Shallow M5.7 earthquake hits off the coast of Oregon, U.S.

A shallow earthquake registered by the USGS as M5.7 hit off the coast of Oregon, U.S. at 03:23 UTC on March 27, 2024 (20:23 LT, March 26). The agency is reporting a depth of 10 km (6.2 miles).

The epicenter was located 178 km (111 miles) WSW of Port Orford, Oregon, and 262 km (163 miles) NW of Eureka, California.

233 000 people are estimated to have felt weak shaking.

There is no tsunami threat from this earthquake.

This event is identified as the potential mainshock of an earthquake sequence. Other earthquakes in this sequence are M3.9 at 03:14 UTC, M4.4 at 03:22 UTC, M4.8 at 03:25 UTC and M3.5 at 03:34 UTC.

“According to our forecast, there is a 5% chance of one or more aftershocks that are larger than magnitude 5, which can be damaging, within the next week,” the USGS said. “There will likely be smaller aftershocks within the next week, with up to 40 magnitude 3 or higher aftershocks. Magnitude 3 and higher aftershocks are large enough to be felt nearby. The number of aftershocks will decrease over time, but a large aftershock can temporarily increase the number of aftershocks.”

The forecast applies to the area where the earthquake and aftershocks are already occurring.

The USGS issued a Green alert for shaking-related fatalities and economic losses. There is a low likelihood of casualties and damage.

Overall, the population in this region resides in structures that are resistant to earthquake shaking, though vulnerable structures exist. The predominant vulnerable building types are unreinforced brick masonry and reinforced masonry construction.

Recent earthquakes in this area have caused secondary hazards such as landslides and liquefaction that might have contributed to losses.

Estimated population exposure to earthquake shaking

Selected cities exposed

Regional seismicity

Featured image credit: TW/SAM, Google