Using UAV and drilling to detect Quaternary activity of the Zhuozishan West Piedmont Fault, provides insight into the structural development of the Wuhai Basin and Northwestern Ordos Block, China

2020 ◽  
Author(s):  
Kuan Liang ◽  
Baoqi Ma ◽  
Qinjian Tian
Keyword(s):  
Hanging Wall ◽  
Slip Rate ◽  
Normal Fault ◽  
Fault System ◽  
Structural Development ◽  
Slip Rates ◽  
Ordos Block ◽  
Elevation Data ◽  
Northwestern Margin ◽  
Regional Tectonic

<p>The Wuhai Basin is in the northwestern corner of the Ordos Block. Analyzing the geometry, and kinematic and dynamic characteristics of the boundary fault, the Zhuozishan West Piedmont Fault (ZWPF), will elucidate the regional tectonic environment and guide earthquake prevention and disaster reduction projects. Six presentative sites were selected for topographic measurements, from northern, middle and southern parts. Displacements of the ZWPF were calculated by measuring the top surface elevation of a widely distributed lacustrine layer in the footwall from outcrops at the sites (using UAV), and in the hanging wall from boreholes. The vertical slip rate of the ZWPF was then calculated based on the displacement and age of the lacustrine layer. Three to four normal fault-controlled terraces have developed on the footwall of the ZWPF, and the top surface of the lacustrine layer is at 1092–1132 m elevation. Data from boreholes showed that the top surface of the lacustrine layer is at an elevation of 1042–1063 m in the hanging wall. Vertical slip rates since 70 ka were estimated as 0.5±0.2 to 1.0±0.2 mm/a. The highest rate of vertical slip was observed at Fenghuang Ridge, in the central part of the fault system, and the vertical slip rate reduced to the south. In the northern Wuhai Basin, normal faulting still controls the piedmont landscape. However, NW-SE trending reverse faults and secondary folding have resulted from dextral strike-slip movement of the fault. The Wuhai Basin developed as a dextral-tensional negative flower structure. This study indicated that stress conditions of the northwestern margin of the Ordos Block include NE–SW compression and NW–SE extension, and an S-shaped rift zone has dominated the scale, structure, and evolution of the Yinchuan, Wuhai and Hetao Basins, and the active mode of faulting in these basins.</p>

scholarly journals Detection of Tectonic and Crustal Deformation using GNSS Data Processing: The Case of PPGnet

2021 ◽  
Vol 7 (1) ◽  
pp. 14-23
Author(s):  
Epameinondas Lyros ◽  
Jakub Kostelecky ◽  
Vladimir Plicka ◽  
Filler Vratislav ◽  
Efthimios Sokos ◽  
...  
Keyword(s):  
Crustal Deformation ◽  
Slip Rate ◽  
Normal Fault ◽  
Fault System ◽  
Double Difference ◽  
International Gnss Service ◽  
Slip Rates ◽  
Phase Measurements ◽  
Fault Systems ◽  
Gnss Network

Aitolo-Akarnania prefecture, western Greece, is an area with strong earthquakes and large active fault systems. The most prominent are the Katouna sinistral strike slip fault and the Trichonis Lake normal fault system. Their proximity to large cities, and the lack of detailed information on their seismogenic potential, calls for multiparametric research. Since 2013, the area’s crustal deformation has been monitored by a dense GNSS Network (PPGNet), consisting of five stations, equipped with Leica and Septentrio receivers. The objective of this network is to define the rate of deformation across these two main fault systems. Data is recorded using two sampling frequencies, 1 Hz and 10Hz, producing hourly and daily files. Daily data is processed using Bernese GNSS Processing Software using final orbits of International GNSS Service. Double-difference solution is computed using phase measurements from the PPGNet network complemented by four stations from Athens’ National Observatory GNSS network and six stations from METRICA network. First results show a NNE movement at PVOG station of 12 mm/y and a similar movement at RETS station of about 9 mm/y. This means that the Trichonis Lake normal fault system, located between these two stations, depicts a slip rate of 3 mm/y. KTCH and RGNI stations move eastwards at a velocity of about 5 mm/y due to the Katouna-Stamna fault system. Data from PPGNet has provided important results on crustal deformation in the area, i.e. slip rates have been attributed to specific fault systems. The comparison and links of these data with broader geodynamic models is now possible and we expect, in a later phase that will provide a more detailed image of the associated seismic hazard for Aitolo-Akarnania. Doi: 10.28991/cej-2021-03091633 Full Text: PDF

scholarly journals New constraints on the exhumation history of the western Tauern Window (European Alps) from thermochronology, thermokinematic modeling, and topographic analysis

2021 ◽  
Author(s):  
Reinhard Wolff ◽  
Ralf Hetzel ◽  
István Dunkl ◽  
Aneta A. Anczkiewicz
Keyword(s):  
Hanging Wall ◽  
Thermal Relaxation ◽  
Slip Rate ◽  
Normal Fault ◽  
European Alps ◽  
Valley Bottom ◽  
Topographic Analysis ◽  
Tauern Window ◽  
History Of ◽  
Exhumation History

AbstractThe Brenner normal fault bounds the Tauern Window to the west and accommodated a significant portion of the orogen-parallel extension in the Eastern Alps. Here, we use zircon (U–Th)/He, apatite fission track, and apatite (U–Th)/He dating, thermokinematic modeling, and a topographic analysis to constrain the exhumation history of the western Tauern Window in the footwall of the Brenner fault. ZHe ages from an E–W profile (parallel to the slip direction of the fault) decrease westwards from ~ 11 to ~ 8 Ma and suggest a fault-slip rate of 3.9 ± 0.9 km/Myr, whereas AFT and AHe ages show no spatial trends. ZHe and AFT ages from an elevation profile indicate apparent exhumation rates of 1.1 ± 0.7 and 1.0 ± 1.3 km/Myr, respectively, whereas the AHe ages are again spatially invariant. Most of the thermochronological ages are well predicted by a thermokinematic model with a normal fault that slips at a rate of 4.2 km/Myr between ~ 19 and ~ 9 Ma and produces 35 ± 10 km of extension. The modeling reveals that the spatially invariant AHe ages are caused by heat advection due to faulting and posttectonic thermal relaxation. The enigmatic increase of K–Ar phengite and biotite ages towards the Brenner fault is caused by heat conduction from the hot footwall to the cooler hanging wall. Topographic profiles across an N–S valley in the fault footwall indicate 1000 ± 300 m of erosion after faulting ceased, which agrees with the results of our thermokinematic model. Valley incision explains why the Brenner fault is located on the western valley shoulder and not at the valley bottom. We conclude that the ability of thermokinematic models to quantify heat transfer by rock advection and conduction is crucial for interpreting cooling ages from extensional fault systems.

Active fault segmentation and seismic hazard in Hoa-Binh reservoir, Vietnam

2013 ◽  
Vol 5 (2) ◽  
Author(s):  
Phan Trinh ◽  
Hoang Vinh ◽  
Nguyen Huong ◽  
Ngo Liem
Keyword(s):  
Seismic Hazard ◽  
Active Fault ◽  
Slip Rate ◽  
Normal Fault ◽  
Seismic Attenuation ◽  
Fault System ◽  
Ground Acceleration ◽  
Hydropower Dam ◽  
Large Dam ◽  
Hoa Binh

AbstractBased on remote sensing, geological data, geomorphologic analysis, and field observations, we determine the fault system which is a potential source of earthquakes in Hoa-Binh reservoir. It is the sub-meridian fault system composed of fault segments located in the central part of the eastern and western flanks of the Quaternary Hoa-Binh Graben: the Hoa-Binh 1 fault is east-dipping (75–80°), N-S trending, 4 km long, situated in the west of the Hoa-Binh Graben, and the Hoa-Binh 2 is a west-dipping (75–80°), N-S trending; 8.4 km long fault, situated in the east of the Hoa-Binh Graben. The slip rate of normal fault in Hoa-Binh hydropower dam was estimated at 0.3–1.1 mm/yr. The Maximum Credible Earthquake (MCE) and Peak Ground Acceleration (PGA) in the Hoa-Binh hydropower dam have been assessed. The estimated MCE of HB.1 and HB.2 is 5.6 and 6.1 respectively, and the maximum PGA at Hoa-Binh dam is 0.30 g and 0.40 g, respectively. The assessment of seismic hazard in Hoa-Binh reservoir is a typical example of seismic hazards of a large dam constructed in an area of low seismicity and lack of law of seismic attenuation.

scholarly journals Hurricane Fault

Geosites ◽  
2019 ◽  
Vol 1 ◽  
pp. 1-12
Author(s):  
Robert Biek
Keyword(s):  
East Coast ◽  
Hanging Wall ◽  
Grand Canyon ◽  
Normal Fault ◽  
Local Area ◽  
Fault Scarp ◽  
Normal Faults ◽  
Slip Rates ◽  
The Town

The Hurricane fault is the big earthquake fault in southwestern Utah. It stretches at least 155 miles (250 km) from south of the Grand Canyon northward to Cedar City and is capable of producing damaging earthquakes of about magnitude 7.0. The Hurricane fault is a “normal” fault, a type of fault that forms during extension of the earth’s crust, where one side of the fault moves down relative to the other side. In this case, the down-dropped side (the hanging wall) is west of the fault; the upthrown side (the footwall) lies to the east. Like most long normal faults, the Hurricane fault is composed of discrete segments that tend to rupture independently (figure 1). The fault lies at or near the base of the Hurricane Cliffs, which form an impressive, little-eroded fault scarp several hundred feet high. Conspicuous, west-tilted, faulted slivers of mostly Triassic and Jurassic red beds are locally exposed at the base of the cliffs, and contrast strongly with gray Permian carbonates exposed in the cliffs themselves. Several Pleistocene basaltic lava flows flowed across and are now offset by the fault zone, dramatically recording long-term slip rates. Should you make the mistake of pronouncing the name “Hurricane” as one would when describing a mighty storm on the East Coast, you should stand to be corrected, for locals pronounce it as “Hurricun” even though pioneers named the town after ferocious winds common to the local area.

scholarly journals Sevier Fault at Red Canyon

Geosites ◽  
2019 ◽  
Vol 1 ◽  
pp. 1-6
Author(s):  
Robert Biek
Keyword(s):  
Lava Flow ◽  
Fault Zone ◽  
Hanging Wall ◽  
Slip Rate ◽  
Normal Fault ◽  
Coarse Grained ◽  
Seismic Reflection Data ◽  
The North ◽  
Total Displacement ◽  
Reflection Data

The Sevier fault is spectacularly displayed on the north side of Utah Highway 12 at the entrance to Red Canyon, where it offsets a 500,000-year-old basaltic lava flow. The fault is one of several active, major faults that break apart the western margin of the Colorado Plateau in southwestern Utah. The Sevier fault is a “normal” fault, a type of fault that forms during extension of the earth’s crust, where one side of the fault moves down relative to the other side. In this case, the down-dropped side (the hanging wall) is west of the fault; the upthrown side (the footwall) lies to the east. The contrasting colors of rocks across the fault make the fault stand out in vivid detail. Immediately south of Red Canyon, the 5-million-year-old Rock Canyon lava flow, which erupted on the eastern slope of the Markagunt Plateau, flowed eastward and crossed the fault (which at the time juxtaposed non-resistant fan alluvium against coarse-grained volcaniclastic deposits) (Biek and others, 2015). The flow is now offset 775 to 1130 feet (235-345 m) along the main strand of the fault, yielding an anomalously low vertical slip rate of about 0.05 mm/yr (Lund and others, 2008). However, this eastern branch of the Sevier fault accounts for only part of the total displacement on the fault zone. A concealed, down-to-the-west fault is present west of coarse-grained volcaniclastic strata at the base of the Claron cliffs. Seismic reflection data indicate that the total displacement on the fault zone in this area is about 3000 feet (900 m) (Lundin, 1987, 1989; Davis, 1999).

scholarly journals Segmentation of the Wassuk Range normal fault system, Nevada (USA): Implications for earthquake rupture and Walker Lane dynamics

2021 ◽  
Author(s):  
Ben Surpless ◽  
Sarah Thorne
Keyword(s):  
Seismic Hazard Assessment ◽  
Normal Fault ◽  
Relative Strength ◽  
Fault System ◽  
Normal Faults ◽  
Slip Rates ◽  
Future Evolution ◽  
Walker Lane ◽  
Differential Uplift ◽  
Wassuk Range

Normal faults are commonly segmented along strike, with segments that localize strain and influence propagation of slip during earthquakes. Although the geometry of segments can be constrained by fault mapping, it is challenging to determine seismically relevant segments along a fault zone. Because slip histories, geometries, and strengths of linkages between normal fault segments fundamentally control the propagation of rupture during earthquakes, and differences in segment slip rates result in differential uplift of adjacent footwalls, we used along-strike changes in footwall morphology to detect fault segments and the relative strength of the mechanical links between them. We applied a new geomorphic analysis protocol to the Wassuk Range fault, Nevada, within the actively deforming Walker Lane. The protocol examines characteristics of footwall morphology, including range-crest continuity, bedrock-channel long profiles, catchment area variability, and footwall relief, to detect changes in strike-parallel footwall characteristics. Results revealed six domains with significant differences in morphology that we used to identify seismically relevant fault segments and segment boundaries. We integrated our results with previous studies to determine relative strength of links between the six segments, informing seismic hazard assessment. When combined with recent geodetic studies, our results have implications for the future evolution of the Walker Lane, suggesting changes in the accommodation of strain across the region. Our analysis demonstrates the power of this method to efficiently detect along-strike changes in footwall morphology related to fault behavior, permitting future researchers to perform reconnaissance assessment of normal fault segmentation worldwide.

scholarly journals Localized extension in megathrust hanging wall following great earthquakes in western Nepal

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Magali Riesner ◽  
Laurent Bollinger ◽  
Judith Hubbard ◽  
Cyrielle Guérin ◽  
Marthe Lefèvre ◽  
...  
Keyword(s):  
High Resolution ◽  
Hanging Wall ◽  
Ground Surface ◽  
Normal Fault ◽  
Fault Scarp ◽  
Fault System ◽  
Digital Elevation ◽  
Thrust Zone ◽  
Elevation Model ◽  
Short Time

AbstractThe largest (M8+) known earthquakes in the Himalaya have ruptured the upper locked section of the Main Himalayan Thrust zone, offsetting the ground surface along the Main Frontal Thrust at the range front. However, out-of-sequence active structures have received less attention. One of the most impressive examples of such faults is the active fault that generally follows the surface trace of the Main Boundary Thrust (MBT). This fault has generated a clear geomorphological signature of recent deformation in eastern and western Nepal, as well as further west in India. We focus on western Nepal, between the municipalities of Surkhet and Gorahi where this fault is well expressed. Although the fault system as a whole is accommodating contraction, across most of its length, this particular fault appears geomorphologically as a normal fault, indicating crustal extension in the hanging wall of the MHT. We focus this study on the reactivation of the MBT along the Surkhet-Gorahi segment of the surface trace of the newly named Reactivated Boundary Fault, which is ~ 120 km long. We first generate a high-resolution Digital Elevation Model from triplets of high-resolution Pleiades images and use this to map the fault scarp and its geomorphological lateral variation. For most of its length, normal motion slip is observed with a dip varying between 20° and 60° and a maximum cumulative vertical offset of 27 m. We then present evidence for recent normal faulting in a trench located in the village of Sukhetal. Radiocarbon dating of detrital charcoals sampled in the hanging wall of the fault, including the main colluvial wedge and overlying sedimentary layers, suggest that the last event occurred in the early sixteenth century. This period saw the devastating 1505 earthquake, which produced ~ 23 m of slip on the Main Frontal Thrust. Linked or not, the ruptures on the MFT and MBT happened within a short time period compared to the centuries of quiescence of the faults that followed. We suggest that episodic normal-sense activity of the MBT could be related to large earthquakes rupturing the MFT, given its proximity, the sense of motion, and the large distance that separates the MBT from the downdip end of the locked fault zone of the MHT fault system. We discuss these results and their implications for the frontal Himalayan thrust system.

scholarly journals Active faults sources for the Pátzcuaro–Acambay fault system (Mexico): fractal analysis of slip rates and magnitudes <i>M</i><sub>w</sub> estimated from fault length

2018 ◽  
Vol 18 (11) ◽  
pp. 3121-3135
Author(s):  
Avith Mendoza-Ponce ◽  
Angel Figueroa-Soto ◽  
Diana Soria-Caballero ◽  
Víctor Hugo Garduño-Monroy
Keyword(s):  
Time Domain ◽  
Fractal Analysis ◽  
Active Faults ◽  
Slip Rate ◽  
Spatial Domain ◽  
Fault System ◽  
Slip Rates ◽  
Oblique Convergence ◽  
Definition Of ◽  
Intrinsic Definition

Abstract. The Pátzcuaro–Acambay fault system (PAFS), located in the central part of the Trans-Mexican Volcanic Belt (TMVB), is delimited by an active transtensive deformation area associated with the oblique subduction zone between the Cocos and North American plates, with a convergence speed of 55 mm yr−1 at the latitude of the state of Michoacán, Mexico. Part of the oblique convergence is transferred to this fault system, where the slip rates range from 0.009 to 2.78 mm yr−1. This has caused historic earthquakes in Central Mexico, such as the Acambay quake (Ms=6.9) on 19 November 1912 with surface rupture, and another in Maravatío in 1979 with Ms=5.6. Also, paleoseismic analyses are showing Quaternary movements in some faults, with moderate to large magnitudes. Notably, this zone is seismically active, but lacks a dense local seismic network, and more importantly, its neotectonic movements have received very little attention. The present research encompasses three investigations carried out in the PAFS. First, the estimation of the maximum possible earthquake magnitudes, based on 316 fault lengths mapped on a 15 m digital elevation model, by means of three empirical relationships. In addition, the Hurst exponent Hw and its persistence, estimated for magnitudes Mw (spatial domain) and for 32 slip-rate data (time domain) by the wavelet variance analysis. Finally, the validity of the intrinsic definition of active fault proposed here. The average results for the estimation of the maximum and minimum magnitudes expected for this fault population are 5.5≤Mw≤7. Also, supported by the results of H at the spatial domain, this paper strongly suggests that the PAFS is classified in three different zones (western PAFS, central PAFS, and eastern PAFS) in terms of their roughness (Hw=0.7,Hw=0.5,Hw=0.8 respectively), showing different dynamics in seismotectonic activity and; the time domain, with a strong persistence Hw=0.949, suggests that the periodicities of slip rates are close in time (process with memory). The fractal capacity dimension (Db) is also estimated for the slip-rate series using the box-counting method. Inverse correlation between Db and low slip-rate concentration was observed. The resulting Db=1.86 is related to a lesser concentration of low slip-rates in the PAFS, suggesting that larger faults accommodate the strain more efficiently (length ≥3 km). Thus, in terms of fractal analysis, we can conclude that these 316 faults are seismically active, because they fulfill the intrinsic definition of active faults for the PAFS.

Fragmentation of the Sinai Plate indicated by spatial variation in present-day slip rate along the Dead Sea Fault System

2020 ◽  
Vol 221 (3) ◽  
pp. 1913-1940
Author(s):  
Francisco Gomez ◽  
William J Cochran ◽  
Rayan Yassminh ◽  
Rani Jaafar ◽  
Robert Reilinger ◽  
...  
Keyword(s):  
Continental Margin ◽  
Plate Boundary ◽  
Slip Rate ◽  
Dead Sea ◽  
Fault System ◽  
Slip Rates ◽  
Dead Sea Fault System ◽  
The Dead ◽  
Gps Velocities ◽  
Splay Faults

SUMMARY A comprehensive GPS velocity field along the Dead Sea Fault System (DSFS) provides new constraints on along-strike variations of near-transform crustal deformation along this plate boundary, and internal deformation of the Sinai and Arabian plates. In general, geodetically derived slip rates decrease northwards along the transform (5.0 ± 0.2 to 2.2 ± 0.5 mm yr−1) and are consistent with geological slip rates averaged over longer time periods. Localized reductions in slip rate occur where the Sinai Plate is in ∼N–S extension. Extension is confined to the Sinai side of the fault and is associated with prominent changes in transform geometry, and with NW–SE striking, left-lateral splay faults, including the Carmel Fault in Israel and the Roum Fault in Lebanon. The asymmetry of the extensional velocity gradients about the transform reflects active fragmentation of the Sinai Plate along the continental margin. Additionally, elastic block modelling of GPS velocities requires an additional structure off-shore the northern DSF segment, which may correspond with a fault located along the continental margin, suggested by prior geophysical studies.

scholarly journals Segmentation and termination of the surface rupture zone produced by the 1932 Ms 7.6 Changma earthquake: New insights into the slip partitioning of the eastern Altyn Tagh fault system

Lithosphere ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 19-39
Author(s):  
Jiaxin Du ◽  
Bihong Fu ◽  
Qiang Guo ◽  
Pilong Shi ◽  
Guoliang Xue ◽  
...  
Keyword(s):  
Slip Rate ◽  
Rupture Zone ◽  
Fault System ◽  
Surface Rupture ◽  
Altyn Tagh Fault ◽  
Slip Rates ◽  
Leading Role ◽  
Surface Rupture Zone ◽  
Altyn Tagh ◽  
Slip Partitioning

Abstract The 1932 Ms 7.6 earthquake struck the active Changma fault in the NE Tibetan Plateau, and produced a distinct surface rupture along the fault zone. However, the segmentation and termination of the surface rupture zone are still unclear. In this paper, the active tectonic analyses of multiple satellite images complemented by field investigations present the 120-km-long surface rupture zone, which can be divided into five discrete first-order segments, ranging from 14.4 to 39.56 km in length, linked by step-overs. Our results also indicate that the 1932 rupture zone could jump across step-overs 0.3–4.5 km long and 2.2–5.4 km wide in map view, but was terminated by a 6.3-km-wide restraining step-over at the eastern end. The left-lateral slip rates along the mid-eastern and easternmost segments of the Changma fault are 3.43 ± 0.5 mm/yr and 4.49 ± 0.5 mm/yr since 7–9 ka, respectively. The proposed tectonic models suggest that the slip rates on the Changma fault are similar to the slip rate on the eastern segment of the Altyn Tagh fault system near the junction point with the Changma fault. These results imply that the Changma fault plays a leading role in the slip partitioning of the easternmost segment of the Altyn Tagh fault system.

Sign in / Sign up

Export Citation Format

Share Document