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Does calving matter? Evidence for significant submarine melt

Earth and Planetary Science Letters

By:
, , and
DOI: 10.1016/j.epsl.2013.08.014

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Abstract

During the summer in the northeast Pacific Ocean, the Alaska Coastal Current sweeps water with temperatures in excess of 12 °C past the mouths of glacierized fjords and bays. The extent to which these warm waters affect the mass balance of Alaskan tidewater glaciers is uncertain. Here we report hydrographic measurements made within Icy Bay, Alaska, and calculate rates of submarine melt at Yahtse Glacier, a tidewater glacier terminating in Icy Bay. We find strongly stratified water properties consistent with estuarine circulation and evidence that warm Gulf of Alaska water reaches the head of 40 km-long Icy Bay, largely unaltered. A 10–20 m layer of cold, fresh, glacially-modified water overlies warm, saline water. The saline water is observed to reach up to 10.4 °C within 1.5 km of the terminus of Yahtse Glacier. By quantifying the heat and salt deficit within the glacially-modified water, we place bounds on the rate of submarine melt. The submarine melt rate is estimated at >9 m d−1, at least half the rate at which ice flows into the terminus region, and can plausibly account for all of the submarine terminus mass loss. Our measurements suggest that summer and fall subaerial calving is a direct response to thermal undercutting of the terminus, further demonstrating the critical role of the ocean in modulating tidewater glacier dynamics.

Geospatial Extents

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Does calving matter? Evidence for significant submarine melt
Series title:
Earth and Planetary Science Letters
DOI:
10.1016/j.epsl.2013.08.014
Volume
380
Year Published:
2013
Language:
English
Publisher:
Elsevier
Contributing office(s):
Alaska Science Center Water
Description:
10 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Earth and Planetary Science Letters
First page:
21
Last page:
30
Country:
United States
State:
Alaska
Other Geospatial:
Icy Bay