What Are the Characteristics of Foreshocks for Large Earthquakes?

map of circum-Pacific foreshocks

28 June 2023–Seismologists agree that foreshocks are the most widely identified signal of an upcoming mainshock earthquake. But do these foreshock sequences have distinctive characteristics that separate them from aftershock sequences, and could these characteristics be used to help forecast mainshocks? In a new paper in Seismological Research Letters, Nadav … Continue Reading »

Hundreds of Very Shallow Earthquakes Detected in California’s Long Beach and Seal Beach

SRL Yan 2023 Figure 2 of Long Beach research areas

5 April 2023–Seismic arrays deployed in California’s Long Beach and Seal Beach areas detected more than a thousand tiny earthquakes over eight months, many of them located at surprisingly shallow depths of less than two kilometers below the surface. The findings, reported in Seismological Research Letters, confirm that the region’s … Continue Reading »

Dark Fiber Helps Pick Up Acoustic Signals of Iceland Meteoroid

meteoroid

17 November 2022–Data collected by a large-N seismic array and distributed acoustic sensing (DAS) in Iceland offer one of the most detailed acoustic fingerprints of a meteoroid entering and disintegrating in the atmosphere. The dense record, described in Seismological Research Letters, allowed the researchers to distinguish acoustic phases that are … Continue Reading »