220 results found
Greenbaum JS, Blankenship DD, Young DA, et al., 2015, Ocean access to a cavity beneath Totten Glacier in East Antarctica, NATURE GEOSCIENCE, Vol: 8, Pages: 294-298, ISSN: 1752-0894
Bingham RG, Rippin DM, Karlsson NB, et al., 2015, Ice-flow structure and ice dynamic changes in the Weddell Sea sector of West Antarctica from radar-imaged internal layering, JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE, Vol: 120, Pages: 655-670, ISSN: 2169-9003
Young DA, Lindzey LE, Blankenship DD, et al., 2015, Land-ice elevation changes from photon-counting swath altimetry: first applications over the Antarctic ice sheet, Journal of Glaciology, Vol: 61, Pages: 17-28, ISSN: 1727-5652
Satellite altimetric time series allow high-precision monitoring of ice-sheet mass balance.Understanding elevation changes in these regions is important because outlet glaciers along ice-sheetmargins are critical in controlling flow of inland ice. Here we discuss a new airborne altimetry datasetcollected as part of the ICECAP (International Collaborative Exploration of the Cryosphere by AirborneProfiling) project over East Antarctica. Using the ALAMO (Airborne Laser Altimeter with MappingOptics) system of a scanning photon-counting lidar combined with a laser altimeter, we extend the2003–09 surface elevation record of NASA’s ICESat satellite, by determining cross-track slope and thusindependently correcting for ICESat’s cross-track pointing errors. In areas of high slope, cross-trackerrors result in measured elevation change that combines surface slope and the actual z=t signal.Slope corrections are particularly important in coastal ice streams, which often exhibit both rapidlychanging elevations and high surface slopes. As a test case (assuming that surface slopes do not changesignificantly) we observe a lack of ice dynamic change at Cook Ice Shelf, while significant thinningoccurred at Totten and Denman Glaciers during 2003–09.
Kennicutt MC, Chown SL, Cassano JJ, et al., 2015, A roadmap for Antarctic and Southern Ocean science for the next two decades and beyond, Antarctic Science, Vol: 27, Pages: 3-18, ISSN: 1365-2079
Antarctic and Southern Ocean science is vital to understanding natural variability, the processesthat govern global change and the role of humans in the Earth and climate system. The potential for newknowledge to be gained from future Antarctic science is substantial. Therefore, the international Antarcticcommunity came together to ‘scan the horizon’ to identify the highest priority scientific questions thatresearchers should aspire to answer in the next two decades and beyond. Wide consultation was afundamental principle for the development of a collective, international view of the most important futuredirections in Antarctic science. From the many possibilities, the horizon scan identified 80 key scientificquestions through structured debate, discussion, revision and voting. Questions were clustered into seventopics: i) Antarctic atmosphere and global connections, ii) Southern Ocean and sea ice in a warming world,iii) ice sheet and sea level, iv) the dynamic Earth, v) life on the precipice, vi) near-Earth space and beyond,and vii) human presence in Antarctica. Answering the questions identified by the horizon scan will requireinnovative experimental designs, novel applications of technology, invention of next-generation field andlaboratory approaches, and expanded observing systems and networks. Unbiased, non-contaminatingprocedures will be required to retrieve the requisite air, biota, sediment, rock, ice and water samples.Sustained year-round access to Antarctica and the Southern Ocean will be essential to increase winter-timemeasurements. Improved models are needed that represent Antarctica and the Southern Ocean in theEarth System, and provide predictions at spatial and temporal resolutions useful for decision making.A co-ordinated portfolio of cross-disciplinary science, based on new models of international collaboration,will be essential as no scientist, programme or nation can realize these aspirations alone.
Rose KC, Ross N, Jordan TA, et al., 2015, Ancient pre-glacial erosion surfaces preserved beneath the West Antarctic Ice Sheet, EARTH SURFACE DYNAMICS, Vol: 3, Pages: 139-152, ISSN: 2196-6311
Rose KC, Ross N, Bingham RG, et al., 2014, A temperate former West Antarctic ice sheet suggested by an extensive zone of subglacial meltwater channels, Geology, Vol: 42, Pages: 971-974, ISSN: 0091-7613
Several recent studies predict that the West Antarctic Ice Sheet will become increasingly unstable under warmer conditions. Insights on such change can be assisted through investigations of the subglacial landscape, which contains imprints of former ice-sheet behavior. Here, we present radio-echo sounding data and satellite imagery revealing a series of ancient large sub-parallel subglacial bed channels preserved in the region between the Möller and Foundation Ice Streams, West Antarctica. We suggest that these newly recognized channels were formed by significant meltwater routed along the icesheet bed. The volume of water required is likely substantial and can most easily be explained by water generated at the ice surface. The Greenland Ice Sheet today exemplifies how significant seasonal surface melt can be transferred to the bed via englacial routing. For West Antarctica, the Pliocene (2.6–5.3 Ma) represents the most recent sustained period when temperatures could have been high enough to generate surface melt comparable to that of present-day Greenland. We propose, therefore, that a temperate ice sheet covered this location during Pliocene warm periods.
Kennicutt MC, Chown SL, Cassano JJ, et al., 2014, Polar Research: Six priorities for Antarctic science, NATURE, Vol: 512, Pages: 23-25, ISSN: 0028-0836
Rippin DM, Bingham RG, Jordan TA, et al., 2014, Basal roughness of the Institute and Moller Ice Streams, West Antarctica: Process determination and landscape interpretation, GEOMORPHOLOGY, Vol: 214, Pages: 139-147, ISSN: 0169-555X
Aitken ARA, Young DA, Ferraccioli F, et al., 2014, The subglacial geology of Wilkes Land, East Antarctica, GEOPHYSICAL RESEARCH LETTERS, Vol: 41, Pages: 2390-2400, ISSN: 0094-8276
Siegert MJ, Ross N, Corr H, et al., 2014, Boundary conditions of an active West Antarctic subglacial lake: implications for storage of water beneath the ice sheet, CRYOSPHERE, Vol: 8, Pages: 15-24, ISSN: 1994-0416
Wright AP, Young DA, Bamber JL, et al., 2014, Subglacial hydrological connectivity within the Byrd Glacier catchment, East Antarctica, JOURNAL OF GLACIOLOGY, Vol: 60, Pages: 345-352, ISSN: 0022-1430
Siegert MJ, Makinson K, Blake D, et al., 2014, An assessment of deep hot-water drilling as a means to undertake direct measurement and sampling of Antarctic subglacial lakes: experience and lessons learned from the Lake Ellsworth field season 2012/13, ANNALS OF GLACIOLOGY, Vol: 55, Pages: 59-73, ISSN: 0260-3055
Wright AP, Le Brocq AM, Cornford SL, et al., 2014, Sensitivity of the Weddell Sea sector ice streams to sub-shelf melting and surface accumulation, CRYOSPHERE, Vol: 8, Pages: 2119-2134, ISSN: 1994-0416
Ross N, Jordan TA, Bingham RG, et al., 2014, The Ellsworth Subglacial Highlands: Inception and retreat of the West Antarctic Ice Sheet, GEOLOGICAL SOCIETY OF AMERICA BULLETIN, Vol: 126, Pages: 3-15, ISSN: 0016-7606
Le Brocq AM, Ross N, Griggs JA, et al., 2013, Evidence from ice shelves for channelized meltwater flow beneath the Antarctic Ice Sheet, NATURE GEOSCIENCE, Vol: 6, Pages: 945-948, ISSN: 1752-0894
Siegert M, Ross N, Corr H, et al., 2013, Late Holocene ice-flow reconfiguration in the Weddell Sea sector of West Antarctica, Quaternary Science Reviews, Vol: 78, Pages: 98-107, ISSN: 0277-3791
Here we report Late Holocene ice sheet and grounding-line changes to the Weddell Sea sector of West Antarctica. Internal radio-echo layering within the Bungenstock Ice Rise, which comprises very slow-flowing ice separating the fast-flowing Institute and Möller ice streams, reveals ice deformed by former enhanced flow, overlain by un-deformed ice. The ice-rise surface is traversed by surface lineations explicable as diffuse ice-flow generated stripes, which thus capture the direction of flow immediately prior to the creation of the ice rise. The arrangement of internal layers can be explained by adjustment to the flow path of the Institute Ice Stream, during either a phase of ice sheet retreat not longer than ∼4000 years ago or by wholesale expansion of the grounding-line from an already retreated situation not sooner than ∼400 years ago. Some combination of these events, involving uplift of the ice rise bed during ice stream retreat and reorganisation, is also possible. Whichever the case, the implication is that the ice sheet upstream of the Bungenstock Ice Rise, which currently grounds over a >1.5 km deep basin has been, and therefore may be, susceptible to significant change.
Bamber JL, Siegert MJ, Griggs JA, et al., 2013, Paleofluvial Mega-Canyon Beneath the Central Greenland Ice Sheet, SCIENCE, Vol: 341, Pages: 997-999, ISSN: 0036-8075
Siegert M, Bradwell T, 2013, Antarctic Earth Sciences: Preface, EARTH AND ENVIRONMENTAL SCIENCE TRANSACTIONS OF THE ROYAL SOCIETY OF EDINBURGH, Vol: 104, Pages: 1-1, ISSN: 1755-6910
Jordan TA, Ferraccioli F, Ross N, et al., 2013, Inland extent of the Weddell Sea Rift imaged by new aerogeophysical data, TECTONOPHYSICS, Vol: 585, Pages: 137-160, ISSN: 0040-1951
Cavitte MGP, Blankenship DD, Young DA, et al., Radar stratigraphy connecting Lake Vostok and Dome C, East Antarctica, constrains the EPICA/DMC ice core time scale, The Cryosphere Discussions, Vol: 7, Pages: 321-342
<jats:p><p><strong>Abstract.</strong> New airborne radar sounding surveys at 60 MHz are used to trace internal layering between the Vostok and EPICA Dome C ice core sites. Eleven layers, spanning two glacial cycles from the last glacial maximum back to the MIS 7c interglacial, are used to correlate the two ice core chronologies. Independent of palaeoclimate signals, radar sounding enables correlation of the timescales, with a radar depth uncertainty equivalent to hundreds of years, which is small relative to the ice core dating uncertainties of thousands of years. Along the radar transects, horizons belonging to the last glacial cycle are impacted by aeolian stratigraphic reworking that increases radar technique uncertainty for this interval. However, older layers are used to propagate the higher resolution Vostok ages to the lower resolution Dome C ice core using the Suwa and Bender (2008) Vostok O<sub>2</sub> / N<sub>2</sub> chronology to give a recalibration of the Parrenin et al. (2007) EPICA EDC3 timescale between 1597 m and 2216 m depth (126 ka to 247 ka age interval).</p> </jats:p>
White J, Siegert M, 2013, One minute with ... Martin Siegert, NEW SCIENTIST, Vol: 217, Pages: 25-25, ISSN: 0262-4079
Fretwell P, Pritchard HD, Vaughan DG, et al., 2013, Bedmap2: improved ice bed, surface and thickness datasets for Antarctica, CRYOSPHERE, Vol: 7, Pages: 375-393, ISSN: 1994-0416
Wright A, Siegert M, 2012, A fourth inventory of Antarctic subglacial lakes, ANTARCTIC SCIENCE, Vol: 24, Pages: 659-664, ISSN: 0954-1020
Siegert M, 2012, Hunt for life under Antarctic ice heats up (vol 491, pg 506, 2012), NATURE, Vol: 491, Pages: 651-651, ISSN: 0028-0836
Ross N, Bingham RG, Corr HFJ, et al., 2012, Steep reverse bed slope at the grounding line of the Weddell Sea sector in West Antarctica, NATURE GEOSCIENCE, Vol: 5, Pages: 393-396, ISSN: 1752-0894
Wright AP, Young DA, Roberts JL, et al., 2012, Evidence of a hydrological connection between the ice divide and ice sheet margin in the Aurora Subglacial Basin, East Antarctica, JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE, Vol: 117, ISSN: 2169-9003
Siegert MJ, Clarke RJ, Mowlem M, et al., 2012, CLEAN ACCESS, MEASUREMENT, AND SAMPLING OF ELLSWORTH SUBGLACIAL LAKE: A METHOD FOR EXPLORING DEEP ANTARCTIC SUBGLACIAL LAKE ENVIRONMENTS, REVIEWS OF GEOPHYSICS, Vol: 50, ISSN: 8755-1209
Ross N, Siegert MJ, Woodward J, et al., 2011, Holocene stability of the Amundsen-Weddell ice divide, West Antarctica, GEOLOGY, Vol: 39, Pages: 935-938, ISSN: 0091-7613
Vieli GJ-MCL, Hindmarsh RCA, Siegert MJ, et al., 2011, Time-dependence of the spatial pattern of accumulation rate in East Antarctica deduced from isochronic radar layers using a 3-D numerical ice flow model, JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE, Vol: 116, ISSN: 2169-9003
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