Overall Orange Earthquake in Japan on 20 Apr 2026 07:53 UTC

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M 7.4 Earthquake and Tsunami (1 m) in Japan on 20 Apr 2026 07:53 UTC

Global Telecommunication Service

GTS (Global Telecommunication Service) is the official Warning and Alerting channel by the World Meteorological Organization (WMO) adopted by several Warning Organizations. As soon as a new GTS message regarding Tropical Cyclones(WT) or Tsunami(WE) the messages are processed and possibly assigned to the specific event. When a new GTS message is present an new tab in the specific event report page is present.The presence of a GTS message is shown in the homepage with a dedicated icon.

Click on the messages list to visualize on the right the detailed text.

Measurements Levels

SOURCE	GAUGE LOCATION	LAT	LON	TIME (UTC)	HEIGHT (m)	PERIOD (min)
PTWC	Ofunato Honshu Jp	39	141.8	08: 30	0.16	06

20/04 11:41 WEPA40RJTD201140

20/04 11:15 WEPA40RJTD201115

20/04 09:25 WEPA40PHEB200924

20/04 09:00 WEPA40RJTD200900

20/04 08:45 WEPA40PHEB200844

20/04 08:40 WEPA40RJTD200840

20/04 08:32 WEPA40RJTD200832

20/04 08:08 WEPA40RJTD200808

20/04 08:05 WEAK53PAAQ200804

20/04 08:04 WEIO20DEMS200803

20/04 08:04 WEPA40RJTD200803

20/04 08:03 WEIO22WIIX200803

20/04 08:02 WEPA40PHEB200802

20/04 08:02 WEIO24AMMC200801

20/04 07:55 WEPA40RJTD200755

2026-04-20 11:41 message from JMA link

Key information extracted from original GTS message :

Evaluation

There is a possibility of a destructive local TSUNAMI near the epicenter estimation at forecast points - no TSUNAMI waves with an amplitude of 0.3 meters or more are expected at any forecast point
However in some coastal areas (particularly near the epicenter) higher TSUNAMI waves than estimated MAY arrive
Authorities should be aware of this possibility

Original Message :

WEPA40 RJTD 201140
TSUNAMI BULLETIN NUMBER 005
ISSUED BY NWPTAC(JMA)
ISSUED AT 1140Z 20 APR 2026
PART 01 OF 01 PARTS

HYPOCENTRAL PARAMETERS
ORIGIN TIME:0752Z 20 APR 2026
PRELIMINARY EPICENTER:LAT39.8NORTH LON143.2EAST
OFF EAST COAST OF HONSHU, JAPAN
JAPAN - KURIL ISLANDS - KAMCHATKA PENINSULA
MAG:7.5 (MW)

EVALUATION
THERE IS A POSSIBILITY OF A DESTRUCTIVE LOCAL TSUNAMI
NEAR THE EPICENTER

ESTIMATION AT FORECAST POINTS - NO TSUNAMI WAVES WITH AN AMPLITUDE
OF 0.3 METERS OR MORE ARE EXPECTED AT ANY FORECAST POINT.

HOWEVER, IN SOME COASTAL AREAS (PARTICULARLY NEAR THE EPICENTER),
HIGHER TSUNAMI WAVES THAN ESTIMATED MAY ARRIVE.
AUTHORITIES SHOULD BE AWARE OF THIS POSSIBILITY.

MEASUREMENTS OR REPORTS OF TSUNAMI (REVISION)
LOCATION COORDINATES ARRIVAL TIME AMPL
HANASAKI 43.3N 145.6E
MAXIMUM TSUNAMI WAVE 1105Z 20 APR 0.1M
SEKINEHAMA 41.4N 141.2E
MAXIMUM TSUNAMI WAVE 0912Z 20 APR 0.2M
OFUNATO 39.0N 141.8E
MAXIMUM TSUNAMI WAVE 0828Z 20 APR 0.2M

MAXIMUM TSUNAMI WAVE - HALF THE AMPLITUDE FROM THE TROUGH
TO THE CREST

THIS WILL BE THE FINAL BULLETIN UNLESS CHANGES IN THE POTENTIAL
FOR TSUNAMI GENERATION ARE DEEMED POSSIBLE BASED ON EARTHQUAKE
RE-EVALUATION OR REPORTS INDICATING TSUNAMI OBSERVATION ARE
RECEIVED.

=

2026-04-20 11:15 message from JMA link

Original Message :

WEPA40 RJTD 201115
TSUNAMI BULLETIN ISSUED BY JMA AT 1115Z 20 APR

ORIGIN TIME 0752Z 20 APR
PRELIMINARY EPICENTER LAT 39.8 N. LON 143.2 E.
E OFF NORTHERN HONSHU
FOCAL DEPTH 19 KM MAG 7.7

TSUNAMI ADVISORIES ARE IN EFFECT
FOR THE FOLLOWING COASTAL AREAS OF JAPAN:
PACIFIC COASTS OF NORTH JAPAN
WESTERN COASTS OF NORTH JAPAN
=

2026-04-20 09:25 message from NTWC link

Key information extracted from original GTS message :

Evaluation

An earthquake with a preliminary magnitude of 7.4 occurred off the east coast of honshu JAPAN at 0753 UTC on monday APRIL 20 2026
Based on all available data the TSUNAMI threat from this earthquake has now passed

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 LOCATION	LAT	LON	TIME (UTC)	HEIGHT (m)	PERIOD (min)
Ofunato Honshu Jp	39	141.8	08: 30	0.16	06

Original Message :

WEPA40 PHEB 200924
TSUPAC

TSUNAMI MESSAGE NUMBER 3
NWS PACIFIC TSUNAMI WARNING CENTER HONOLULU HI
0923 UTC MON APR 20 2026

...PTWC FINAL TSUNAMI THREAT MESSAGE...

**** NOTICE **** NOTICE **** NOTICE **** NOTICE **** NOTICE *****

THIS MESSAGE IS ISSUED FOR INFORMATION ONLY IN SUPPORT OF THE
UNESCO/IOC PACIFIC TSUNAMI WARNING AND MITIGATION SYSTEM AND IS
MEANT FOR NATIONAL AUTHORITIES IN EACH COUNTRY OF THAT SYSTEM.

NATIONAL AUTHORITIES WILL DETERMINE THE APPROPRIATE LEVEL OF
ALERT FOR EACH COUNTRY AND MAY ISSUE ADDITIONAL OR MORE REFINED
INFORMATION.

**** NOTICE **** NOTICE **** NOTICE **** NOTICE **** NOTICE *****

THE TSUNAMI FORECAST IS UPDATED IN THIS MESSAGE.

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

* MAGNITUDE 7.4
* ORIGIN TIME 0753 UTC APR 20 2026
* COORDINATES 39.9 NORTH 143.3 EAST
* DEPTH 10 KM / 6 MILES
* LOCATION OFF THE EAST COAST OF HONSHU JAPAN

EVALUATION
----------

* AN EARTHQUAKE WITH A PRELIMINARY MAGNITUDE OF 7.4 OCCURRED
OFF THE EAST COAST OF HONSHU, JAPAN AT 0753 UTC ON MONDAY
APRIL 20 2026.

* 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)
-------------------------------------------------------------
OFUNATO HONSHU JP 39.0N 141.8E 0830 0.16M/ 0.5FT 06

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.

$$

2026-04-20 09:00 message from JMA link

Key information extracted from original GTS message :

Evaluation

There is a possibility of a destructive local TSUNAMI near the epicenter estimation at forecast points - no TSUNAMI waves with an amplitude of 0.3 meters or more are expected at any forecast point
However in some coastal areas (particularly near the epicenter) higher TSUNAMI waves than estimated MAY arrive
Authorities should be aware of this possibility

Original Message :

WEPA40 RJTD 200900
TSUNAMI BULLETIN NUMBER 004
ISSUED BY NWPTAC(JMA)
ISSUED AT 0900Z 20 APR 2026
PART 01 OF 01 PARTS

HYPOCENTRAL PARAMETERS
ORIGIN TIME:0752Z 20 APR 2026
PRELIMINARY EPICENTER:LAT39.8NORTH LON143.2EAST
OFF EAST COAST OF HONSHU, JAPAN
JAPAN - KURIL ISLANDS - KAMCHATKA PENINSULA
MAG:7.5 (MW)

EVALUATION
THERE IS A POSSIBILITY OF A DESTRUCTIVE LOCAL TSUNAMI
NEAR THE EPICENTER

ESTIMATION AT FORECAST POINTS - NO TSUNAMI WAVES WITH AN AMPLITUDE
OF 0.3 METERS OR MORE ARE EXPECTED AT ANY FORECAST POINT.

HOWEVER, IN SOME COASTAL AREAS (PARTICULARLY NEAR THE EPICENTER),
HIGHER TSUNAMI WAVES THAN ESTIMATED MAY ARRIVE.
AUTHORITIES SHOULD BE AWARE OF THIS POSSIBILITY.

MEASUREMENTS OR REPORTS OF TSUNAMI (REVISION)
LOCATION COORDINATES ARRIVAL TIME AMPL
SEKINEHAMA 41.4N 141.2E
MAXIMUM TSUNAMI WAVE 0853Z 20 APR 0.1M
OFUNATO 39.0N 141.8E
MAXIMUM TSUNAMI WAVE 0828Z 20 APR 0.2M

MAXIMUM TSUNAMI WAVE - HALF THE AMPLITUDE FROM THE TROUGH
TO THE CREST

THIS WILL BE THE FINAL BULLETIN UNLESS CHANGES IN THE POTENTIAL
FOR TSUNAMI GENERATION ARE DEEMED POSSIBLE BASED ON EARTHQUAKE
RE-EVALUATION OR REPORTS INDICATING TSUNAMI OBSERVATION ARE
RECEIVED.

=

2026-04-20 08:45 message from NTWC link

Key information extracted from original GTS message :

Evaluation

An earthquake with a preliminary magnitude of 7.4 occurred off the east coast of honshu JAPAN at 0753 UTC on monday APRIL 20 2026
Based on all available data hazardous TSUNAMI waves are forecast for some coasts

Original Message :

WEPA40 PHEB 200844
TSUPAC

TSUNAMI MESSAGE NUMBER 2
NWS PACIFIC TSUNAMI WARNING CENTER HONOLULU HI
0844 UTC MON APR 20 2026

...PTWC TSUNAMI THREAT MESSAGE...

**** NOTICE **** NOTICE **** NOTICE **** NOTICE **** NOTICE *****

THIS MESSAGE IS ISSUED FOR INFORMATION ONLY IN SUPPORT OF THE
UNESCO/IOC PACIFIC TSUNAMI WARNING AND MITIGATION SYSTEM AND IS
MEANT FOR NATIONAL AUTHORITIES IN EACH COUNTRY OF THAT SYSTEM.

NATIONAL AUTHORITIES WILL DETERMINE THE APPROPRIATE LEVEL OF
ALERT FOR EACH COUNTRY AND MAY ISSUE ADDITIONAL OR MORE REFINED
INFORMATION.

**** NOTICE **** NOTICE **** NOTICE **** NOTICE **** NOTICE *****

THE TSUNAMI FORECAST IS UPDATED IN THIS MESSAGE.

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

* MAGNITUDE 7.4
* ORIGIN TIME 0753 UTC APR 20 2026
* COORDINATES 39.9 NORTH 143.3 EAST
* DEPTH 10 KM / 6 MILES
* LOCATION OFF THE EAST COAST OF HONSHU JAPAN

EVALUATION
----------

* AN EARTHQUAKE WITH A PRELIMINARY MAGNITUDE OF 7.4 OCCURRED
OFF THE EAST COAST OF HONSHU, JAPAN AT 0753 UTC ON MONDAY
APRIL 20 2026.

* BASED ON ALL AVAILABLE DATA... HAZARDOUS TSUNAMI WAVES ARE
FORECAST FOR SOME COASTS.

TSUNAMI THREAT FORECAST...UPDATED
---------------------------------

* TSUNAMI WAVES REACHING 1 TO 3 METERS ABOVE THE TIDE LEVEL ARE
POSSIBLE ALONG SOME COASTS OF

JAPAN.

* TSUNAMI WAVES ARE FORECAST TO BE LESS THAN 0.3 METERS ABOVE
THE TIDE LEVEL FOR THE COASTS OF

DPR OF KOREA... GUAM... MARSHALL ISLANDS... MIDWAY
ISLAND... NORTHERN MARIANAS... PHILIPPINES... RUSSIA...
AND WAKE ISLAND.

* ACTUAL AMPLITUDES AT THE COAST MAY VARY FROM FORECAST
AMPLITUDES DUE TO UNCERTAINTIES IN THE FORECAST AND LOCAL
FEATURES. IN PARTICULAR MAXIMUM TSUNAMI AMPLITUDES ON ATOLLS
AND AT LOCATIONS WITH FRINGING OR BARRIER REEFS WILL LIKELY
BE MUCH SMALLER THAN THE FORECAST INDICATES.

* FOR OTHER AREAS COVERED BY THIS PRODUCT A FORECAST HAS NOT
YET BEEN COMPUTED. THE FORECAST WILL BE EXPANDED IF
NECESSARY IN SUBSEQUENT PRODUCTS.

RECOMMENDED ACTIONS
-------------------

* GOVERNMENT AGENCIES RESPONSIBLE FOR THREATENED COASTAL AREAS
SHOULD TAKE ACTION TO INFORM AND INSTRUCT ANY COASTAL
POPULATIONS AT RISK IN ACCORDANCE WITH THEIR OWN
EVALUATION... PROCEDURES AND THE LEVEL OF THREAT.

* PERSONS LOCATED IN THREATENED COASTAL AREAS SHOULD STAY ALERT
FOR INFORMATION AND FOLLOW INSTRUCTIONS FROM NATIONAL AND
LOCAL AUTHORITIES.

ESTIMATED TIMES OF ARRIVAL
--------------------------

* ESTIMATED TIMES OF ARRIVAL -ETA- OF THE INITIAL TSUNAMI WAVE
FOR PLACES WITHIN THREATENED REGIONS ARE GIVEN BELOW. ACTUAL
ARRIVAL TIMES MAY DIFFER AND THE INITIAL WAVE MAY NOT BE THE
LARGEST. A TSUNAMI IS A SERIES OF WAVES AND THE TIME BETWEEN
WAVES CAN BE FIVE MINUTES TO ONE HOUR.

LOCATION REGION COORDINATES ETA(UTC)
------------------------------------------------------------
KUSHIRO JAPAN 42.9N 144.3E 0832 04/20
HACHINOHE JAPAN 40.5N 141.5E 0834 04/20
KATSUURA JAPAN 35.1N 140.3E 0851 04/20
SHIMIZU JAPAN 32.8N 133.0E 1017 04/20
NOBEOKA JAPAN 32.5N 131.8E 1022 04/20
SAPPORO JAPAN 43.5N 141.0E 1027 04/20
NIIGATA JAPAN 38.0N 139.0E 1047 04/20
SHIMANE JAPAN 35.8N 133.0E 1146 04/20
NAGASAKI JAPAN 32.7N 129.7E 1202 04/20

POTENTIAL IMPACTS
-----------------

* A TSUNAMI IS A SERIES OF WAVES. THE TIME BETWEEN WAVE CRESTS
CAN VARY FROM 5 MINUTES TO AN HOUR. THE HAZARD MAY PERSIST
FOR MANY HOURS OR LONGER AFTER THE INITIAL WAVE.

* IMPACTS CAN VARY SIGNIFICANTLY FROM ONE SECTION OF COAST TO
THE NEXT DUE TO LOCAL BATHYMETRY AND THE SHAPE AND ELEVATION
OF THE SHORELINE.

* IMPACTS CAN ALSO VARY DEPENDING UPON THE STATE OF THE TIDE AT
THE TIME OF THE MAXIMUM TSUNAMI WAVES.

* PERSONS CAUGHT IN THE WATER OF A TSUNAMI MAY DROWN... BE
CRUSHED BY DEBRIS IN THE WATER... OR BE SWEPT OUT TO SEA.

NEXT UPDATE AND ADDITIONAL INFORMATION
--------------------------------------

* THE NEXT MESSAGE WILL BE ISSUED IN ONE HOUR... OR SOONER IF
THE SITUATION WARRANTS.

* 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.

$$

2026-04-20 08:40 message from JMA link

Key information extracted from original GTS message :

Evaluation

There is a possibility of a destructive local TSUNAMI near the epicenter estimation at forecast points - no TSUNAMI waves with an amplitude of 0.3 meters or more are expected at any forecast point
However in some coastal areas (particularly near the epicenter) higher TSUNAMI waves than estimated MAY arrive
Authorities should be aware of this possibility

Original Message :

WEPA40 RJTD 200840
TSUNAMI BULLETIN NUMBER 003
ISSUED BY NWPTAC(JMA)
ISSUED AT 0840Z 20 APR 2026
PART 01 OF 01 PARTS

HYPOCENTRAL PARAMETERS
ORIGIN TIME:0752Z 20 APR 2026
PRELIMINARY EPICENTER:LAT39.8NORTH LON143.2EAST
OFF EAST COAST OF HONSHU, JAPAN
JAPAN - KURIL ISLANDS - KAMCHATKA PENINSULA
MAG:7.5 (MW)

EVALUATION
THERE IS A POSSIBILITY OF A DESTRUCTIVE LOCAL TSUNAMI
NEAR THE EPICENTER

ESTIMATION AT FORECAST POINTS - NO TSUNAMI WAVES WITH AN AMPLITUDE
OF 0.3 METERS OR MORE ARE EXPECTED AT ANY FORECAST POINT.

HOWEVER, IN SOME COASTAL AREAS (PARTICULARLY NEAR THE EPICENTER),
HIGHER TSUNAMI WAVES THAN ESTIMATED MAY ARRIVE.
AUTHORITIES SHOULD BE AWARE OF THIS POSSIBILITY.

MEASUREMENTS OR REPORTS OF TSUNAMI
LOCATION COORDINATES ARRIVAL TIME AMPL
OFUNATO 39.0N 141.8E
MAXIMUM TSUNAMI WAVE 0828Z 20 APR 0.2M

MAXIMUM TSUNAMI WAVE - HALF THE AMPLITUDE FROM THE TROUGH
TO THE CREST

THIS WILL BE THE FINAL BULLETIN UNLESS CHANGES IN THE POTENTIAL
FOR TSUNAMI GENERATION ARE DEEMED POSSIBLE BASED ON EARTHQUAKE
RE-EVALUATION OR REPORTS INDICATING TSUNAMI OBSERVATION ARE
RECEIVED.

=

2026-04-20 08:32 message from JMA link

Key information extracted from original GTS message :

Evaluation

There is a possibility of a destructive local TSUNAMI near the epicenter estimation at forecast points - no TSUNAMI waves with an amplitude of 0.3 meters or more are expected at any forecast point
However in some coastal areas (particularly near the epicenter) higher TSUNAMI waves than estimated MAY arrive
Authorities should be aware of this possibility
This will be the final bulletin unless changes in the potential for TSUNAMI generation are deemed possible based on earthquake re-evaluation or reports indicating TSUNAMI observation are received

Original Message :

WEPA40 RJTD 200832
TSUNAMI BULLETIN NUMBER 002
ISSUED BY NWPTAC(JMA)
ISSUED AT 0832Z 20 APR 2026
PART 01 OF 01 PARTS

HYPOCENTRAL PARAMETERS (REVISION)
ORIGIN TIME:0752Z 20 APR 2026
PRELIMINARY EPICENTER:LAT39.8NORTH LON143.2EAST
OFF EAST COAST OF HONSHU, JAPAN
JAPAN - KURIL ISLANDS - KAMCHATKA PENINSULA
MAG:7.5 (MW)

EVALUATION
THERE IS A POSSIBILITY OF A DESTRUCTIVE LOCAL TSUNAMI
NEAR THE EPICENTER

ESTIMATION AT FORECAST POINTS - NO TSUNAMI WAVES WITH AN AMPLITUDE
OF 0.3 METERS OR MORE ARE EXPECTED AT ANY FORECAST POINT.

HOWEVER, IN SOME COASTAL AREAS (PARTICULARLY NEAR THE EPICENTER),
HIGHER TSUNAMI WAVES THAN ESTIMATED MAY ARRIVE.
AUTHORITIES SHOULD BE AWARE OF THIS POSSIBILITY.

THIS WILL BE THE FINAL BULLETIN UNLESS CHANGES IN THE POTENTIAL
FOR TSUNAMI GENERATION ARE DEEMED POSSIBLE BASED ON EARTHQUAKE
RE-EVALUATION OR REPORTS INDICATING TSUNAMI OBSERVATION ARE
RECEIVED.

=

2026-04-20 08:08 message from JMA link

Original Message :

WEPA40 RJTD 200808
TSUNAMI BULLETIN ISSUED BY JMA AT 0808Z 20 APR

ORIGIN TIME 0752Z 20 APR
PRELIMINARY EPICENTER LAT 39.8 N. LON 143.2 E.
E OFF NORTHERN HONSHU
FOCAL DEPTH 10 KM MAG 7.5

TSUNAMI WARNINGS ARE IN EFFECT
FOR THE FOLLOWING COASTAL AREAS OF JAPAN:
PACIFIC COASTS OF NORTH JAPAN
TSUNAMI ADVISORIES ARE IN EFFECT
FOR THE FOLLOWING COASTAL AREAS OF JAPAN:
WESTERN COASTS OF NORTH JAPAN
=

2026-04-20 08:05 message from NTWC link

Key information extracted from original GTS message :

Evaluation

There is no TSUNAMI danger for the u s west coast BRITISH columbia or alaska
Based on earthquake information and historic TSUNAMI records the earthquake is not expected to generate a tsunami
An earthquake has occurred with parameters listed below

Original Message :

WEAK53 PAAQ 200804
TIBAK1

Tsunami Information Statement Number 1
NWS National Tsunami Warning Center Palmer AK
104 AM PDT Mon Apr 20 2026

...THIS IS A TSUNAMI INFORMATION STATEMENT FOR ALASKA, BRITISH
COLUMBIA, WASHINGTON, OREGON AND CALIFORNIA...

EVALUATION
----------
* There is no tsunami danger for the U.S. West Coast, British
Columbia, or Alaska.

* Based on earthquake information and historic tsunami records,
the earthquake is not expected to generate a tsunami.

* An earthquake has occurred with parameters listed below.

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

* The following parameters are based on a rapid preliminary
assessment of the earthquake and changes may occur.

* Magnitude 7.4
* Origin Time 2353 AKDT Apr 19 2026
0053 PDT Apr 20 2026
0753 UTC Apr 20 2026
* Coordinates 39.9 North 143.3 East
* Depth 6 miles
* Location off the east coast of Honshu, Japan

ADDITIONAL INFORMATION AND NEXT UPDATE
--------------------------------------
* Refer to the internet site tsunami.gov for more information.

* Pacific coastal regions outside California, Oregon, Washington,
British Columbia, and Alaska should refer to the Pacific Tsunami
Warning Center messages at tsunami.gov.

* This will be the only U.S. National Tsunami Warning Center
message issued for this event unless additional information
becomes available.

$$

2026-04-20 08:04 link

Original Message :

WEIO20 DEMS 200803
---------------------------------------------------------------------
TSUNAMI BULLETIN NOTIFICATION MESSAGE NUMBER 1
IOTWMS TSUNAMI SERVICE PROVIDER INDIA (ITEWC)

ISSUED AT 0803 UTC MONDAY 20 APRIL 2026
---------------------------------------------------------------------
TO: INDIAN OCEAN NATIONAL TSUNAMI WARNING CENTRES (NTWC)
FROM: IOTWMS-TSP INDIA

NOTIFICATION:
IOTWMS-TSP INDIA HAS JUST ISSUED TSUNAMI BULLETIN NUMBER 1

FOR THE INDIAN OCEAN, BASED ON THE FOLLOWING EARTHQUAKE EVENT:

Magnitude : 7.3
Depth : 48.0
Date : 20 Apr 2026
Origin Time : 0753 UTC
Latitude : 40.00 N
Longitude : 142.79 E
Location : Near East Coast of Honshu, Japan

TO VIEW THE BULLETIN GO TO THE IOTWMS-TSP INDIA WEBSITE AT:
https://tsunami.incois.gov.in/TEWS/displaybulletinslatest.jsp?type=TSP&eventId=incois2026htye&aos=exchange&currBullNo=1&latestBullNo=1

NOTE: THIS IS A RESTRICTED-ACCESS WEBSITE CONTAINING TECHNICAL DATA
FOR INDIAN OCEAN NATIONAL TSUNAMI WARNING CENTRES ONLY. IT IS NOT
FOR GENERAL PUBLIC ACCESS.

GENERAL PUBLIC INFORMATION FOR THIS EVENT IS AVAILABLE FROM:

INDIAN TSUNAMI EARLY WARNING CENTRE (ITEWC)
INDIAN NATIONAL CENTRE FOR OCEAN INFORMATION SERVICES (INCOIS)
ADDRESS:OCEAN VALLEY, PRAGATHI NAGAR (BO), NIZAMPET (SO),
HYDERABAD - 500 090, INDIA
PHONE: 91-40-23895011
FAX: 91-40-23895012
EMAIL: tsunami@incois.gov.in
WEB: https://tsunami.incois.gov.in/TEWS/TSP

END OF NOTIFICATION MESSAGE
---------------------------------------------------------------------

2026-04-20 08:04 message from JMA link

Key information extracted from original GTS message :

Evaluation

There is a possibility of a destructive local TSUNAMI near the epicenter estimation at forecast points - no TSUNAMI waves with an amplitude of 0.3 meters or more are expected at any forecast point
However in some coastal areas (particularly near the epicenter) higher TSUNAMI waves than estimated MAY arrive
Authorities should be aware of this possibility
This will be the final bulletin unless changes in the potential for TSUNAMI generation are deemed possible based on earthquake re-evaluation or reports indicating TSUNAMI observation are received

Original Message :

WEPA40 RJTD 200803
TSUNAMI BULLETIN NUMBER 001
ISSUED BY NWPTAC(JMA)
ISSUED AT 0803Z 20 APR 2026
PART 01 OF 01 PARTS

HYPOCENTRAL PARAMETERS
ORIGIN TIME:0752Z 20 APR 2026
PRELIMINARY EPICENTER:LAT39.8NORTH LON143.2EAST
OFF EAST COAST OF HONSHU, JAPAN
JAPAN - KURIL ISLANDS - KAMCHATKA PENINSULA
MAG:7.4 (MJMA)

EVALUATION
THERE IS A POSSIBILITY OF A DESTRUCTIVE LOCAL TSUNAMI
NEAR THE EPICENTER

ESTIMATION AT FORECAST POINTS - NO TSUNAMI WAVES WITH AN AMPLITUDE
OF 0.3 METERS OR MORE ARE EXPECTED AT ANY FORECAST POINT.

HOWEVER, IN SOME COASTAL AREAS (PARTICULARLY NEAR THE EPICENTER),
HIGHER TSUNAMI WAVES THAN ESTIMATED MAY ARRIVE.
AUTHORITIES SHOULD BE AWARE OF THIS POSSIBILITY.

THIS WILL BE THE FINAL BULLETIN UNLESS CHANGES IN THE POTENTIAL
FOR TSUNAMI GENERATION ARE DEEMED POSSIBLE BASED ON EARTHQUAKE
RE-EVALUATION OR REPORTS INDICATING TSUNAMI OBSERVATION ARE
RECEIVED.

=

2026-04-20 08:03 link

Original Message :

WEIO22 WIIX 200803
TSP-InaTEWS-20260420-0803-001
--------------------------------------------------------------------------------
TSUNAMI BULLETIN NOTIFICATION MESSAGE NUMBER 1
IOTWMS TSUNAMI SERVICE PROVIDER INDONESIA (InaTEWS-BMKG)
issued at 0803 UTC, Apr 20, 2026
--------------------------------------------------------------------------------
TO: INDIAN OCEAN NATIONAL TSUNAMI WARNING CENTRES (NTWC)
FROM: IOTWMS-TSP INDONESIA

NOTIFICATION:
IOTWMS-TSP INDONESIA HAS JUST ISSUED TSUNAMI BULLETIN NUMBER 1 FOR
THE INDIAN OCEAN, BASED ON THE FOLLOWING EARTHQUAKE EVENT:

Magnitude : 7.4 Mwp
Depth : 10km
Date : 20 Apr 2026
Origin Time: 07:52:57 UTC
Latitude : 40.02N
Longitude : 142.66E
Location : Near East Coast of Honshu, Japan

TO VIEW THE BULLETIN GO TO THE IOTWMS-TSP INDONESIA WEBSITE AT:

http://rtsp.bmkg.go.id

NOTE: THIS IS A RESTRICTED-ACCESS WEBSITE CONTAINING TECHNICAL DATA
FOR INDIAN OCEAN NATIONAL TSUNAMI WARNING CENTRES ONLY. IT IS NOT
FOR GENERAL PUBLIC ACCESS.

GENERAL PUBLIC INFORMATION FOR THIS EVENT IS AVAILABLE FROM:

INDONESIA TSUNAMI EARLY WARNING SYSTEM (InaTEWS)
THE AGENCY FOR METEOROLOGY CLIMATOLOGY AND GEOPHYSICS (BMKG)
Address: Jl. Angkasa I no.2 Kemayoran, Jakarta, Indonesia, 10720
Tel.: +62 (21) 65867045
Fax: +62 (21) 6546316
P.O. Box 3540 Jakarta
Website: http://rtsp.bmkg.go.id/publicbull.php
Email : inartsp@bmkg.go.id
monitrtwp@bmkg.go.id

END OF NOTIFICATION MESSAGE
--------------------------------------------------------------

2026-04-20 08:02 message from NTWC link

Key information extracted from original GTS message :

Evaluation

An earthquake with a preliminary magnitude of 7.4 occurred off the east coast of honshu JAPAN at 0753 UTC on monday APRIL 20 2026
Based on the preliminary earthquake parameters hazardous TSUNAMI waves are possible for coasts located within 300 km of the earthquake epicenter

Threat Forecast

Hazardous TSUNAMI waves from this earthquake are possible within 300 km of the epicenter along the coasts of japan.

Original Message :

WEPA40 PHEB 200802
TSUPAC

TSUNAMI MESSAGE NUMBER 1
NWS PACIFIC TSUNAMI WARNING CENTER HONOLULU HI
0801 UTC MON APR 20 2026

...PTWC TSUNAMI THREAT MESSAGE...

**** NOTICE **** NOTICE **** NOTICE **** NOTICE **** NOTICE *****

THIS MESSAGE IS ISSUED FOR INFORMATION ONLY IN SUPPORT OF THE
UNESCO/IOC PACIFIC TSUNAMI WARNING AND MITIGATION SYSTEM AND IS
MEANT FOR NATIONAL AUTHORITIES IN EACH COUNTRY OF THAT SYSTEM.

NATIONAL AUTHORITIES WILL DETERMINE THE APPROPRIATE LEVEL OF
ALERT FOR EACH COUNTRY AND MAY ISSUE ADDITIONAL OR MORE REFINED
INFORMATION.

**** NOTICE **** NOTICE **** NOTICE **** NOTICE **** NOTICE *****

PRELIMINARY EARTHQUAKE PARAMETERS - FROM JMA
--------------------------------------------

* MAGNITUDE 7.4
* ORIGIN TIME 0753 UTC APR 20 2026
* COORDINATES 39.9 NORTH 143.3 EAST
* DEPTH 10 KM / 6 MILES
* LOCATION OFF THE EAST COAST OF HONSHU JAPAN

EVALUATION
----------

* AN EARTHQUAKE WITH A PRELIMINARY MAGNITUDE OF 7.4 OCCURRED
OFF THE EAST COAST OF HONSHU, JAPAN AT 0753 UTC ON MONDAY
APRIL 20 2026.

* BASED ON THE PRELIMINARY EARTHQUAKE PARAMETERS... HAZARDOUS
TSUNAMI WAVES ARE POSSIBLE FOR COASTS LOCATED WITHIN 300 KM
OF THE EARTHQUAKE EPICENTER.

TSUNAMI THREAT FORECAST
-----------------------

* HAZARDOUS TSUNAMI WAVES FROM THIS EARTHQUAKE ARE POSSIBLE
WITHIN 300 KM OF THE EPICENTER ALONG THE COASTS OF

JAPAN.

RECOMMENDED ACTIONS
-------------------

* GOVERNMENT AGENCIES RESPONSIBLE FOR THREATENED COASTAL AREAS
SHOULD TAKE ACTION TO INFORM AND INSTRUCT ANY COASTAL
POPULATIONS AT RISK IN ACCORDANCE WITH THEIR OWN
EVALUATION... PROCEDURES AND THE LEVEL OF THREAT.

* PERSONS LOCATED IN THREATENED COASTAL AREAS SHOULD STAY ALERT
FOR INFORMATION AND FOLLOW INSTRUCTIONS FROM NATIONAL AND
LOCAL AUTHORITIES.

ESTIMATED TIMES OF ARRIVAL
--------------------------

* ESTIMATED TIMES OF ARRIVAL -ETA- OF THE INITIAL TSUNAMI WAVE
FOR PLACES WITH A POTENTIAL TSUNAMI THREAT. ACTUAL ARRIVAL
TIMES MAY DIFFER AND THE INITIAL WAVE MAY NOT BE THE
LARGEST. A TSUNAMI IS A SERIES OF WAVES AND THE TIME BETWEEN
WAVES CAN BE FIVE MINUTES TO ONE HOUR.

LOCATION REGION COORDINATES ETA(UTC)
------------------------------------------------------------
HACHINOHE JAPAN 40.5N 141.5E 0834 04/20

POTENTIAL IMPACTS
-----------------

* A TSUNAMI IS A SERIES OF WAVES. THE TIME BETWEEN WAVE CRESTS
CAN VARY FROM 5 MINUTES TO AN HOUR. THE HAZARD MAY PERSIST
FOR MANY HOURS OR LONGER AFTER THE INITIAL WAVE.

* IMPACTS CAN VARY SIGNIFICANTLY FROM ONE SECTION OF COAST TO
THE NEXT DUE TO LOCAL BATHYMETRY AND THE SHAPE AND ELEVATION
OF THE SHORELINE.

* IMPACTS CAN ALSO VARY DEPENDING UPON THE STATE OF THE TIDE AT
THE TIME OF THE MAXIMUM TSUNAMI WAVES.

* PERSONS CAUGHT IN THE WATER OF A TSUNAMI MAY DROWN... BE
CRUSHED BY DEBRIS IN THE WATER... OR BE SWEPT OUT TO SEA.

NEXT UPDATE AND ADDITIONAL INFORMATION
--------------------------------------

* THE NEXT MESSAGE WILL BE ISSUED IN ONE HOUR... OR SOONER IF
THE SITUATION WARRANTS.

* 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.

$$

2026-04-20 08:02 link

Original Message :

WEIO24 AMMC 200801
---------------------------------------------------------------------
TSUNAMI BULLETIN NOTIFICATION MESSAGE NUMBER 1
IOTWMS TSUNAMI SERVICE PROVIDER AUSTRALIA [JATWC]
ISSUED AT 0801 UTC MONDAY 20 APRIL 2026
---------------------------------------------------------------------
TO: INDIAN OCEAN NATIONAL TSUNAMI WARNING CENTRES [NTWC]
FROM: IOTWMS-TSP AUSTRALIA

NOTIFICATION:
IOTWMS-TSP AUSTRALIA HAS JUST ISSUED TSUNAMI BULLETIN NUMBER 1 FOR
THE INDIAN OCEAN, BASED ON AN EARTHQUAKE WITH THE FOLLOWING DETAILS:

MAGNITUDE: 7.5 Mw[Mwp]
DEPTH: 42 km
DATE: 20 Apr 2026
ORIGIN TIME: 0752 UTC
LATITUDE: 39.78N
LONGITUDE: 143.42E
LOCATION: Off East Coast of Honshu, Japan

TO VIEW THE BULLETIN GO TO THE IOTWMS-TSP AUSTRALIA WEBSITE AT:

http://reg.bom.gov.au/tsunami/rtsp

NOTE: THIS IS A RESTRICTED-ACCESS WEBSITE CONTAINING TECHNICAL DATA
FOR INDIAN OCEAN NATIONAL TSUNAMI WARNING CENTRES ONLY. IT IS NOT
FOR GENERAL PUBLIC ACCESS.

GENERAL PUBLIC INFORMATION FOR THIS EVENT IS AVAILABLE FROM:

JOINT AUSTRALIAN TSUNAMI WARNING CENTRE [JATWC]
BUREAU OF METEOROLOGY
MELBOURNE, AUSTRALIA
http://www.bom.gov.au/tsunami

END OF NOTIFICATION MESSAGE
---------------------------------------------------------------------

2026-04-20 07:55 message from JMA link

Original Message :

WEPA40 RJTD 200755
TSUNAMI BULLETIN ISSUED BY JMA AT 0755Z 20 APR

ORIGIN TIME 0752Z 20 APR
PRELIMINARY EPICENTER LAT 39.8 N. LON 143.2 E.
E OFF NORTHERN HONSHU
FOCAL DEPTH 10 KM MAG 7.4

TSUNAMI WARNINGS ARE IN EFFECT
FOR THE FOLLOWING COASTAL AREAS OF JAPAN:
PACIFIC COASTS OF NORTH JAPAN
=

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