ZCZC 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. $$ NNNN