NASA Images Show Continuing Mexico Quake Deformation

[Judi Lynn]

NASA Images Show Continuing Mexico Quake Deformation
Posted on: Friday, 6 August 2010, 19:40 CDT

New NASA airborne radar images of Southern California near the U.S.-Mexico border show Earth's surface is continuing to deform following the April 4 magnitude, 7.2 temblor and its many aftershocks that have rocked Mexico's state of Baja California and parts of the American Southwest.



The data, from NASA's airborne Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR), reveal that some faults in the area west of Calexico, Calif., have continued to move at Earth's surface, most likely in the many aftershocks. This fault motion is likely to be what is known as 'triggered slip,' caused by changes in stress in Earth's crust from the main quake rupture. The new maps, called interferograms, were created by combining data from flights on April 13, 2010, and July 1, 2010, and can be found at: http://photojournal.jpl.nasa.gov/catalog/PIA13314 . Previous radar maps of the region released on June 23, 2010, are at: http://www.nasa.gov/topics/earth/features/UAVSARimage20100623.html . 



The first image shows a UAVSAR interferogram swath measuring 87 by 20 kilometers (54 by 12.5 miles) overlaid atop a Google Earth image. Each colored contour, or fringe, of the interferogram represents 11.9 centimeters (4.7 inches) of surface displacement. The different shades in the image represent ground surface motions of up to a few inches upward or downward. Yellow shaded regions moved to the south or downward, regions in blue moved to the north or upward, and regions shaded in magenta showed no motion. Major fault lines are marked in red, and recent aftershocks are denoted by yellow, orange and red dots, with older earthquakes shown as gray dots.



An enlargement of the interferogram is shown in the second image. This image focuses on the area where most of the aftershocks have been located, west of Calexico. The enlargement, which covers an area measuring about 28 by 18 kilometers (18 by 11.5 miles), reveals many small 'cuts,' or discontinuities, in the interferogram color. These are caused by ground motions on small faults that have occurred since April 13, ranging from less than a centimeter to a few centimeters (half an inch to a few inches) . The thin, colored lines represent faults previously mapped by the U.S. and California Geological Surveys through the end of 2009.

More:
http://www.redorbit.com/news/science/1901895/nasa_images_show_continuing_mexico_quake_deformation/index.html

[aquart]

1. Ooooh.

[Better Believe It]

2. That's what I thought! Those interferogram swaths seemed a bit big and discolored.

:)

[Bobbieo]

3. I read everynight in bed before I go to sleep and I notice

the big hanging plant in the corner seems to swing ewery now and then. HMMM!!!

[Better Believe It]

4. That's because the Earth is tilting on its axle!