Long Beach gets a Tsunami advisory following American Samoa earthquake

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Long Beach Tsnami Hazard Zone

Long Beach Tsnami Hazard Zone

(Editor’s note 9/30/2009 8:00 a.m. The Tsunami Advisory is NO LONGER in effect.)

Yesterday afternoon the Long Beach Police and Fire departments issued alerts, says Councilmember Gerrie Schipske, concerning the impact of the earthquake which hit American Samoa September 29, 2009 and caused the National Weather Service put a Tsunami Advisory in effect.

On Tuesday at 10:48 a.m. Pacific Time, an 8.0 Richter magnitude (approximate) earthquake struck in American Samoa. Subsequent to the earthquake, several islands in the area reported a low to moderate Tsunami.

In response to the earthquake, the NOAA issued a Tsunami Advisory for the islands of Hawaii and for the western coast of the United States, including the Long Beach coastline. Information from Hawaii indicated that the wave passed through at approximately 3:02 p.m. PST, reaching a height of 5 inches (estimated) on the main island, with no reports of damage.

A minor tsunami has also reached portions of the southern and central California coast. The water level station near Port San Luis Harbor recorded tide height fluctuations of up to a foot, and said these fluctuations could increase during the night. Other locations including the Santa Barbara, San Pedro and Santa Monica harbors only reported minor tidal fluctuations generally below four inches.

The State of California Warning Center and the Los Angeles Operational Area is reporting the following information for the California coast. As of this morning, there have not yet been any reports of local damage. The fluctuations of the tides began to diminish after midnight.

The NOAA expected that the wave would arrive in Long Beach last night at approximately 9:06 p.m. The wave was expected to be no higher than about 1 foot and may only have been noticed by the slight movement of boats.

A Tsunami Advisory is the lowest level of warning and inundation is not expected. Strong currents could still affect local conditions. Awells can grow in size as they reach shallow water, however wave surges along the Long Beach coast are expected to remain below the threshold level for potential damage.

Tsunami advisories mean that a tsunami capable of producing strong currents or waves dangerous to persons in or very near water is imminent of expected. Tsunamis are a series of waves potentially dangerous several hours after initial arrival time.

Since 1812, the California coast has had 14 tsunamis with wave heights higher than three feet; six of these were destructive. Based on the historic record, the probability of a tsunami striking the Long Beach coastal area is a very low threat.

“Emergency Management personnel in Long Beach have insured the readiness of the EOC should information change,” said Schipske in an email to Long Beach residents last night. “We will continue to monitor information from the various sources and will update you as needed.”

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