WEAK51 PAAQ 290831 TSUAK1 BULLETIN Public Tsunami Message Number 5 NWS National Tsunami Warning Center Palmer AK 1231 AM AKDT Thu Jul 29 2021 UPDATES ------- * A tsunami has been confirmed and some impacts are expected * Updated observations * Revised alert areas ...THE TSUNAMI ADVISORY REMAINS IN EFFECT... Tsunami Advisory in Effect for; * SOUTH ALASKA AND THE ALASKA PENINSULA, Pacific coasts from Hinchinbrook Entrance, Alaska (90 miles E of Seward) to Unimak Pass, Alaska (80 miles NE of Unalaska) * ALEUTIAN ISLANDS, Unimak Pass, Alaska (80 miles NE of Unalaska) to Samalga Pass, Alaska (30 miles SW of Nikolski) Alerts in the following areas have been canceled because additional information and analysis have better defined the threat. * The Tsunami Advisory is canceled for the coastal areas of Aleutian Islands from Samalga Pass, Alaska (30 miles SW of Nikolski) to Amchitka Pass, Alaska (125 miles W of Adak) For other US and Canadian Pacific coasts in North America, the level of tsunami danger is being evaluated. Further information will be provided in supplementary messages. FORECASTS OF TSUNAMI ACTIVITY ----------------------------- * A tsunami has been generated. The first waves are forecasted to arrive at the following locations and specified times. * Forecast tsunami duration is the approximate length of time which the tsunami may produce dangerous currents and waves. * Forecast max tsunami height is the highest expected water level above the tide. * Forecasts are not provided for sites which have been impacted more than an hour prior to the time of this message. FORECAST FORECAST FORECAST START TSUNAMI MAX TSUNAMI SITE OF TSUNAMI DURATION HEIGHT ---- ---------- -------- ------------- * Alaska Unalaska 2350 AKDT Jul 28 less than 1ft Cold Bay 2355 AKDT Jul 28 less than 1ft Kodiak 2355 AKDT Jul 28 less than 1ft Seward 0020 AKDT Jul 29 less than 1ft Homer 0115 AKDT Jul 29 less than 1ft OBSERVATIONS OF TSUNAMI ACTIVITY - UPDATED ------------------------------------------ * Observed max tsunami height is the highest recorded water level above the tide level up to the time of this message. TIME OBSERVED MAX SITE OF MEASUREMENT TSUNAMI HEIGHT ---------------------------- ---------------- -------------- Sand Point Alaska 0042 PDT Jul 29 0.5ft Old Harbor Alaska 0057 PDT Jul 29 0.7ft PRELIMINARY EARTHQUAKE PARAMETERS --------------------------------- * Magnitude 8.2 * Origin Time 2216 AKDT Jul 28 2021 2316 PDT Jul 28 2021 0616 UTC Jul 29 2021 * Coordinates 55.3 North 157.8 West * Depth 20 miles * Location 75 miles SE of Chignik, Alaska 500 miles SW of Anchorage, Alaska RECOMMENDED ACTIONS - UPDATED ----------------------------- Actions to protect human life and property will vary within tsunami advisory areas. If you are in a tsunami advisory area; * Move out of the water, off the beach, and away from harbors, marinas, breakwaters, bays and inlets. * Be alert to and follow instructions from your local emergency officials because they may have more detailed or specific information for your location. * If you feel a strong earthquake or extended ground rolling take immediate protective actions such as moving inland and/or uphill preferably by foot. * Boat operators, * Where time and conditions permit, move your boat out to sea to a depth of at least 180 feet. * If at sea avoid entering shallow water, harbors, marinas, bays, and inlets to avoid floating and submerged debris and strong currents. * Do not go to the shore to observe the tsunami. * Do not return to the coast until local emergency officials indicate it is safe to do so. IMPACTS ------- Impacts will vary at different locations in the advisory areas. If you are in a tsunami advisory area; * A tsunami with strong waves and currents is possible. * Waves and currents can drown or injure people who are in the water. * Currents at beaches and in harbors, marinas, bays, and inlets may be especially dangerous. * Some impacts may continue for many hours to days after arrival of the first wave. * The first wave may not be the largest so later waves may be larger. * Each wave may last 5 to 45 minutes as a wave encroaches and recedes. * Coasts facing all directions are threatened because the waves can wrap around islands and headlands and into bays. * Strong shaking or rolling of the ground indicates an earthquake has occurred and a tsunami may be imminent. * A rapidly receding or receded shoreline, unusual waves and sounds, and strong currents are signs of a tsunami. * The tsunami may appear as water moving rapidly out to sea, a gentle rising tide like flood with no breaking wave, as a series of breaking waves, or a frothy wall of water. ADDITIONAL INFORMATION AND NEXT UPDATE -------------------------------------- * Refer to the internet site tsunami.gov for more information. * Pacific coastal residents outside California, Oregon, Washington, British Columbia and Alaska should refer to the Pacific Tsunami Warning Center messages at tsunami.gov. * This message will be updated within 30 minutes. $$