Very strong 7.0 magnitude quake in Vanuatu Islands, no tsunami threat to Hawaii

Magnitude

7.0

Time

2016-04-28 19:33:26 (UTC)

2016-04-28 09:33:26 HST

Nearby Places

5.0 km (3.1 mi) WSW of Norsup, Vanuatu

64.0 km (39.8 mi) SSE of Luganville, Vanuatu

209.0 km (129.9 mi) NNW of Port-Vila, Vanuatu

533.0 km (331.2 mi) N of We, New Caledonia

676.0 km (420.0 mi) N of Dumbea, New Caledonia

TSUNAMI MESSAGE NUMBER 4

NWS PACIFIC TSUNAMI WARNING CENTER EWA BEACH HI

2122 UTC THU APR 28 2016

…PTWC FINAL TSUNAMI THREAT MESSAGE…

PRELIMINARY EARTHQUAKE PARAMETERS

———————————

* MAGNITUDE 7.0

* ORIGIN TIME 1933 UTC APR 28 2016

* COORDINATES 16.2 SOUTH 167.7 EAST

* DEPTH 10 KM / 6 MILES

* LOCATION VANUATU

EVALUATION

———-

* AN EARTHQUAKE WITH A PRELIMINARY MAGNITUDE OF 7.0 OCCURRED IN

THE VANUATU ISLANDS AT 1933 UTC ON THURSDAY APRIL 28 2016.

* BASED ON ALL DATA AVAILABLE TO THIS CENTER… THE TSUNAMI

THREAT FROM THIS EARTHQUAKE HAS NOW MOSTLY PASSED. ANY

REMAINING THREAT SHOULD BE EVALUATED BY LOCAL AUTHORITIES IN

IMPACTED AREAS.

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 OF UP TO 0.3 METERS ABOVE AND

BELOW THE NORMAL TIDE MAY CONTINUE OVER THE NEXT FEW HOURS.

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.