The 5.2-magnitude earthquake Tuesday night shook many parts of Southern California, bringing attention to an important aspect of seismic events: their depth.
The temblor, which struck near Mettler in Kern County at 9:09 p.m. on Tuesday occurred at a depth of approximately 7 miles below the Earth’s surface.
According to the United States Geological Survey (USGS), this recent earthquake is classified as “shallow.”
The USGS categorizes earthquake depths into three zones: shallow (0-70 km), intermediate (70-300 km) and deep (300 – 700 km.)
The earthquake was felt widely across Southern California, with reports coming in from as far south as San Diego. And this wide range is related to its shallow depth, according to an expert.
“The depth definitely influenced how we feel it,” Robert de Groot from USGS ShakeAlert System said. “Shallow earthquakes, like the one we just had, tend to produce stronger shaking at the surface compared to deeper quakes of the same magnitude.”
He also noted that the soft soil in the Los Angeles area can cause the wave to “bounce around,” amplifying the shake.
“What we feel might be larger than expected,” de Groot said.
According to USGS, knowing the depth of an earthquake also helps visualize subduction zones, a boundary where one tectonic plate slides beneath another, providing valuable insights about Earth’s structure and tectonic settings.
In continental regions like Southern California, earthquakes typically occur in the shallow crust, usually around 10 miles.
“The earthquake (Tuesday) night was fairly common in terms of the depth,” de Groot added.
