HISEAS Frontier Research in Earth Sciences

How much and why did Ice Sheets melt during the Last Interglacial?

PALEOCLIMATE SEA LEVEL ICE SHEETS EARTH SYSTEMS

150 ka to late Holocene

Ice Core Record

190 ppm CO2
150 ka BP NOAA/NCEI Vostok ice core
Vostok CO2

Data: NOAA/NCEI Vostok ice core, Barnola et al.

Motivation

Clues in the past about a warming world

The Last Interglacial was the most recent interval when Greenland and Antarctic ice sheets melted significantly beyond their current state. HISEAS uses that interval to test which melt histories are physically plausible, which mechanisms are required, and how local shoreline records can constrain global ice loss.

Team

Meet the HISEAS team

Investigators Collaborators Research Scientists Postdocs Students
Jacqueline Austermann

Investigators

Jacqueline Austermann

Lead PI - Geodynamics

Columbia University

Research webpage

Leads HISEAS with expertise in geodynamics, glacial isostatic adjustment, sea-level observations, and paleoclimate. Connects shoreline evidence with sea-level fingerprinting to test physically plausible ice-melt histories.

Jerry McManus

Andy Aschwanden

Oana Dumitru

Torsten Albrecht

Alessio Rovere

Steven Goldstein

Brad Linsley

Timothy C. Kenna

Jannik Martens

Otillia Steadman

Emalee Ott

Jonney Mitchell

Anna Chen

Lisa S. Oelkers

Multidisciplinary Approach

Natural Earth basemap with published Last Interglacial sea surface temperature records colored as cooler, neutral, or warmer.
SST site data from Turney et al. (2020), Earth System Science Data

Field Sites

Past sea level

HISEAS work uses WALIS (a global database of sea-level records) and new surveyed sites and geochronology to turn local sea-level histories into ice sheet melt constraints. GIA modeling, sea-level fingerprints, emulators, and Bayesian inversion determine when and where excess LIG ice volume was lost.

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HISEAS team inspecting Last Interglacial reef limestone at Ka'ena Point.
Surveyed and sampled

O'ahu and Moloka'i

New geochronology and elevation data from O'ahu and Moloka'i constrain LIG sea level in the North Pacific.

San Andres limestone exposure with a field researcher under coastal vegetation.
Surveyed and sampled

San Andres

Slight uplift in San Andres reveals extensive LIG records.

HISEAS field team surveying makatea along a Southern Cook Islands coastline.
Surveyed and sampled

Cook Islands

Limestone reefs (makatea) exposed across four of the southern Cook Islands tell us about local geodynamics and LIG sea level.

Esri satellite image centered on Aruba in the southern Caribbean.
Proposed field campaign

Aruba and Curaçao

Multiple limestone terraces offer insight into LIG sea level as well as earlier interglacial periods.

Outreach

From sea-level science to community conversations.

Cook Islands school visits and local reporting connect raised-reef fieldwork with students, educators, and public discussion of coastal change.

HISEAS field team member speaking with Cook Islands students seated in a classroom circle. Cook Islands student and HISEAS field team member discussing a board drawing during a school visit. HISEAS field team sharing sea-level science with Cook Islands students and community members. Cook Islands student and HISEAS field team member working with a periodic table during a classroom visit.
Cook Islands Sharing sea-level science with local students and communities.

Publications

Peer-reviewed research advancing understanding of sea level, ice sheets, and Earth-system change.

Figure 2 from Dean et al. 2026 showing the Myrtle Beach study area, mapped scarps, field sites, and a generalized scarp and formation profile.
Figure 2 from Dean et al. (2026).

Last interglacial relative sea-level changes at Myrtle Beach, South Carolina

New luminescence ages from Myrtle Beach outcrops constrain Last Interglacial relative sea level and are compared with GIA model outputs.

S. Dean, N. Georgiou, R. Poirier, W.R. Doar, D. Brill, D. Chauveau, C. Cerrone, J. Austermann, A. Rovere Quaternary Science Reviews, Volume 375, 109769 (2026).

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More peer-reviewed publications

Future publications will be added here.