge on the south side with an inward-flowing, higher-salinity area underneath and to the north. Observations and model results during the low wind surveys indicate that stratification substantially decreases with increased tidal amplitude and decreased river discharge; the velocity field is less variable among surveys. Model analysis indicates strong sensitivities to both tides and river discharge; with discharge response strongest for salinity and freshwater flux and tidal response larger for velocities, volume flux, and salt flux. The long-term average net freshwater and salt fluxes are outward and inward, respectively. For both flux types, subtidal shear dispersion is twice tidal oscillatory diffusion, and both contributions are in the same direction as the net flux. The uniform flow contribution is small for freshwater flux, yet it is the largest single term for salt flux and partially counters the inward contributions.

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Ito, Yoshihiro, Spahr C. Webb, Yoshihiro Kaneko, Laura M. Wallace, and Ryota Hino. "Sea Surface Gravity Waves Excited by Dynamic Ground Motions from Large Regional Earthquakes." Seismological Research Letters 91, no. 4 (June 3, 2020): 2268–77. http://dx.doi.org/10.1785/0220190267.

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Abstract Infragravity waves on the sea surface near coastlines are occasionally excited by static displacement caused by large local earthquakes and recorded as tsunamis. However, tsunamis induced by ground motions from seismic waves are rarely observed, especially far from earthquake focal areas. We investigated seafloor pressure variations in the infragravity band at the Hikurangi subduction zone following the M 7.8 Kaikōura and M 7.1 Te Araroa earthquakes. Anomalous infragravity waves were observed at 0.2–20 mHz at sites overlying a low-velocity accretionary wedge offshore of the east coast of New Zealand’s North Island accompanying the Rayleigh-wave arrivals. The maximum amplitude of these ultra-low-frequency waves was similar to the tsunami that propagated from the earthquake focal area hours later. The amplitude of the pressure signal from these waves observed offshore varied inversely with water depth, suggesting that sea surface gravity waves were excited by Rayleigh or Love waves amplified within the accretionary wedge.

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Teng, Fang-Zhen, Yan Hu, and Catherine Chauvel. "Magnesium isotope geochemistry in arc volcanism." Proceedings of the National Academy of Sciences 113, no. 26 (June 14, 2016): 7082–87. http://dx.doi.org/10.1073/pnas.1518456113.

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Incorporation of subducted slab in arc volcanism plays an important role in producing the geochemical and isotopic variations in arc lavas. The mechanism and process by which the slab materials are incorporated, however, are still uncertain. Here, we report, to our knowledge, the first set of Mg isotopic data for a suite of arc lava samples from Martinique Island in the Lesser Antilles arc, which displays one of the most extreme geochemical and isotopic ranges, although the origin of this variability is still highly debated. We find the δ26Mg of the Martinique Island lavas varies from −0.25 to −0.10, in contrast to the narrow range that characterizes the mantle (−0.25 ± 0.04, 2 SD). These high δ26Mg values suggest the incorporation of isotopically heavy Mg from the subducted slab. The large contrast in MgO content between peridotite, basalt, and sediment makes direct mixing between sediment and peridotite, or assimilation by arc crust sediment, unlikely to be the main mechanism to modify Mg isotopes. Instead, the heavy Mg isotopic signature of the Martinique arc lavas requires that the overall composition of the mantle wedge is buffered and modified by the preferential addition of heavy Mg isotopes from fluids released from the altered subducted slab during fluid−mantle interaction. This, in turn, suggests transfer of a large amount of fluid-mobile elements from the subducting slab to the mantle wedge and makes Mg isotopes an excellent tracer of deep fluid migration.

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Hiscott, Richard N., and Ali E. Aksu. "Quaternary Sedimentary Processes and Budgets in Orphan Basin, Southwestern Labrador Sea." Quaternary Research 45, no. 2 (March 1996): 160–75. http://dx.doi.org/10.1006/qres.1996.0017.

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AbstractThe continental slope in Orphan Basin, northeast of Newfoundland, is underlain by several seaward-thinning debris-flow wedges alternating with acoustically stratified, regionally extensive, mainly hemipelagic sediments. δ18O stratigraphy and volcanic ash layers in a 11.67-m core indicate that the uppermost debris-flow wedge formed during the last of several sea-level lowstands in isotopic stages 2–4. Similarly, seismic reflection correlation of dated levels at DSDP Site 111 with the Orphan Basin succession suggests that two deeper debris-flow wedges were deposited during oxygen isotopic stages 6 and 8. The oldest of the debris-flow deposits in at least three of the wedges formed well into the corresponding glacial cycle, after ice sheets had reached the edge of the continental shelf. Slower deposition by hemipelagic processes and ice rafting formed the acoustically stratified units, including Heinrich layers. The youngest three debris-flow wedges each have volumes of 1300–1650 km3. Approximately two-thirds of this material is attributed to glacial erosion of Mesozoic and Tertiary strata beneath the Northeast Newfoundland Shelf. The remainder is believed to have been derived by glacial erosion of older bedrock that now forms the island of Newfoundland. The observed sediment volumes and the inferred basal and upper ages of the debris-flow wedges imply an average glacial denudation rate of about 0.13 mm/yr for this older bedrock, and an average of about 60 m of glacial bedrock erosion since oxygen isotope stage 22. This denudation rate is similar to estimates from the Barents Sea region off Norway.

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Haase, Karsten M., and Christoph Beier. "Chapter 3.2b Bransfield Strait and James Ross Island: petrology." Geological Society, London, Memoirs 55, no. 1 (2021): 285–301. http://dx.doi.org/10.1144/m55-2018-37.

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AbstractYoung volcanic centres of the Bransfield Strait and James Ross Island occur along back-arc extensional structures parallel to the South Shetland island arc. Back-arc extension was caused by slab rollback at the South Shetland Trench during the past 4 myr. The variability of lava compositions along the Bransfield Strait results from varying degrees of mantle depletion and input of a slab component. The mantle underneath the Bransfield Strait is heterogeneous on a scale of approximately tens of kilometres with portions in the mantle wedge not affected by slab fluids. Lavas from James Ross Island east of the Antarctic Peninsula differ in composition from those of the Bransfield Strait in that they are alkaline without evidence for a component from a subducted slab. Alkaline lavas from the volcanic centres east of the Antarctic Peninsula imply variably low degrees of partial melting in the presence of residual garnet, suggesting variable thinning of the lithosphere by extension. Magmas in the Bransfield Strait form by relatively high degrees of melting in the shallow mantle, whereas the magmas some 150 km further east form by low degrees of melting deeper in the mantle, reflecting the diversity of mantle geodynamic processes related to subduction along the South Shetland Trench.

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Cecere, Jacopo G., Licia Calabrese, Gerard Rocamora, and Carlo Catoni. "Movement Patterns and Habitat Selection of Wedge-tailed Shearwaters (Puffinus pacificus) Breeding at Aride Island, Seychelles." Waterbirds 36, no. 4 (December 2013): 432–37. http://dx.doi.org/10.1675/063.036.0414.

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Kondo, Reisuke, Sumiko Tsukamoto, and Tatsuhiko Sakamoto. "Luminescence chronology of a fossil periglacial wedge and volcanic fan in Rishiri Island, northern Hokkaido, Japan." Quaternary Research (Daiyonki-Kenkyu) 53, no. 2 (2014): 95–101. http://dx.doi.org/10.4116/jaqua.53.95.

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Ledneva, G. V., J. I. Garver, J. Lederer, K. T. Hollocher, M. N. Shapiro, and M. T. Brandon. "Provenance and tectonic settings of accretionary wedge sediments on northeastern Karaginski Island (Kamchatka, Russian Far East)." Russian Journal of Earth Sciences 6, no. 2 (June 3, 2004): 105–32. http://dx.doi.org/10.2205/2004es000152.

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47

Bancroft, Wesley J., Mark J. Garkaklis, and J. Dale Roberts. "Continued expansion of the Wedge-tailed Shearwater, Puffinus pacificus, nesting colonies on Rottnest Island, Western Australia." Emu - Austral Ornithology 104, no. 1 (March 2004): 79–82. http://dx.doi.org/10.1071/mu03010.

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ZHENG, Yanpeng. "Structural control of the Gagua “Wedge” Zone east of Taiwan Island on the southern Okinawa Trough." Science in China Series D 48, no. 8 (2005): 1165. http://dx.doi.org/10.1360/03yd0246.

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Dyer, P. K., and G. J. E. Hill. "An Integrated Mapping Approach to Monitoring Burrowing Birds: Wedge-tailed Shearwaters on North Stradbroke Island, Queensland." Emu - Austral Ornithology 95, no. 1 (March 1995): 62–66. http://dx.doi.org/10.1071/mu9950062.

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Fraser, Robert, Steven Kokelj, Trevor Lantz, Morgan McFarlane-Winchester, Ian Olthof, and Denis Lacelle. "Climate Sensitivity of High Arctic Permafrost Terrain Demonstrated by Widespread Ice-Wedge Thermokarst on Banks Island." Remote Sensing 10, no. 6 (June 15, 2018): 954. http://dx.doi.org/10.3390/rs10060954.

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Journal articles on the topic 'Wedge Island'

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