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Regional-scale deformation analysis using multiple-acquisition inSAR in Western Anatolia (RIWA)

English title Regional-scale deformation analysis using multiple-acquisition inSAR in Western Anatolia (RIWA)
Applicant Jónsson Sigurjón
Number 117882
Funding scheme Project funding
Research institution Institut für Geophysik ETH Zürich
Institution of higher education ETH Zurich - ETHZ
Main discipline Geophysics
Start/End 01.11.2008 - 30.04.2010
Approved amount 124'502.00
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All Disciplines (2)

Discipline
Geophysics
Other disciplines of Engineering Sciences

Keywords (8)

satellite radar interferometry; inSAR; persistent scatterers; geodetic strain field; seismic hazard; Glacial earthquakes; Seismology; Greenland ice sheet

Lay Summary (English)

Lead
Lay summary
In this project we will install state-of-the art seismic stations in Greenland as a part of a new international broadband seismic capability for Greenland, the GreenLand Ice Sheet monitoring Network (GLISN)-a real-time sensor array that enhances and upgrades performance of the very-limited existing Greenland seismic infrastructure for detecting and characterizing glacial earthquakes and other phenomena emitting seismic waves. The Greenland Ice Sheet is changing, and seismology has the means to “hear” and measure these changes. Continuous, long-term monitoring of the dynamics of the Greenland Ice Sheet and its relationship to global climate change is a fundamental observational enterprise which requires multi-sensing techniques. The development of GLISN brings the seismology component into focus for monitoring Greenland’s Ice Sheet.Glacial earthquakes have been observed along the edges of Greenland with strong seasonality and in-creasing frequency since 2002 by continuously monitoring data from the Global Seismographic Network (GSN). These glacial earthquakes in the magnitude range 4.6-5.1 may be modeled as a large glacial ice mass sliding down-hill several meters (e.g. 10 cubic-km by 10 m) on its basal surface over a duration of 30 to 60 seconds. Although the mechanics of sudden sliding motions at the glacial base are not known, seasonal and temporal patterns are consistent with a dynamic response to climate warming driven by an increase in surface melting and supply of meltwater to the glacial base, and suggest that the glacial earthquakes may serve as a marker of ice-sheet response to external forcing.The detection and characterization of smaller glacial earthquakes are limited by the propagation distance to globally distributed seismic stations. However, some glacial earthquakes have been observed at seismic stations within Greenland, but the current station coverage is very sparse. In order to define the fine structure and detailed mechanisms of glacial earthquakes within the Greenland Ice Sheet, a broadband, real-time seismic network needs to be installed throughout the Ice Sheet and perimeter. Because of the long durations of sliding, these glacial earth-quakes do not appear in standard earthquake catalogs, and are best detected by broadband seismometers, which accurately measure both fast (< second) and slow (> 100sec) vibrations. Through denser close-in coverage, the magnitude threshold for detecting glacial earthquakes may be reduced by about one magnitude unit (an order of magnitude in size) with concomitant improvements for locating the event accurately.Such seismic monitoring of the Greenland Ice Sheet via glacial earthquakes will complement both surficial GPS monitoring and remote sensing from satellites, by providing sensitivity to the dynamics of the glaciers at basal depths. In addition, real-time detection of glacial earthquakes permits rapid response and focusing of other sensing techniques to the dynamic region of the Ice Sheet.
Direct link to Lay Summary Last update: 21.02.2013

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