A magnitude 8.7 earthquake struck off Russia's Kamchatka Peninsula on July 29, triggering tsunami alerts for the entire U.S. West Coast and portions of the Alaska Aleutian Islands, the U.S. Geological Survey said.
The earthquake was recorded at 7:24 p.m. ET, about 78 miles east-southeast of of Petropavlovsk-Kamchatsky, Russia, the U.S. Geological Survey (USGS) said in its updated assessment. The agency said the quake was shallow, at a depth of about 11 miles.
A tsunami warning was in place along Alaska’s remote Aleutian Islands. Residents in the islands were advised to move out of the water and away from beaches, harbors, marines and inlets.
Tsunamis can generate strong waves and currents, with waves that may last up to 45 minutes as it encroaches and recedes, the warning center stated. Coasts facing all directions are threatened because the waves can wrap around islands and headlands and into Bays.
The warning center also issued a tsunami watch for the West Coast, including southern Alaska, British Columbia, Washington state, Oregon, and California, including Los Angeles Harbor. The watch extends inland along the Salish Sea in Washington to Port Angeles, Port Townsend, and Bellingham.
Emergency management officials in Hawaii issued a tsunami watch for the state. The agency noted that if tsunami waves were to impact the state, the earliest estimated time of arrival would be 7:17 p.m., Hawaii Standard Time.
"This is a significant, real event," said Reid Wolcott, a meteorologist with the weather service in Seattle. "The imminent threat is for Alaska and areas near the quake. The National Tsunami Warning Center needs additional observation information before more is known about the threat to the US West Coast."
Tsunami activity possible in Alaska
The tsunami warning for Alaska includes coastal areas from Attu to Samalga Pass. The tsunami advisory has been expanded to areas from Samalga Pass to Chignik Bay. Expected tsunami start times in Alaska include the following: 6:45 p.m., Unalaska; 7:25 p.m., Sand Point and 8:00 p.m. Cold Bay.The National Tsunami Warning Center advises that tsunami activity is possible at Shemya, Alaska beginning at 4:46 p.m., Alaskan Daylight Time, then at 5:46 p.m. at Adak and 7:06 p.m. at Saint Paul, about 760 miles west of Anchorage.
Possible tsunami start times stretch from 8:20 p.m. local time in Kodiak, Alaska, southward along the coast to La Jolla, California, where tsunami activity would be expected to begin by 1:15 a.m. local time.
Earthquake in Russia was 'the strongest in decades of tremors'
The powerful earthquake generated a tsunami of up to 13 feet in Russia, prompting evacuations and damaging buildings, officials said."Today's earthquake was serious and the strongest in decades of tremors," Kamchatka Governor Vladimir Solodov said in a video posted on the Telegram messaging app, according to Reuters. He added that according to preliminary information there were no injuries, but a kindergarten was damaged.
Kamchatka and Russia's Far East sit on the Pacific Ring of Fire, a geologically active region that is prone to major earthquakes and volcanic eruptions.
Tsunami alerts issued for Japan, Pacific Islands
The Japan Weather Agency upgraded its warning, saying it expected tsunami waves of up to 10 feet to reach large coastal areas starting around 10:00 a.m. local time. Broadcast NHK said evacuation orders had been issued by the government for some areas.The U.S. Tsunami Warning System also issued a warning of "hazardous tsunami waves" within the next three hours along some coasts of Russia, Japan and Hawaii. A tsunami watch was also in effect for the U.S. island territory of Guam and other islands of Micronesia.
What do tsunami alerts mean?
The National Weather Service said tsunami messages are issued by the tsunami warning centers to alert local authorities and the public of a possible tsunami. There are four levels of tsunami alerts, according to the weather service:- Tsunami Warning: "Take Action—Danger! A tsunami that may cause widespread flooding is expected or occurring. Dangerous coastal flooding and powerful currents are possible and may continue for several hours or days after initial arrival."
- Tsunami Advisory: "Take Action—A tsunami with potential for strong currents or waves dangerous to those in or very near the water is expected or occurring. There may be flooding of beach and harbor areas."
- Tsunami Watch: "Be Prepared—A distant earthquake has occurred. A tsunami is possible."
- Tsunami Information Statement: "Relax—An earthquake has occurred, but there is no threat or it was very far away and the threat has not been determined. In most cases, there is no threat of a destructive tsunami."
It may only end up being 3 feet.