Calving and ice-shelf break-up processes investigated by proxy: Antarctic tabular iceberg evolution during northward drift

Authors: Scambos, T.; Ross, R.; Bauer, R.; Yermolin, Y.; Skvarca, P.; Long, D.; Bohlander, J.; Haran, T.

Source: Journal of Glaciology, Volume 54, Number 187, December 2008 , pp. 579-591(13)

Publisher: International Glaciological Society

Buy & download fulltext article:

OR

Price: $37.61 plus tax (Refund Policy)

Abstract:

Using a combination of satellite sensors, field measurements and satellite-uplinked in situ observing stations, we examine the evolution of several large icebergs drifting east of the Antarctic Peninsula towards South Georgia Island. Three styles of calving are observed during drift: 'rift calvings', 'edge wasting' and 'rapid disintegration'. Rift calvings exploit large pre-existing fractures generated in the shelf environment and can occur at any stage of drift. Edge wasting is calving of the iceberg perimeter by numerous small edge-parallel, sliver-shaped icebergs, preserving the general shape of the main iceberg as it shrinks. This process is observed only in areas north of the sea-ice edge. Rapid disintegration, where numerous small calvings occur in rapid succession, is consistently associated with indications of surface melt saturation (surface lakes, firn-pit ponding). Freeboard measurements by ICESat indicate substantial increases in ice-thinning rates north of the sea-ice edge (from <10ma−1 to >30ma−1), but surface densification is shown to be an important correction (>2m freeboard loss before the firn saturates). Edge wasting of icebergs in 'warm' surface water (sea-ice-free, >−1.8 °C) implies a mechanism based on waterline erosion. Rapid disintegration ('Larsen B-style' break-up) is likely due to the effects of surface or saturated-firn water acting on pre-existing crevasses, or on wave- or tidally induced fractures. Changes in microwave backscatter of iceberg firn as icebergs drift into warmer climate and experience increased surface melt suggest a means of predicting when floating ice plates are evolving towards disintegration.

Document Type: Research Article

DOI: http://dx.doi.org/10.3189/002214308786570836

Publication date: December 1, 2008

More about this publication?
  • The Journal of Glaciology is published six times per year. It accepts submissions from any discipline related to the study of snow and ice. All articles are peer reviewed. The Journal is included in the ISI Science Citation Index.
  • Editorial Board
  • Information for Authors
  • ingentaconnect is not responsible for the content or availability of external websites
Related content

Tools

Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content

Text size:

A | A | A | A
Share this item with others: These icons link to social bookmarking sites where readers can share and discover new web pages. print icon Print this page