Magnitude
7.5
Date-Time
Saturday, January 05, 2013 at 08:58:16 UTC
Friday, January 04, 2013 at 11:58:16 PM at epicenter
Friday, January 04, 2013 at 10:58:19 PM (HST) – Hawaii Standard (Honolulu)
Location
55.238°N, 134.777°W
Depth
9.9 km (6.2 miles)
Region
SOUTHEASTERN ALASKA
Distances
102 km (63 miles) W of Craig, Alaska
303 km (188 miles) WNW of Prince Rupert, Canada
335 km (208 miles) S of Juneau, Alaska
402 km (249 miles) WNW of Terrace, Canada
TSUNAMI INFORMATION STATEMENT NUMBER 2 NWS PACIFIC TSUNAMI WARNING CENTER EWA BEACH HI 1146 PM HST FRI JAN 04 2013 TO - CIVIL DEFENSE IN THE STATE OF HAWAII SUBJECT - TSUNAMI INFORMATION STATEMENT THIS STATEMENT IS FOR INFORMATION ONLY. NO ACTION REQUIRED. AN EARTHQUAKE HAS OCCURRED WITH THESE PRELIMINARY PARAMETERS ORIGIN TIME - 1058 PM HST 04 JAN 2013 COORDINATES - 55.3 NORTH 134.9 WEST LOCATION - SOUTHEASTERN ALASKA MAGNITUDE - 7.6 MOMENT MEASUREMENTS OR REPORTS OF TSUNAMI WAVE ACTIVITY GAUGE LOCATION LAT LON TIME AMPL PER ------------------- ----- ------ ----- --------------- ----- PORT ALEXANDER AK 56.2N 134.6W 0929Z 0.13M / 0.4FT 10MIN LAT - LATITUDE (N-NORTH, S-SOUTH) LON - LONGITUDE (E-EAST, W-WEST) TIME - TIME OF THE MEASUREMENT (Z IS UTC IS GREENWICH TIME) AMPL - TSUNAMI AMPLITUDE MEASURED RELATIVE TO NORMAL SEA LEVEL. IT IS ...NOT... CREST-TO-TROUGH WAVE HEIGHT. VALUES ARE GIVEN IN BOTH METERS(M) AND FEET(FT). PER - PERIOD OF TIME IN MINUTES(MIN) FROM ONE WAVE TO THE NEXT. EVALUATION THE WEST COAST AND ALASKA TSUNAMI WARNING CENTER HAS ISSUED A REGIONAL TSUNAMI WARNING AND/OR WATCH AND/OR ADVISORY FOR OTHER PARTS OF THE PACIFIC LOCATED CLOSER TO THE EARTHQUAKE. BASED ON ALL AVAILABLE DATA THERE IS NO DESTRUCTIVE TSUNAMI THREAT TO HAWAII. HOWEVER... SOME COASTAL AREAS IN HAWAII COULD EXPERIENCE SMALL NON-DESTRUCTIVE SEA LEVEL CHANGES AND STRONG OR UNUSUAL CURRENTS LASTING UP TO SEVERAL HOURS. THE ESTIMATED TIME SUCH EFFECTS MIGHT BEGIN IS 0428 AM HST SAT 05 JAN 2013 THIS WILL BE THE ONLY STATEMENT ISSUED FOR THIS EVENT UNLESS ADDITIONAL DATA ARE RECEIVED.
West Coast/Alaska Tsunami Warning Center Bulletin #4
BULLETIN PUBLIC TSUNAMI MESSAGE NUMBER 4 NWS WEST COAST/ALASKA TSUNAMI WARNING CENTER PALMER AK 158 AM AKST SAT JAN 5 2013 ...THE TSUNAMI WARNING IS CANCELLED... CANCELLATIONS ------------- * THE TSUNAMI WARNING IS CANCELED FOR THE COASTAL AREAS OF BRITISH COLUMBIA AND ALASKA FROM THE NORTH TIP OF VANCOUVER ISLAND BRITISH COLUMBIA TO CAPE FAIRWEATHER ALASKA/LOCATED 80 MILES SE OF YAKUTAT/ 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 ---------------------------- --------------- -------------- PORT ALEXANDER AK 1026 UTC 01-05 00.5FT SITKA AK 1041 UTC 01-05 00.3FT HEIGHT - OBSERVED MAX TSUNAMI HEIGHT IS THE WATER LEVEL ABOVE THE TIDE LEVEL AT THE TIME OF MEASUREMENT. DEEP OCEAN PRESSURE SENSORS DID NOT RECORD A TSUNAMI. NEXT UPDATE AND ADDITIONAL INFORMATION -------------------------------------- * THIS WILL BE THE LAST WEST COAST/ALASKA TSUNAMI WARNING CENTER BULLETIN ISSUED FOR THIS EVENT. * REFER TO THE INTERNET SITE WCATWC.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 FOR INFORMATION 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.
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