Earthquake Deformations Research Articles

Dating drainage reversal using mineral provenance along the Yangsan Fault, South Korea.

Tectonics is broadly accepted as one of the main factors controlling long-term landscape evolution. The impact of tectonics on short timescales is most often observed through earthquake rupturings that produce localized, metric-scale deformations. Although these deformations significantly affect the landscape, it remains challenging to precisely correlate major landscape changes with these localized earthquake deformations. Therefore, linking instantaneous deformation to long-term morphological changes often involves a thought experiment with potentially limited temporal resolution. At a paleoseismological site along the slow-moving strike-slip Yangsan Fault in South Korea, we employed optically stimulated luminescence (OSL) dating and detrital zircon analysis on all exposed unconsolidated layers in trench walls. The results reveal a significant provenance shift in the sediments accumulating in the trench, indicating a major reorganization of the drainage network. Based on our OSL and detrital zircon data, we estimate that this change occurred around 70ka. We propose that this drastic drainage reorganization was caused by a combination of very slow, yet continuous, earthquake activity and a temporary reduction in river erosion during the onset of the cold, dry spell characteristic of the MIS4 stage across the Korean Peninsula.

Earthquakes on the Once-Punctured Torus

We study earthquake deformations on Teichmüller space associated with simple closed curves of the once-punctured torus. We describe two methods to get an explicit form of the earthquake deformation for any simple closed curve. The first method is rooted in linear recurrence relations, the second in hyperbolic geometry. The two methods align, providing both an algebraic and geometric interpretation of the earthquake deformations. We convert the expressions to other coordinate systems for Teichmüller space to examine earthquake deformations further. Two families of curves are used as examples. Examining the limiting behavior of each gives insight into earthquakes about measured geodesic laminations, of which simple closed curves are a special case.

Complex analysis of earthquake deformations using SAR images: Examples from Croatia and Greece

This study presents an assessment of the displacements of the Earth’s crust generated by two earthquakes: one in Croatia on 29th December 2020 and one in Greece on 3rd March 2021. The main data source is SAR satellite images from Sentinel-1A and B (ascending and descending orbits) in the form of images of the amplitude and phase signals. The data is processed via SNAP software package. The results are obtained applying the differential radar interferometry method (DInSAR). The Line of Sight (LoS) displacements are converted into vertical displacements and compared with modeled deformations of the Earth’s surface using rectangle finite source model proposed by Okada.

New data on seismic events established by archaeoseismological studies

In the present work, only some of the results obtained from a comparative analysis of the known seismological data and the data from the new archaeoseismological studies are described. Earthquake deformations have been found on structures from the earliest (Eneolithic) era, to effects on better-preserved medieval archaeological sites.

3D Modelling of Archaeoseismic Damage in the Roman Site of Baelo Claudia (Gibraltar Arc, South Spain)

This study deals with the morphometric characterization and quantification of earthquake damage in the ancient Roman city of Baelo Claudia in South Spain (Gibraltar Arc) by means of the use of 3D modelling from drone imagery. Baelo Claudia is a world-renowned archaeological site recording recurrent earthquake destruction during the first and third centuries AD. The first earthquake destroyed the lower littoral zone of the city, allowing its reconstruction from the year c. 60–70 CE, but the second earthquake in 365–390 CE led to the complete destruction of the renewed city and its eventual abandonment. This second earthquake imprinted important deformations in the main monumental zone of the city, including the basilica temples, macellum, city walls, aqueducts and funerary monuments, as well as in the main paved zones of the city. This is the case for the Forum, Decumanus and Cardos, which show a variety of folds, pop-up structures, conjugate fractures and impact marks susceptible to be measured in a 3D format. The current study presents detailed (up to 3 mm/pixel) surface models of iconic monuments within the city. The 3D models were obtained by means of serial orthophotos taken with a UAV Mavic Pro 2 (DJI) Drone device equipped with a 20 mpx camera and a 1” CMOS sensor. Each individual image was captured in a geo-referenced jpg format and processed with the Agisoft Metashape Professional software®. Depending on the measured monument, the final images consisted of 250 to 700 photographs clustered by 50,000 to 150,000 tie points. In all studied items (Decumanus, city walls and bath dish), we follow the same workflow of analysis: (1) alignment of photos with support points; (2) building a dense cloud of points; (3) creation of the surface texture; (4) creation of the Digital Elevation Model (DEM); (5) creation of the orthomosaic; and finally, (6) the building of the high-quality 3D tiled surface models. The obtained models allow the geometric quantification of earthquake deformations (displacements, amplitudes, orientation, etc.) in a GIS-based 3D environment suitable to quantify oriented damage of seismic origin. In a complementary way, these 3D models deserve to be considered for their potential role as digital seismoscopes of ancient archaeological sites and/or heritage buildings.

Surface deformation and landslides caused by the 6th nuclear test of North Korea on September 3, 2017 detected by satellite SAR and InSAR techniques

The 6th nuclear test of North Korea on September 3, 2017 produced an mb 6.1 artificial earthquake and significant surface deformations detectable from satellite observations. Wang et al. (2018) have reported the surface displacement of the Mt. Mantap caused by the explosion by applying offset-tracking method to TerraSAR-X SAR images. Based on the assumption of elastic behaviour of the mountain body, they have modelled the rise and collapse of the mountain and suggested the location, depth and energy of the explosion. However, we suspect that the surface displacement might be caused by landslide in which case the elastic modelling would be misleading. In this paper, we use both SAR interferometry and offset-tracking method to quantify the elastic and random deformation caused by the explosion. The 3-D displacement vectors around the rim of the explosion, where the inter-ferometric coherence is maintained, were obtained by using three ALOS-2 interferograms acquired in different orbits. Only east-west component of the displacement vector was valid due to orbital characteristics, which indicates the explosive tendency of the bedrock of up to 25 cm in the rim of the mountain. Deformation on the ruptured zone, where the interferometric coherence is lost, was detected through visual inspection and offset tracking by using two pairs of high-resolution ALOS-2 and TerraSAR-X images. It showed up to 3.5 m displacement on the mountain slope towards the direction of gravity, which is similar to the results of Wang et al. (2018). However, we have visually identified many stable points and features that have not moved at all in the mountain flank surrounded by active surface deformation, which is believed to be stable bedrocks and outcrops. This implies that the displacements observed by the offset method in the mountain flank of the ruptured zone were mostly of landslides caused by the topsoil and boulder stones. It is suggested that elastic behaviour of the mountain body due to the 6th nuclear test of North Korea is unidentifiable and the subsequent modelling might be invalid in the mountain flank of the ruptured zone where surface motion from landslides is dominant.

Seismology of the 2017 Hojedk earthquakes (MN 6.0–6.1), Kerman province, SE Iran

Three moderate earthquakes on 1 and 12 December 2017 with MN magnitudes of 6.0–6.1 (MS1, MS2 and MS3) occurred in the SE Iran. They happened in the area between Nayband and Kuh Banan fault systems, NE of the Kerman metropolice. We combined satellite imagery, seismicity, focal mechanism solutions, strong motions, and Coulomb stress to investigate the earthquakes. These events were located near the southeastern splay of the N-S Lakar Kuh right-lateral strike-slip fault. Active tectonics of the Lakar Kuh fault as well as the earthquake deformations were confirmed by satellite imagery and field photographs, respectively. Hypocenters of the three Mw ~6.0 earthquakes and their aftershocks indicated a migration of faulting from the SE towards the NW. According to high resolution satellite imagery, the third earthquake produced ~6 km of coseismic surface rupture in the alluvial fan deposits (east of Mian Kuh) with maximum deformation in the middle part. The focal mechanisms of both the mainshocks and the strongest aftershocks (MN > 4.6) determined from P wave first motions indicated ~NW-SE fault strikes for the 3 events (dipping SW for MS3), with dominant reverse slip and minor strike-slip components. General northwestward migration of mainshocks as well as strong motions recorded at accelerometers nearby showed evidence for northwestward rupture directivity in all three earthquakes. It was in accordance with the rupture geometry, hypocenter and centroid depth of MS3. The Coulomb stress investigation also revealed that the aftershocks of the 3 events partially covered the increasing areas of Coulomb stress.

Segments and Gaps in Tide Gauge Records

The tide-gauge stations all over the globe frequently include gaps, earthquake deformations of reference level, damages of stations and re-locations of sites. In meaningful reconstruction of past sea level change all such structures must be handled with great care. In the original databases of PSMSL and NOAA they are ignored, invalidating meaningful long-term mean trend analyses.

OPTIMUM CONDITIONS FOR DIFFERENTIAL SAR INTERFEROMETRY TECHNIQUE TO ESTIMATE HIMALAYAN GLACIER VELOCITY

Abstract. Differential SAR Interferometry (DInSAR) is the process of differencing two Interferograms for measuring surface movement with an accuracy of millimeter range. The DInSAR process can be applied to observe glacier movement, earthquake deformations, volcanic activities and rate of subsidence or uplift caused due to the extraction of groundwater or coal. By using single pass interferometry technique we can also generate accurate DEM. In this paper, we are presenting the movement of a Chhota Shigri glacier with the help two pass DInSAR technique and mainly we concentrated on the optimum conditions for estimating glacier movement using DInSAR. We got good coherence and Interferogram fringes for L-band sensor with less temporal baseline. Therefore, we generated glacier velocity using ALOS-2 data with 14 days temporal baseline. Initially, we generated Interferogram (defo-pair) by taking 10th March 2015 image as a master and 24th March 2015 image as a slave. But this generated Interferogram also having topographic information and atmospheric errors with the displacement component. Therefore, we used SRTM DEM for removing topographic information from the Interferogram. Because we are using L-band data, results may not be affected by troposphere. Maximum glacier velocity we observed in the accumulation zone as 7.285 cm/day in the month of March and while it’s moving towards ablation zone the glacier velocity is decreasing.

Deformations of fundamental group representations and earthquakes on $${\textit{SO}}(n,1)$$ SO ( n , 1 ) surface groups

In this article we construct a type of deformations of representations \(\pi _1(M)\rightarrow G\) where G is an arbitrary lie group and M is a large class of manifolds including \(\hbox {CAT}(0)\) manifolds. The deformations are defined based on codimension 1 hypersurfaces with certain conditions, and also on disjoint union of such hypersurfaces, i.e. multi-hypersurfaces. We show commutativity of deforming along disjoint hypersurfaces. As application, we consider Anosov surface groups in \({\textit{SO}}(n,1)\) and show that the construction can be extended continuously to measured laminations, thus obtaining earthquake deformations on these surface groups.

Seismic displacement of gently-sloping coastal and marine sediment under multidirectional earthquake loading

Gentle sediment-laden slopes are typical of the onshore coastal zone and offshore continental shelf and slope. Coastal sediment are commonly young weakly consolidated materials that are well stratified, have low strength, and can mobilize shear displacements at low levels of stress. Seismically-driven plastic displacements of these sediment pose a hazard to coastal cities, buried onshore utilities, and offshore infrastructure like harbor protection and outfalls. One-dimensional rigid downslope-directed Newmark sliding block analyses have been used to predict earthquake deformations generally on steeper slopes that are modeled as frictional materials. This study probes the effect of multidirectional earthquake motions on inertial displacements of gently sloping ground of the coastal and offshore condition where soft-compliant soil is expected. Toward that objective, this investigation seeks to understand the effect on Newmark-type displacements of [1] multidirectional earthquake shaking and [2] soil compliance. In order to model multidirectional effects, the earthquake motions are rotated into the local slope strike- and dip-components. On gently sloping ground, including the strike component of motion always results in a larger and more accurate shear stress vector. Strike motions are found to contribute to downslope deformations on any declivity. Compliant response of the soil mass also influences the plastic displacements. The magnitude of seismic displacements can be estimated with a simplified model using only the estimated soil yield-acceleration (ky) and the peak ground velocity (Vmax) of the earthquake motions. Compliance effects can be effectively mapped using the concept of Plastic Displacement Response Spectra (PDRS).

Higher derivative of length functions along earthquake deformations

Higher derivative of length functions along earthquake deformations

Towards a complete model of soil liquefaction: the importance of fluid flow and grain motion

When loosely packed water-saturated granular soils, for example sands, are subjected to strong earthquake shaking, they may liquefy, causing large deformations with great destructive power. The phenomenon is quite general and occurs in any fluid-saturated granular material and is a consequence of the transfer of stress from inter-grain contacts to water pressure. In modern geotechnical practice, soil liquefaction is commonly considered to be an ‘undrained’ phenomenon; pressure is thought to be generated because earthquake deformations are too quick to allow fluid flow, which enables water depressurization. Here, we show via a first principles analysis that liquefaction is not a strictly undrained process; and, in fact, it is the interplay between grain rearrangement, fluid migration and changes in permeability, which causes the loss of strength observed in so many destructive earthquake events around the world. The results call into question many of the common laboratory and field methods of evaluating the liquefaction resistance of soil and indicate new directions for the field, laboratory and scale-model study of this important phenomenon.

Seismologic applications of GRACE time-variable gravity measurements

The Gravity Recovery and Climate Experiment (GRACE) has been measuring temporal and spatial variations of mass redistribution within the Earth system since 2002. As large earthquakes cause significant mass changes on and under the Earth’s surface, GRACE provides a new means from space to observe mass redistribution due to earthquake deformations. GRACE serves as a good complement to other earthquake measurements because of its extensive spatial coverage and being free from terrestrial restriction. During its over 10 years mission, GRACE has successfully detected seismic gravitational changes of several giant earthquakes, which include the 2004 Sumatra–Andaman earthquake, 2010 Maule (Chile) earthquake, and 2011 Tohoku-Oki (Japan) earthquake. In this review, we describe by examples how to process GRACE time-variable gravity data to retrieve seismic signals, and summarize the results of recent studies that apply GRACE observations to detect co- and post-seismic signals and constrain fault slip models and viscous lithospheric structures. We also discuss major problems and give an outlook in this field of GRACE application.

Investigation of Effective Parameters on the Embankment Dam Filter Behavior in Simultaneous Cracking in the Core and Filter

Cracks in filter can develop as a result of earthquake deformations or post-construction settlement and in some cases cracks extended through both the core and filter. Hence, a test apparatus has been developed to investigate filter performance in the case of filter and core material cracking in the embankment dams. The apparatus allows testing of incomplete cylindrical test specimens of 10 cm diameter and height of 20 cm. If the filters work well and successfully, crack filling occur, also the flow rate decrease, and the head water pressure increase to the range of early pressure. In the failed filters case, the flow rate do not decrease and remain high, also a very low head water pressure take place. In this research, variations of pressure, fines contents of filter soils, compaction time, PI of the base material and amount of eroded materials was evaluated. Results showed that prime flow rate increased as hydraulic gradient increased, but decreased in a little time and reach to a stable value. Filter with 15% of non-plastic fine content, had ability to slump to fill the crack, but its coefficient of permeability decreased significantly, hence, cannot be used as a filter in embankment dams.

Regional gravity decrease after the 2010 Maule (Chile) earthquake indicates large‐scale mass redistribution

We report small but detectable changes in the GRACE satellites' relative trajectory after the M8.8 Maule, Chile earthquake on 27 February 2010 that can be used to delineate the shift in the gravity field. A gravity anomaly of −5 μGal with a spatial scale of 500 km was found east of the epicenter after the earthquake. Based on coseismic models, the long‐wavelength negative gravity change is primarily the result of crustal dilatation as well as surface subsidence in the onland region. The offshore positive gravity anomaly predicted from finite fault coseismic models is considerably smaller because the gravity changes due to surface uplift and interior deformation are opposite in polarity. Our study suggests a role for large‐scale gravity observations in deciphering changes of the Earth's interior during great earthquakes by filling in the seldom‐observed long‐wavelength spectrum of earthquake deformations as a complement to surface geodetic measurements and seismic data.

Prehistoric earthquake deformations near Masada, Dead Sea graben

Research Article| August 01, 1995 Prehistoric earthquake deformations near Masada, Dead Sea graben Shmuel Marco; Shmuel Marco 1Institute of Earth Sciences, Hebrew University, Jerusalem 91904, Israel2Geological Survey of Israel, 30 Malkhe Israel, Jerusalem 95501, Israel Search for other works by this author on: GSW Google Scholar Amotz Agnon Amotz Agnon 1Institute of Earth Sciences, Hebrew University, Jerusalem 91904, Israel Search for other works by this author on: GSW Google Scholar Author and Article Information Shmuel Marco 1Institute of Earth Sciences, Hebrew University, Jerusalem 91904, Israel2Geological Survey of Israel, 30 Malkhe Israel, Jerusalem 95501, Israel Amotz Agnon 1Institute of Earth Sciences, Hebrew University, Jerusalem 91904, Israel Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1995) 23 (8): 695–698. https://doi.org/10.1130/0091-7613(1995)023<0695:PEDNMD>2.3.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Shmuel Marco, Amotz Agnon; Prehistoric earthquake deformations near Masada, Dead Sea graben. Geology 1995;; 23 (8): 695–698. doi: https://doi.org/10.1130/0091-7613(1995)023<0695:PEDNMD>2.3.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Earthquake-induced fluidizations and suspensions of lake sediments, associated with syndepositional faults, form a paleoseismic record in the Dead Sea graben. The association of fluidized beds with surface faulting supports the recognition of mixed layers as reliable earthquake indicators and provides a tool for the study of very long term (>70 kar) seismicity along the Dead Sea transform. The faults compose a fault zone that offsets laminated sediments of the late Pleistocene Lake Lisan. They exhibit displacements of as much as 2 m. Layers of massive mixtures of laminated fragments are interpreted as disturbed beds, each formed by an earthquake. The undisturbed laminated layers between these mixed layers represent the interseismic interval. A typical vertical slip of about 0.5 m per event is separated by several hundred years of quiescence. The fault zone lies within the Dead Sea graben, 2 km east of Masada, where archaeology and historical accounts indicate repeated strong earthquake damage. The distribution of strikes in the fault zone resembles that of the faults exposed in and around the graben, including the seismogenic ones. The excellent exposures over hundreds of metres allow an unprecedented temporal and spatial resolution of slip events on faults. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Four thousand years of seismicity along the Dead Sea Rift

A study of major earthquake occurrence along the Dead Sea transform (35.5°–36.5° E; 27.2°–37.5° N) during the past four millenia has been attempted. Geological, archaeological, biblical, historical, and seismological evidence were integrated in an effort to quantify the space‐time distribution of seismicity in the said province. The overall earthquake activity in the conterminous Near East indicates a stable pattern and appeared to have been stationary over the examined time window. About 110 earthquakes in the magnitude range 6.7 ≤ ML ≤ 8.3 affected the area during the past 2500 years. Of these, 42 originated along the Dead Sea fault system itself, while 68 were imported from the Helenic‐Cyprian arcs and the Anatolian‐Elburz‐Zagros fault systems. These events were responsible for the repeated destruction of many cultural centers. In the Dead Sea region proper, the major seismic activity since 2100 B.C.E. (Before Christian Era), has been confined to the vicinity of its eastern shore with extremal seismicity at its southern tip near the prehistorical site of Bab‐a‐Dara'a (31° 15'N, 35° 32'E). This may constitute the first solid evidence that the Biblical “cities of the Plain” (Sodom, Gommorah, etc.) were located there. Recent studies of earthquake deformations in the Lisan deposits near Bab‐a‐Dara'a, agree with our findings. At the present time, a magnitude 6¾ earthquake is pending at the northern edge of the Levant rift, with its average recurrence interval (83 years) exceeded by one standard deviation (32 years).

Earthquake deformations in the Lisan deposits and seismotectonic implications

Earthquake deformations and induced sedimentary structures preserved in Quaternary sediments include faults, folds, fissures, slumps, sand boils and other effects of liquefaction. Such deformations and structures are well preserved in the Lisan deposits of the Dead Sea. Of most importance are the fold-type deformations known as décollement structures which are present all along the eastern side of the Lisan and seem to decrease gradually westwards to disappear in the middle of the Lisan. These may indicate that palaeoearthquakes originating along the Araba fault have triggered such structures due to shaking of elastoplastic unconsolidated sediments over gentle slopes dipping to the west. Preliminary results from studies on décollement structures preserved in a section representing some 1733 years of continuous deposition in the uppermost? Pleistocene, in the vicinity of Wadi Araba, indicate that: (1) seismic activity has fluctuated with time. Average recurrence period is about 340 ∓ 20yr for earthquakes with magnitudes greater than or equal to 6.5. Earthquakes with magnitude greater than 7 seem to have occurred along the Araba fault. (2) Deduced earthquake magnitudes conform to the frequency-magnitude relationship: log N = 5.24 - 0.68M. (3) The deduced seismic slip rate along the Araba fault seems to be not less than 0.64 5 0.04 cm yr-1.

Ground deformations associated with the 1977–1978 eruption of USU volcano, Japan

Abstract The activity of Usu volcano situated at southern Hokkaido is characterized by the persistent occurrence of earthquake swarms and remarkable ground deformations including the formation of lava domes, both of which are due to the high viscosity of its magma. After the pumice eruptions of August 1977, the central part of the summit crater bounded by a U-shaped fault upheaved day after day at the maximum rate of 1 m/day. Although the rate has decreased, the total upheaval reached to about 180 m as of September 1981 resulting in formation of a new cryptodome. The doming at the summit has caused the northeastern rim to thrust towards the northeast about 180 m, and consequently caused corrugation of the ground at the northeastern foot of the volcano. The two kinds of the deformations, upheavals and thrusts, are closely related with each other. To examine the relationship between the earthquake occurrences and the deformations, a quasi-continuous observation of the distance from the northeastern rim of the summit crater to the foot of the volcano, was carried out by an optical distancemeter for 44 hours. It was found that the thrusts were episodic and accompanied by relatively large earthquakes. This supports that the earthquake swarms are caused by stick-slip motions of frictional sliding at the planes of the doming faults.