Detection of the Tectonic Motion of the Roer Valley Rift System using
Radar Interferometry.

M. Caro Cuenca and R. F. Hanssen

The Roer Valley Rift System, RVRS is located in Southern Netherlands
crossing the borders with Germany and Belgium. Its current extension
phase started during the late Oligocene, probably as consequence of
the Alpine collision and the mid-Atlantic ridge push. The area has
been proving continuous tectonic activity during the last decades, as
shown by the earthquakes in Roermond , (The Netherlands) in 1992 and
in Aachen (Germany) in 2002, both with magnitude higher than 5. The
main block of this rift structure, the Roer Valley Graben, is limited
by the Feldbiss Fault Zone in the South-West and the Peel Boundary
Fault Zone in the North-East.

The proposed technique, Persistent Scatterer Interferometry, (PSI),
uses time series of radar images to estimate land deformation. The
subsidence rate of the graben is expected to be somewhere between 0.05
and 1 .5 mm/yr, which is close to the limit precision of PSI. Thus,
the detection of the tectonic deformation happening in RVSR poses a
great challenge to the current PSI algorithm, which therefore is
subjected to improvements and fine tuning. This contribution presents
the first the results of the processing of the southern part of the
RVRS using PSI.