scholarly journals Active faulting in the Gulf of Aqaba: New knowledge from the MW 7.3 earthquake of 22 November 1995

1999 ◽  
Vol 89 (4) ◽  
pp. 1025-1036 ◽  
Author(s):  
Yann Klinger ◽  
Luis Rivera ◽  
Henri Haessler ◽  
Jean-Christophe Maurin
Keyword(s):  
Body Wave ◽  
Background Level ◽  
Dead Sea ◽  
Strike Slip ◽  
Historical Seismicity ◽  
Global Network ◽  
Arabian Plate ◽  
Gulf Of Aqaba ◽  
African Plate ◽  
Slip Mechanism

Abstract On 22 November 1995 the largest earthquake instrumentally recorded in the area, with magnitude MW 7.3, occurred in the Gulf of Aqaba. The main rupture corresponding to the strike-slip mechanism is located within the gulf of Aqaba, which forms the marine extension of the Levantine fault, also known as the Dead Sea fault. The Levantine fault accommodates the strike-slip movement between the African plate and the Arabian plate. The Gulf of Aqaba itself is usually described as the succession of three deep pull-apart basins, elongated in the N-S direction. Concerning historical seismicity, only two large events have been reported for the last 2000 years, but they are still poorly constrained. The seismicity recorded since installation of regional networks in the early 1980s had been characterized by a low background level punctuated by brief swarmlike activity a few months in duration. Three swarms have already been documented in the Gulf of Aqaba in 1983, 1990, and 1993, with magnitudes reaching at most 6.1 (MW). We suggest that the geometry of the rupture for the 1995 event is related to the spatial distribution of these previous swarms. Body-wave modeling of broadband seismograms from the global network, along with the analysis of the aftershock distribution, allow us to propose a well-constrained model for the rupture process. Northward propagation of the rupture has been found. We have demonstrated that three successive subevents are necessary to obtain a good fit between observed and synthetic wave forms. The total seismic moment released was 7.42 × 1019 N-m. The location of the subsevents shows that the three stages of the rupture involve three different segments within the gulf. Substantial surface breakage showing only normal motion (up to 20 cm) affecting beachrock was observed along the Egyptian coast. We show that these ruptures are only a secondary feature and are in no case primary ruptures. The stress tensor derived from striations collected in quaternary sediments shows radial extension. This result supports landsliding of the beach terraces under the action of the earthquake shaking.

scholarly journals Seismic zonation of the Dead Sea Transform Fault area

2000 ◽  
Vol 43 (1) ◽  
Author(s):  
K. Khair ◽  
G. F. Karakaisis ◽  
E. E. Papadimitriou
Keyword(s):  
Dead Sea ◽  
Historical Seismicity ◽  
Arabian Plate ◽  
Mountain Range ◽  
Transform Fault ◽  
Jordan Valley ◽  
Seismic Zonation ◽  
African Plate ◽  
Dead Sea Transform ◽  
The Dead

The Dead Sea Transform Fault constitutes the northwestern boundary of the Arabian plate, accommodating the plate’s lateral movement relative to the African plate. A complete and homogeneous catalogue of historical earthquakes has been compiled and used in the subdivision of the fault area into the following segments: 1) Araba segment, which extends along Wadi Araba and the southernmost part of the Dead Sea (29.5°-31.3°N) and trends SSW-NNE with scarce historical and instrumental seismicity; 2) Jordan-valley segment, which extends along the central and northern parts of the Dead Sea and the Jordan valley to the Huleh depression (31.3°-33.1° N) and trends S-N with moderate historical seismicity; 3) Beqa’a segment, which extends along the western margin of the Beqa’a valley in Lebanon (33.1°-34.5°N) and trends SSW-NNE with strong historical seismicity; 4) El-Ghab segment, which extends along the eastern flank of the coastal mountain range of Syria (34.5°-35.8°N) and trends S-N with moderate historical seismicity; 5) Karasu segment, which extends along the Karasu valley in SE Turkey (35.8°-37.3°N) and trends SSW-NNE, exhibiting the strongest historical seismicity of the area. Probabilities for the generation of strong (M > 6.0) earthquakes in these segments during the next decade are given, by the application of the regional time and magnitude predictable model.

Bathymetry and uplift rate of the Gulf of Aqaba, Dead Sea Fault.

2021 ◽  
Author(s):  
Matthieu Ribot ◽  
Yann Klinger ◽  
Edwige Pons-Branchu ◽  
Marthe Lefevre ◽  
Sigurjón Jónsson
Keyword(s):  
High Resolution ◽  
Tectonic Evolution ◽  
Active Faults ◽  
Major Change ◽  
Dead Sea ◽  
Fault System ◽  
Arabian Plate ◽  
Gulf Of Aqaba ◽  
Uplift Rate ◽  
The Dead

<p>Initially described in the late 50’s, the Dead Sea Fault system connects at its southern end to the Red Sea extensive system, through a succession of left-stepping faults. In this region, the left-lateral differential displacement of the Arabian plate with respect to the Sinai micro-plate along the Dead Sea fault results in the formation of a depression corresponding to the Gulf Aqaba. We acquired new bathymetric data in the areas of the Gulf of Aqaba and Strait of Tiran during two marine campaigns (June 2018, September 2019) in order to investigate the location of the active faults, which structure and control the morphology of the area. The high-resolution datasets (10-m posting) allow us to present a new fault map of the gulf and to discuss the seismic potential of the main active faults.</p><p>We also investigated the eastern margin of the Gulf of Aqaba and Tiran island to assess the vertical uplift rate. To do so, we computed high-resolution topographic data and we processed new series of U-Th analyses on corals from the uplifted marine terraces.</p><p>Combining our results with previous studies, we determined the local and the regional uplift in the area of the Gulf of Aqaba and Strait of Tiran.</p><p>Eventually, we discussed the tectonic evolution of the gulf since the last major change of the tectonic regime and we propose a revised tectonic evolution model of the area.</p><p> </p>

Numerical simulation of structural growth in the Lebanese restraining bends, Dead Sea fault system

2021 ◽  
Author(s):  
Jakub Fedorik ◽  
Francesco E. Maesano ◽  
Abdulkader M. Alafifi
Keyword(s):  
Numerical Simulation ◽  
Lateral Displacement ◽  
Dead Sea ◽  
Geometrical Model ◽  
Experimental Models ◽  
Strike Slip ◽  
Boundary Element Methods ◽  
Fault System ◽  
Arabian Plate ◽  
Restraining Bend

<p>Strike-slip structures are rarely validated because commonly used 2D restoration techniques are not applicable. Here we present the results of 3D numerical simulation of the restraining bends in Lebanon using boundary element methods of fault deformation implemented in MOVE™. The Lebanon restraining bend is the largest transpressional feature along the Dead Sea Transform (DST), and consists of two mountain ranges: Mount Lebanon on the west, dominated by the active Yammouneh fault, and the Anti-Lebanon Range to the east, influenced by the Serghaya and other faults. We built a new 3D geometrical model of the fault surfaces based on previous mapping of faults onshore and offshore Lebanon, complemented by interpretation of satellite images and DEM, and analogy with experimental models of restraining bend or transpressional structures. The model was simulated in response to the regional stress produced by the left-lateral displacement of the Arabian plate. The simulation accurately predicted the shape and magnitude of positive and negative topographic changes and faults slip directions throughout Lebanon. Furthermore, this simulation supports the hypothesis that the formation of the Anti-Lebanon Range was influenced by the intersection of the DST with the older Palmyrides belt, resulting in failed restraining bend. In contrast, the structure of Mt. Lebanon is similar to laboratory experiments of a restraining bend without inheritance. In addition, our simulation presents an approach of how strike-slip structural models may be validated in areas where subsurface data are limited.</p>

Exploring the dynamics of the Dead-Sea Transform fault using data-integrated numerical models

2021 ◽  
Author(s):  
Thomas Ulrich ◽  
Alice-Agnes Gabriel ◽  
Yann Klinger ◽  
Jean-Paul Ampuero ◽  
Percy Galvez ◽  
...  
Keyword(s):  
Dead Sea ◽  
Strike Slip ◽  
Fault System ◽  
Gulf Of Aqaba ◽  
Back Projection ◽  
Earthquake Cycle ◽  
Transform Fault ◽  
Dynamic Rupture ◽  
Dead Sea Transform ◽  
The Dead

<p>The Dead-Sea Transform fault system, a 1200 km-long strike-slip fault forming the tectonic boundary between the African Plate and the Arabian Plate, poses a major seismic hazard to the eastern Mediterranean region. The Gulf of Aqaba, which terminates the Dead Sea fault system to the South, results from a succession of pull-apart basins along the Dead-Sea Transform fault system. The complexity of the fault system in the Gulf has been recently evidenced by Ribot et al. (2020), who compiled a detailed map of its fault traces, based on a new multibeam bathymetric survey of the Gulf. Part of the Gulf of Aqaba was ruptured by an Mw 7.3 earthquake in 1995. Teleseismic data analysis suggests that it may have been a multi-segment rupture (Klinger et al., 1999). This event occurred offshore, in a poorly instrumented region, and therefore the exact sequence of faults that ruptured is not precisely known. The detailed fault mapping of Ribot et al. (2020) offers a fresh view of this earthquake. In particular, it identifies many oblique faults between the major strike-slip faults, which may have linked these segments.</p><p>Relying on this new dataset, on a new back-projection study, and on 3D dynamic rupture modeling with SeisSol (https://github.com/SeisSol/SeisSol), we revisit the 1995 Aqaba earthquake. Using back projection, we identify 2 strong radiators, which we associate with 2 step-overs. Using 3D dynamic rupture modeling, we propose scenarios of the 1995 earthquake, compatible with the various dataset available. Our modeling allows constraining the regional state of stress in the region, acknowledging transtension, offers constraints on the nucleation location and confirms the role of the oblique faults in propagating the rupture to the North. It offers new constraints on the regional seismic hazard, in particular on the expected maximum moment magnitude.</p><p>Finally, we explore the dynamics of the Gulf of Aqaba fault system using earthquake cycle modeling. For that purpose, we rely on QDYN (https://github.com/ydluo/qdyn), a boundary element software, which simulates earthquake cycles under the quasi-dynamic approximation on faults governed by rate-and-state friction and embedded in elastic media. We inform our parameterization of the earthquake cycle modeling using the previously described datasets and modeling results. Recently Galvez et al. (2020) demonstrated the capability of the method to model the dynamics of complex fault system in 3D. Here new code developments are required to adapt the method to the Gulf of Aqaba fault system, e.g. to allow accounting for normal stress changes and for variations in the fault rake.</p><p>Overall, we aim to better understand how large earthquakes may nucleate, propagate, and interact across a complex transform fault network. Our findings, e.g. on fault segmentation or the conditions that promote larger earthquakes, will have important implications for other large strike-slip fault systems worldwide.</p>

scholarly journals Seismic discontinuities in the lithospheric mantle at the Dead Sea Transform

2020 ◽  
Vol 223 (3) ◽  
pp. 1948-1955
Author(s):  
Ayman Mohsen ◽  
Rainer Kind ◽  
Xiaohui Yuan
Keyword(s):  
Receiver Function ◽  
Open Data ◽  
Dead Sea ◽  
Arabian Plate ◽  
African Plate ◽  
Dead Sea Transform ◽  
Entire Area ◽  
Seismic Discontinuities ◽  
S Receiver Function ◽  
The Dead

SUMMARY The Dead Sea Transform (DST) was formed in the mid-Cenozoic, about 18 Myr ago, as a result of the breakaway of the Arabian plate from the African plate. Higher resolution information about the sub-Moho structure is still sparse in this region. Here, we study seismic discontinuities in the mantle lithosphere in the region of the DST using a modified version of the P- and S-receiver function methods. We use open data from permanent and temporary seismic stations. The results are displayed in a number of depth profiles through the study area. The Moho is observed on both sides of the transform at nearly 40 km depth by S-to-p and in P-to-s converted signals. The lithosphere–asthenosphere boundary (LAB) on the eastern side of the DST is observed near 180–200 km depth, which is according to our knowledge the first LAB observation at that depth in this region. This observation could lead to the conclusion that the thickness of the Arabian lithosphere east of the DST is likely cratonic. In addition, we observe in the entire area a negative velocity gradient at 60–80 km depth, which was previously interpreted as LAB.

New structural model of strike-slip tectonics of the Gulf of Aqaba, southern Dead Sea Transform

2020 ◽  
Author(s):  
Jakub Fedorik ◽  
Abdulkader Afifi
Keyword(s):  
Dead Sea ◽  
Strike Slip ◽  
Fault System ◽  
Gulf Of Aqaba ◽  
Normal Faults ◽  
Dead Sea Transform ◽  
Internal Fault ◽  
Riedel Shear ◽  
The One ◽  
Riedel Shears

<p>The Dead Sea Transform is an active left lateral, strike-slip plate boundary. The Gulf of Aqaba corresponds to its southern segment, where the largest amount of opening is observed. The gulf itself is deformed by a set of en echelon faults which are bounded by normal faults. These en echelon faults show structural styles of Riedel shears which are typically observed in strike-slip tectonics. However, their orientation is the opposite to the one observed in well described models or natural cases. In this study, we compare a compiled dataset to analogue models which simulate the displacement in various strike-slip systems. This comparison to a sandbox model highlights the importance of the tectonic load in a strike-slip fault system. The model is composed of two base plates with only one straight velocity discontinuity. X-Ray Computed Tomography is used as a technique to carry out a 4D analysis of internal fault structures of the model. The 10°-transtensional model generates a set of Riedel shear faults, which merge during the later stages of deformation. The 30°-transtensional tectonic load shows two major steep bounding faults with a dip-slip component and a set of en echelon faults - opposite Riedel shears in between them. A higher amount of transtension rotates the classic Riedel shear faults to the opposite position. This fault pattern is very similar to the one observed in the Gulf of Aqaba, where the internal fault system is composed of opposite Riedel shears bounded by normal faults. These observations can increase the understanding of the structural styles seen in the Gulf of Aqaba. Moreover, our study describes a new strike-slip fault system.</p>

scholarly journals Midyan Peninsula, northern Red Sea, Saudi Arabia: Seismic imaging and regional interpretation

GeoArabia ◽  
2014 ◽  
Vol 19 (3) ◽  
pp. 165-184
Author(s):  
Robert E. Tubbs ◽  
Hussein G. Aly Fouda ◽  
Abdulkader M. Afifi ◽  
Nickolas S. Raterman ◽  
Geraint W. Hughes ◽  
...  
Keyword(s):  
Saudi Arabia ◽  
Red Sea ◽  
Seismic Data ◽  
Field Studies ◽  
Dead Sea ◽  
Strike Slip ◽  
Fault System ◽  
Gulf Of Aqaba ◽  
Geologic History ◽  
Angular Unconformity

ABSTRACT The Midyan Peninsula of northwest Saudi Arabia offers an exceptional opportunity to observe a complex interplay of rifting, salt tectonics, and strike-slip faulting. Recently onshore 3-D, transition zone 2-D, and offshore 2-D seismic data have been acquired in the area. In addition, ongoing fieldwork and an active drilling program have provided new insights into the geologic history of the region. The initial stages of continental rifting began during the Early Oligocene (ca. 33 Ma) and often utilized pre-existing basement fault trends. The early syn-rift sedimentary record is typified by formation of deep half-grabens filled with thick wedges of primarily continental sediments, with lesser amounts of evaporitic and marine deposits. Seismic data show a distinct break in deposition occurred ca. 21 Ma characterized by a persistent angular unconformity near the basin-bounding fault, before a shift to marine and offshore deposits of the Lower Miocene Burqan Formation. Post-Burqan a second angular unconformity termed the mid-clysmic event is evident away from the basin edge. This surface exhibits significant relief created by re-activation of older EW-trending faults and lower Maqna Group sediments display substantial thickening across these faults. Overall, the Maqna section transitions from normal marine sedimentation to more restricted basin conditions before being succeeded by the thick-layered evaporite sequence of the Mansiyah Formation. Approximately 15–12 Ma active strike-slip faults appeared in the Red Sea and shifted the extension from rift normal to highly oblique directed at N15°–20°E, parallel to the Gulf of Aqaba. During this transition the composition of the rift-fill changed as well from basin-wide precipitates to thick siliciclastic wedges of the Ghawwas Formation. Seismic images of the Ghawwas show abrupt thickness changes and stratal geometries that date deposition as coincident with both the growth of Mansiyah Formation diapirs and the movement of a large detachment at the base of the Mansiyah. Roughly five million years ago, organized seafloor spreading began in the southern Red Sea and strike-slip motion intensified as deformation began to focus along the Dead Sea/Aqaba strike-slip fault system. Adjacent to Midyan, a pull-apart basin in the Gulf of Aqaba has opened over 26 km perpendicular to the strike-slip system resulting in significant footwall uplift. The positive interference of the Aqaba/Dead Sea and Red Sea footwall uplifts has uniquely exposed the full syn-rift stratigraphic section from basement to Upper Miocene at Midyan, making the area an ideal locality for field studies. Presence of the complete Miocene section on the Aqaba shoulder uplift clearly indicates the uplift occurred after the Miocene. Salt-filled pull-apart basins in the same orientation as the Gulf of Aqaba are also observed on 3-D seismic data in the Ifal Basin.

scholarly journals Lithostratigraphy and Depositional History of Part of the Midyan Region, Northwestern Saudi Arabia

GeoArabia ◽  
1999 ◽  
Vol 4 (4) ◽  
pp. 503-542 ◽  
Author(s):  
G. Wyn Hughes ◽  
David J. Grainger ◽  
Abdul-Jaleel Abu-Bshait ◽  
M. Jarad Abdul-Rahman
Keyword(s):  
Red Sea ◽  
Upper Cretaceous ◽  
Middle Miocene ◽  
Dead Sea ◽  
Arabian Plate ◽  
Gulf Of Aqaba ◽  
Eastern Coast ◽  
Lower Miocene ◽  
Sedimentary Succession ◽  
The Dead

ABSTRACT The Midyan region provides a unique opportunity in which to examine exposures of the Upper Cretaceous and Neogene sedimentary succession. Recent investigations have yielded new interpretations of its depositional environments, stratigraphic relationships, and structure. In this paper, all the lithostratigraphic units of the Midyan succession are considered to be informal in advance of an on-going process of formalization. The region is bounded to the north and northeast by mountains of Proterozoic rocks and to the west and south by the Gulf of Aqaba and the Red Sea, respectively. The Wadi Ifal plain occupies most of the eastern half of the region, beneath which is a thick sedimentary succession within the Ifal basin. The oldest sedimentary rocks are the fluviatile Upper Cretaceous Adaffa formation and marine siliciclastics and carbonates of the lower Miocene Tayran group, unconformable on the Proterozoic basement. The Tayran group is unconformably overlain by the deep-marine lower Miocene Burqan formation that, in turn, is overlain by marine mudstones, carbonates, and evaporites of the middle Miocene Maqna group. The poorly exposed middle Miocene Mansiyah and middle to upper Miocene Ghawwas formations consist of marine evaporites and shallow to marginal marine sediments, respectively. The youngest rocks are alluvial sands and gravels of the Pliocene Lisan formation. A complex structural history is due to Red Sea Oligocene-Miocene extension tectonics, and Pliocene-Recent anti-clockwise rotation of the Arabian Plate relative to Africa on the Dead Sea Transform Fault. The Upper Cretaceous succession is a probable pre-rift unit. The Oligocene?-Miocene syn-rift 1 phase of continental extension caused slow subsidence (Tayran group). Syn-rift 2 was an early Miocene phase of rapid subsidence (Burqan formation) whereas syn-rift 3 (early to middle Miocene) was another phase of slow deposition (Maqna group). The middle to late Miocene syn-rift 4 phase coincided with the deposition of the Mansiyah and Ghawwas formations. The Lower Pliocene to Recent succession is related to the drift (post-rift) phase during which about 45 kilometers of sinistral movement occurred on the Dead Sea Fault. The structural control on sedimentation is evident: the Ifal basin was formed by east-west lithospheric extension; pull-apart basins occur along major left-lateral faults on the eastern coast of the Gulf of Aqaba; and basin-bounding faults controlled deposition of the Burqan, Ghawwas, and Lisan formations. Pliocene to Recent earth movements may be responsible for activating salt diapirism in the Ifal basin. Extensive Quaternary faulting and regional uplift caused the uplift of coral reefs to at least 6 to 8 meters above sea level.

A review of the tectonics of the northern Middle East region

1984 ◽  
Vol 121 (6) ◽  
pp. 577-587 ◽  
Author(s):  
P. E. R. Lovelock
Keyword(s):  
Late Cretaceous ◽  
Kinematic Model ◽  
Continental Collision ◽  
Dead Sea ◽  
Plate Motion ◽  
Arabian Plate ◽  
Southern Boundary ◽  
The North ◽  
The Dead ◽  
Two Stages

AbstractThe structure of the northern part of the Arabian platform is reviewed in the light of hitherto unpublished exploration data and the presently accepted kinematic model of plate motion in the region. The Palmyra and Sinjar zones share a common history of development involving two stages of rifting, one in the Triassic–Jurassic and the other during late Cretaceous to early Tertiary times. Deformation of the Palmyra zone during the Mio-Pliocene is attributed to north–south compression on the eastern block of the Dead Sea transcurrent system which occurred after continental collision in the north in southeast Turkey. The asymmetry of the Palmyra zone is believed to result from northward underthrusting along the southern boundary facilitated by the presence of shallow Triassic evaporites. An important NW-SE cross-plate shear zone has been identified, which can be traced for 600 km and which controls the course of the River Euphrates over long distances in Syria and Iraq. Transcurrent motion along this zone resulted in the formation of narrow grabens during the late Cretaceous which were compressed during the Mio-Pliocene. To a large extent, present day structures in the region result from compressional reactivation of old lineaments within the Arabian plate by the transcurrent motion of the Dead Sea fault zone and subsequent continental collision.

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