A tsunami, or tidal wave,  is a series of waves created by a sudden, significant displacement of the ocean floor. They can be generated by an underwater earthquake or landslide. Tsunami waves may be generated by an event thousands of miles away and take several hours to reach our coast. They may also be generated locally and arrive in as little as 10-15 minutes, before there is time for an official warning from local emergency notification systems.

The Valley does have a tsunami inundation zone running along the Cook Inlet coastline. If a tsunami should occur, people in the inundation zone are at risk of drowning. Experts have determined that a tsunami that produces significant damage is extremely unlikely to occur in the coastal areas of the Matanuska-Susitna Borough, but not impossible.

NOAA Weather Radios and Emergency Alert System broadcasts via television and radio will also be used to notify the public of potential tsunamis.

If you are on or near the beach, any beach anywhere, and observe the water receding in an unusually rapid manner, immediately evacuate eastward to higher ground—even if no official warning has been issued.

When evacuating the inundation area:

• Walk to higher ground
• Bring your pets in a carrier or on a leash
• Offer assistance to persons who are mobility impaired;
• Take only necessary items (keys, wallet, ID, mobile phone, appropriate outerwear)
• Wait for the “all clear” message before returning to low-lying areas. Tsunami waves can continue to arrive for several hours after the initial wave and sometimes may be spaced an hour or more apart.