Nadav Wetzler

Geological Survey of Israel

Foreshocks are the only currently widely identified precursory seismic behavior, yet their utility and even identifiability are problematic, in part because of extreme variation in behavior. Here, we establish some global trends that help identify the expected frequency of foreshocks as well the type of earthquake most prone to foreshocks. We estab...

The earthquake sequence, with a maximum earthquake magnitude of MW 3.8, that occurred during January–February 2022 at the northern Dead Sea fault, is shown to be induced by extensive groundwater abstraction in Wadi Al‐Arab basin. Wadi Al‐Arab basin, which is bordered in the west by the Dead Sea fault, has been overexploited by extensive groundwater...

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...

Faulting of rocks is a dominant earth process that governs small-scale fracturing, formation of tectonic plate boundaries, and earthquakes occurrence. Since the 18th century, the mechanics of rock faulting was commonly analyzed with the Coulomb criterion that offers empirical, useful tools for scientific and engineering applications. Here we revisi...

Measures of foreshock occurrence are systematically examined using earthquake catalogs for eight regions (Italy, southern California, northern California, Costa Rica, Onshore Japan, Alaska, Turkey, and Greece) after imposing a magnitude ≥3.0 completeness level. Foreshocks are identified using three approaches: a magnitude-dependent space + fixed-ti...

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...

Bends and stepovers in strike-slip fault systems along active plate boundaries are widespread and introduce stress heterogeneities, affecting the regional strain field. The strain field associated with these complex fault structures has been extensively studied. Asymmetric uplift of the Lebanon Mountains, located at the fringe of an active plate bo...

Faulting of rocks is a dominant earth process that governs small-scale fracturing, formation of tectonic plate boundaries, and earthquakes occurrence1–4. Since the 18th century, the mechanical settings for rock faulting were commonly analyzed with the Coulomb criterion5 that offers empirical, useful tools for scientific and engineering applications...

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...

The seismic activity in Israel and its surrounding neighbors originates mainly from the active Dead Sea fault system. The historical and archeological records suggest a recurrence interval of approximately 102 and 103 yr for earthquakes of M 6 and 7, respectively. Despite the existing hazard, local advancements on this topic have been slow and incr...

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...

This report presents (in Hebrew) the Tsunami Alert Decision Assistant Module (TADAM) – A tool developed at the Israeli Tsunami Warning Center (ITWS) to automatically aggregate Tsunami warning relevant data and to determine, based on a pre-designed decision matrix, the recommended Tsunami alert level. The report shortly describes the Tsunami hazard...

Here we compile numerous regional seismic profiles, gravity profiles/campaigns obtained from both oil and gas industry explorations and researches conducted in the region to construct a new geological based 3-D velocity model for the Levant region. We then use the 3-D version of Nonlinloc to locate earthquakes at the periphery of Israel.

In 2013 and 2018, earthquake swarms with a maximum moment magnitude of 4.5 occurred ~5 km from the northern section of the Dead Sea Transform Fault. Here we show that aquifer pressure data, interferometric synthetic aperture radar surface deformation time series, and seismic monitoring suggest that groundwater withdrawal triggered these earthquakes...

The Israeli Seismic Network is operational in its digital form since the 1980’s, collecting data from ~25 seismometers and ~50 triggered accelerometers, at the Seismological Division’s acquisition center in Lod. Since October 2017, the network is undergoing significant upgrades and modifications, with new stations added or upgraded, using new senso...

Fault slip during plate boundary earthquakes releases a portion of the shear stress accumulated due to frictional resistance to relative plate motions. Investigation of 101 large [moment magnitude (Mw) ≥ 7] subduction zone plate boundary mainshocks with consistently determined coseismic slip distributions establishes that 15 to 55% of all master ev...

Large earthquakes on subduction zone plate boundary megathrusts result from intervals of strain accumulation and release. The mechanism diversity and spatial distribution of moderate size aftershocks is influenced by the mainshock rupture depth extent. Mainshocks that rupture across the shallow megathrust to near the trench have greater intraplate...

The total number of aftershocks increases with mainshock magnitude, resulting in an overall well-defined relationship. Observed variations from this trend prompt questions regarding influences of regional environment and individual mainshock rupture characteristics. We investigate how aftershock productivity varies regionally and with mainshock sou...

• © 2016 by the Seismological Society of America In this article, we note that the database of the relocated catalog can be downloaded from a webpage on the Geological Survey of Israel (GSI) website. On 1 January 2016, GSI transferred to a new website and many of the web links were broken. This database is now available within the webpage of Ittai...

More than 15,000 seismic events were recorded by the Israel Seismic Network (ISN) during the past 30 years, at the vicinity of the Dead Sea fault (DSF) zone. During those years, locations were obtained using several velocity models, which resulted in inconsistent locations. In addition, we found that seismicity is biased to very shallow depth estim...

The evolution of an asymmetric basin at the edge of a pull-apart structure is studied using geophysical observations and mechanical modeling. A new seismic analysis of the northern edge of the Dead Sea basin indicates recent subsidence, folding and oblique faulting along the Jericho strike-slip fault, a main segment of the Dead Sea Transform fault....

In this work, we study the structure and tectonics of the Galilee area, including the northern section of the Dead Sea Transform (DST), and its association with recorded earthquake activity. A 3-D lithosphere model is constructed including the geometry and mechanical properties of the main geological layers of the study area using geological observ...

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...

The DSB is a seismic active zone characterized by dozens of small earthquakes per year and by M>6 earthquakes every several hundreds years. The basin is about 150 km long and 15-20 km wide; the sedimentary fill exceeds 10 km. The 1985-2009 seismic catalogue of the DSB includes ~1000 earthquakes with initial locations determined by the Geophysical I...

Spectacular deformations observed in lake sediments in an earthquake prone region (Lisan Formation, pre-Dead Sea lake) appear in phases of laminar, moderate folds, billow-like asymmetric folds, coherent vortices, and turbulent chaotic structures. These deformations are tied to earthquake events which are speculated to be intensified by seiche (mini...

By quantifying the geometry of soft sediment deformation in the Lisan Formation, we conclude that these structures, which were once under water, are now evidence for the Dead Sea region earthquakes, and a good case study for turbulent behavior. The various intensities and scales of soft sediment folding reflect various stages of deformation. Our a...

By quantifying the geometry of soft sediment deformation in the Lisan Formation, we conclude that these structures, which were once under water, are now evidence for the Dead Sea region earthquakes, and a good case study for turbulent behavior. The various intensities and scales of soft sediment folding reflect various stages of deformation. Our a...