An earthquake with the preliminary magnitude of 7.3 occured near Russia at 7:02 a.m. HST on Thursday, December 20, 2018. Based on all available data a destructive pacific-wide tsunami is not expected and there is no tsunami threat to Hawaii.

Hawaii County Civil Defense Audio Message

TSUNAMI MESSAGE NUMBER 3
NWS PACIFIC TSUNAMI WARNING CENTER EWA BEACH HI
1824 UTC THU DEC 20 2018

..PTWC FINAL TSUNAMI THREAT MESSAGE...

THE TSUNAMI FORECAST IS UNCHANGED IN THIS MESSAGE.


PRELIMINARY EARTHQUAKE PARAMETERS
---------------------------------

 * MAGNITUDE      7.3
 * ORIGIN TIME    1702 UTC DEC 20 2018
 * COORDINATES    54.8 NORTH  164.8 EAST
 * DEPTH          33 KM / 20 MILES
 * LOCATION       KOMANDORSKIYE OSTROVA  RUSSIA REGION


EVALUATION
----------

 * AN EARTHQUAKE WITH A PRELIMINARY MAGNITUDE OF 7.3 OCCURRED IN
   THE KOMANDORSKIYE OSTROVA, RUSSIA REGION AT 1702 UTC ON
   THURSDAY DECEMBER 20 2018.

 * 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.


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.

 * FURTHER INFORMATION ABOUT THIS EVENT MAY BE FOUND 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
   WWW.TSUNAMI.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 WWW.TSUNAMI.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.