DOCSLIB.ORG

45. Amery Group Red Beds in Prydz Bay, Antarctica1

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
45. Amery Group Red Beds in Prydz Bay, Antarctica1 Barron, J., Larsen, B., et al., 1991 Proceedings of the Ocean Drilling Program, Scientific Results, Vol. 119 45. AMERY GROUP RED BEDS IN PRYDZ BAY, ANTARCTICA1 Barbara H. Keating2 and Hideo Sakai3 ABSTRACT A thick sequence of continental red beds was drilled at ODP Site 740, on the continental margin of Antarctica. The red beds lack dateable fossils. Paleomagnetic studies were undertaken to establish the age of formation for these rocks. Many of the rocks sampled were found to be thermally remagnetized and yielded paleomagnetic inclinations similar to those of intrusive units within outcrops of red beds in Antarctica. Based upon the similarities in lithology, sequence of rock types, thickness, magnetic properties, and thermal histories, a correlation is made with the Amery Group of Per- mian age. Red beds of this group are exposed in the Prince Charles Mountains, inland of Prydz Bay. INTRODUCTION the northern Prince Charles Mountains (Crohn, 1959; Mond, 1972; Bennett and Taylor, 1972). These units were mapped by During Leg 119 of the Ocean Drilling Program (ODP), sev- McKelvey and Stephenson (1990). At least 2000 m of upper Per- eral holes were drilled on the continental margin of Antarctica. mian Amery Group conglomerates and sandstones is overlain At Hole 740A, the hole nearest the shoreline (Fig. 1), continen- by coal measures, dipping to the south-southeast at about 10° tal red beds were recovered. Sedimentologic studies indicate that to 20°. Drilling at Site 741, which is roughly 25 km from Site these red beds represent fluvial deposits. No fossils were found 740, cored 104 m of black shales, sandstones, and coal placed in the red bed unit, apart from undatable algal spores. The age roughly 1500 m higher in the geologic section than the red beds was designated "unknown" (Barron, Larsen, et al., 1989), and of Hole 740A (Barron, Larsen, et al., 1989). The stratigraphic subsequent fossil studies have not produced age constraints for sequence and thickness found by ODP drilling in Prydz Bay are this unit (Truswell, this volume). Thus, paleomagnetic studies thus similar to those reported at Beaver Lake by McKelvey and were undertaken to estimate the age of the sequence. Correla- Stephenson (1990), but because the sediments at Site 741 are of tions are made with nearby outcrops of the Amery Group on post-rift Early Cretaceous age according to Truswell (this vol- the basis of lithology and stratigraphy and supported by paleo- ume), they are not equivalent stratigraphically to the lower Per- magnetic correlations (including the inclination and polarity, mian Amery sequence. the character of the secondary magnetization, as well as rock The Permian Amery Group is the only known in-situ Paleo- magnetic characteristics). An age of Permian is suggested for zoic sedimentary sequence in all of MacRobertson Land. The the red bed sequence cored at ODP Hole 740A. flora contained in these rocks are described by Kemp (1973) and White (1973). The correlation of these rocks with part of the BACKGROUND Beacon Supergroup of western Antarctica was suggested by Prydz Bay is located on the eastern Antarctic continental Mond (1972). Within the southern Prince Charles Mountains margin, seaward of the Lambert Graben and Prince Charles fine-grained red siltstone debris containing Glossopteris plant Mountains (Fig. 1). At Site 740A, 56 m of glacial and gla- fossils like those found in the red beds of the Amery Group at ciomarine overburden and 58 m of continental red beds were Beaver Lake and the Beacon Supergroup elsewhere (Ruker, 1963; penetrated. Seismic-reflection profiles, collected as part of pre- White, 1962) was recovered in a moraine. drilling site surveys of the seaward-dipping sedimentary section The Amery sediments at Beaver Lake have been intruded by at Prydz Bay, revealed the stratified sequence at Hole 740A two geochemically distinct intrusive units. The red beds are in- (Barron, Larsen, et al., 1989). Outcrops of rock formations up- truded by alnoite sills and strongly altered alkaline mafic dikes. dip from Hole 740A include a lithologically correctable red bed The chilled margins and calcite veins and coatings on joint sur- unit on shore in the vicinity of Prydz Bay (McKelvey and faces in the sills extend into the surrounding strata. McKelvey Stephenson, 1990). and Stephenson (1990) reported only one K-Ar age of 110 Ma The outcrops of the red beds described by McKelvey and (mid-Cretaceous). Red bed sequences, containing thick intrusive Stephenson (1990) occur in the Prince Charles Mountains and bodies that have baked adjoining sediments, have been recorded are drained by the Amery Ice Shelf system. The southern Prince throughout Gondwanaland. The red beds are loosely dated as Charles Mountains consist of numerous nunataks forming moun- Devonian through Triassic. It is suggested that the red bed se- tain fringes of the Lambert and Kaliningrad glaciers (Hofman, quence drilled at Hole 740A corresponds to the Amery Group 1982). A complex of Archean to upper Proterozoic metamor- in the Prince Charles Mountains. phic rocks, locally intruded by granites and unconformably The paleolatitude results derived from this study are dis- overlain by Permian sediments (Tingey, 1972), forms the moun- cussed in the framework of the Permian tectonic configuration tains (Grew, 1982; Ravich and Fedorov, 1982). Upper Permian of Gondwanaland. Low paleolatitudes were observed in the red clastic sediments are present in exposures around Beaver Lake in beds from Hole 740A. The paleoinclinations are consistent with those observed from intrusives found within red bed sequences throughout Antarctica. Paleomagnetic studies conducted on the 1 Barron, J., Larsen, B., et al., 1991. Proc. ODP, Sci. Results, 119: College Beacon Supergroup red beds (Turnbull, 1959; Bull and Irving, Station, TX (Ocean Drilling Program). 1960; Bull et al., 1962; Hamilton, 1965; Christoffel, 1981; 2 Hawaii Institute of Geophysics, University of Hawaii, Honolulu, HI 96822, U.S.A. Funaki, 1983; Sakai and Funaki, 1988) evidence that thermal 3 Department of Earth Sciences, Toyama University, Gofuku 3190, Toyama alteration of the red beds is abundant and very similar in nature City 930, Japan. to that observed in ODP Hole 740A. 795 B. H. KEATING, H. SAKAI Lutzow-Holm Bay Enderby Land J Amery Ice Shelf 270° W. 90° E. 136°E 180 142°E \ 70° ( 60° 65° 80° Beardmore Glacier \ 65° 60° 1— 80c \ Lambert Glacier / 75° X Amery Ice Shelf / Kaliningard Glacier -~ v_^^^ ) Prydz V Bay Beacon Heights )C^\ Ferrar Glacier ..Windy Gully [Λ *π"*π"ayloa r Glacier C ^-70° 75 Site 740- Site741 ^N 80°^ McMurdo •> Sound \ 5 Mawson Glacier — 80° I c - 75° 150 7cθ 7 70° \ 180° K A ^ B Figure 1. Map of Antarctica showing the location of (A) Sites 740 and 741 and (B) other paleomagnetic studies of Beacon Group sedi- ments. 796 AMERY GROUP RED BEDS IN PRYDZ BAY RED BEDS FROM HOLE 740A Hole 740A. The lower unit is well stratified and corresponds to the lower part of the sequence in Hole 740A. Stagg (1985) ar- Turner (this volume) described the depositional environment gued that the only well-stratified sediments observed within the and petrography of the red sediments from Hole 740A. The red Prydz Bay area were the Permian red beds and suggested that sediments collected consist of 58 m of sandstone interbedded the lower unit consisted of red beds similar to those in the with siltstone and claystone. The siltstones and claystones repre- Prince Charles Mountains. sent fine-grained flood plain deposits. The numerous erosively based sequences observed are believed to represent sandy braided PALEOMAGNETIC STUDIES stream deposits. Discharge fluctuations in the braided streambeds Paleomagnetic studies were undertaken in order to place con- were not great because significant amounts of trapped fine- straints on the age of the red beds drilled at Hole 740A. The grained sediments occur throughout the sandstones. Turner studies included detailed stepwise thermal demagnetization. Nearly concluded that much of the deposition of sandstones took place 150 red bed samples were studied. under steady-state flow conditions. Turner observed that pedo- genic carbonate is absent other than in root structures and sug- Instrumentation and Laboratory Experiments gested that the climate may have been too wet for extensive cal- The samples were inscribed with orientation lines prior to ex- crete formation. traction from the core. The samples for this study consist of Modal analysis of sandstones and siltstones indicates they cubes cut from the lithified sediments using a rock saw and are arkosic wackes composed of quartz, mica, and feldspar with stored in plastic sample cubes. Generally, three samples were subordinate rock fragments, garnet, and opaque minerals set in taken from each core section. Shipboard pilot studies were con- a clay matrix that makes up 17%-66% of the rock. Chlorite and ducted using both alternating field demagnetization and ther- sericite, some of diagenetic origin, are common constituents of mal demagnetization; the thermal demagnetization studies sug- the matrix. Turner (this volume) found in some thin sections gested a complicated picture of multicomponent magnetization. that the matrix consists of a coarse mat of biotite, muscovite, Subsequent to the cruise, the samples were shipped to the Uni- sericite, and chlorite of medium-silt grade. Authigenic vermicu- versity of Hawaii. The plastic sample cubes were opened so that lar chlorite was also present in the matrix. In the more clay-rich the samples dried in air. The samples were labeled with white sandstones the red sands are impregnated with iron oxides (mainly ink so that they could be identified after thermal demagnetiza- hematite). The green sandstones are rich in chlorite. Some tion and were placed in a doubly shielded mu-metal room for 2 quartz grains show poorly developed secondary overgrowths de- weeks prior to measurement. They were measured within the fined by a thin dust and iron oxide.
Load more

Recommended publications
  • PROGETTO ANTARTIDE Rapporto Sulla Campagna Antartica Estate Australe 1996
    PROGRAMMA NAZIONALE DI RICERCHE IN ANTARTIDE Rapporto sulla Campagna Antartica Estate Australe 1996 - 97 Dodicesima Spedizione PROGETTO ANTARTIDE ANT 97/02 PROGRAMMA NAZIONALE DI RICERCHE IN ANTARTIDE Rapporto sulla Campagna Antartica Estate Australe 1996 - 97 Dodicesima Spedizione A cura di J. Mϋller, T. Pugliatti, M.C. Ramorino, C.A. Ricci PROGETTO ANTARTIDE ENEA - Progetto Antartide Via Anguillarese,301 c.p.2400,00100 Roma A.D. Tel.: 06-30484816,Fax:06-30484893,E-mail:[email protected] I N D I C E Premessa SETTORE 1 - EVOLUZIONE GEOLOGICA DEL CONTINENTE ANTARTICO E DELL'OCEANO MERIDIONALE Area Tematica 1a Evoluzione Geologica del Continente Antartico Progetto 1a.1 Evoluzione del cratone est-antartico e del margine paleo-pacifico del Gondwana.3 Progetto 1a.2 Evoluzione mesozoica e cenozoica del Mare di Ross ed aree adiacenti..............11 Progetto 1a.3 Magmatismo Cenozoico del margine occidentale antartico..................................17 Progetto 1a.4 Cartografia geologica, geomorfologica e geofisica ...............................................18 Area Tematica 1b-c Margini della Placca Antartica e Bacini Periantartici Progetto 1b-c.1 Strutture crostali ed evoluzione cenozoica della Penisola Antartica e del margine coniugato cileno ......................................................................................25 Progetto 1b-c.2 Indagini geofisiche sul sistema deposizionale glaciale al margine pacifico della Penisola Antartica.........................................................................................42
    [Show full text]
  • Amanda Bay, Ingrid Christensen Coast, Princess Elizabeth Land, East Antarctica
    MEASURE 3 - ANNEX Management Plan for Antarctic Specially Protected Area No 169 AMANDA BAY, INGRID CHRISTENSEN COAST, PRINCESS ELIZABETH LAND, EAST ANTARCTICA Introduction Amanda Bay is located on the Ingrid Christensen Coast of Princess Elizabeth Land, East Antarctica at 69°15' S, 76°49’59.9" E. (Map A). The Antarctic Specially Protected Area (ASPA) is designated to protect the breeding colony of several thousand pairs of emperor penguins annually resident in the south-west corner of Amanda Bay, while providing for continued collection of valuable long- term research and monitoring data and comparative studies with colonies elsewhere in East Antarctica. Only two other emperor penguin colonies along the extensive East Antarctic coastline are protected within ASPAs (ASPA 120, Point Géologie Archipelago and ASPA 167 Haswell Island). Amanda Bay is more easily accessed, from vessels or by vehicle from research stations in the Larsemann Hills and Vestfold Hills, than many other emperor penguin colonies in East Antarctica. This accessibility is advantageous for research purposes, but also creates the potential for human disturbance of the birds. The Antarctic coastline in the vicinity of Amanda Bay was first sighted and named the Ingrid Christensen Coast by Captain Mikkelsen in command of the Norwegian ship Thorshavn on 20 February 1935. Oblique aerial photographs of the coastline were taken by the Lars Christensen expedition in 1937 and by the US Operation Highjump in 1947 for reconnaissance purposes. In the 1954/55 summer, the Australian National Antarctic Research Expedition (ANARE) on the Kista Dan explored the waters of Prydz Bay, and the first recorded landing in the area was made by a sledging party led by Dr.
    [Show full text]
  • S41467-018-05625-3.Pdf
    ARTICLE DOI: 10.1038/s41467-018-05625-3 OPEN Holocene reconfiguration and readvance of the East Antarctic Ice Sheet Sarah L. Greenwood 1, Lauren M. Simkins2,3, Anna Ruth W. Halberstadt 2,4, Lindsay O. Prothro2 & John B. Anderson2 How ice sheets respond to changes in their grounding line is important in understanding ice sheet vulnerability to climate and ocean changes. The interplay between regional grounding 1234567890():,; line change and potentially diverse ice flow behaviour of contributing catchments is relevant to an ice sheet’s stability and resilience to change. At the last glacial maximum, marine-based ice streams in the western Ross Sea were fed by numerous catchments draining the East Antarctic Ice Sheet. Here we present geomorphological and acoustic stratigraphic evidence of ice sheet reorganisation in the South Victoria Land (SVL) sector of the western Ross Sea. The opening of a grounding line embayment unzipped ice sheet sub-sectors, enabled an ice flow direction change and triggered enhanced flow from SVL outlet glaciers. These relatively small catchments behaved independently of regional grounding line retreat, instead driving an ice sheet readvance that delivered a significant volume of ice to the ocean and was sustained for centuries. 1 Department of Geological Sciences, Stockholm University, Stockholm 10691, Sweden. 2 Department of Earth, Environmental and Planetary Sciences, Rice University, Houston, TX 77005, USA. 3 Department of Environmental Sciences, University of Virginia, Charlottesville, VA 22904, USA. 4 Department
    [Show full text]
  • Geology of the Northern Convoy Range, Victoria Land, Antarctica
    Journal of Maps ISSN: (Print) (Online) Journal homepage: https://www.tandfonline.com/loi/tjom20 Geology of the northern Convoy Range, Victoria Land, Antarctica Giovanni Capponi , Chiara Montomoli , Stefano Casale & Matteo Simonetti To cite this article: Giovanni Capponi , Chiara Montomoli , Stefano Casale & Matteo Simonetti (2020) Geology of the northern Convoy Range, Victoria Land, Antarctica, Journal of Maps, 16:2, 702-709, DOI: 10.1080/17445647.2020.1822218 To link to this article: https://doi.org/10.1080/17445647.2020.1822218 © 2020 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group View supplementary material Published online: 08 Oct 2020. Submit your article to this journal View related articles View Crossmark data Full Terms & Conditions of access and use can be found at https://www.tandfonline.com/action/journalInformation?journalCode=tjom20 JOURNAL OF MAPS 2020, VOL. 16, NO. 2, 702–709 https://doi.org/10.1080/17445647.2020.1822218 Science Geology of the northern Convoy Range, Victoria Land, Antarctica Giovanni Capponi a, Chiara Montomoli b, Stefano Casalec and Matteo Simonettib aDISTAV, University of Genoa, Genoa, Italy; bDipartimento di Scienze della Terra, University of Turin, Turin, Italy; cDipartimento di Scienze della Terra, University of Pisa, Pisa, Italy ABSTRACT ARTICLE HISTORY In this paper, we supply a geological map of the area between 76°–76°30′S and 159°–163°E, that Received 14 November 2019 was the only missing portion to complete an entire coverage of Victoria Land, filling the gap Revised 17 March 2020 between the GIGAMAP program (to the north) and the maps by the New Zealand Antarctic Accepted 7 September 2020 program (to the south).
    [Show full text]
  • Flow of the Amery Ice Shelf and Its Tributary Glaciers
    18th Australasian Fluid Mechanics Conference Launceston, Australia 3-7 December 2012 Flow of the Amery Ice Shelf and its Tributary Glaciers M. L. Pittard1 2 , J. L. Roberts3 2, R. C. Warner3 2, B.K Galton-Fenzi2, C.S. Watson4 and R. Coleman1 1Institute for Marine and Antarctic Studies University of Tasmania, Private Bag 129, Hobart, Tasmania 7001, Australia 2Antarctic Climate & Ecosystems Cooperative Research Centre University of Tasmania, Private Bag 80, Hobart, Tasmania 7001, Australia 3Department of Sustainability, Environment, Water, Population and Communities, Australian Antarctic Division Hobart, Tasmania, Australia 4 School of Geography and Environmental Studies University of Tasmania, Private Bag 76, Hobart, Tasmania 7001, Australia Abstract thickness across the grounding zone to provide information on ice discharge. Strain rates and vorticity can be used to investi- The Amery Ice Shelf (AIS) is a major ice shelf that drains ap- gate the dynamics of the flow. The longitudinal strain rate gives proximately 16% of the East Antarctic Ice Sheet [1]. Here we insight into the way the velocity changes along the flow and use a sequence of visible spectrum Landsat7 satellite images may reflect influences of features beneath the ice. The shear to track persistent surface features over the southern portion of component of the strain rate highlights the localisation of shear the AIS and its three major tributary glaciers. A spatially in- stresses at the margin of the flow. Vorticity displays a combina- complete velocity field is calculated by comparing the distances tion of rotation in flow direction and strong shear deformations. features have moved between image pairs. Key features of the flow field including the vorticity and strain rate distributions are The AIS is one of the largest ice shelves bordering the East discussed.
    [Show full text]
  • History of Benthic Colonisation Beneath the Amery Ice Shelf, East Antarctica
    Vol. 344: 29–37, 2007 MARINE ECOLOGY PROGRESS SERIES Published August 23 doi: 10.3354/meps06966 Mar Ecol Prog Ser History of benthic colonisation beneath the Amery Ice Shelf, East Antarctica Alexandra L. Post1,*, Mark A. Hemer1, Philip E. O’Brien1, Donna Roberts2, Mike Craven3 1Marine and Coastal Environment Group, Geoscience Australia, GPO Box 378, Canberra, ACT 2601, Australia 2Institute of Antarctic and Southern Ocean Studies, University of Tasmania, Private Bag 77, Hobart, Tasmania 7001, Australia 3Australian Antarctic Division and Antarctic Climate and Ecosystems Co-operative Research Centre, Private Bag 80, Hobart, Tasmania 7001, Australia ABSTRACT: This study presents compelling evidence for a diverse and abundant seabed community that developed over the course of the Holocene beneath the Amery Ice Shelf, East Antarctica. Fossil analysis of a 47 cm long sediment core revealed a rich modern fauna dominated by filter feeders (sponges and bryozoans). The down-core assemblage indicated a succession in the colonisation of this site. The lower portion of the core (before ~9600 yr BP) was completely devoid of preserved fauna. The first colonisers (at ~10 200 yr BP) were mobile benthic organisms. Their occurrence was matched by the first appearance of planktonic taxa, indicating a retreat of the ice shelf following the last glaciation to within sufficient distance to advect planktonic particles via bottom currents. The benthic infauna and filter feeders emerged during the peak abundance of the planktonic organisms, indicating their dependence on the food supply sourced from the open shelf waters of Prydz Bay. Understanding patterns of species succession in this environment has important implications for determining the potential significance of future ice shelf collapse.
    [Show full text]
  • Ocean-Driven Thinning Enhances Iceberg Calving and Retreat of Antarctic Ice Shelves
    Ocean-driven thinning enhances iceberg calving and retreat of Antarctic ice shelves Yan Liua,b, John C. Moorea,b,c,d,1, Xiao Chenga,b,1, Rupert M. Gladstonee,f, Jeremy N. Bassisg, Hongxing Liuh, Jiahong Weni, and Fengming Huia,b aState Key Laboratory of Remote Sensing Science, College of Global Change and Earth System Science, Beijing Normal University, Beijing 100875, China; bJoint Center for Global Change Studies, Beijing 100875, China; cArctic Centre, University of Lapland, 96100 Rovaniemi, Finland; dDepartment of Earth Sciences, Uppsala University, Uppsala 75236, Sweden; eAntarctic Climate and Ecosystems Cooperative Research Centre, University of Tasmania, Hobart, Tasmania, Australia; fVersuchsanstalt für Wasserbau, Hydrologie und Glaziologie, Eidgenössische Technische Hochschule Zürich, 8093 Zurich, Switzerland; gDepartment of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, MI 48109-2143; hDepartment of Geography, McMicken College of Arts & Sciences, University of Cincinnati, OH 45221-0131; and iDepartment of Geography, Shanghai Normal University, Shanghai 200234, China Edited by Anny Cazenave, Centre National d’Etudes Spatiales, Toulouse, France, and approved February 10, 2015 (received for review August 7, 2014) Iceberg calving from all Antarctic ice shelves has never been defined as the calving flux necessary to maintain a steady-state directly measured, despite playing a crucial role in ice sheet mass calving front for a given set of ice thicknesses and velocities along balance. Rapid changes to iceberg calving naturally arise from the the ice front gate (2, 3). Estimating the mass balance of ice sporadic detachment of large tabular bergs but can also be shelves out of steady state, however, requires additional in- triggered by climate forcing.
    [Show full text]
  • Detection of Iceberg Calving Events in Prydz Bay, East Antarctica During 2013 – 2015 Using LISS-IV/IRS-P6 Satellite Data
    CZECH POLAR REPORTS 8 (2): 275-285, 2018 Detection of iceberg calving events in Prydz Bay, East Antarctica during 2013 – 2015 using LISS-IV/IRS-P6 satellite data Shridhar Digambar Jawak1,2*, Meghna Sengupta3,4, Alvarinho Joaozinho Luis2 1Svalbard Integrated Arctic Earth Observing System (SIOS), SIOS Knowledge Centre, University Centre in Svalbard (UNIS), P.O. Box 156, N-9171, Longyearbyen, Svalbard, Norway 2Polar Remote Sensing Section, Polar Sciences Group, Earth System Science Organiza- tion (ESSO), National Centre for Antarctic and Ocean Research (NCAOR), Ministry of Earth Sciences (MoES), Govt. of India, Headland Sada, Goa 403804, India 3Department of Civil Engineering, SRM University, Chennai, Tamil Nadu–603203, India 4Department of Environment, Faculty of Science, University of Auckland, New Zealand Abstract This study discusses the calving event took place in Prydz Bay of East Antarctica during the epoch of 2013–2015 using high resolution multispectral data from Indian Linear Imaging Self Scanning Sensor (LISS-IV) aboard IRS-P6 satellite. The present study has been conducted on Larsemann Hills, Prydz Bay, East Antarctica. The two LISS-IV images (5.8 m spatial resolution) acquired specifically 384 days apart (December 31, 2013 and January 19, 2015) were utilized to study the significant changes that have occurred in icebergs during this short epoch. A total of 369 common icebergs present in both images were identified for analysing the changes in their dimensions because of surface melting. All of these icebergs were found to have lost mass because of surface melting and ocean forced base melting; therefore, they have reduced in dimension depicted by 12.51% lapse in terms of surface area.
    [Show full text]
  • (FIPS) for Land-Fast Sea Ice at Prydz Bay, East Antarctica: an Operational Service for CHINARE
    Annals of Glaciology Fast Ice Prediction System (FIPS) for land-fast sea ice at Prydz Bay, East Antarctica: an operational service for CHINARE Jiechen Zhao1,2, Bin Cheng3 , Timo Vihma3, Petra Heil4, Fengming Hui5,6, Article Qi Shu7,2 , Lin Zhang1 and Qinghua Yang8,6 Cite this article: Zhao J, Cheng B, Vihma T, Heil P, Hui F, Shu Q, Zhang L, Yang Q (2020). 1Key Laboratory of Marine Hazards Forecasting, National Marine Environmental Forecasting Centre (NMEFC), Fast Ice Prediction System (FIPS) for land-fast Ministry of Natural Resources, Beijing 100081, China; 2Laboratory for Regional Oceanography and Numerical sea ice at Prydz Bay, East Antarctica: an Modelling, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; 3Finnish operational service for CHINARE. Annals of Meteorological Institute (FMI), Helsinki 00101, Finland; 4Australia Antarctic Division & Australian Antarctic Glaciology 61(83), 271–283. https://doi.org/ Programmer Partnership, Private Bag 80, Hobart, TAS 7001, Australia; 5School of Geospatial Engineering and 10.1017/aog.2020.46 Science, Sun Yat-sen University, Zhuhai 519082, China; 6Southern Marine Science and Engineering Guangdong 7 Received: 26 November 2019 Laboratory (Zhuhai), Zhuhai 519082, China; First Institute of Oceanography, Ministry of Natural Resources, 8 Revised: 1 June 2020 Qingdao 266061, China and School of Atmospheric Sciences, and Guangdong Province Key Laboratory for Accepted: 2 June 2020 Climate Change and Natural Disaster Studies, Sun Yat-sen University, Zhuhai 519082, China First published online: 9 July 2020 Key words: Abstract Antarctica; land-fast sea ice; operational A Fast Ice Prediction System (FIPS) was constructed and is the first regional land-fast sea-ice service; Prydz Bay; snow and ice thickness; forecasting system for the Antarctic.
    [Show full text]
  • Draft Comprehensive Environmental Evaluation of New Indian Research Base at Larsemann Hills, Antarctica
    Draft Comprehensive Environmental Evaluation of New Indian Research Base at Larsemann Hills, Antarctica 4. ALTERNATIVES TO PROPOSED ACTIVITY A review of the Indian Antarctic Programme was undertaken by an Expert Committee (Rao, 1996), which recommended broadening of India’s scientific data base in Antarctica for having a regional spread of the data rather than a localized one. A Task Force was, therefore, constituted to go into the details and recommend a suitable site after considering all the pros and cons. This Task Force undertook reconnaissance traverses all along the eastern coast of Antarctica from India Bay at 11° E. longitude to 78°E longitude in Prydz Bay, to examine all possible alternatives suiting the scientific and logistic requirements set for the future station. 4.1 Alternative Locations at Regional Level Three alternatives were suggested in the Review Report, mentioned above, based on the scrutiny of published literature and feedback from different Indian and international expeditions to Antarctica. These were: a) Antarctic Peninsula, b) Filchner Ice shelf c) Amery Ice shelf – Prydz Bay area 4.1.1 Antarctic Peninsula Antarctic Peninsula is the most crowded place in Antarctica, so far as the stations of different nations and the visits of the tourists to the icy continent are concerned. The area is also very sensitive to the global warming as has been demonstrated by the international studies, which have shown that the Peninsula has warmed by 2° C since 1950 (Cook et al., 2005). 4.1.2 Filchner Ice Shelf The Filchner Ice Shelf poses serious logistic constraints in maintaining a research station as the sea ice condition in this area are very tough.
    [Show full text]
  • Properties of a Marine Ice Layer Under the Amery Ice Shelf, East Antarctica
    Journal of Glaciology, Vol. 55, No. 192, 2009 717 Properties of a marine ice layer under the Amery Ice Shelf, East Antarctica Mike CRAVEN,1 Ian ALLISON,1 Helen Amanda FRICKER,2 Roland WARNER1 1Australian Antarctic Division and Antarctic Climate and Ecosystems CRC, Hobart, Tasmania 7001, Australia E-mail: [email protected] 2Institute of Geophysics and Planetary Physics, Scripps Institution of Oceanography, University of California–San Diego, La Jolla, California 92093-0225, USA ABSTRACT. The Amery Ice Shelf, East Antarctica, undergoes high basal melt rates near the southern limit of its grounding line where 80% of the ice melts within 240 km of becoming afloat. A considerable portion of this later refreezes downstream as marine ice. This produces a marine ice layer up to 200 m thick in the northwest sector of the ice shelf concentrated in a pair of longitudinal bands that extend some 200 km all the way to the calving front. We drilled through the eastern marine ice band at two locations 70 km apart on the same flowline. We determine an average accretion rate of marine ice of 1.1 Æ 0.2 m a–1, at a reference density of 920 kg m–3 between borehole sites, and infer a similar average rate of 1.3 Æ 0.2 m a–1 upstream. The deeper marine ice was permeable enough that a hydraulic connection was made whilst the drill was still 70–100 m above the ice-shelf base. Below this marine close-off depth, borehole video imagery showed permeable ice with water-filled cavities and individual ice platelets fused together, while the upper marine ice was impermeable with small brine-cell inclusions.
    [Show full text]
  • Dynamics of Dalk Glacier in East Antarctica Derived from Multisource Satellite Observations Since 2000
    remote sensing Article Dynamics of Dalk Glacier in East Antarctica Derived from Multisource Satellite Observations Since 2000 Yiming Chen 1,2 , Chunxia Zhou 1,2,*, Songtao Ai 1,2 , Qi Liang 1,2, Lei Zheng 1,2, Ruixi Liu 1,2 and Haobo Lei 1,2 1 Chinese Antarctic Center of Surveying and Mapping, Wuhan University, Wuhan 430079, China; [email protected] (Y.C.); [email protected] (S.A.); [email protected] (Q.L.); [email protected] (L.Z.); [email protected] (R.L.); [email protected] (H.L.) 2 Key Laboratory of Polar Surveying and Mapping, Ministry of Natural Resources of the People’s Republic of China, Wuhan 430079, China * Correspondence: [email protected] Received: 26 April 2020; Accepted: 1 June 2020; Published: 3 June 2020 Abstract: Monitoring variability in outlet glaciers can improve the understanding of feedbacks associated with calving, ocean thermal forcing, and climate change. In this study, we present a remote-sensing investigation of Dalk Glacier in East Antarctica to analyze its dynamic changes. Terminus positions and surface ice velocities were estimated from Landsat and Sentinel-1 data, and the high-precision Worldview digital elevation model (DEM) was generated to determine the location of the potential ice rumple. We detected the cyclic behavior of glacier terminus changes and similar periodic increases in surface velocity since 2000. The terminus retreated in 2006, 2009, 2010, and 2016 and advanced in other years. The surface velocity of Dalk Glacier has a 5-year cycle with interannual speed-ups in 2007, 2012, and 2017.
    [Show full text]