TSUNAMI INFORMATION STATEMENT NUMBER 1
NWS PACIFIC TSUNAMI WARNING CENTER EWA BEACH HI
0545 UTC TUE APR 23 2019
PRELIMINARY EARTHQUAKE PARAMETERS
MAGNITUDE 6.6
ORIGIN TIME 0538 UTC APR 23 2019
COORDINATES 11.9 NORTH 125.2 EAST
DEPTH 86 KM / 54 MILES
LOCATION SAMAR PHILIPPINES
EVALUATION
AN EARTHQUAKE WITH A PRELIMINARY MAGNITUDE OF 6.6 OCCURRED IN
SAMAR, PHILIPPINES AT 0538 UTC ON TUESDAY APRIL 23 2019.
BASED ON ALL AVAILABLE DATA… THERE IS NO TSUNAMI THREAT
FROM THIS EARTHQUAKE.
RECOMMENDED ACTIONS
NO ACTION IS REQUIRED.
NEXT UPDATE AND ADDITIONAL INFORMATION
THIS WILL BE THE ONLY STATEMENT ISSUED FOR THIS EVENT UNLESS
ADDITIONAL DATA ARE RECEIVED OR THE SITUATION CHANGES.
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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