Instability of the Northeast Greenland Ice Stream over the last 45,000 years

TY - JOUR

T1 - Instability of the Northeast Greenland Ice Stream over the last 45,000 years

AU - Larsen, Nicolaj

AU - Levy, Laura B.

AU - Carlson, Anders E.

AU - Buizert, Christo

AU - Olsen, Jesper

AU - Strunk, Astrid

AU - Bjørk, Anders Anker

AU - Skov, Daniel

PY - 2018/12/1

Y1 - 2018/12/1

N2 - The sensitivity of the Northeast Greenland Ice Stream (NEGIS) to prolonged warm periods is largely unknown and geological records documenting such long-Term changes are needed to place current observations in perspective. Here we use cosmogenic surface exposure and radiocarbon ages to determine the magnitude of NEGIS margin fluctuations over the last 45 kyr (thousand years). We find that the NEGIS experienced slow early Holocene ice-margin retreat of 30-40 m a-1, likely as a result of the buttressing effect of sea-ice or shelf-ice. The NEGIS was ~20-70 km behind its present ice-extent ~41-26 ka and ~7.8-1.2 ka; both periods of high orbital precession index and/or summer temperatures within the projected warming for the end of this century. We show that the NEGIS was smaller than present for approximately half of the last ~45 kyr and is susceptible to subtle changes in climate, which has implications for future stability of this ice stream.

AB - The sensitivity of the Northeast Greenland Ice Stream (NEGIS) to prolonged warm periods is largely unknown and geological records documenting such long-Term changes are needed to place current observations in perspective. Here we use cosmogenic surface exposure and radiocarbon ages to determine the magnitude of NEGIS margin fluctuations over the last 45 kyr (thousand years). We find that the NEGIS experienced slow early Holocene ice-margin retreat of 30-40 m a-1, likely as a result of the buttressing effect of sea-ice or shelf-ice. The NEGIS was ~20-70 km behind its present ice-extent ~41-26 ka and ~7.8-1.2 ka; both periods of high orbital precession index and/or summer temperatures within the projected warming for the end of this century. We show that the NEGIS was smaller than present for approximately half of the last ~45 kyr and is susceptible to subtle changes in climate, which has implications for future stability of this ice stream.

U2 - 10.1038/s41467-018-04312-7

DO - 10.1038/s41467-018-04312-7

M3 - Journal article

C2 - 29760384

SN - 2041-1723

VL - 9

JO - Nature Communications

JF - Nature Communications

M1 - 1872

ER -