TSUNAMI MESSAGE NUMBER 3 NWS PACIFIC TSUNAMI WARNING CENTER EWA BEACH HI 2258 UTC TUE JAN 3 2017 ...PTWC FINAL TSUNAMI THREAT MESSAGE... THE TSUNAMI FORECAST IS UNCHANGED IN THIS MESSAGE. PRELIMINARY EARTHQUAKE PARAMETERS --------------------------------- * MAGNITUDE 7.0 * ORIGIN TIME 11:53 AM HST JAN 3 2017 * COORDINATES 19.5 SOUTH 176.2 EAST * DEPTH 10 KM / 6 MILES * LOCATION SOUTH OF THE FIJI ISLANDS EVALUATION ---------- * AN EARTHQUAKE WITH A PRELIMINARY MAGNITUDE OF 7.0 OCCURRED SOUTH OF THE FIJI ISLANDS AT 2153 UTC ON TUESDAY JANUARY 3 2017. * BASED ON ALL AVAILABLE DATA... THE TSUNAMI THREAT FROM THIS EARTHQUAKE HAS NOW PASSED. TSUNAMI THREAT FORECAST...UPDATED --------------------------------- * THERE IS NO LONGER A TSUNAMI THREAT FROM THIS EARTHQUAKE. RECOMMENDED ACTIONS ------------------- * REMAIN OBSERVANT AND EXERCISE NORMAL CAUTION NEAR THE SEA. OTHERWISE... NO ACTION IS REQUIRED. POTENTIAL IMPACTS ----------------- * MINOR SEA LEVEL FLUCTUATIONS MAY OCCUR IN SOME COASTAL AREAS NEAR THE EARTHQUAKE OVER THE NEXT FEW HOURS. TSUNAMI OBSERVATIONS -------------------- * THE FOLLOWING ARE TSUNAMI WAVE OBSERVATIONS FROM COASTAL AND/OR DEEP-OCEAN SEA LEVEL GAUGES AT THE INDICATED LOCATIONS. THE MAXIMUM TSUNAMI HEIGHT IS MEASURED WITH RESPECT TO THE NORMAL TIDE LEVEL. GAUGE TIME OF MAXIMUM WAVE COORDINATES MEASURE TSUNAMI PERIOD GAUGE LOCATION LAT LON (UTC) HEIGHT (MIN) ------------------------------------------------------------- SUVA VITI LEVU FJ 18.1S 178.4E 2231 0.01M/ 0.0FT 10 NEXT UPDATE AND ADDITIONAL INFORMATION -------------------------------------- * THIS WILL BE THE FINAL STATEMENT ISSUED FOR THIS EVENT UNLESS NEW INFORMATION IS RECEIVED OR THE SITUATION CHANGES. * AUTHORITATIVE INFORMATION ABOUT THE EARTHQUAKE FROM THE U.S. GEOLOGICAL SURVEY CAN BE FOUND ON THE INTERNET AT EARTHQUAKE.USGS.GOV/EARTHQUAKES -ALL LOWER CASE-. * FURTHER INFORMATION ABOUT THIS EVENT MAY BE FOUND AT PTWC.WEATHER.GOV AND AT WWW.TSUNAMI.GOV. * COASTAL REGIONS OF HAWAII... AMERICAN SAMOA... GUAM... AND CNMI SHOULD REFER TO PACIFIC TSUNAMI WARNING CENTER MESSAGES SPECIFICALLY FOR THOSE PLACES THAT CAN BE FOUND AT PTWC.WEATHER.GOV. * COASTAL REGIONS OF CALIFORNIA... OREGON... WASHINGTON... BRITISH COLUMBIA AND ALASKA SHOULD ONLY REFER TO U.S. NATIONAL TSUNAMI WARNING CENTER MESSAGES THAT CAN BE FOUND AT NTWC.ARH.NOAA.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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