My_Photo Ran Novitsky Nof
Seismological Division
The Geological Survey of Israel

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Rising of the lowest place on Earth:

The Dead Sea water-level has been dropping at an exceedingly increasing rate since 1960, and between 1993 and 2001, the interval of the InSAR data examined in this study, it has dropped at an average rate of 0.88 m per year. Such a water-level change could potentially give rise to a resolvable lithospheric rebound and regional uplift, with spatial extent and amplitude that are controlled by the effective mechanical properties of the crust and upper mantle combined. We measure that deformation for the years 1993 to 2001, using 149 short baseline interferograms made of 31 ERS-1 and ERS-2 Synthetic Aperture Radar (SAR) images and continuous GPS data from the Survey of Israel recorded between 1997 and 2011. The uplift rate at the Dead Sea is small (up to 4 mm/year), and the basin topography is almost a mirror of the displacement, introducing a strong trade-off between uplift and stratified atmosphere noise. To overcome this complication, we impose a linearity constraint on the satellite to ground Line Of Sight (LOS) phase changes based on the steady uplift observed by a continuous GPS station in the area of interest, and simultaneously solve for the LOS change rate, Digital Elevation Model (DEM) errors and the elevation-phase correlation. While the LOS rate and DEM errors are solved for each pixel independently, the elevation-phase correlation is solved for each SAR acquisition independently. Using this approach we separated the stratified atmospheric delay from the ground displacement. We observed a regional uplift around the Dead Sea northern basin, with maximum uplift close to the shorelines, and diminishing to zero by the Mediterranean coast. We modeled the effect of water load changes using a homogeneous elastic half-space, and found a good agreement between modeled and observed ground displacements using elastic properties that are compatible with seismic and gravity data down to a depth of 15 km below the Dead Sea basin, suggesting that the response of the crust to the sea level drop is controlled mainly by the elastic properties of the upper-crust immediately below the Dead Sea basin.

Velocity map and profile Abstract from: Nof, R. N., A. Ziv, M.-P. Doin, G. Baer, Y. Fialko, S. Wdowinski, Y. Eyal, and Y. Bock (2012), Rising of the lowest place on Earth due to Dead Sea water-level drop: Evidence from SAR interferometry and GPS, J. Geophys. Res., 117, B05412, doi:10.1029/2011JB008961 (PDF).
Velocity map
and profile

From the Press:
El País Dec. 9, 2013 / Un trasvase de agua del mar Rojo para resucitar al mar Muerto by David Alandete

Science News Jul. 14, 2012 / Lowest point getting higher by Alexandra Witze (pdf). May 30, 2012 / Dead Sea rising.

kennislink Jun. 1, 2012 / blogpost by Adiel Klompmaker (in Dutch). May 30, 2012 / Dead Sea rising.

Science Now May 29, 2012 / ScienceShot by Sid Perkins.

GeoSpace - AGU Blogosphere May 25, 2012 / A blog post by Eric Villard.

Reshet Bet May 6, 2012 / Radio interview in "Shalosh" with Anat Dolev (in Hebrew):

NRG Maarive Apr. 9, 2012 / by Alex Doron (in Hebrew)