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Data Event Response to the 29 July 2015 Mw 6.3 Earthquake 70km SSW of Redoubt Volcano, Alaska

Written by David Phillips & Beth Bartel
10 September 2015

Tectonic Summary

From the USGS Event Page:
59.894°N 153.196°W depth=119.3 km (74.1 mi)

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.

Most of the seismicity along the Aleutian arc results from thrust faulting that occurs along the interface between the Pacific and North America plates, extending from near the base of the trench to depths of 40 to 60 km. Slip along this interface is responsible for generating devastating earthquakes. Deformation also occurs within the subducting slab in the form of intermediate-depth earthquakes that can reach depths of 250 km. Normal faulting events occur in the outer rise region of the Aleutian arc resulting from the bending of the oceanic Pacific plate as it enters the Aleutian trench. Additionally, deformation of the overriding North America plate generates shallow crustal earthquakes.

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

UNAVCO Response

GPS data
In response to the Mw 6.3 earthquake 70km SSW of Redoubt Volcano, Alaska on July 29, 2015, one-sample-per-second (1-sps) GPS data were collected for a 7-day period around the event (day of event ± 3 days). The data are available from ftp://data-out.unavco.org/pub/highrate/.

Stations downloaded and their horizontal distances to the epicenter, in km:
AC47, 32.36
AC59, 46.71
AV17, 58.93
AV11, 60.75
AUGL, 60.77
AV03, 61.02
AV18, 61.10
AV16, 62.62
AV05, 62.68
AV04, 63.11
AV19, 63.38
AV01, 63.85
AV20, 64.42
AV02, 65.95
AC03, 69.14
AC37, 74.78
AB22, 90.99
SELD, 91.87
AC17, 93.06
AC27, 94.60
AC08, 112.61
AC18, 117.78
AC06, 123.20
AC23, 137.67
AC35, 141.00
AC39, 148.47
AC36, 179.69
AC51, 190.68
AC15, 196.75
AC26, 197.28
AC43, 198.21

GPS velocities
The GAGE GPS Analysis Center Coordinator estimates coseismic offsets for any stations that experience horizontal displacements of > 1mm. If such offsets are observed, station offset files are made available from ftp://data-out.unavco.org/pub/products/event/. No such offsets were observed for this event.

Borehole strainmeter data
No borehole strainmeter (BSM) data were processed for this event.

Borehole seismic data
PBO seismic data (1-sps and 100-sps) are available from the IRIS DMC under the network code “PB.” The nearest PBO seismic stations are located in the Pacific Northwest. PBO seismic data can be accessed from http://www.unavco.org/data/strain-seismic/seismic-data/seismic-data.html and http://ds.iris.edu/ds/nodes/dmc/data/types/waveform-data/.

UNAVCO Data and Support

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

Related Links

Map Center:
Redoubt, Alaska


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