Sharon Mau

USGS news Earthquake Samoa Islands Region

Samoa Islands Region Earthquake Summary

News this morning from the Pacific Tsunami Warning Center has issued a Tsunami warning. An earthquake occurred near Samoa and it is currently estimated that the preliminary magnitude was about 8.0, which is a very strong earthquake. On the local news this morning it is said that the earliest time a Tsunami would reach Hawai’i is around 1:11pm (1311).

NOAA Pacific Tsunami Warning Center
“AN EARTHQUAKE HAS OCCURRED WITH THESE PRELIMINARY PARAMETERS – NOTE MOMENT MAGNITUDE INCREASE TO 8.3”

ORIGIN TIME – 0748 AM HST 29 SEP 2009
COORDINATES – 15.3 SOUTH 171.0 WEST
LOCATION – SAMOA ISLANDS REGION
MAGNITUDE – 8.3 MOMENT
MAGNITUDE – 8.0 RICHTER (MS)

Waves as high as 10 feet have come ashore on Samoa and flowed inland about 100 yards near Pago Pago. At this time there are no reports of any injuries or structural damage.

Hawai’i State Civil Defense states that a tsunami watch means that there is a possibility of a damaging wave hitting Hawai’i. The next step would be a tsunami warning which calls for the evacuation of coastal areas.

A tsunami warning was in effect for American Samoa, Samoa, Niue Island, the Wallis and Futuna Islands, the Tokelau atolls, the Cook Islands, Tuvalu, Kiribati, the Kermadec Islands, the Baker and Howland Islands, Jarvis Island, French Polynesia and the Palmyra Islands.

Please check back for updates. We are on alert for the Tsunami siren alarms. If you are on the coast and hear the sirens, it is recommended you walk and/or run out, and do not drive a car. They don’t know what areas of the Hawaiian islands may be affected at this point because of the “wraparound” effect.

A tsunami warning is in effect for American Samoa, Samoa, Niue, Wallis-Futuna, Tokelau, Cook Islands, Tonga, Tuvalu, Kiribati, Kermadec Islands, Howland-Baker, Jarvis Island, New Zealand, French Polynesia and Palmyra Atoll.

Hawai’i is listed as under a tsunami watch along with Vanuatu, Nauru, Marshall Islands, Solomon Islands, Johnston Atoll, New Caledonia, Kosrae, Papua New Guinea, Pohnpeo, Wake Island, Pitcairn Island and Midway.

Tsunami facts Frequently Asked Questions NOAA

“Tsunami” comes from the Japanese words for harbor (“tsu”) and wave (“nami”).

Tsunami waves travel at speeds comparable to that of a commercial jet plane, with speeds of up to 600 miles per hour.

As large tsunami waves approach islands, they may refract or bend around them and diffract through the channels between the islands as well. The ability of a tsunami wave to bend around and through the islands is called the wrap-around effect. During the wrap-around effect, the energy of the tsunami often decreases resulting in smaller wave heights. Sometimes tsunami waves will reflect off of a land mass instead of bending around, thereby increasing wave height of the approaching wave.

USGS Earthquakes

The broad-scale Australia/Pacific plate boundary is one of the most active earthquake regions in the world. Earthquakes occur on the thrust-fault boundary between the Australia and Pacific plates, within the Pacific plate on both sides of the trench, and within and on the boundaries of the small plates that compose the eastern edge of the overall Australia plate.

Sharon Mau
29 September 2009