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Data Event Response to the 29 May 2015 Mw 6.7 Earthquake 111km NNW of Chirikof Island, Alaska

Written by David Phillips & Beth Bartel
29 May 2015

Tectonic Summary

From the USGS Event Page:
The Aleutian arc extends approximately 3,000 km from the Gulf of Alaska in the east to the Kamchatka Peninsula in the west. It marks the region where the Pacific plate subducts into the mantle beneath the North America plate. This subduction is responsible for the generation of the Aleutian Islands and the deep offshore Aleutian Trench.

The curvature of the arc results in a westward transition of relative plate motion from trench-normal (i.e., compressional) in the east to trench-parallel (i.e., translational) in the west, accompanied by westward variations in seismic activity, volcanism, and overriding plate composition. The Aleutian arc is generally divided into three regions: the western, central, and eastern Aleutians. Relative to a fixed North America plate, the Pacific plate is moving northwest at a rate that increases from roughly 60 mm/yr at the arc's eastern edge to 76 mm/yr near its western terminus. The eastern Aleutian arc extends from the Alaskan Peninsula in the east to the Fox Islands in the west. Motion along this section of the arc is characterized by arc-perpendicular convergence and Pacific plate subduction beneath thick continental lithosphere. This region exhibits intense volcanic activity and has a history of megathrust earthquakes.

For more information, see the USGS Earthquake Hazards Program event page.

UNAVCO Response

In response to the Mw 6.7 Alaska earthquake on May 29, 2015 at 07:00, one-sample-per-second (1-sps) GPS data will be collected for a 7-day period around the event (day of event ± 3 days). Once downloaded, data will be available from ftp://data-out.unavco.org/pub/highrate/.

UNAVCO is also producing a fully processed 1-sps borehole strainmeter (BSM) dataset spanning the time period of this event, made available at Geophysical Event Response.

The GAGE GPS Analysis Center Coordinator will estimate coseismic offsets for any stations that experience horizontal displacements of > 1mm. If such offsets are observed then station offset files will be made available from ftp://data-out.unavco.org/pub/products/event/.

UNAVCO Data and Support

  • Please contact archive-gpsunavco.org for information on data availability

Related Links

Map Center:
Chirikof Island, Alaska


Last modified: 2020-02-06  00:23:17  America/Denver