Radar images show that an April earthquake near the Mexico-California border caused the Earth's surface to move 31 inches downward and to the south.
The magnitude-7.2 earthquake that struck near Calexico on Easter Sunday shifted the Earth's crust in the area about 31 inches downward and to the south, according to radar images and data collected by researchers at NASA's Jet Propulsion Laboratory.
Figure 1. Overview of the UAVSAR interferogram of the magnitude 7.2 Baja California earthquake of April 4, 2010, overlaid atop a Google Earth image of the region. Major fault systems are shown by red lines, while recent aftershocks are denoted by yellow, orange and red dots.
Figure 2. Full-resolution portion of the portion of the UAVSAR interferogram where the largest deformation (up to 80 centimeters, or 31 inches) was measured.
Figure 3. Detail of the UAVSAR interferogram in the area of the June 14 magnitude 5.7 aftershock, showing major faults and recent aftershocks.
Airborne radar images of the area taken by the JPL-developed Uninhabited Aerial Vehicle Synthetic Aperture Radar were posted online by NASA for the first time today.
Researchers used data collected by the airborne radar to detect changes in the distance between the aircraft and the ground over repeated GPS-guided flights. According to JPL, they combined data from flights on Oct. 21 and April 13 to determine the deformities in the Earth's crust.
The UAVSAR has been mapping the San Andreas and other faults from north of San Francisco to the Mexican border every six months since spring 2009, looking for ground motion and increased strain along faults, according to NASA.
"The goal of the ongoing study is to understand the relative hazard of the San Andreas and other faults to its west like the Elsinore and San Jacinto faults, and capture ground displacements from larger quakes,'' said JPL geophysicist Andrea Donnellan.
The magnitude-7.2 earthquake that struck near Calexico on Easter Sunday shifted the Earth's crust in the area about 31 inches downward and to the south, according to radar images and data collected by researchers at NASA's Jet Propulsion Laboratory.
