Nature Geoscience, published online 14 February 2010; doi: 10.1038/ngeo765
Rapid submarine melting of the calving faces of West Greenland glaciers
Eric Rignot* (University of California, Earth System Science, Irvine, CA 92617, U.S.A., and the Jet Propulsion Laboratory, Pasadena, CA 91109, U.S.A.), Michele Koppes (University of British Columbia, Department of Geography, Vancouver, British Columbia, V6T 1Z2, Canada) and Isabella Velicogna (University of California, Earth System Science, Irvine, CA 92617, U.S.A., and the Jet Propulsion Laboratory, Pasadena, CA 91109, U.S.A.)
Abstract
Widespread glacier acceleration has been observed in Greenland in the past few years1, 2, 3, 4 associated with the thinning of the lower reaches of the glaciers as they terminate in the ocean5, 6, 7. These glaciers thin both at the surface, from warm air temperatures, and along their submerged faces in contact with warm ocean waters8. Little is known about the rates of submarine melting9, 10, 11 and how they may affect glacier dynamics. Here we present measurements of ocean currents, temperature and salinity near the calving fronts of the Eqip Sermia, Kangilerngata Sermia, Sermeq Kujatdleq and Sermeq Avangnardleq glaciers in central West Greenland, as well as ice-front bathymetry and geographical positions. We calculate water-mass and heat budgets that reveal summer submarine melt rates ranging from 0.7±0.2 to 3.9±0.8 m d−1. These rates of submarine melting are two orders of magnitude larger than surface melt rates, but comparable to rates of iceberg discharge. We conclude that ocean waters melt a considerable, but highly variable, fraction of the calving fronts of glaciers before they disintegrate into icebergs, and suggest that submarine melting must have a profound influence on grounding-line stability and ice-flow dynamics.
*Correspondence e-mail: erignot@uci.edu
Link to abstract: http://www.nature.com/ngeo/journal/vaop/ncurrent/abs/ngeo765.html
Posts
No comments:
Post a Comment