TY - CONF

T1 - Historical aerial imagery reveals rapid frontal retreat following the 1920’s warming in southeast Greenland

T2 - American Geophysical Union Fall Meeting 2011

AU - Bjørk, Anders Anker

AU - Kjær, Kurt H.

AU - Korsgaard, Niels Jákup

AU - Khan, Shfaqat Abbas

AU - Kjeldsen, Kristian Kjellerup

AU - Andresen, Camilla Snowman

PY - 2011/12

Y1 - 2011/12

N2 - The Greenland ice sheet (GIS) is undergoing massive changes in its frontal positions, velocity structure, and overall mass balance. Since 2000, marine and terrestrial terminating glaciers in southeast Greenland have experienced dramatic frontal retreat and dynamic thinning in response to increased sea surface and air temperatures. However, little is known about the long term glacier history prior to the satellite era. Here we show a unique record of the frontal history of 132 glaciers in southeast Greenland based on historical aerial and satellite imagery from 1933 to 2010.Our results demonstrate decadal sensitivity to temperature changes with rapid retreat following the early century warming (1919-1932) and glacial advance during a minor, but profound mid century cooling (1955-1972) succeeded by the present warming again leading to massive retreat. One significant finding lies in the similarity of the retreat following the early century warming and the latest decade, with a majority of the 132 glaciers exhibiting larger retreat rates in the early period. Furthermore, during the mid century cooling glaciers in southeast Greenland showed a surprisingly rapid response to the cooling, indicating that stabilization and subsequent advance can occur with a short cooling period. Marine terminating glaciers originating from the GIS experienced the largest frontal fluctuations often out of sync with local glaciers and ice caps indicating a larger coherence with ocean temperatures, whereas local glaciers and ice caps and GIS terrestrial terminating glaciers shows frontal fluctuations closely related to the air temperature.

AB - The Greenland ice sheet (GIS) is undergoing massive changes in its frontal positions, velocity structure, and overall mass balance. Since 2000, marine and terrestrial terminating glaciers in southeast Greenland have experienced dramatic frontal retreat and dynamic thinning in response to increased sea surface and air temperatures. However, little is known about the long term glacier history prior to the satellite era. Here we show a unique record of the frontal history of 132 glaciers in southeast Greenland based on historical aerial and satellite imagery from 1933 to 2010.Our results demonstrate decadal sensitivity to temperature changes with rapid retreat following the early century warming (1919-1932) and glacial advance during a minor, but profound mid century cooling (1955-1972) succeeded by the present warming again leading to massive retreat. One significant finding lies in the similarity of the retreat following the early century warming and the latest decade, with a majority of the 132 glaciers exhibiting larger retreat rates in the early period. Furthermore, during the mid century cooling glaciers in southeast Greenland showed a surprisingly rapid response to the cooling, indicating that stabilization and subsequent advance can occur with a short cooling period. Marine terminating glaciers originating from the GIS experienced the largest frontal fluctuations often out of sync with local glaciers and ice caps indicating a larger coherence with ocean temperatures, whereas local glaciers and ice caps and GIS terrestrial terminating glaciers shows frontal fluctuations closely related to the air temperature.

M3 - Poster

Y2 - 5 December 2011 through 9 December 2011

ER -