Earthquake, Magnitude: 7.8 Alaska – Tsunami Warning in Effect

WEAK51 PAAQ 220619
TSUAK1

BULLETIN
Public Tsunami Message Number 1
NWS National Tsunami Warning Center Palmer AK
1019 PM AKDT Tue Jul 21 2020

...A TSUNAMI WARNING IS NOW IN EFFECT...


Tsunami Warning in Effect for;

 * SOUTH ALASKA AND THE ALASKA PENINSULA, Pacific coasts from
   Kennedy Entrance, Alaska (40 miles SW of Homer) to Unimak
   Pass, Alaska (80 miles NE of Unalaska)


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.


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    2213 AKDT Jul 21 2020
                  2313  PDT Jul 21 2020
                  0613  UTC Jul 22 2020
 * Coordinates    55.2 North 158.6 West
 * Depth          8 miles
 * Location       75 miles S of Chignik, Alaska
                  520 miles SW of Anchorage, Alaska


FORECASTS OF TSUNAMI ACTIVITY
-----------------------------
 * Tsunami activity is forecasted to start at the following
   locations at the specified times.

                 FORECAST
                 START
SITE             OF TSUNAMI
----             ----------

 * Alaska
Sand Point       2315 AKDT Jul 21
Kodiak           0005 AKDT Jul 22
Cold Bay         0015 AKDT Jul 22


OBSERVATIONS OF TSUNAMI ACTIVITY
--------------------------------
 * No tsunami observations are available to report.


RECOMMENDED ACTIONS
-------------------
Actions to protect human life and property will
vary within tsunami warning areas.

If you are in a tsunami warning area;

 * Evacuate inland or to higher ground above and beyond
   designated tsunami hazard zones or move to an upper floor
   of a multi-story building depending on your situation.

 * 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 warning
areas.

If you are in a tsunami warning area;

 * A tsunami with damaging waves and powerful currents is
   possible.

 * Repeated coastal flooding is possible as waves arrive
   onshore, move inland, and drain back into the ocean.

 * Strong and unusual waves, currents and inland flooding
   can drown or injure people and weaken or destroy structures
   on land and in water.

 * Water filled with floating or submerged debris that can
   injure or kill people and weaken or destroy buildings and
   bridges is possible.

 * Strong and unusual currents and waves in harbors,
   marinas, bays, and inlets may be especially
   destructive.

 * 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.

$$