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Breakup of the Larsen B Ice Shelf triggered by chain reaction drainage of supraglacial lakes


Type

Article

Change log

Authors

Banwell, AF 
MacAyeal, DR 
Sergienko, OV 

Abstract

The explosive disintegration of the Larsen B Ice Shelf poses two unresolved questions: What process (1) set a horizontal fracture spacing sufficiently small to pre-dispose the subsequent ice-shelf fragments to capsize, and (2) synchronized the widespread drainage of >2750 supraglacial meltwater lakes observed in the days prior to break-up? We answer both questions through analysis of the ice shelf’s elastic-flexure response to the supraglacial lakes on the ice shelf prior to break-up. By expanding the previously articulated role of lakes beyond mere water-reservoirs supporting hydrofracture, we show that lake-induced flexural stresses produce a fracture network with appropriate horizontal spacing to induce capsize-driven break-up. The analysis of flexural stresses suggests that drainage of a single lake can cause neighboring lakes to drain, which, in turn, cause farther removed lakes to drain. Such self-stimulating behavior can account for the sudden, widespread appearance of a fracture system capable of driving explosive break-up.

Description

Keywords

ice shelves, surface lakes, surface hydrology, melting

Journal Title

Geophysical Research Letters

Conference Name

Journal ISSN

0094-8276
1944-8007

Volume Title

40

Publisher

American Geophysical Union (AGU)
Sponsorship
This research is supported by the U.S. National Science Foundation under grant GEOP/ANT – 0944248 awarded to D.R.M and grants ANT-0838811 and ARC-0934534 awarded to O.V.S.