The overarching objective of the Past Antarctic Ice Sheet dynamics (PAIS) Scientific Research Programme was to provide geological and ice core evidence of Antarctic Ice Sheet response to a broad range of past climatic and oceanic conditions. That evidence is used to constrain paleo-simulations of regional Antarctic climate, ice sheet dynamics and sea-level models, as well as to improve the physics of climate and ice sheet models used in projections.
A video on the aims and achievements of the PAIS SRP:
PAIS has progressed understanding of the complexity of Antarctic ice sheet sub-glacial, proximal and distal environments and of their response to past climate changes at different time scales. The results obtained improve our knowledge of Southern high-latitude polar amplification in the past. Polar amplification is projected to increase and the rate at which polar areas respond to ongoing and future climate change is yet to be determined, as highlighted by the 2019 IPCC Special Report on the Ocean and Cryosphere in a Changing Climate (SROCC).
PAIS organized conferences and supported workshops during its term, to coordinate the scientific community to share ideas, integrate multi-disciplinary knowledge, produce a large amount of high-impact scientific publications, to submit innovative international scientific proposals, and facilitate large international research consortia (e.g. the International Ocean Discovery Program, IODP).
PAIS supported schools to train the next generation of researchers. Participants were given intensive training on deep sea drilling, seismic stratigraphy, and use of different proxies for reconstructing environmental changes. Information about the IODP-PAIS school in 2019 can be found in the pdf IODP-PAIS Antarctic School Report (1.73 MB) . A second edition of the school is planned for the Summer of 2022.
PAIS edited a book “Antarctic Ice Sheet Evolution”, published in October 2021. The book is the product of a large PAIS-community effort, presenting a comprehensive synthesis of many papers, which represents the current knowledge of Past Antarctic Ice Sheet dynamics, the legacy from previous SCAR programmes, and the challenges for the future.
Next Research Programme
During its lifetime, PAIS evolved and became more transdisciplinary, working with solid Earth geodynamicists, oceanographers, climate scientists and modellers. This led to the development of a white paper that reflected a convergence of scientific interest across SCAR’s science groups on improving the understanding of Antarctica’s dynamic ice sheet contribution to global sea-level rise, which in turn led to the development of the multi-disciplinary new SCAR INSTANT Scientific Research Programme. The former PAIS website is now a legacy section on INSTANT's website.
Outstanding Research Questions
A large conference was organized in 2017 in Trieste (Italy) to discuss the state of the art. Details can be found on the PAIS legacy page of the INSTANT website.
During this conference a bottom-up white paper was written listing outstanding research questions still to be addressed.
PAIS has delivered a significant amount of products with respect to the implementation plan, under the coordination of the six PAIS subcommittees:
- Palaeoclimate Records from the Antarctic Margin and Southern Ocean (PRAMSO):
- Completion of International Ocean Discovery Program (IODP) Exp. 374 (Ross Sea), 379 (Amundsen Sea), 382 (Scotia Sea) and shallow drilling (Amundsen Sea).
- Publication from previous drilling campaigns (IODP Exp 318, SHALDRIL, ANDRILL-1 and 2 and CRP-1,2,3 and older) in high impact factor journals.
- Submission of new drilling proposals (e.g. Sabrina Coast, Weddell Sea, Antarctic Peninsula, Wilkes Land, Ekström Ice Shelf and Kamb Ice Stream).
- Paleotopographic-Palaeobathymetric reconstructions showing changes in bedrock elevations, landforms and configuration of Antarctica over the past ~100 million years, by seismic stratigraphic mapping and sediment restoration models. The elevation change in subglacial topography of various AIS sectors from sub-aerial to marine was caused by tectonic subsidence, increasing ice sheet volume and load, and prolonged and repeated ice bed excavation, since the onset of widespread glaciations.
- Sub-glacial geophysical reconstructions of ice bedrock roughness and sub-glacial drainage networks, from land to the coast to the shelf margin relied on:
- Airborne radio-echo sounding surveys like AGAP, Rosetta-ice, ICECAP.
- Over snow geophysical surveys (e.g. Whillans subglacial lake and Kamb Ice Stream grounding zone; Thwaites Glacier).
- Ice flux modelling. iv) Multibeam surveys over the continental shelf, revealing LGM and previous subglacial and sub-ice shelf features.
- Integrating ice and marine sediment cores from:
- ultra-high resolution and expanded Holocene sediment and ice stratigraphy;
- cross-linkage of multiple datasets of Pleistocene sediment and ice core records to reconstruct regional versus local climate forcings, processes and environmental changes.
- Recent Ice Sheet extent reconstructions since the LGM, by integrating numerical models constrained by a large range of observations. The latter include data on past grounding-line positions and dynamics from ice proximal and offshore geophysical surveys and marine sediment cores, and on past ice-sheet thickness changes from exposure-age dating on land and constraints from ice and lake sediment cores (e.g. The RAISED Consortium, 2014).
- Deep-Time Ice Sheet reconstructions since the onset of glaciations by integrating numerical models with the observations providing indirect estimates of:
- ancient ice volume and sea-level histories;
- ice sheet sensitivity to astronomic, atmospheric CO2, temperature and oceanic forcings;
- glacial/interglacial ice sheet extent amplitude, frequency and dynamics;
- AIS sensitivity to far-field and near-field sea level changes, GIA and dynamic topography.
Outcomes of the all six PAIS subcommittees are publications on the Antarctic contribution to future global sea level changes based on ice sheet models calibrated to AIS reconstructions for the Pliocene, the last interglacial (LIG, 130 ka) or post-LGM deglaciation.
PAIS has promoted publicly available data:
- the Antarctic Seismic Data Library System (SDLS) open-source database,
- the International Bathymetric Chart of the Southern Ocean (IBCSO),
- the ice thickness and subglacial topographic models Bedmap2 and Bedmap3,
- the International Ocean Discover Program (IODP) core repositories and national core repositories.
Information about new cruises, projects and publications was communicated and shared via SCAR and via the PAIS portal.
View members of the pdf PAIS leadership team and steering committee (85 KB) .
Reports and Documents
Other documents can be found in the folder PAIS folder of the SCAR Library .