Investigation of Zagros Thrust-fold-belt deformation using SAR interferometry
Faramarz Nilforoushan(1) , Christopher Talbot(1)
, and Eric J. Fielding(2)
(2) Jet Propulsion Laboratory, M.S. 300-233, 4800 Oak Grove Drive, Pasadena, Cali, 91109, United States
Recent GPS studies of the Zagros Mountains (south central Iran),
estimate that about half of the deformation involved with Arabia-Eurasia
convergence is taken up in this young active thrust-fold-belt.
To study Zagros deformation in more detail, we use ERS
satellite images and the SRTM global DEM, to do 2-pass SAR
interferometry with the free software SAR Processor (DORIS).
We are hoping that this approach will allow us to map the
uplift rates in different parts of the Zagros.
Preliminarily interferograms for SE of the Zagros
near the Persian Gulf have been generated from two
pairs of descending ERS1 and 2 images taken in 1992
and 1999. Since the study area has a topographic relief of
about 3000 meters near the extremely warm water of the Persian Gulf,
the results seems to be contaminated by a high content of water vapor that
varies with elevation. The estimated LOS changes correlate with the topography
so strongly (~62%) that our interferograms show the DEM rather than the deformation.
Changes in the atmospheric water vapor content between the
acquisition times of our radar images (92/07/06 & 99/05/20) may have
generated some fringes that are mixed with any tectonic deformation signal.
We have ordered more images to process, and if we succeed in generating
interferograms, will attempt to separate such atmospheric noise from any tectonic signal.
We will investigate some empirical atmospheric corrections and
stacking multiple interferograms to try to enhance the signal.
The ERS data were supplied by European Space Agency
(ESA), under the Cat-1 Project number 3174.