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Revisiting Past Earthquakes and Seismo-Volcanic Crises Using Declassified Optical Satellite Imagery

Hollingsworth, James and Leprince, Sébastien and Ayoub, François and Avouac, Jean-Philippe (2009) Revisiting Past Earthquakes and Seismo-Volcanic Crises Using Declassified Optical Satellite Imagery. In: 2009 American Geophysical Union Fall Meeting, 14-18 December 2009, San Francisco, CA.

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Recent development of the user-friendly software package “Co-registration of Optically Sensed Images and Correlation” (COSI-Corr), which allows for automatic and precise ortho-rectification, co-registration, and sub-pixel correlation of pushbroom satellite and aerial images, has enabled Earth’s surface dynamics to be accurately monitored using optical imagery [1]. This technique compares two images of the Earth’s surface that were acquired at different times, and estimates any potential pixel shifts between them with an accuracy typically better than 1/10 of the pixel size. Correlation of both satellite and aerial images has been successfully used to identify coseismic ground ruptures and quantify fault offsets during large earthquakes [2]–[4], as well as monitoring sand dune migration, landsliding, ice flow [5] [6], and volcanic activity [7] [8]. In this study, we demonstrate that recently declassified US spy satellite images can be used to measure ground deformation resulting from seismotectonic and volcanic events using optical sub-pixel correlation. KH-9 Hexagon satellite images, with a swath size of 250×125 km, were acquired by the US government between 1971 and 1980, and are available for purchase from the United States Geological Survey (USGS) at small cost ($30 per image). During this period, around 29,000 images were acquired globally [9], providing a comprehensive record of the Earth’s surface at 6–9m resolution.

Item Type:Conference or Workshop Item (Paper)
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URLURL TypeDescription
Hollingsworth, James0000-0003-0122-296X
Leprince, Sébastien0000-0003-4555-8975
Ayoub, François0000-0002-7389-8400
Avouac, Jean-Philippe0000-0002-3060-8442
Group:Seismological Laboratory
Record Number:CaltechAUTHORS:20200810-153624897
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:104901
Deposited By: Tony Diaz
Deposited On:10 Aug 2020 22:51
Last Modified:10 Aug 2020 22:51

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