Shmuel Marco

Tel Aviv University | TAU · Department of Geophysics

The frequency-magnitude distribution follows the Gutenberg-Richter empirical law, in which the scaling between small and large earthquakes is represented by the b-value. Laboratory experiments have shown that the b-value is related to fault mechanics with an inverse dependency to the differential stress, as was also inferred from observational data...

Despite the recognition that bed-parallel slip (BPS) must operate during gravity-driven deformation of basinal sediments, there is a general paucity of detailed outcrop-based observations to characterise and detect such a process. We therefore present detailed timing relationships between BPS and steeper dip-slip faults that were both created durin...

In lakes and oceans, links between modern sediment density flow processes and deposits preserved in long-term geological records are poorly understood. Consequently, it is unclear whether, and if so how, long-term climate changes affect the magnitude/frequency of sediment density flows. One approach to answering this question is to analyze a compre...

The Dead Sea seismites comprise the world longest record of earthquakes. The seismites appear as deformed layers enclosed between undeformed layers of alternating millimetre‐thick laminae with annual pairs of winter detritus and summer evaporitic aragonite. Understanding the physical conditions that govern their formation will promote the recovery...

自20世纪70年代以来，位于构造活跃区的盆地沉积序列的岩性、粒度与沉积速率的正向突变，常被用来指示区域新构造活动。然而，这种常规方法已经受到国内外学者强有力的质疑——用来推断构造活动的沉积学证据也可由气候因素引起。因而，需寻找某种独立于气候因素的沉积学证据，来可靠的指示新构造活动。震积岩，由地震震动引起的、保存于湖相或海相地层序列中的事件沉积，能可靠的指示区域新构造活动。新兴的交叉研究方向——湖泊/海洋古地震学，通过研究保存于水下沉积序列中的震积岩，可延长强震记录，加深对断裂带活动性的认识。 文章以死海盆地（中东地区）和柴达木盆地（青藏高原东北缘）为例，从水下事件沉积响应的视角，借助超长尺度的震积岩序列，理解千年-构造尺度上的区域新构造活动特性。基于死海湖心457 m 长的ICDP 501...

Although sedimentary dykes have been widely reported across a range of settings, sedimentary sills have received somewhat less attention, perhaps due to the potential difficulties in identifying largely conformable intrusions within bedded sequences. Most outcrop descriptions of clastic intrusions are based on deep-water marine sequences, with few...

Soft-sediment deformation structures associated with slumps and mass transport deposits (MTDs) are generally considered to form at the surface when unlithified sediment moves downslope under the influence of gravity. Where stratigraphic sequences contain several deformed horizons, the question arises as to whether repeated slope failure at the sedi...

The Dead Sea pull-apart basin (DSB), which is located within the Dead Sea Transform fault system, displays tectonic asymmetry between its eastern and western longitudinal zones. We investigate the seismological and mechanical signature of this asymmetry by the analyzing the hypocenter distribution and focal-mechanisms of 114 Mw = 1.5–5.2 earthquake...

Archaeological structures built across active faults and ruptured by earthquakes have been used as markers to measure the amount of displacement caused by ground motion and thus to estimate the magnitude of ancient earthquakes. The example used in this study is the Crusader fortress at Tel Ateret (Vadum Iacob) in the Jordan Gorge, north of the Sea...

We seek to define new empirical relations between the spectral signature of rock surfaces and their geomechanical characteristics. By this means, proxy tools can be developed to classify the quality of rock masses in situations where access is restricted or impossible. In rock mechanics research, remote sensing technologies are mainly used for mapp...

Plain Language Summary Some researchers propose that lowering sea‐level leads to mass failures, while, others suggest that raising sea‐level induces mass failures. In contrast, other researchers conclude that no clear correlation exists between mass failures and sea‐level change as the ages of failure events are random. This dispute is due largely...

Although most models of thrusting assume that the hangingwall is actively displaced up the thrust ramp while the footwall remains passive, it has been suggested that this could be an oversimplification and the footwall may also deform. Despite this, there are relatively few detailed investigations of thrusts where the footwall is deformed, perhaps...

The literary corpus found in Ugarit/Ras Shamra includes some 1500 administrative and religious texts found so far. One of the most famous texts is the myth of Aqhat, who was murdered by an assassin, and whose death was avenged by his family. Many literary and grammatical aspects of this text have been widely discussed during the last decades. They...

Plain Language Summary The generally NW‐SE‐trending thrusts developed north of the Kunlun Range are the most prominent morphological feature in the western Qaidam Basin, NE Tibet. These folds have played a key role in the Miocene‐Quaternary uplift of the region. However, little is known about the long‐term rupture behavior of this active thrust zon...

Plain Language Summary Seismogenic turbidites are widely used for geohazard assessment. The use of turbidites as an earthquake indicator requires a clear demonstration that an earthquake, rather than non‐seismic factors, is the most plausible trigger. The seismic origin is normally verified either by correlating the turbidites to historic earthquak...

Large earthquakes (magnitude ≥ 7.0) are rare, especially along slow-slipping plate boundaries. Lack of large earthquakes in the instrumental record enlarges uncertainty of the recurrence time; the recurrence of large earthquakes is generally determined by extrapolation according to a magnitude-frequency relation. We enhance the seismological catalo...

Fold duplexes transfer displacement from a lower to an upper bounding detachment system via trains of folds with broadly parallel geometries. While they have been previously recognised in orogenic systems where they are considered to be kinematically equivalent to imbricating thrust ramps, we here describe the first example from a gravity-driven fo...

The cities of Elat, Israel and neighboring Aqaba, Jordan are major economic, cultural, and seaport centers. They are located on the northern shore of the Gulf of Aqaba/Elat (GAE) directly on the Dead Sea Transform. Yet the precise location of the fault trace and its tectonic activity are lacking. The interpretation of seismic reflection profiles ac...

Characterizing the inelastic strain field around co-seismic faults is a key to understanding earthquake rupture processes. We aim to detect zones of inelastic deformation around surface ruptures, using Anisotropy of Magnetic Susceptibility (AMS) analyses. To characterize the paleo-seismic setting we measured 29 normal faults, which cut the late Ple...

Gravity-driven mass transport deposits (MTDs) form by the downslope-directed movement of sediment associated with slope failure. Simple models suggest that extension forms at the upslope (head) area, contraction is focussed in the downslope toe of the slump, while differential shear associated with strike-slip is restricted to the lateral margins o...

We present a methodology for mapping faults that constitute a potential hazard to structures, with an emphasis on ground shake hazards and on surface rupture nearby critical facilities such as dams and nuclear power plants. The methodology categorises faults by hierarchic seismo-tectonic criteria, which are designed according to the degree of certa...

Bed-parallel slip (BPS), where neighbouring beds slide past one another along bedding planes, is notoriously difficult to identify without reference to pre-existing features such as steep faults or dykes that act as markers to record BPS offset. While BPS is intuitively thought to operate during downslope sliding of mass transport deposits (MTDs) i...

We present a methodology for mapping faults that constitute a potential hazard to structures, with an emphasis on special facilities such as dams and nuclear power plants. The methodology categorises faults by hierarchical seismo-tectonic criteria, which are designed according to the degree of certainty for recent activity and the accessibility of...

In order to reconstruct the strain field along the southern segment of the Dead Sea Fault (DSF) plate boundary, we analyzed the magnetic fabrics of carbonate rocks, outcropping along it. The magnetic fabrics provide a microstructural indicator that help to approximate the principal strain directions in the rocks. Our analysis includes ~900 cores fr...

The large and well-studied archaeological record of Israel offers a unique opportunity for collecting high resolution archaeomagnetic data from the past several millennia. Here, we initiate the first catalog of archaeomagnetic directions from Israel, with data covering the past four millennia. The catalog consists of 76 directions, of which 47 fulf...

The detailed analysis of folding in rocks was in part pioneered by John Ramsay and resulted in a range of techniques and criteria to define folds. Although folding of unlithified or 'soft-sediments' is typically assumed to produce similar geometries to those in 'hard rocks', there has to date been little detailed analysis of such folds. The aim of...

Characterizing seismites is a key factor in understanding earthquake kinematics, dynamics and resulting hazards. In order to understand the kinematics and dynamics of seismites, we analyzed the anisotropy of magnetic susceptibility (AMS) of various seismite types of known origin, which have formed during paleoseismic activity along the Dead Sea fau...

The Late Pleistocene Lisan Formation outcropping around the Dead Sea preserves exceptional 3-D exposures of fold and fault systems generated during soft-sediment slumping associated with Mass Transport Deposits (MTDs). Vergence of slump folds outcropping to the West of the Dead Sea is systematically (>90%) towards the East and consistent with depoc...

We present a new procedure for separating magnetic fabrics in coccolith-bearing chalk samples, demonstrated in the case studies of three sites located within the Dead-Sea-Fault (DSF) plate boundary. The separation is achieved by combining measurements of room-temperature and low-temperature anisotropy of magnetic susceptibility (RT-AMS and LT-AMS,...

Seismically disturbed sedimentary sequences (seismites) in the last glacial (70-14 ka) Lisan Formation are exposed in the marginal terraces of the Dead Sea and recovered from sedimentary core drilled by the International Continental Scientific Drilling Programs at the depocenter of the lake at water depth of 300 m. The core reveals various types of...

Historical events are sometimes expressed in destruction layers. We present here a study in which aspects of construction, destruction, and chronostratigraphy of fired mud bricks were explored using archaeomagnetism, infrared spectroscopy, and micromorphology. We measured 88 oriented samples mostly collected from one stratum, dated ca. 1000 B.C.E.,...

Sitting on top of a hill overlooking the Sea of Galilee, the ancient city of Hippos-Sussita has been repeatedly struck by strong earthquakes. These tremblors caused typical damage to the masonry, such as directional collapsing of walls and toppling of columns, which have been exposed in archaeological excavations. The source of the earthquakes is t...

The trends of faults and fractures in overburden next to a salt diapir are generally considered to be either parallel to the salt margin to form concentric patterns, or at right angles to the salt contact to create an overall radial distribution around the diapir. However, these simple diapir-related patterns may become more complex if regional tec...

n unconsolidated granular media, the state of stress has a major effect on the elastic properties and wave velocities. Effective media modeling of granular packs shows that a vertically oriented uniaxial state of stress induces vertical transverse isotropy (VTI), characterized by five independent elastic parameters. The Rayleigh wave velocity is se...

We have studied the history of earthquakes over the past 70 kyr by analyzing disturbed sedimentary layers around the margins of the Dead Sea. However, we know little about disturbances in the basin depocenter, where water depth is ~300 m, and accessible only by drilling. In this study, we compare disturbances from the Dead Sea depocenter, with the...

The correct identification of 'sedimentary' folds and fabrics created during gravity-driven deformation of unlithified successions from those 'tectonic' structures formed during regional deformation is essential when interpreting geological histories preserved within the rock record. This topic has become increasingly relevant over the past 40 year...

The internal deformation and movement directions of Mass Transport Deposits (MTDs) are key factors in understanding the kinematics and dynamics of their emplacement. Although these are relatively easy to recover from well-bedded sediments, they are more difficult to deduce from massive beds without visible strain markers. In order to test the appli...

In certain regions and under favorable geologic conditions, precariously balanced rocks may form. These types of unusual formations have been used to estimate yield ground motions. Because such balanced rocks have not been 'unbalanced', they can be used as a rough estimate for ground motions which have not been reached or exceeded since the balance...

While much research has recently been focussed on downslope-verging systems of gravity-driven fold and thrust belts within mass transport deposits (MTDs), rather less attention has been paid to back thrusts, which are defined as displaying the opposite vergence to the main transport direction in thrust systems. A fundamental question arises over wh...

Extensive exposures of spectacular slump sheets in lake deposits within the Dead Sea Basin are interpreted as seismites related to the activity of the plate-bounding Dead Sea Fault. The late-Pleistocene Lisan Formation and subsequent Dead Sea deposits comprise alternating aragonite laminae precipitated from the hypersaline lake and detrital laminae...

The Dead Sea drainage basin offers a rare combination of well-documented substantial climate change, intense tectonics and abundant archaeological evidence for past human activity in the Southern Levant. It serves as a natural laboratory for understanding how sedimentation rates in a deep basin are related to climate change, tectonics, and anthropo...

Fold and thrust systems in Mass Transport Deposits. G.I. Alsop1, S. Marco2, T. Levi3, R. Weinberger3, 4 1) Department of Geology and Petroleum Geology, School of Geosciences, University of Aberdeen, Aberdeen, UK. (e-mail: Ian.Alsop@abdn.ac.uk) 2) Department of Geosciences, Tel Aviv University, Israel. 3) Geological survey of Israel, Jerusalem, Isr...

Extensive exposures of spectacular slump sheets in lake deposits within the Dead Sea Basin (Fig. 1) are interpreted as seismites related to the activity of the plate-bounding Dead Sea Fault [1]. The late- Pleistocene Lisan Formation comprises aragonite laminae precipitated from the hypersaline lake, while detrital laminae are formed from material w...

This study examines the limitations of the method of low-temperature anisotropy of magnetic susceptibility (LT-AMS) measurements in air and presents technical improvements that significantly reduce the instrumental drift and measurement errors. We analyzed the temperature profile of porous chalk core after cooling in liquid nitrogen and found that...

Deformed arches are often key elements of archaeoseismic studies; arches have been in use for more than three millennia and damage, particularly moved keystones, are clear indications of a seismogenic cause. We introduce a damage evaluation scheme that allows a straightforward determination of the degree of damage to an arch based on laser scan mod...

Although it has long been recognised that passive salt diapirism may encompass sub-ordinate cycles of active diapirism, where sedimentary overburden is periodically shed off the roof of the rising salt, there has been very little study of this process around exposed salt (halite) diapirs. However, the Late Miocene-Pliocene Sedom salt wall, on the w...

To exploit the potential of anisotropy of magnetic susceptibility (AMS) as a tool to estimate the strain field around major faults, we measured the AMS of calcite-bearing diamagnetic rocks that crop out next to the Dead Sea Fault (DSF) in northern Israel. Through integrated magnetic and geochemical methods we found that the rocks are almost pure ca...

Abstract

Located at the Northern tip of the Gulf of Aqaba-Elat, the on-land continuation of the submarine Avrona Fault underlies the Hotels District of Elat, where seismic deformation was documented after the 1995 Nuweiba (Sinai) earthquake (7.2 Mw). This active segment of the Dead Sea Fault is the transition between the deep marine basin of the Gulf and th...

The abundant silt and sand along the coastal plain of Israel have long been considered susceptible to liquefaction, but previous searches have failed to find field evidence for it. We report the first finding of typical liquefaction features and silty sand injections in trenches that were excavated behind a fourth century Byzantine dam on the Tanin...

About 1100 micro-earthquakes that occurred along the Dead Sea basin during the past 25 years express ongoing seismic activity along mostly obscured fault segments. We apply seismological and statistical methods, in order to associate seismic activity with geological and geophysical data, and to locate and characterize active fault segments in the b...

Early Holocene seismic activity triggered fluidization and clastic-dike emplacement within Late Pleistocene lacustrine Lisan Formation sediments in the Dead Sea basin (DSB). Hundreds of opening-mode clastic dikes were documented cross-cutting the Lisan Formation in four distinct sites in relatively small ( 6.5). The injection of clastic dikes in di...

We present new results from a paleoseismic trenching campaign at a site across the Jordan Gorge Fault (JGF), the primary strand of the Dead Sea Transform in northern Israel. In addition to the previously recognized earthquakes of 1202 and 1759 C. E., we observe evidence for eight surface-rupturing earthquakes prior to the second millennium C. E. Th...

The aim of this short note is to provide a summary over on-fault palaeoseismic works on the behavior of the Dead Sea fault (DSF). Key achievements of these studies include: the determination of slip rate of the DSF across different space and time resolutions, which converges at around 4–5 mm/a, confirmation of the sinistral relative motion between...

SUMMARY The anisotropy of magnetic susceptibility (AMS) of soft rocks was measured in order to distinguish between the effect of remote and local strain fields, determine the size of the related inelastic damage zone and resolve the fault-plane solutions of past earthquakes. The AMS fabrics were explored next to late Pleistocene syndepositional nor...

A sedimentary sequence that was highly sensitive to fault rupture-driven changes in water level and sediment supply has been used to extract a continuous record of 22 large earthquakes on the Alpine fault, the fastest-slipping fault in New Zealand. At Hokuri Creek, in South Westland, an 18 m thickness of Holocene sediments accumulated against the A...

Deep lake mass transport deposits in Dead Sea