47 research outputs found
A community-based geological reconstruction of Antarctic Ice Sheet deglaciation since the Last Glacial Maximum
A robust understanding of Antarctic Ice Sheet deglacial history since the Last Glacial Maximum is important in order to constrain ice sheet and glacial-isostatic adjustment models, and to explore the forcing mechanisms responsible for ice sheet retreat. Such understanding can be derived from a broad range of geological and glaciological datasets and recent decades have seen an upsurge in such data gathering around the continent and Sub-Antarctic islands. Here, we report a new synthesis of those datasets, based on an accompanying series of reviews of the geological data, organised by sector. We present a series of timeslice maps for 20ka, 15ka, 10ka and 5ka, including grounding line position and ice sheet thickness changes, along with a clear assessment of levels of confidence. The reconstruction shows that the Antarctic Ice sheet did not everywhere reach the continental shelf edge at its maximum, that initial retreat was asynchronous, and that the spatial pattern of deglaciation was highly variable, particularly on the inner shelf. The deglacial reconstruction is consistent with a moderate overall excess ice volume and with a relatively small Antarctic contribution to meltwater pulse 1a. We discuss key areas of uncertainty both around the continent and by time interval, and we highlight potential priorit. © 2014 The Authors
A roadmap for Antarctic and Southern Ocean science for the next two decades and beyond
Antarctic and Southern Ocean science is vital to understanding natural variability, the processes
that govern global change and the role of humans in the Earth and climate system. The potential for new
knowledge to be gained from future Antarctic science is substantial. Therefore, the international Antarctic
community came together to âscan the horizonâ to identify the highest priority scientific questions that
researchers should aspire to answer in the next two decades and beyond. Wide consultation was a
fundamental principle for the development of a collective, international view of the most important future
directions in Antarctic science. From the many possibilities, the horizon scan identified 80 key scientific
questions through structured debate, discussion, revision and voting. Questions were clustered into seven
topics: 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 require
innovative experimental designs, novel applications of technology, invention of next-generation field and
laboratory approaches, and expanded observing systems and networks. Unbiased, non-contaminating
procedures will be required to retrieve the requisite air, biota, sediment, rock, ice and water samples.
Sustained year-round access toAntarctica and the Southern Ocean will be essential to increase winter-time
measurements. Improved models are needed that represent Antarctica and the Southern Ocean in the
Earth 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.Tinker Foundation, Antarctica New Zealand, The New Zealand
Antarctic Research Institute, the Scientific Committee on
Antarctic Research (SCAR), the Council of Managers of
National Antarctic Programs (COMNAP), the Alfred
Wegner Institut, Helmholtz Zentrum fĂŒr Polar und
Meeresforschung (Germany), and the British Antarctic
Survey (UK).http://journals.cambridge.org/action/displayJournal?jid=ANShb201