Publication Date:
2019-07-17
Description:
Over the past 50 years, warming of the Antarctic Peninsula has been accompanied by accelerating glacier mass loss and the
retreat and collapse of ice shelves. A key driver of ice loss is summer melting; however, it is not usually possible to specifically
reconstruct the summer conditions that are critical for determining ice melt in Antarctic. Here we reconstruct changes in
ice-melt intensity and mean temperature on the northern Antarctic Peninsula since AD 1000 based on the identification of
visible melt layers in the James Ross Island ice core and local mean annual temperature estimates from the deuterium content
of the ice. During the past millennium, the coolest conditions and lowest melt occurred from about AD 1410 to 1460, when mean
temperature was 1:6 �C lower than that of 1981–2000. Since the late 1400s, there has been a nearly tenfold increase in melt
intensity from 0.5 to 4.9%. The warming has occurred in progressive phases since about AD 1460, but intensification of melt
is nonlinear, and has largely occurred since the mid-twentieth century. Summer melting is now at a level that is unprecedented
over the past 1,000 years.We conclude that ice on the Antarctic Peninsula is now particularly susceptible to rapid increases in
melting and loss in response to relatively small increases in mean temperature.
Repository Name:
EPIC Alfred Wegener Institut
Type:
Article
,
isiRev
