NASA Maps Surface Changes From California Quakes

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Damage from two strong earthquakes that rattled Southern California on July 4 and July 5 — a magnitude 6.4 and a magnitude 7.1, respectively — can be seen from space.

Damage from two strong earthquakes that rattled Southern California on July 4 and July 5 — a magnitude 6.4 and a magnitude 7.1, respectively — can be seen from space. The epicenter of the quakes was near the city of Ridgecrest, about 150 miles (241 kilometers) northeast of Los Angeles. According to the U.S. Geological Survey, the 7.1 quake was one of the largest to hit the region in some 40 years.

The Advanced Rapid Imaging and Analysis (ARIA) team at NASA's Jet Propulsion Laboratory in Pasadena, California, used synthetic aperture radar (SAR) data from the ALOS-2 satellite to produce a map showing surface displacement from the earthquakes. The post-quake imagery was acquired on July 8, 2019, and compared with April 8, 2018, data from the same region.

Each color cycle represents 4.8 inches (12 centimeters) of ground displacement either toward or away from the satellite. The linear features that cut the color fringes in the southeast indicate likely locations of surface rupture caused by the earthquakes, and the "noisy" areas in the northwest may indicate locations where the ground surface was disturbed by them.

The USGS reported over 1,000 aftershocks in the region following the July 5 earthquake. State and federal scientists, including those from the California Geological Survey and USGS, are using this surface deformation map in the field for assessing the damages and mapping the faults that broke during the two major earthquakes as well as the thousands of aftershocks.

Read more at: NASA

NASA's Advanced Rapid Imaging and Analysis (ARIA) team created this co-seismic Interferometric Synthetic Aperture Radar (InSAR) map, which shows surface displacement caused by the recent major earthquakes in Southern California, including the magnitude 6.4 and the magnitude 7.1 events on July 4 and July 5, 2019, respectively. (Photo Credit: NASA/JPL-Caltech)