S U M M A R YTo address one of the central questions of plate tectonics-How do large transform systems work and what are their typical features?-seismic investigations across the Dead Sea Transform (DST), the boundary between the African and Arabian plates in the Middle East, were conducted for the first time. A major component of these investigations was a combined reflection/refraction survey across the territories of Palestine, Israel and Jordan. The main results of this study are: (1) The seismic basement is offset by 3-5 km under the DST, (2) The DST cuts through the entire crust, broadening in the lower crust, (3) Strong lower crustal reflectors are imaged only on one side of the DST, (4) The seismic velocity sections show a steady increase in the depth of the crust-mantle transition (Moho) from ∼26 km at the Mediterranean to ∼39 km under the Jordan highlands, with only a small but visible, asymmetric topography of the Moho under the DST. These observations can be linked to the left-lateral movement of 105 km of the two plates in the last 17 Myr, accompanied by strong deformation within a narrow zone cutting through the entire crust. Comparing the DST and the San Andreas Fault (SAF) system, a strong asymmetry in subhorizontal lower crustal reflectors and a deep reaching deformation zone both occur around the DST and the SAF. The fact that such lower crustal reflectors and deep deformation zones are observed in such different transform systems suggests that these structures are possibly fundamental features of large transform plate boundaries.

Jordan is located in an arid to semi arid region where around 90% of its land receives an average annual precipitation of less than 100 mm while only 3% of the land receives an average annual precipitation of 300 mm or more. Jordan is characterised as a “water scarce” country because the current <i>per capita</i> share of water is estimated to be of the order of 140 m³ per year which is well below the 1000 m3 threshold. Rainwater harvesting is the accumulating and storing, of rainwater. It has been used to provide drinking water, water for livestock, water for irrigation or to refill aquifers as a groundwater recharge. GIS has been widely used in selecting the best sites for water harvesting schemes. This research aims at selecting optimum sites for water harvesting schemes in the Jordan arid lands (Badia) using indigenous knowledge and geo-informatics. To achieve this aim, a community-based research and desktop investigating is applied. The community-based research focused on consulting with 200 stakeholders form local communities where they provided knowledge on opportunities and constrains form their experience on water management in the arid lands where they live and interact. Also they provided information on potential location for water collecting sites that has been used for ages to provide water to humans and livestock. On the other hand, desktop research is conducted on sitting criteria for water harvesting based on physical and socio-economic characteristics. The physical criteria include rainfall volumes, slope, distance to water courses (wadis), distance form geologic faults and soil texture, where socio-economic criteria include distance to groundwater wells, distance to urban area, distance to agriculture activities and distance to international brooders. This selecting criterion in combination with indigenous knowledge is used within GIS environment to identify optimum sites for water harvesting. GIS analysis resulted in identifying 118 potential sites. Of those, 30 sites had already recommended by the community consultations

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The Northern Jordan Valley (NJV) is an important and significant water basin in Jordan where most of Jordan's agricultural crops are produced. Knowing that the aquifer system is mainly composed of alluvial deposits, it is important to assess the potential of ground water for pollution. For this purpose intrinsic vulnerability was assessed using SINTACS model with the aid of geographic information system (GIS) techniques. The final results show that about 40% of the investigated area has been classified as high to very high vulnerable to groundwater pollution. These results were correlated with measured concentration of nitrate (NO −1 3 ) at different locations. A high correlation was found between areas of high nitrate concentrations and those of high vulnerability category. To validate the model results, a sensitivity analysis has been carried out to assess the influence of each of SINTACS parameters on the obtained vulnerability values. It was found that the soil overburden attenuation capacity parameter (T) and the depth to the groundwater parameter (S) are the most sensitive parameters to SINTACS vulnerability model. The effective-weights analysis was also performed in this study to revise the weights in the computed vulnerability index. It was noticed that the effective weights for each parameter were sometimes varies from the theoretical weights assigned by the SINTACS method.