View M7.9 – 24km SE of Little Sitkin Island, Alaska – 2014-06-23 20:53:09 UTC in a larger map
Magnitude
M7.9 (revised by USGS)
Event Time
2014-06-23 20:53:09 UTC
2014-06-23 11:53:09 UTC-09:00 at epicenter
2014-06-23 10:53:09 UTC-10:00 system time
Location
51.797°N 178.760°E depth=107.5km (66.8mi)
Nearby Cities
24km (15mi) SE of Little Sitkin Island, Alaska
1370km (851mi) E of Petropavlovsk-Kamchatskiy, Russia
1387km (862mi) E of Vilyuchinsk, Russia
1388km (862mi) E of Yelizovo, Russia
2957km (1837mi) W of Whitehorse, Canada
UPDATED (2:48 PM on 6/23/2014)
PUBLIC TSUNAMI MESSAGE NUMBER 6 NWS NATIONAL TSUNAMI WARNING CENTER PALMER AK 435 PM AKDT MON JUN 23 2014 ...THE TSUNAMI ADVISORY IS CANCELLED... CANCELLATIONS ------------- * THE TSUNAMI ADVISORY IS CANCELED FOR THE COASTAL AREAS OF ALASKA FROM NIKOLSKI ALASKA TO ATTU ALASKA IMPACTS - UPDATED ----------------- * A TSUNAMI WAS GENERATED DURING THIS EVENT BUT NO LONGER POSES A THREAT. * SOME AREAS MAY CONTINUE TO SEE SMALL SEA LEVEL CHANGES. * THE DETERMINATION TO RE-OCCUPY HAZARD ZONES MUST BE MADE BY LOCAL OFFICIALS. RECOMMENDED ACTIONS - UPDATED ----------------------------- * DO NOT RE-OCCUPY HAZARD ZONES UNTIL LOCAL EMERGENCY OFFICIALS INDICATE IT IS SAFE TO DO SO. OBSERVATIONS OF TSUNAMI ACTIVITY - UPDATED ------------------------------------------ TIME OBSERVED MAX SITE OF MEASUREMENT TSUNAMI HEIGHT ---------------------------- --------------- -------------- AMCHITKA AK 2322 UTC 06-23 00.7FT SHEMYA AK 2305 UTC 06-23 00.2FT ADAK AK 2302 UTC 06-23 00.2FT NIKOLSKI AK 2323 UTC 06-23 00.2FT ST PAUL IS. AK 2329 UTC 06-23 00.2FT DUTCH HARBOR AK 2330 UTC 06-23 00.3FT ATKA AK 2350 UTC 06-23 00.6FT HEIGHT - OBSERVED MAX TSUNAMI HEIGHT IS THE WATER LEVEL ABOVE THE TIDE LEVEL AT THE TIME OF MEASUREMENT. NEXT UPDATE AND ADDITIONAL INFORMATION -------------------------------------- * THIS WILL BE THE FINAL U.S. NATIONAL TSUNAMI WARNING CENTER MESSAGE ISSUED FOR THIS EVENT. * REFER TO THE INTERNET SITE NTWC.ARH.NOAA.GOV FOR MORE INFORMATION. * PACIFIC COASTAL REGIONS OUTSIDE CALIFORNIA... OREGON... WASHINGTON... BRITISH COLUMBIA AND ALASKA SHOULD REFER TO THE PACIFIC TSUNAMI WARNING CENTER MESSAGES AT PTWC.WEATHER.GOV.
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.
Leave a Reply