Significant seismic activity has been recorded along the Pacific Ring of Fire over the last 24 hours, with earthquakes reported in the United States, Japan, and Indonesia.
A magnitude 4.9 earthquake struck the Brookdale region of California early Thursday, the United States Geological Survey reported.
The quake was centered in the Santa Cruz Mountains at a depth of 9 kilometers (about 5.6 miles), USGS said. Strong shaking was reported in Oakland, San Francisco, and as far away as Petaluma.
The temblor hit the Bay Area just before 1:45 a.m., with an initial magnitude reading of 5.1 that was quickly revised down to 4.9.
Earthquake alerts sounded on numerous cellphones across the area. No immediate reports of damage were available.
Across the Pacific, a strong earthquake also struck eastern Japan on Wednesday morning, the Japan Meteorological Agency said.
The magnitude 5 temblor hit north of Tokyo shortly after 10 a.m., with its epicenter in southern Ibaraki Prefecture.
Officials warned that the risk of rockfalls and landslides had increased in areas that felt strong shaking. They urged residents to stay alert for about one week for possible aftershocks of up to a lower 5 intensity, noting that large earthquakes often follow within two to three days.
Professor Sakai Shinichi of the University of Tokyo’s Earthquake Research Institute said the temblor occurred near where the Philippine Sea Plate sinks beneath a continental plate.
About 3,000 miles south of Japan, a magnitude 7.4 earthquake struck in the Molucca Sea off Indonesia’s Ternate island early Thursday, killing at least one person and triggering a brief tsunami warning that was later lifted.
The quake hit at 6:48 a.m. local time at a depth of 35 kilometers, according to authorities, toppling buildings in parts of northern Indonesia. A 70-year-old woman in North Sulawesi’s Manado city died after being crushed by falling debris, Indonesia’s national news agency Antara reported. Another resident broke a leg jumping from a building.
Strong shaking lasting 10 to 20 seconds was felt in Bitung and Manado in North Sulawesi province and in Ternate in North Maluku province. The Pacific Tsunami Warning Center initially said waves less than 0.3 meters were possible along coasts in several countries, including the Philippines, Malaysia, and Taiwan. The alert was canceled after two hours.
Nearly 50 aftershocks followed, including ones of magnitude 5.5 and 5.2.
