20 Characterizing Paleoseismic Parameters of Crustal Faults from the Subduction Margin to the Hinterland

Wednesday, 13 May 2015
1:30 PM - 5:30 PM
Room 116

RECENT NOTABLE EARTHQUAKES IN ALASKA

Paper number: 20-2
Program: Theme Sessions
Time: 1:35 PM – 1:55 PM

Authors

Abstract

In 2014 Alaska Earthquake Center reported record number of earthquakes in Alaska and Aleutian Islands. A total of 40,411 seismic events were reported, a 40% increase from 2012 and 2013. Partly, this increase in seismicity is due to strong earthquakes with active aftershock sequences and earthquake swarms that occurred throughout the year in Alaska and Aleutian Islands. In addition, notable portion of the increase in earthquake reporting is attributable to better seismic network performance and data processing techniques. Some of the notable 2014 earthquake sequences are:

1) M6.1 February 26 earthquake in Fox Islands occurred at nearly 300 km depth;

2) April-June Noatak earthquake swarm in northwest Brooks Range produced five M5.7-5.8 earthquakes;

3) M7.9 June 23 Rat Islands earthquake occurred at 110 km depth and produced over 2,000 aftershocks;

4) M6.0 July 17 Seward Glacier earthquake occurred near Alaska-Canadian border on the Fairweather fault;

5) M6.1 July 25 Palma Bay earthquake occurred on the Fairweather fault and caused underwater landslide that severed the fiber optic cable;

6) August-October Minto earthquake sequence in interior Alaska produced three M5-5.2 earthquakes and numerous aftershocks;

7) M6.3 September 25 Skwentna earthquake occurred at about 100 km depth and produced strongest ground shaking recorded in Anchorage in years.

This presentation will discuss seismological details and tectonic setting of these events.