Cave detection and 4-D monitoring: A microgravity case history near the Dead Sea, 2001, Rybakov M. , Goldshmidt V. , Fleischer L. , Rotstein Y. ,

Collapse and subsidence associated with salt karstification along the Dead Sea, 2001, Frumkin Amos, Raz Eli

Historic Dead Sea level fluctuations calibrated with geological and archaeological evidence, 2002, Frumkin, A. , And Elitzur, Y.

The Dead Sea, the Holocene terminal lake of the Jordan River catchment, has fluctuated during its history in response to climatic change. Biblical records, calibrated by radiocarbon-dated geological and archaeological evidence, reinforce and amplify the chronology of the lake-level fluctuations. There are three historically documented phases of the Dead Sea in the Biblical record: low lake levels c. 2000-1500 B.C.E. (Before Common Era); high lake levels c. 1500-1200 century B.C.E.; and low lake levels between c. 1000 and 700 B.C.E. The Biblical evidence indicate that during the dry periods the southern basin of the Dead Sea dried up, a fact that was not clear from the geological data.

Dating large infrequent earthquakes by damaged cave deposits, 2005, Kagan Elisa J. , Agnon Amotz, Barmatthews Miryam, Ayalon Avner,

The long-term recurrence patterns of past earthquakes are of considerable consequence for hazard assessments, and have implications for earthquake physics. We introduce a rigorously dated record of earthquakes from an extensive number of well-preserved preseismic and postseismic precipitates from caves located off the Dead Sea transform. We dated events directly at the paleoseismic contact by means of a novel correlation method with the oxygen isotope record of the speleothems recovered in one of the caves. Within the 185 k.y. covered, we dated 38 seismite samples. These stem from 13-18 earthquakes with a mean recurrence interval of [~]10-14 k.y. We show that the deformational events dated in the study caves complement independent near-fault paleoseismic records by temporal correlation with the earthquakes recorded therein. This opens up a significant new avenue of earthquake research that will provide precise dating and observational constraints on large infrequent earthquakes

Al-Daher Cave (Bergish), Jordan, the first extensive Jordanian limestone cave: a convective Carlsbad-type cave?, 2006, Kempe S. , Almalabeh A. , Alshreideh A. , Henschel Hv.

In spite of the vast limestone area present in Jordan, no karstic caves to speak of were known there until 1995 when Al-Daher Cave was discovered. The cave is situated east of Bergish Reserve for Ecotourism in the mountains of Bergish at about 830 m above sea level. The cave formed in the Wadi As Sir Limestone Formation of Upper Cretaceous age. It is a maze developed along NW-SE and NE-SW striking joints which owe their existence to the Dead Sea Transform Fault situated a few kilometers to the west of the cave. Rooms, with a total area of 1750 m2, were formed within a square of 70 × 70 m. The cave is constrained to certain limestone strata, laminated and non-laminated, divided by four chert layers that form distinctive markers throughout the cave. Chert nodules occur also within the limestone layers. The cave formed phreatically exclusively by dissolution within a small body of rising and convecting water. It is suggested that the very localized solution capacity derived from the oxidation of either H2S, or possibly even CH4, by oxygen present near the former water table. Thus, Al-Daher Cave may have formed by a process similar to that which formed the Guadalupe Mountain caves, New Mexico, among them Carlsbad Cavern. The altitude of the cave suggests that it may be as old as upper Miocene. The cave contains several relict generations of speleothems but also active forms. The local government is hoping to develop the cave into a show cave; it would be the first in Jordan.

Sinkhole 'swarms' along the Dead Sea coast: Reflection of disturbance of lake and adjacent groundwater systems, 2006, Yechieli Yoseph, Abelson Meir, Bein Amos, Crouvi Onn, Shtivelman Vladimir,

More than a thousand sinkholes have developed along the western coast of the Dead Sea since the early 1980s, more than 75% of them since 1997, all occurring within a narrow strip 60 km long and <1 km wide. This highly dynamic sinkhole development has accelerated in recent years to a rate of [~]150-200 sinkholes per year. The sinkholes cluster mostly over specific sites up to 1000 m long and 200 m wide, which spread parallel to the general direction of the fault system associated with the Dead Sea Transform. Research employing borehole and geophysical tools reveals that the sinkhole formation results from the dissolution of an [~]10,000-yr-old salt layer buried at a depth of 20-70 m below the surface. The salt dissolution by groundwater is evidenced by direct observations in test boreholes; these observations include large cavities within the salt layer and groundwater within the confined subaquifer beneath the salt layer that is undersaturated with respect to halite. Moreover, the groundwater brine within the salt layer exhibits geochemical evidence for actual salt dissolution (Na/Cl = 0.5-0.6 compared to Na/Cl = 0.25 in the Dead Sea brine). The groundwater heads below the salt layer have the potential for upward cross-layer flow, and the water is actually invading the salt layer, apparently along cracks and active faults. The abrupt appearance of the sinkholes, and their accelerated expansion thereafter, reflects a change in the groundwater regime around the shrinking lake and the extreme solubility of halite in water. The eastward retreat of the shoreline and the declining sea level cause an eastward migration of the fresh-saline water interface. As a result the salt layer, which originally was saturated with Dead Sea water over its entire spread, is gradually being invaded by fresh groundwater at its western boundary, which mixes and displaces the original Dead Sea brine. Accordingly, the location of the western boundary of the salt layer, which dates back to the shrinkage of the former Lake Lisan and its transition to the current Dead Sea, constrains the sinkhole distribution to a narrow strip along the Dead Sea coast. The entire phenomenon can be described as a hydrological chain reaction; it starts by intensive extraction of fresh water upstream of the Dead Sea, continues with the eastward retreat of the lake shoreline, which in turn modifies the groundwater regime, finally triggering the formation of sinkholes

Late Quaternary environmental and human events at En Gedi, reflected by the geology and archaeology of the Moringa Cave (Dead Sea area, Israel), 2007, Lisker, S. , Porat, R. , Davidovich, U. , Eshel, H. , Steinerik Lauritzen, S. E. , Frumkin

The Moringa Cave within Pleistocene sediments in the En Gedi area of the Dead Sea Fault Escarpment contains a sequence of various Pleistocene lacustrine deposits associated with higher-than-today lake levels at the Dead Sea basin. In addition it contains Chalcolithic remains and 5th century BC burials attributed to the Persian period, cemented and covered by Late Holocene travertine flowstone. These deposits represent a chain of Late Pleistocene and Holocene interconnected environmental and human events, echoing broader scale regional and global climate events. A major shift between depositional environments is associated with the rapid fall of Lake Lisan level during the latest Pleistocene. This exposed the sediments, providing for cave formation processes sometime between the latest Pleistocene (ca. 15 ka) and the Middle Holocene (ca. 4500 BC), eventually leading to human use of the cave. The Chalcolithic use of the cave can be related to a relatively moist desert environment, probably related to a shift in the location of the northern boundary of the Saharo-Arabian desert belt. The travertine layer was U?Th dated 2.46± 0.10 to 2.10±0.04 ka, in agreement with the archaeological finds from the Persian period. Together with the inner consistency of the dating results, this strongly supports the reliability of the radiometric ages. The 2.46?2.10 ka travertine deposition within the presently dry cave suggests a higher recharge of the Judean Desert aquifer, correlative to a rising Dead Sea towards the end of the 1st millennium BC. This suggests a relatively moist local and regional climate facilitating human habitation of the desert.

The Holocene climatic record of the salt caves of Mount Sedom, Israel: The Holocene, 2007, Frumkin, A. , Magaritz, M. , Carmi, I. And Zak, I.

Mount Sedom is a salt diapir, on the southwestern shore of the Dead Sea, which has been rising above the local base level throughout the Holocene. Karst development within the salt body has kept pace with the rising, forming sub-horizontal cave passages with vertical shafts. Wood fragments found embedded in flood sediments that were deposited in the cave passages yielded 14C ages ranging from ca. 7100 to 200 YBP. A paleoclimatic sequence was constructed, based on parameters that include: relative abundance of plant types or floral communities, the elevations of the corresponding cave passages and the ratio of their width to present passage width. The results were correlated to the Holocene sedimentary sequence of the Dead Sea Basin, and other features associated with shifting lake levels. Moister climatic stages are indicated by relatively abundant wood remains, by wide cave passages and by elevated outlets, indicating high Dead Sea level. Arid periods are marked by a scarcity of wood remains, by narrow cave passages and by low-level outlets. The Holocene sequence of Mount Sedom is subdivided into ten climatic stages: A moist stage in the early Holocene, older than 7000 YBP, and nine subsequent stages of drier climate, fluctuating between conditions that are somewhat drier, up to somewhat moister than those of today. The Dead Sea Level dropped from ca. -300 MSL during the early moist period to -400 MSL or lower during the subsequent arid periods.

The role of hydrogeological base level in the formation of sub-horizontal caves horizons, example from the Dead Sea Basin, Israel, 2010, Kafri Uri, Yechieli Yoseph

The Dead Sea sinkhole hazard: Geophysical assessment of salt dissolution and collapse, 2011, Frumkin Amos, Ezersky Michael, Alzoubi Abdallah, Akkawi Emad, Abueladas Abdelrahman

A geophysical approach is presented for analyzing processes of subsurface salt dissolution and associated sinkhole hazard along the Dead Sea. The implemented methods include Seismic Refraction (SRFR), Transient Electromagnetic Method (TEM), Electric Resistivity Tomography (ERT), and Ground Penetration Radar (GPR). The combination of these methods allows the delineation of the salt layer boundaries, estimating its porosity distribution, finding cavities within the salt layer, and identifying deformations in the overlying sediments. This approach is shown to be useful for anticipating the occurrence of specific sinkholes, as demonstrated on both shores of the Dead Sea. These sinkholes are observed mainly along the edge of a salt layer deposited during the latest Pleistocene, when Lake Lisan receded to later become the Dead Sea. This salt layer is dissolved by aggressive water flowing from adjacent and underlying aquifers which drain to the Dead Sea. Sinkhole formation is accelerating today due to the rapid fall of the Dead Sea levels during the last 30 years, caused by anthropogenic use of its water.

Fault — Dissolution front relations and the Dead Sea sinkhole problem, 2013, Ezersky Michael, Frumkin Amos

There are two conflicting models of sinkhole development along the Dead Sea (DS). The first one considers structural control on sinkholes, constraining them to tectonic lineaments. This hypothesis is based on seismic reflection studies suggesting that sinkholes are the surface manifestations of active neotectonic faults that may serve as conduits for under-saturated groundwater, enabling its access across aquiclude layers. Another hypothesis, based on results of multidisciplinary geophysical studies, considers the salt edge dissolution front as themajor site of sinkhole formation. This hypothesis associates sinkholes with karstification of the salt edge by deep and shallow undersaturated groundwater. Our recent seismic reflection and surface wave studies suggest that salt formed along the active neotectonic faults. Sinkholes form in a narrow strip (60–100 m wide) along a paleo-shoreline constrained by faults and alluvial fans which determined the edge of the salt layer. This scenario reconciles the two major competing frameworks for sinkhole formation.