Big earthquakes appear to follow a brief episode of “shallow mantle creep” and “seismic swarms,” suggests new research at Oregon State University that offers an explanation for the foreshocks observed prior to large temblors.
Published today in Nature Geoscience, the findings are an important step toward understanding the relationship and interactions between aseismic slip and seismic slip. Also known as silent slip or slow slip, aseismic slip is displacement along a fault that occurs without notable earthquake activity.
The research involved the Blanco Transform Fault off the coast of Oregon; a transform fault is a plate boundary at which the motion is mainly horizontal.
Under the sea, transform faults connect offset mid-ocean “spreading centers,” places at seafloor ridges where new oceanic crust is formed through volcanic activity and gradually moves away from the ridge.
Read more at Oregon State University
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