Magnitude
6.2
Date-Time
Friday, August 10, 2012 at 18:37:44 UTC
Friday, August 10, 2012 at 10:37:44 AM at epicenter
Friday, August 10, 2012 at 08:37:44 AM (HST) – Hawaii Standard (Honolulu)
Location
52.695°N, 167.469°W
Depth
19 km (11.8 miles)
Region
FOX ISLANDS, ALEUTIAN ISLANDS, ALASKA
Distances
97 km (61 miles) ESE (106°) from Nikolski, AK
147 km (91 miles) SSW (206°) from Unalaska, AK
195 km (121 miles) SW (215°) from Akutan, AK
1422 km (884 miles) SW (236°) from Anchorage, AK

TSUNAMI SEISMIC INFORMATION STATEMENT
NWS WEST COAST/ALASKA TSUNAMI WARNING CENTER PALMER AK
1040 AM AKDT FRI AUG 10 2012

…THIS IS AN INFORMATION STATEMENT…

EVALUATION
AN EARTHQUAKE HAS OCCURRED WITH A MAGNITUDE SUCH THAT A TSUNAMI IS NOT EXPECTED. THIS WILL BE THE ONLY WCATWC MESSAGE ISSUED FOR THIS EVENT.

PRELIMINARY EARTHQUAKE PARAMETERS
MAGNITUDE – 6.3
TIME – 1038 AKDT AUG 10 2012
1138 PDT AUG 10 2012
1838 UTC AUG 10 2012
LOCATION – 52.6 NORTH 167.4 WEST
70 MILES/113 KM SE OF NIKOLSKI ALASKA
400 MILES/644 KM E OF ADAK ALASKA
DEPTH – 19 MILES/31 KM

THE LOCATION AND MAGNITUDE ARE BASED ON PRELIMINARY INFORMATION. FURTHER INFORMATION WILL BE ISSUED BY THE UNITED STATES GEOLOGICAL SURVEY – EARTHQUAKE.USGS.GOV – OR THE APPROPRIATE REGIONAL SEISMIC NETWORK.

USGS: How large does an earthquake have to be to cause a tsunami?

Magnitudes below 6.5
Earthquakes of this magnitude are very unlikely to trigger a tsunami.

Magnitudes between 6.5 and 7.5
Earthquakes of this size do not usually produce destructive tsunamis. However, small sea level changes may be observed in the vicinity of the epicenter. Tsunamis capable of producing damage or casualties are rare in this magnitude range but have occurred due to secondary effects such as landslides or submarine slumps.

Magnitudes between 7.6 and 7.8
Earthquakes of this size may produce destructive tsunamis especially near the epicenter; at greater distances small sea level changes may be observed. Tsunamis capable of producing damage at great distances are rare in the magnitude range.

Magnitude 7.9 and greater
Destructive local tsunamis are possible near the epicenter, and significant sea level changes and damage may occur in a broader region.

Note that with a magnitude 9.0 earthquake, the probability of an aftershock with a magnitude exceeding 7.5 is not negligible. To date, the largest aftershock recorded has been magnitude 7.1 that did not produce a damaging tsunami.