Recent Projects

At work in the Dead Sea
Image Courtesy of David Slater

DESERT 2000 is an ongoing multi-national and interdisciplinary project designed to study the crustal structure and geodynamics of the Dead Sea Rift system. The project is coordinated by the GeoForschungsZentrum (GFZ) Potsdam (Germany), in cooperation with Tel Aviv University (Israel), the Hebrew University (Israel), the Geophysical Institute of Israel, the Natural Resources Authority (Jordan), the An-Najah National University (Palestine), and several Universities in Germany.

Submarine study of the north end of the northern Dead Sea basin

 November, 1999, brought a unique study to the Dead Sea. Mr. Michael Sanders of Mysteries of the Bible raised the interest of Channel 4 (England) and NBC (USA) in a quest for the lost cities of Sodom and Gomorrah. Together they funded the project - brining a two man submersible to the Dead Sea.

A refraction/wide-angle reflection experiment

A seismic refraction/wide-angle reflection experiment was carried out in 1993 under the supervision of Prof. A. Ginzburg and Prof. Z. Ben-Avraham. During the experiment, which was done in collaboration with Prof. J. Makris of Hamburg University, several OBS were deployed in a north-south line in the northern basin of the Dead Sea and portable seismic land stations were placed north and south of the lake. The energy source were 20 kg explosive charges.
 A paper on the results of the refraction/wide-angle reflection experiment has been published by Ginzburg and Ben-Avraham. The main highlights of the experiments are the  probable detection of salt bodies in the north basin and the large difference in depth to basement between the north basin, where it is about 6 km, and the south basin, where it is about 12 km.

A microseismicity study

 After the seismic refraction/wide-angle reflection experiment was completed, in 1993, the OBS were replaced in a grid in the lake and the seismic land stations were placed west of the lake for two months to record microseismicity in this area. A number of small earthquakes were detected, but in terms of larger events, it turned out that our study hit a very quiet period. The study was done in collaboration with the Seismological Division.
 Preliminary analysis of the seismicity data has been completed as an M.Sc. thesis by Jorg Stacker of the University of Hamburg..

A coring campaign in the Sea

 A coring program, a joint Center and GFZ project, was carried out also in 1993 under the supervision of Prof. J. Negendank and Prof. Z. Ben-Avraham. A 3.5 Khz seismic site survey and extensive logistical effort preceded the coring program.
 As it was expected that hard salt layers would be encountered during the coring operations, a Selcore vibration corer was rented from Selantic Subsea Technology, Norway,  in addition to a Kuhlenberg piston corer. Since deck space was limited on the only vessel available on the lake (and was therefore insufficient) a platform was constructed from pontoons on which the equipment could be mounted and which was towed to the coring locations by the boat. The coring positions were selected at locations where the sediments were undisturbed. Ten cores, up to 4.5 meters long, were recovered in the southern part of the lake in water depth up to 315 meters, and four at the mouth of River Jordan. While the cores were not as long  as hoped for, they are the longest yet recovered in the Dead Sea.  This study yielded much information on the sedimentation regime in the Dead Sea and on paleoclimate variability in the region during the past 2000 years.
 A scientific technical report by Heim et al. describes the main results of the cores. C. Heim has completed his Ph.D. on the material from the cores. A paper on the results of the analysis was published by Heim et al., in Naturwissenschaften. The physical properties of the salt recovered in the cores and of salt samples from the southern basin of the Dead Sea were investigated at Stanford University by Tuntuncu et al. The results of this study have been used for the interpretation of 3.5 Khz seismic profiles collected in the Dead Sea. The comparison of the core stratigraphy and the seismic profiles has been investigated by Ben-Avraham et al. and was submitted to JGR.

Environmental history of the Dead Sea area during the past 15,000 years

 A coring campaign on the western margin of the northern Dead Sea basin was carried out during November-December 1997 by a team from GFZ Potsdam under the scientific leadership of Prof. J. Negendank and Dr. M. Stein of the Hebrew University. This work is part of a joint study of the history of the Dead Sea region in the Holocene (past 15 kyr) between scientists from the Hebrew University, the Geological Survey of Israel, the Dead Sea Research Center and GFZ Potsdam. It was partly funded by the German-Israel Foundation (GIF) and the Dead Sea Research Center.
 The sharp retreat of the Dead Sea in the past 20 years (~0.8 m/y) caused the formation of erosional gullies on the plains of retreat and exposed the post-Lisan sediments. The drillings were performed in the plains of retreat of the Dead Sea in several sites (Zeelim terrace; En Geddi Spa; Hever terrace and En Fescha Nature Reserve). The overall lengths of the drilled tubes is about 95 m of sediment.
 The drilled sediments consist of laminated aragonite and detritus, thick clastic layers of clay and sand. We expect to recover 13-15 kyrs of the Holocene section.

3.5 Khz seismic profiles

Over the years more than 2000 km profiles were collected in the Dead Sea by Prof. Z. Ben-Avraham and colleagues, the majority of them prior to the establishment of the Center. The seismic profiles present a remarkable detailed, almost three-dimensional, picture of the basin and its western margin. The resolution is about 20 cm and penetration in the deep water portion reaches about 30 m which were probably deposited during the last 8000 years. These data served as basis for a series of studies conducted by Prof. Z. Ben-Avraham and two Post-Doctorate fellows, Dr. T. Niemi from Stanford University and Dr. R. Lubberts from the Free University, Amsterdam. The results of these studies were published in several papers.

Multichannel seismic study of the north basin of the Dead Sea

 A multichannel seismic survey in the Dead Sea was carried out in 1996 under the supervision of Prof. Z. Ben-Avraham and Prof. J. Makris of Hamburg University. The instruments came from Hamburg University and Russia. Altogether 300 km of profiles were collected in the western part of the northern basin of the Dead Sea.  For the survey 6 technicians from Russia and 2 from Germany came to Israel.
 In order to carry out the survey, similarly to what was done in the coring campaign, a platform was constructed from patoons on which equipment  could be mounted and which was towed during the survey by the boat. Average speed during the seismic profiling was about 2 knots. Processing of the seismic data is being done at Tel Aviv University and Hamburg University.  Part of the new data served as a basis for the M.Sc. thesis of  Mr. Mark Gropius from Hamburg University. At Tel Aviv University the Center is equipped with a complete set of processing and interpretation software. The equipment comprises of two workstations - A Sun Microsystems Sparc workstation with an ITA seismic processing package and a Silicon Graphics Indy workstation equipped with the latest version of the Geodepth imaging software made available to the Center by Paradigm Geophysical. The processing at Tel Aviv University is done by Prof. A. Ginzburg and Dr. M. Reshef.

Reprocessing and reevaluation of exploration seismic data

 These workstations, as well as conventional interpretation techniques, are being used to reevaluate multichannel seismic reflection data acquired in the course of petroleum exploration in the south basin of the Dead Sea. The quality of the data made available to the Center by the Israel Oil Corp. is generally good, particularly those data obtained in the course of the more recent surveys. The interpretation of these data is being carried out (in two separate projects) by Ms. Birgitte Larsen, as part of her Ph.D.  research and Mr. Haim Shulman and will give a good and detailed insight into the seismic stratigraphy and sedimentation history of the basin fill. It is expected that the reprocessing and depth imaging of key lines carried out by Prof. A. Ginzburg will enhance the mapping of the salt structures within the fill as well as the structure of the pre-fill basement underlying the Dead Sea.

Evaluation of potential field and thermal data from the Dead Sea

 A project combining interpretation of gravity magnetic and thermal data from the Dead Sea and its surrounding area was carried out by Dr. L. Eppelbaum. In the course of the work, a combined 3-D interpretation of gravity and magnetic data was compared with the thermal data.  New models reflecting the deep structure and temperatures under the Dead Sea basin were constructed.

Geographic information system (GIS) for the Dead Sea

 A GIS model for the Dead Sea was constructed by Dr. Gideon Tibor. At present it incorporates part of the available geophysical and geological data from the area, including bathymetry and topography; satellite images; gravity field; magnetic field; location maps of multichannel and single channel surveys in the northern basin of the Dead Sea; location and description of cores from the Dead Sea.  Other available data such as location of drill holes on land and location of multichannel surveys in the southern basin will be incorporated into the model.
 Much data from the eastern side are slowly becoming available.  They will be added to the model which will be accessible to everybody working in this area.

Hyperspectral imaging

 As part of an ongoing research program with the GFZ, Potsdam, Germany, under the supervision of Dr. H. Kaufmann, a unique data set of hyperspectral images along the Dead Sea rift was collected in collaboration with the Center which also provided partial financial support. This set includes data from two recent campaigns over the Dead Sea basin (CASI - April 1997, DAIS - August 1997) and over the Sea of Galilee (CASI - 1997). The advantage of hyperspectral data lies in its high spatial and spectral resolution allowing for better quantitative analysis of the research area. The DIAS campaign offered a special chance to collaborate with the German Space Agency (DLR). The Sea of Galilee data were used as the basis for a M.Sc. research program of Mr. M. Lazar on the monitoring of the suspended matter in the water of the lake, while the Dead Sea data provide information for a Ph.D. research program of Mr. A. Zock on the distribution of evaporitic minerals in the Lisan area and for a M.Sc. research program of Mr. M. Schodlok of the Free University Berlin on the geology of Mount Sodom.

Aerosol transport and sedimentation over the Dead Sea Valley

 The study of the formation of a haze layer in the Dead Sea Valley, was started under the leadership of Prof. Zev Levin. It serves as the Ph.D. research program of Mr. H. Gershon. A haze layer which is formed almost daily in the Dead Sea Valley, reduces the amount of solar radiation reaching the surface and decreases the evaporation rate from the Dead Sea. The causes of this haze layer are investigated by the use  of: 1) a numerical model of airflow from the Mediterranean coast to the Dead Sea area. 2) a haze growth model incorporating the chemical composition of the particles and the moisture resulting from evaporation of the Dead Sea. 3) through the use of ground based instruments and airborne measurements conducted to measure the aerosol composition and size distribution as well as temperature and humidity. The results will be used in evaluating the effect of the haze on the incoming radiation and the potential cooling effect of these particles. Results obtained so far indicate that air and particles from the pollution sources along the Mediterranean coast are transported into the Dead Sea Valley by the sea breeze. In the Valley, internal circulation produces an inversion layer at a height of about 700m above sea surface (300 ASL). This inversion traps the particles during the day, causes them to absorb water vapor and to produce the observed haze layer. The particles are removed by winds in the late afternoon.

Summary of main research results

 The main results of the research activities in the Dead Sea Research Center are:

* The basement configuration under the Dead Sea Basin as mapped by seismic
   refraction is markedly different in the North basin and South basin; in the North
   basin, the basement is 6 km deep, while in the South basin it is 12 km deep.
* The Lynch Straits, in the divide area between the North and South basins, is at
   present the most seismically active.
* As indicated by the cores from the North basin, there were pronounced climatic
   fluctuations in the region during the past 2000 years, which are reflected in the
   depositional pattern in the lake. For example, 2000 years ago the area was more
   humid than today.
*  The sedimentary sequence of the top 4 m in the deep water part of the lake is
   composed of alternating layers of salt and marl which are related to the
   hydrological conditions. The salt sequences were precipitated during periods of
   higher aridity. The marl sequence is composed of a series of seasonally laminated
   evaporitic and detrital layers deposited during periods of higher humidity.
* Seismic velocities in the Dead Sea salt are depth dependent.
* The North basin is bounded by active faults and the intervening sediments are
   relatively undeformed.
* The western longitudinal fault at the North basin is divided into several segments
   with different orientations.
* The Jordan River delta has experienced several slumping episodes, the last one
   occurred as a result of the 1927 earthquake.
* GPS measurements suggest that during the period July 1996 - July 1997 there was
   no significant motion between the two sides of the Dead Sea transform.
* Air and particles from the pollution sources along the Mediterranean coast are
   transported into the Dead Sea Valley by the sea breeze.