SIGNIFICANT EARTHQUAKES IN 2002: Alaska Earthquakes of Magnitude 5.5 or larger

Summary: Alaska is the most seismically active part of the United States. Ten earthquakes of magnitude 5.5 or larger were reported in Alaska during 2002 including the largest earthquake anywhere on earth during the year - the November 3 Denali earthquake described in the Global earthquake summary. The Aleutian arc was notably quiet this year, producing only three large events.

Date Time (UTC)

Depth (km)

Magnitude (mb)

Magnitude (Ms)

Magnitude (Mw)

Location, Comments

MAY

25 05 36 32

33

5.5

6.4

6.5

SOUTH OF ALASKA. 90 miles SW of Chernabura Island, AK. Not reported felt.

OCTOBER

23 11 27 20

10

6.1

6.7

6.7

CENTRAL ALASKA. 30 miles ENE of Cantwell, AK, 85 miles S of Fairbanks on a segment of the Denali fault. Felt from Fairbanks to Anchorage. Items knocked from shelves at Anchorage, Big Lake, Fairbanks, Eagle River and Talkeetna. Foreshock of the Nov. 3 earthquake.

NOVEMBER

03 11 27 20

5

7

8.5

7.9

CENTRAL ALASKA. 43 miles ENE of Cantwell, AK, 85 miles S of Fairbanks on the Denali fault. Felt from Fairbanks to Anchorage. Items knocked from shelves at Anchorage, Big Lake, Fairbanks, Eagle River and Talkeetna. One person injured. Damage estimated at $20 million. Felt by people in high-rise buildings in Seattle. Surface waves triggered seiches in Lake Union, WA, Idaho, Oklahoma, Missouri, Wisconsin, Pennsylvania and Louisiana. Triggered seismicity in Yellowstone, Mammoth Lakes and the Geysers, CA. 300 km long surface rupture with right-lateral slip of at least 7 meters.

03 22:32:17

4

5.7

6.0

CENTRAL ALASKA. Aftershock of above. Felt in Achorage, Valdez, Eagle River.

04 00:50:42

5

5.6

5.5

CENTRAL ALASKA. Aftershock of 11/3.

07 15:14:06

33

5.9

6.4

6.6

RAT ISLANDS, ALEUTIAN ISLANDS. 25 miles SE of Amchitka, 175 miles SW of Adak. Not reported felt.

08 04:04:17

1

5.3

5.4

5.5

CENTRAL ALASKA. Aftershock of 11/3. Felt throughout east-central Alaska.

26 00 48 15

19

5.9

5.8

6.1

ANDREANOF ISLANDS, ALEUTIAN ISLANDS. Felt on Atka.

27 01 35 07

1

5.5

5.2

5.6

ALASKA PENNINSULA. Felt Perryvlle and Sand Point.

DECEMBER

28 09 36 12

33

5.7

4.9

5.8

FOX ISLANDS, ALEUTIAN ISLANDS. Not reported felt.

 

Magnitudes: mb body wave magnitude, Ms surface wave magnitude, Mw moment magnitude, ML local magnitude.

This information compiled by Lori Dengler, Humboldt Earthquake Education Center based on information provided by the U.S. Geological Survey, Berkeley Seismological Laboratory, California Institute of Technology, and Harvard University, January 10, 2003.