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Title: Tidally Modulated Glacial Slip and Tremor at Helheim Glacier, Greenland
Abstract

Numerical modeling of ice sheet motion and hence projections of global sea level rise require information about the evolving subglacial environment, which unfortunately remains largely unknown due to its difficulty of access. Here we advance such subglacial observations by reporting multi‐year observations of seismic tremor likely associated with glacier sliding at Helheim Glacier. This association is confirmed by correlation analysis between tremor power and multiple environmental forcings on different timescales. Variations of the observed tremor power indicate that different factors affect glacial sliding on different timescales. Effective pressure may control glacial sliding on long (seasonal/annual) timescales, while tidal forcing modulates the sliding rate and tremor power on short (hourly/daily) timescales. Polarization results suggest that the tremor source comes from an upstream subglacial ridge. This observation provides insights on how different factors should be included in ice sheet modeling and how their timescales of variability play an essential role.

 
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Award ID(s):
2151295
NSF-PAR ID:
10498695
Author(s) / Creator(s):
; ; ; ;
Publisher / Repository:
AGU
Date Published:
Journal Name:
Geophysical Research Letters
Volume:
51
Issue:
1
ISSN:
0094-8276
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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