Honolulu (US), Jul 30 (AP): A powerful 8.8 magnitude earthquake off Russia's Kamchatka Peninsula triggered tsunami warnings and advisories across the Pacific, including Alaska, Hawaii, and the U.S. West Coast. The earthquake hit early Wednesday local time, which was Tuesday in the U.S., as reported by the US Geological Survey.
Dave Snider, the tsunami warning coordinator at Alaska’s National Tsunami Warning Center, described it as “absolutely notable” and “a significant earth event.”
What is a tsunami? Tsunamis result from earthquakes, underwater volcanic eruptions, or submarine landslides. They occur when the seafloor rises or drops, displacing water and creating waves. Contrary to common belief, tsunamis aren't just one wave but multiple successive waves reaching the shore like a rapid tide. As Dave Snider notes, “Tsunamis cross the ocean at hundreds of miles an hour -- as fast as a jet airplane -- in deep water. When they reach the shore, they slow down and stack up, increasing inundation risks.”
While some tsunamis cause minimal damage, others, like the one in 2004 off Indonesia’s coast with a 9.1 magnitude quake, can lead to catastrophic destruction, resulting in 230,000 fatalities across Southeast and South Asia.
How are tsunami warnings issued? In Hawaii, authorities use cell phone alerts, TV, radio broadcasts, and sirens to warn residents. Alaskan communities employ sirens, weather, and public radio alerts while also using social media and cellphone notifications. In some areas, officials inform residents door-to-door. During a recent earthquake near Alaska's Aleutian Islands, affected communities were alerted to evacuation zones and instructed to seek higher ground.
What actions should be taken during a tsunami alert? Authorities advise relocating to higher ground if a tsunami warning is issued. In Hawaii, residents are guided to check hazard maps and, if necessary, evacuate. People should stay at least 100 feet away from marinas and inland waterways. Some regions mark high ground buildings as meeting points during alerts. For those in designated zones, it's recommended to grab a "go bag" and evacuate either horizontally outside the zone or vertically to minimum the fourth floor of a 10-story building.
In the U.S., the National Weather Service categorizes alerts: a warning suggests potential widespread flooding from a tsunami, and evacuation is advised; an advisory warns of strong currents or dangerous waves, recommending staying away from beaches and waterways; a watch indicates the possibility of a tsunami and suggests preparation.
How quickly do tsunamis reach land? The arrival time depends on the earthquake's location. Locations close to a quake’s epicenter may experience waves in minutes, whereas distant areas might see them hours later. Speed is also affected by ocean depth — faster over deep water and slower upon approaching shallow regions.
Current effects observed: Waves under a foot above tide levels reached Alaskan communities like Amchitka and Adak. In Japan, NHK footage depicted waves washing ashore in northern locales like Hokkaido and closer areas like Ibaraki and Chiba. The Japan Meteorological Agency recorded a 50-centimeter tsunami at northern Japan’s Ishinomaki port.
Alaska’s Tsunami Warning Center indicated prolonged impacts for some areas, such as Adak, for possibly more than a day. Hawaii was under a tsunami warning, with expected first waves landing post 7 p.m. local time. The Honolulu-based Pacific Tsunami Warning Center indicated potential coastline damage across the Hawaiian islands.
The Pacific coast from Canada’s British Columbia stretching down through the U.S. West Coast into Mexico was on a tsunami advisory. Threats of waves up to 5.7 feet were reported for Northern California’s Crescent City, prompting warning sirens to activate.
In Oregon, authorities used Facebook to advise of small expected waves between 1 to 3 feet from around 11:40 p.m. local time. Residents were informed to avoid beaches, harbors, and marinas and remain safe inland until advisories lifted. “This is not a major tsunami, yet dangerous currents and potent waves could endanger those near water,” stated the Oregon Department of Emergency Management.
Mexico’s navy acknowledged possible waves between 1 to 3.3 feet along its coast.
(Only the headline of this report may have been reworked by Editorji; the rest of the content is auto-generated from a syndicated feed.)
