The U.S. Coast Guard cutter Myrtle Hazard departs Apra Harbor, Guam, ahead of potential tsunami waves caused by a large earthquake in eastern Russia, July 30, 2025. (Sebastian Sanchez/U.S. Coast Guard)
YOKOSUKA NAVAL BASE, Japan — U.S. military bases across the Pacific went on alert and braced for potential tsunamis Wednesday after a powerful earthquake struck eastern Russia, triggering widespread warnings and precautionary evacuations, though no significant impact was reported.
The magnitude 8.8 temblor hit just off the Kamchatka Peninsula at 8:24 a.m. local time, prompting tsunami alerts across coastal Japan. Guam, the Northern Mariana Islands, Hawaii, Alaska and the U.S. West Coast also issued warnings and evacuations orders.
Japan’s Meteorological Agency warned of possible wave heights between 3 and 10 feet by 10 a.m. along the country’s southern coastline. By midafternoon waves between 8 inches and 2 feet were observed.
At Yokosuka — home of the U.S. 7th Fleet about 25 miles southwest of Tokyo — people evacuated to higher ground or sheltered in multistory buildings.
While most Navy ships remained docked, at least six vessels at a nearby Japan Maritime Self-Defense Force base moved into Tokyo Bay to ride out any potential waves; they moved back toward their port around 1 p.m.
The U.S. Coast Guard declared Heavy Weather Condition Zulu for Guam and the Northern Marianas at 2 p.m. local time, according to a news release by U.S. Coast Guard Forces Micronesia/Sector Guam.
Zulu is the highest level of weather alert, restricting operations by commercial vessels under 200 tons, cargo transfers and all recreational maritime traffic, spokeswoman Chief Warrant Officer 2 Sara Muir said by email that afternoon.
“We anticipate resuming Port Heavy Weather Condition Whiskey (our standard posture) and reopening the ports later this evening once the National Weather Service confirms any waves have subsided and we know we don’t have any major impact or obstructions that could present a hazard,” she wrote.
Japan Maritime Self-Defense Force patrol boats anchor in Tokyo Bay ahead of a potential tsunami, July 30, 2025. (Alex Wilson/Stars and Stripes)
Coast Guard cutters and small boats were sent into open waters, while shore-based crews evacuated from low-lying areas, the release said.
Across the International Date Line in Hawaii, Joint Base Pearl Harbor-Hickam and other installations were placed on alert around 3:45 p.m. Tuesday, with personnel instructed to evacuate specific coastal areas or move to higher ground.
On the U.S. West Coast, military installations also followed guidance from the National Weather Service’s National Tsunami Warning Center.
Naval Base San Diego and Marine Corps Base Camp Pendleton advised personnel to steer clear of the coast, although no formal evacuation orders were in place by 1:30 a.m. Wednesday local time.
Naval Base Kitsap in Bremerton, Wash., was under a tsunami watch but had not ordered evacuations or issued any guidance as of 1:30 a.m. local time, said a duty officer who declined to identify herself by phone early that morning.
