scholarly journals Empirical Relationship for Assessing the Near-Field Horizontal Coseismic Displacement Using GPS Seismology Data

2021 ◽  
Vol 60 (1) ◽  
pp. 31-50
Author(s):  
Ryad Darawcheh ◽  
Riad Al Ghazzi ◽  
Mohamad Khir Abdul-wahed

In this research, a data set of horizontal GPS coseismic displacement in the near-field has been assembled around the world in order to investigate a potential relationship between the displacement and the earthquake parameters. Regression analyses have been applied to the data of 120 interplate earthquakes having the magnitude (Mw 4.8-9.2). An empirical relationship for prediction near-field horizontal GPS coseismic displacement as a function of moment magnitude and the distance between hypocenter and near field GPS station has been established using the multi regression analysis. The obtained relationship allows assessing the coseismic displacements associated with some large historical earthquakes occurred along the Dead Sea fault system. Such a fair relationship could be useful for assessing the coseismic displacement at any point around the active faults.

2021 ◽  
Author(s):  
Matthieu Ribot ◽  
Yann Klinger ◽  
Edwige Pons-Branchu ◽  
Marthe Lefevre ◽  
Sigurjón Jónsson

<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>


2011 ◽  
Vol 12 (12) ◽  
pp. n/a-n/a ◽  
Author(s):  
Eid al Tarazi ◽  
Jafar Abu Rajab ◽  
Francisco Gomez ◽  
William Cochran ◽  
Rani Jaafar ◽  
...  

1999 ◽  
Vol 42 (4) ◽  
Author(s):  
M. Anzidei ◽  
P. Baldi ◽  
A. Galvani ◽  
A. Pesci ◽  
I. Hunstad ◽  
...  

On September 26,1997 two earthquakes of Mw 5.7 (00.33 GMT) and Mw 6.0 (9.40 GMT), occurred in the Umbria-Marche region (Central Apennines, Italy). The epicentres were located in an area of the Apenninic chain that experienced historical earthquakes up to X degrees of the MCS scale. During the time span 1992-1996, the Italian Istituto Geografico Militare (IGM) set up a new national geodetic network measured by Global Positioning System space geodetic technique, consisting of more than 1200 vertices uniformly distributed on the Italian peninsula and islands. From October 7 to 11, 1997, a short while after the main shocks of the Umbria-Marche seismic sequence, we reoccupied thirteen stations belonging to the IGM and TYRGEONET networks to measure coseismic displacement. The determinations of the post-seismic coordinates at 13 GPS monuments detected significant coseismic displacements. The comparison between the preseismic and postseismic data sets show maximum displacements of 14 cm and 25 cm in the horizontal and vertical components respectively. In this paper, the GPS network, the field work, the data processing procedures and the computed coseismic displacements measured at the geodetic monuments are discussed with the aim to provide a data set useful to the scientific


2012 ◽  
Vol 12 (7) ◽  
pp. 2311-2328 ◽  
Author(s):  
A. Polonia ◽  
L. Torelli ◽  
L. Gasperini ◽  
P. Mussoni

Abstract. The Calabrian Arc (CA) subduction complex is located at the toe of the Eurasian Plate in the Ionian Sea, where sediments resting on the lower plate have been scraped off and piled up in the accretionary wedge due to the African/Eurasian plate convergence and back arc extension. The CA has been struck repeatedly by destructive historical earthquakes, but knowledge of active faults and source parameters is relatively poor, particularly for seismogenic structures extending offshore. We analysed the fine structure of major tectonic features likely to have been sources of past earthquakes: (i) the NNW–SSE trending Malta STEP (Slab Transfer Edge Propagator) fault system, representing a lateral tear of the subduction system; (ii) the out-of-sequence thrusts (splay faults) at the rear of the salt-bearing Messinian accretionary wedge; and (iii) the Messina Straits fault system, part of the wide deformation zone separating the western and eastern lobes of the accretionary wedge. Our findings have implications for seismic hazard in southern Italy, as we compile an inventory of first order active faults that may have produced past seismic events such as the 1908, 1693 and 1169 earthquakes. These faults are likely to be source regions for future large magnitude events as they are long, deep and bound sectors of the margin characterized by different deformation and coupling rates on the plate interface.


Author(s):  
David McCallen ◽  
Houjun Tang ◽  
Suiwen Wu ◽  
Eric Eckert ◽  
Junfei Huang ◽  
...  

Accurate understanding and quantification of the risk to critical infrastructure posed by future large earthquakes continues to be a very challenging problem. Earthquake phenomena are quite complex and traditional approaches to predicting ground motions for future earthquake events have historically been empirically based whereby measured ground motion data from historical earthquakes are homogenized into a common data set and the ground motions for future postulated earthquakes are probabilistically derived based on the historical observations. This procedure has recognized significant limitations, principally due to the fact that earthquake ground motions tend to be dictated by the particular earthquake fault rupture and geologic conditions at a given site and are thus very site-specific. Historical earthquakes recorded at different locations are often only marginally representative. There has been strong and increasing interest in utilizing large-scale, physics-based regional simulations to advance the ability to accurately predict ground motions and associated infrastructure response. However, the computational requirements for simulations at frequencies of engineering interest have proven a major barrier to employing regional scale simulations. In a U.S. Department of Energy Exascale Computing Initiative project, the EQSIM application development is underway to create a framework for fault-to-structure simulations. This framework is being prepared to exploit emerging exascale platforms in order to overcome computational limitations. This article presents the essential methodology and computational workflow employed in EQSIM to couple regional-scale geophysics models with local soil-structure models to achieve a fully integrated, complete fault-to-structure simulation framework. The computational workflow, accuracy and performance of the coupling methodology are illustrated through example fault-to-structure simulations.


Author(s):  
D Spallarossa ◽  
M Cattaneo ◽  
D Scafidi ◽  
M Michele ◽  
L Chiaraluce ◽  
...  

Summary The 2016–17 central Italy earthquake sequence began with the first mainshock near the town of Amatrice on August 24 (MW 6.0), and was followed by two subsequent large events near Visso on October 26 (MW 5.9) and Norcia on October 30 (MW 6.5), plus a cluster of 4 events with MW > 5.0 within few hours on January 18, 2017. The affected area had been monitored before the sequence started by the permanent Italian National Seismic Network (RSNC), and was enhanced during the sequence by temporary stations deployed by the National Institute of Geophysics and Volcanology and the British Geological Survey. By the middle of September, there was a dense network of 155 stations, with a mean separation in the epicentral area of 6–10 km, comparable to the most likely earthquake depth range in the region. This network configuration was kept stable for an entire year, producing 2.5 TB of continuous waveform recordings. Here we describe how this data was used to develop a large and comprehensive earthquake catalogue using the Complete Automatic Seismic Processor (CASP) procedure. This procedure detected more than 450,000 events in the year following the first mainshock, and determined their phase arrival times through an advanced picker engine (RSNI-Picker2), producing a set of about 7 million P- and 10 million S-wave arrival times. These were then used to locate the events using a non-linear location (NLL) algorithm, a 1D velocity model calibrated for the area, and station corrections and then to compute their local magnitudes (ML). The procedure was validated by comparison of the derived data for phase picks and earthquake parameters with a handpicked reference catalogue (hereinafter referred to as ‘RefCat’). The automated procedure takes less than 12 hours on an Intel Core-i7 workstation to analyse the primary waveform data and to detect and locate 3000 events on the most seismically active day of the sequence. This proves the concept that the CASP algorithm can provide effectively real-time data for input into daily operational earthquake forecasts, The results show that there have been significant improvements compared to RefCat obtained in the same period using manual phase picks. The number of detected and located events is higher (from 84,401 to 450,000), the magnitude of completeness is lower (from ML 1.4 to 0.6), and also the number of phase picks is greater with an average number of 72 picked arrival for a ML = 1.4 compared with 30 phases for RefCat using manual phase picking. These propagate into formal uncertainties of ± 0.9km in epicentral location and ± 1.5km in depth for the enhanced catalogue for the vast majority of the events. Together, these provide a significant improvement in the resolution of fine structures such as local planar structures and clusters, in particular the identification of shallow events occurring in parts of the crust previously thought to be inactive. The lower completeness magnitude provides a rich data set for development and testing of analysis techniques of seismic sequences evolution, including real-time, operational monitoring of b-value, time-dependent hazard evaluation and aftershock forecasting.


2020 ◽  
Author(s):  
Matthieu Ribot ◽  
Yann Klinger ◽  
Sigurjón Jónsson ◽  
Ulas Avsar ◽  
Edwige Pons-Branchu ◽  
...  

2020 ◽  
Vol 57 (4) ◽  
pp. 309-354
Author(s):  
Jason Eleson ◽  
Chip Oakes ◽  
Graham McClave

Limited horizontal drilling has occurred within the Niobrara-equivalent section of the Mancos Shale in the Piceance Basin, and the results from individual wells are highly variable. Prior studies have suggested that thermal maturity and completion techniques were the primary drivers for the observed production trends, but further analysis of well results indicates there are more variables at play. This study leveraged a comprehensive data set from the Piceance Basin, including core analyses, pressure data, and drilling and completion methods to provide additional context for the production results. From this analysis, several key trends were identified. North/south variations in thermal maturity were confirmed, as well as additional trends were identified revealing later exhumation south of the Rangely fault system resulted in significant depressurization, particularly in the western Piceance Basin. The semi-regional depressurization was the result of decrease in overburden pressures that allowed vertical migration of hydrocarbons out of the Mancos Shale. In addition to the semi-regional depressurization, there were more local depressurization events that resulted from faulting in areas such as the Orchard Unit in the southern Piceance Basin where thrust faults allowed hydrocarbons to migrate vertically into overlying formations. Northwest to southeast production trends are present in the southern Piceance Basin and are interpreted to reflect structurally undeformed areas based on high formation pressures and better producing horizontal wells. Parent-child effects have been observed locally and are linked to lower initial production rates and faster decline rates. The northern Piceance Basin exhibits higher reservoir pressure in the liquids window than was observed to the south due to the relatively low degree of exhumation and/or faulting in areas where horizontal Niobrara wells were drilled. Horizontal well results in the northern Piceance Basin have been mixed, largely due to inefficient completion strategies. By comparing the northern Piceance Basin wells with similar horizontal Niobrara wells in the Powder River Basin of northeastern Wyoming, it is concluded that drilling into the over-pressured liquids rim and utilizing slickwater frac fluid with friction reducer and 100 mesh sand will yield improved economic results over those obtained so far in the Piceance Basin. Though relatively few laterals have been drilled in the Piceance Basin Niobrara play, the basin has great future potential.


2020 ◽  
Vol 224 (1) ◽  
pp. 416-434
Author(s):  
Dezheng Zhao ◽  
Chunyan Qu ◽  
Xinjian Shan ◽  
Roland Bürgmann ◽  
Wenyu Gong ◽  
...  

SUMMARY We investigate the coseismic and post-seismic deformation due to the 6 February 2018 Mw 6.4 Hualien earthquake to gain improved insights into the fault geometries and complex regional tectonics in this structural transition zone. We generate coseismic deformation fields using ascending and descending Sentinel-1A/B InSAR data and GPS data. Analysis of the aftershocks and InSAR measurements reveal complex multifault rupture during this event. We compare two fault model joint inversions of SAR, GPS and teleseismic body waves data to illuminate the involved seismogenic faults, coseismic slip distributions and rupture processes. Our preferred fault model suggests that both well-known active faults, the dominantly left-lateral Milun and Lingding faults, and previously unrecognized oblique-reverse west-dipping and north-dipping detachment faults, ruptured during this event. The maximum slip of ∼1.6 m occurred on the Milun fault at a depth of ∼2–5 km. We compute post-seismic displacement time series using the persistent scatterer method. The post-seismic range-change fields reveal large surface displacements mainly in the near-field of the Milun fault. Kinematic inversions constrained by cumulative InSAR displacements along two tracks indicate that the afterslip occurred on the Milun and Lingding faults and the west-dipping fault just to the east. The maximum cumulative afterslip of 0.4–0.6 m occurred along the Milun fault within ∼7 months of the main shock. The main shock-induced static Coulomb stress changes may have played an important role in driving the afterslip adjacent to coseismic high-slip zones on the Milun, Lingding and west-dipping faults.


Author(s):  
Luis Moya ◽  
Fumio Yamazaki ◽  
Wen Liu ◽  
Tatsuro Chiba

Abstract. The spatial distribution of the coseismic displacements that occurred along the Futagawa fault during the 2016 Kumamoto earthquake of Mw 7.0 was estimated using airborne light detection and ranging (Lidar) data. In this study, a pair of digital surface models (DSMs) obtained from the high-density Lidar data before and after the mainshock on April 16, 2016, was used. A window matching search approach based on the correlation coefficient between the two DSMs was used to estimate the geodetic displacement in the near-field region. The results showed good agreements with the geodetic displacements calculated from strong-motion acceleration records and coincided with the fault line surveyed by the Geological Survey of Japan.


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