ERS Studies of Landforms and Surface Deformation

Tom G. Farr, Diane L. Evans, Eric Fielding, Frank Webb
Jet Propulsion Laboratory
California Institute of Technology
Pasadena, CA
tom.farr@jpl.nasa.gov
phone: 818-354-9057
fax: 818-354-9476

Mark Simons
Department of Geological and Planetary Science
California Institute of Technology
Pasadena, CA

ERS Investigation:  AO2.USA112

We are pursuing a variety of studies of landforms and surface deformation
processes in several sites around the world. Landforms in western China are
being studied for their relationship to climate change and tectonic rates.
In particular, ERS interferometric data were used to create a DEM from
which the shapes of alluvial fans are being measured to show how
depositional sources and rates have changed with climate, and to show the
amount and direction of offset from an active fault that cuts the fans.

In Long Valley, California, a region of recent volcanic activity (surface
eruptions within the last 800 years), we are interested in assessing the
volcanic hazard by measuring the deformation of the resurgent dome in the
center of the caldera. This region also provides us with experimental
challenges since it has very rugged terrain, experiences strong seasonal
variations, and has a variety of vegetation types. Finally, the region is
well-instrumented with other geodetic devices thereby providing us with a
good calibration.

In Chile, we are investigating the deformation field associated with a
recent large subduction-zone earthquake. We are interested in the pre- co-
and post-seismic deformation and its relationship to the earthquake cycle
in the region. The area affected by the earthquake is very large.
Preliminary results show up to 0.5 meter of subsidence inland and several
cm of coastal uplift. This agrees very well with the existing (but very
sparse) geodetic data available for this earthquake.

We recently collected data from NASA's Airborne Visible Infrared Imaging
Spectrometer (AVIRIS), underflying 4 passes of ERS-1 and 2 over an area of
the Mojave Desert, California. The AVIRIS data will be used to map water
vapor over an area of about 10x20 km, which will be correlated with
interferometric phase delays in the ERS data.

Keywords: ERS, interferometry, DEM, deformation

* Work done under contract with NASA.

Keywords: ESA European Space Agency - Agence spatiale europeenne, observation de la terre, earth observation, satellite remote sensing, teledetection, geophysique, altimetrie, radar, chimique atmospherique, geophysics, altimetry, radar, atmospheric chemistry