Figure - available from: Tectonics
This content is subject to copyright. Terms and conditions apply.
Geological and geomorphological interpretation map of the Dongwugaigou site (Site 3). (a) Geomorphic interpretive map of the Dongwugaigou site. (b) One trench has been excavated on the low terrace (see a). (c) Cross‐sectional view of the terrace near the trench. The heights of the high terrace and low terrace from the basin are 15.3 and 3.3 m, respectively. (d and e) The Dongwugaigou trench reveals three earthquake events. A detailed stratum description of this trench can be found in Appendix B1.
Source publication
The activity of major active faults around the Ordos Block is of great interest to seismologists, as at least four M ≥ 8 earthquakes have been recorded. However, the Linhe Basin, which has the thickest Cenozoic sediments, has no record of large earthquakes. Does this basin have the structural conditions required for large earthquakes? The northern...
Similar publications
Mobile edge computing has been developed as a promising technology to extend diverse services to the edge of the Internet of Things system. Motivated by the high flexibility and controllability of unmanned aerial vehicles (UAVs), a multi‐UAVs‐assisted mobile edge computing system is studied to reduce the total consumption of time and energy of term...
Citations
... Over the last 40 years, scholars have extensively studied the characteristics of the Late Quaternary activity, vigorous earthquake activity, and seismic risk of those northern boundary faults, which provide insights into active structures and recurrence patterns of local strong earthquakes along active faults (Ma et al., 1998;Ma et al., 2000;Deng et al., 1999;Jiang et al., 2001;Ran et al., 2002Ran et al., , 2003bYang et al., 2002;Yang et al., 2003;Nie et al., 2011;Rao et al., 2016;Rao et al., 2019;Liang et al., 2019;He et al., 2020). More recent results showed that the LPF-SPF experienced seven paleoearthquakes during the Holocene, with a recurrence period of 1.37 ± 0.11 ka and an earthquake risk of M > 8.0 (Dong, 2016;Dong, 2016;Liang et al., 2021;Ma and Dong, 2024). The fourteen paleoearthquake events occurred during the Holocene in the DPF, including the 849 A.D. earthquake Yuan et al., 2023). ...
... In other words, the Late Quaternary activity of the Langshan Piedmont Fault, Sertengshan Piedmont Fault, Daqingshan Piedmont Fault, and Wulashan Piedmont Fault are the most active. According to related studies, the maximum possible magnitude of the earthquake in the Langshan Piedmont Fault -Sertengshan Piedmont Fault is 8.1 (Liang et al., 2021). The Daqingshan Piedmont Fault has the highest probability of producing an earthquake with a magnitude of 7.0 or 7.5 in the next 100 years and the Wulashan Piedmont Fault is more likely to produce an earthquake with a magnitude 7.0 or more significant in the next hundred years (Pan, 2021). ...
The Late Quaternary activity characteristics of secondary faults located between the main active faults at the boundaries of large basins are of great significance to the overall understanding of regional seismic hazards. The Wulashan Northern Fault (WNF) is located on the northern side of the Ordos Block, within the Northern Margin Fault Basin in North China, between the Sertengshan Piedmont Fault and Daqingshan Piedmont Fault. Current research on the geometry and kinematics of the WNF needs to be improved. In this study, we aimed to determine the shallow structural characteristics and Late Quaternary activity of the WNF using shallow seismic exploration and composite drilling geological cross-sectional analysis. The results indicate that the WNF is not a single surface fault but multiple branches with a northward-dipping stepped surface distribution. The latest activity of the F1 branch with a maximum coseismic vertical dislocation of 0.9 m occurred before 47.08 ± 3.7 ka B.P. The latest and older activities of the branch of F2 with a maximum coseismic vertical dislocation of 0.96 m and 1.15 m occurred before 73.8 ± 2.8 ka B.P. and 91.2 ± 4.4 ka B.P., respectively. According to a series of empirical relationships between length of surface rupture and magnitude, the maximum potential magnitude of the earthquake was determined to be M = 6.5–7.0. We argue that even though the Late Quaternary activity of the WNF was weaker than that of the other boundary faults of the Hetao Basin, the local urban and rural planning and land and resources construction in the Hetao Basin region should pay attention to the seismic risk of the WNF as an independent section in the future for the effect of secular tectonic loading.
... The formation of the Hetao-Yinchuan graben system is generally controlled by normal faulting activities concentrated along the piedmont sides of these grabens (Figs 1 d and e). Although strong earthquakes are mainly governed by piedmont faults (Fig. 1 b, Ran et al. 2003 ;Dong et al. 2018 ;Liang et al. 2021 ), buried faults also possess the potential to generate strong earthquakes (Chai et al. 2006 ;Lin et al. 2013Lin et al. , 2015Liang et al. 2018 ). ...
... In contrast to the significant crustal e xtension observ ed in the western se gment of the Hetao graben, no prominent strike-slip motion is evident in Fig. 4 (h). This indicates that the Langshan Fault is dominated by normal dip-slip faulting, consistent with previous geological studies (Dong et al. 2018 ;Liang et al. 2021 ). Fig. 5 shows that the nor ther n segment of the western margin of the Ordos block undergoes right-lateral shear motion accompanied by crustal extension. ...
The northwestern margin of the Ordos block is structurally separated by the Yinchuan–Hetao graben system. As one of the most active intracontinental graben systems within the Eurasian continent, its kinematic pattern of crustal extension is crucial for unraveling the ongoing processes of intracontinental graben formation, while it remains unclear principally due to a lack of geological constraints on crustal deformation. We obtained and analysed a densified GNSS (Global Navigation Satellite System) velocity field in this region. Our results suggest that the western margin of the Hetao graben exhibits the NW-directed crustal extension (∼ 1.1 mm yr−1), which can be attributed to the conjugate transtension resulting from the left-lateral motion along the E–W-trending northern boundaries of the Alashan and Ordos blocks, as well as the right-lateral motion along the N–S-trending western margin of the Ordos block. Additionally, in response to the NE-directed extrusion of the Tibetan Plateau, the Alashan block undergoes approximately NE-directed contraction (4.9 ± 1.1 nanostrain yr−1) and NW-directed extrusion (2.8 ± 0.8 nanostrain yr−1), which vacates space for the crustal extension of the Yinchuan graben with a rate of 0.9 ± 0.1 mm yr−1. Although it is challenging to determine whether the left-lateral motion (approximately 1 mm yr−1) along the E–W-trending Hetao graben is the far-field effect of western Pacific subduction, the gradual decrease in right-lateral motion from the N–S-trending western margin of the Ordos block toward the north side of the Yinshan Orogen manifests the far-field effect of the Indo-Eurasian plate convergence extending into the Mongolian Plateau.
... Dong et al. [27] had proposed the "link-up" model of the NE-striking Langshan Piedmont Fault and further inferred that link-up occurred in the late Pleistocene. The Langshan Piedmont Fault is now connected to the Sertengshan Piedmont Fault [60,71]. Abandoned fault branches after fault linkage are extensive, not only from the viewpoint of theoretical model research [64][65][66] and geological observation case study [67][68][69]. ...
... Different activity properties were observed in different sections of the Sertengshan. At the fault turning point, the western sections of the Sertengshan Piedmont Fault continue eastward after passing through Wubulangkou, and the eastern sections of the Sertengshan Piedmont Fault continue northwest, which are gradually connected by the compressive stress caused by the movement and connection of the fault zones towards each other [71]. Tectonic activity is strong at the fault turning point, and geomorphological evolution occurs in the juvenile and prime stages. ...
Geomorphic parameters, which reflect the migration of drainage divide responses, are widely used to assess tectonic activity. There have been several large earthquakes in the history of the Hetao Basin, within which the Sertengshan Piedmont Fault is important. This study highlights certain references for regional seismic risk assessment. Few studies have been conducted on the Sertengshan area from the perspective of geomorphic parameters. In this paper, ksn, HI, and Vf were obtained to indicate the tectonic activity in the Sertengshan area, and and Gilbert metrics were extracted to explore the state of the drainage basin. The results show that the tectonic activity varies spatially and is strong in the western part of the southern Sertengshan region and the northern part corresponding to the turning point of the fault. Most of the Sertengshan area is in the prime and old stages of geomorphological evolution, whereas some areas are in the juvenile stage. The old stage was mainly concentrated in the northern region, and the southern part was younger than the northern region. Overall, the Sertengshan area is tectonically active and affected by the activity of the Sertengshan Piedmont Fault. The western part of the divide migrated northwest, while the central and eastern parts tended to move southward. We suggest that the divide migration is influenced by tectonic activity and tends to move towards the direction of lower tectonic activity.
... Next, we briefly discuss the tectonic significance of the Qinghe fault from the perspective of continental rifts. The Weihe rift and other rifts (Shanxi rift system, Yinchuan rift, Jilantai rift, Hetao rift) around the Ordos block differ significantly in tectonic activity (Deng et al., 1984;Deng and Liao, 1996;Lei et al., 2008;Middleton et al., 2017;Liang et al., 2021;Su et al., 2021). The main differences can be summarized as follows. ...
The Weihe graben is an active Cenozoic continental rift with frequent seismic activity. The previous work focused on the graben boundary faults, but less work has been conducted on the faults in the internal graben. The Weihe basin is an economically developed and densely populated area. Therefore, identifying these potential risks is significant for the evaluation of regional seismic hazards and to understand the evolution of continental rifts. Prior work used oil exploration methods to document a fault (we named it “Qinghe fault”) in the Qinghe river area of Sanyuan County, north of Xi’an. But the shallow structure and activity was not clear. Therefore, we carried out shallow seismic detection and borehole exploration, as well as a geological survey in the area. Based on seismic reflection profile and boreholes, the Qinghe fault is the main fault and with other secondary faults, together they constitute a typical Y-shaped structure, with a fracture zone width ∼4 km. Combined with the field survey, we provide evidence that the Qinghe fault is a Holocene active fault and capable of earthquakes of magnitude 5.2–5.5. The discovery of the Qinghe fault shows that the Weihe rift is active, and the faults inside the rift play an important role in tectonic deformation.
... The epicentres of the latter two historical earthquakes were located southward of the central section of the Serteng Shan fault. Moreover, the precisely occurring time of events on the central section provides clues to the cascade rupture pattern along the Serteng Shan fault (Liang et al. 2021;Peng et al. 2022). However, the rupture history of the earthquake, notably the most recent earthquake, along this section remains controversial (Liang et al. 2021;Peng et al. 2022). ...
... Moreover, the precisely occurring time of events on the central section provides clues to the cascade rupture pattern along the Serteng Shan fault (Liang et al. 2021;Peng et al. 2022). However, the rupture history of the earthquake, notably the most recent earthquake, along this section remains controversial (Liang et al. 2021;Peng et al. 2022). Thus, additional palaeoevents from supplemental trenches are required to improve and extend the rupture history along the central section of the Serteng Shan fault. ...
... Previous palaeoseismic investigations presented doses of events data recorded in the 12 trenches along the Serteng Shan fault (Wu et al. 1996;Yang et al. 2002Yang et al. , 2003Li-chun et al. 2003;He et al. 2018). Liang et al. (2021) analysed these data combing with event sequence of the Lang Shan fault to conclude that the latest event occurred in 7 BC However, Peng et al. (2022) that the earthquake in 7 BC only ruptured the Lang Shan fault. Recently, Bi et al. (2022) mapped the offset terraces and measured their cumulative vertical displacements along the Serteng fault based on the 185 km long 1-m-resolution DEM (digital elevation model) derived from airborne Lidar (Light Detection and Ranging) data. ...
Reliable palaeoseismological data are crucial for understanding the rupture history and seismic hazard assessment of a specific seismogenic structure. Many large earthquakes occurred around
the Ordos Block of northern China. However, due to insufficient age data and event interpretations, the rupture patterns of the block are still poorly known. This study focuses on the central section of the Serteng Shan fault that is situated at the north margin of the Ordos Block. We present palaeoseismic sequence of faults using trenches combined with dating methods, including optically stimulated luminescence and 14C dating. We collected eleven optically stimulated luminescence (OSL) and seven radiocarbon samples to constrain the timing of palaeoseismic events in the excavated trench exposures along the fault strand. The results show that the studied samples were deposited since the latest Pleistocene, and the ages are, within uncertainty, in the stratigraphic order. The cause of the most recent surface rupture is still not clear. Four other older events, which occurred in 3.1–3.9 ka, 5.8−6.5 ka, 10.8–13.1 ka, and 14.2–16.5 ka, likely extended at different lengths along the Serteng Shan fault.
... Trenching is the most direct and efficient approach in paleoseismology to reveal evidence of faulting recorded in surface sediments. This method enables determining the paleoearthquake history of a fault (including the timing of earthquake occurrences, co-seismic displacement, and elapsed time) and understanding its rupture behavior, which is of great significance in accessing its seismic risk (Wallace, 1981;Sun et al., 2015;Liang et al., 2021). The key problem in the study of the paleoearthquake is the selection of the excavation site, which determines the success of its paleoseismic research. ...
The Liulengshan Fault (LLSF), which lies on the northeastern edge of the Ordos Plateau, is a controlling boundary fault in the northern part of the Shanxi Rift system (SRS). The displaced landforms show that the fault has undergone strong and frequent late-Quaternary seismic activities. In 1989 and 1991, two moderate–strong earthquake swarms (Ms=6.1 and Ms=5.8) successively occurred in the LLSF, and GPS velocity shows that the areas are extending at around 1–2 mm/a. However, there is no surface-rupturing earthquake reported on the LLSF in historical records. Thus, the study of paleoseismic history and rupture behavior of paleoearthquakes in late-Quaternary on the LLSF is of fundamental importance for understanding the future seismic risk of this fault. To solve these problems, we conducted paleoseismological trench excavations at two sites on the LLSF to establish its paleoearthquake history. On the basis of the field geological survey and interpretation of high-precision topographic data, we carried out large-scale fault mapping and excavated two trenches in Xujiabao and Luofengwa across the LLSF. Then, four events in the Xujiabao trench and three events in the Luofengwa trench are identified. Finally, combined with radiocarbon dating (C14), optically stimulated luminescence (OSL) and OxCal modeling, we constrained the ages of these events. Together with the previous results of paleoseismology in Yin et al. (1997), we consider that different segments of the LLSF may rupture together at the same time. Therefore, a total of six paleoearthquake events since late-Quaternary have been finally confirmed at 44,151–30881a, 40,163-28045a, 28,233-19215a, 16,742-12915a, 12,788-8252a, and 8203–2300a BP. According to the empirical relationships between moment magnitude and rupture length, the best estimated magnitude is inferred to be in the range between Mw 6.9 and Mw 7.7. Considering the strong late-Quaternary activity and a long earthquake elapsed time, we propose that the LLSF might have a high seismic hazard potential in the near future.
... The Hetao Basin has a long history of tectonic activity. The Quaternary witnessed strong tectonic activity and frequent and strong earthquakes (China Earthquake Administration "Ordos Peripheral Active Fault System" research group, 1988, He et al., 2018;Liang et al., 2022). Since the twentieth century, several earthquakes have successively occurred in the rift basin, including the 1929 Bikeqi M6.0 earthquake, the 1934 Wuyuan M6 3/4 earthquake, the 1976 Helinger M6 1/3 earthquake, the 1976 Bayanmuren M6.2 earthquake, the 1979 Wuyuan M6.0 earthquake, and the 1996 Baotou M6.0 earthquake (Figure 1), as well as several small to moderate earthquakes of M4-5 (Chen, 2002;Ran et al., 2002). ...
... The Hetao Basin comprises three subbasins in a right-order diagonal, including the Linhe, Baiyanhua, and Hubao basins, which are asymmetrical basins that are deep in the north and shallow in the south, controlled by the Sertengshan, Wulashan, and Daqingshan piedmont normal faults on the north side. The maximum thickness of the Quaternary strata can reach 2,400 m (Li & Nie, 1987;Liang et al., 2022). The Sertengshan piedmont fault, with a total length of approximately 150 km, is divided into the Langshankou, Hongqicun, Kuluebulong, and Dashetai segments from west to east . ...
... EL1 is jointly defined by the Dongwugaigou Trench (TS1) and Fanrong Trench (TS2). Liang et al. (2022) revealed two paleoearthquake events in the Dongwugaigou Trench; Event 1 occurred later than 2.44 ± 0.03 ka, and Event 2 occurred slightly earlier than 5.45 ± 0.03 ka. The latest event revealed by Rao et al. (2016) in the Fanrong Trench occurred from 1.88 ± 0.03 to 2.05 ± 0.03 ka. ...
Long paleoearthquake series are crucial for understanding the recurrence patterns of active faults and evaluating the seismic hazards of faults. In this study, the first semiquantitative evaluation of paleoearthquake events from trenches was applied to normal faults, and classification criteria for identifying paleoearthquakes in trenches on normal faults are proposed to demonstrate the feasibility of semiquantitative evaluations of paleoearthquake events on normal faults. In this study, 72 paleoearthquake trench sites on normal faults around the world were analyzed, and the main indicators for identifying paleoearthquakes on normal faults include the presence of vertical offset (VO), collapse wedge (CW), fissure (FIS), buried paleosol (BP), angular unconformity (AU), upward termination (UT), and sand liquefaction (LF) features. To describe and apply this semiquantitative evaluation method for paleoearthquake events on normal faults, 33 trenches for paleoearthquakes on a fault system in the northern margin of the Hetao Basin were comprehensively analyzed to determine Holocene paleoearthquake events on the Sertengshan, Wulashan, and Daqingshan piedmont faults, and the reliability of paleoearthquake events is discussed. The integrity of the paleoearthquake events obtained was tested by the displacement limit method. The Holocene paleoearthquake recurrence on the three faults was quasiperiodic; the coefficients of variation (COVs) were 0.44, 0.58, and 0.4.
... Dong et al. (2018a) and Rao et al. (2016) revealed that the fault is an important seismic zone in the Hetao Basin through trenching, dating, and other methods. The average recurrence period of strong earthquakes is about 2,500 A, and the average magnitude of each earthquake reaches 7-8 (Dong et al., 2018a(Dong et al., , 2018bLiang et al., 2021). At present, the recurrence period of strong earthquakes at the fault has been exceeded, so there is a great possibility of destructive, strong earthquakes occurring again (Dong et al., 2018a). ...
... Li et al. (2015) and Rao et al. (2016) believe that the latest earthquake rupture event of LPF may be related to the great earthquake in 7 BC. Liang et al. (2021) believe that the magnitude of the earthquake in 7 BC reached 8.1, and there is still a risk of magnitude 7.4-8.0 earthquakes in this area. ...
... earthquakes in this area. Due to the lack of large earthquakes recorded by modern instruments in the fault depression structural area of LLA, the existing research results in this area focus on geomorphology and paleoseismology (Jia et al., 2016;Rao et al., 2016;He et al., 2017He et al., , 2018Dong et al., 2018aDong et al., , 2018bDong et al., , 2018cHe et al., 2020;Zhang et al., 2020;Li J. et al., 2021;Liang et al., 2021;Xu et al., 2022). The results obtained lack the support of deep geophysical data. ...
A series of fault depression structures have developed around the Ordos Block. The Langshan Mountain-Linhe Basin area (LLA), located on the northwest edge of the Ordos Block, is a typical, normal tension fault system. A geological survey shows that the Langshan Piedmont fault (LPF) in this area has a large slip rate and indicates risk of earthquake preparation. Broadband magnetotelluric (MT) exploration research was recently carried out across the LLA in the NW–SE direction, and the three-dimensional deep electrical structure thus obtained revealed that the LPF in the LLA is an evident electrical boundary zone on the whole crustal scale and is the main boundary fault of the primary structural block of the Alxa and Ordos Blocks. The MT results also show that the Linhe Basin and Ordos Block belong to the same tectonic basement. The Linhe and Dengkou faults belong to the internal faults of the Ordos Block. The upper crust of the Langshan Mountain on the west side of LPF is characterized by high-resistivity, the middle and lower crust have a low-resistivity layer, and the Linhe Basin on the east side has a Cenozoic low-resistivity sedimentary layer of approximately 10 km thick, which reveals that the Linhe Basin is a faulted basin with sedimentary thickness around the Ordos Block. This indicates that the LLA has experienced continuous and strong tension, normal fault depression sedimentary activities since the Cenozoic era. The current Global Positioning System velocity field shows that there is an apparent NW–SE acceleration zone in the LLA. The leveling data indicate that Linhe Basin shows a subsidence trend relative to the Ordos Block, indicating that the area is undergoing continuous NW–SE tension and faulting. It is speculated that there is a risk of earthquake preparation in the LPF.
The Yabrai range‐front fault (YRF) is a large‐scale fault within the Alashan Block, located northeast of the Tibetan Plateau, which has undergone several surface rupture events on the southwestern and middle segments since the late Quaternary. As no relevant research has been conducted on the northeastern segment, paleoseismic data for this area are lacking, which restricts our overall understanding of the spatiotemporal and intensity distribution of strong earthquakes on the YRF. To address this problem, we conducted investigations based on trench wall interpretation and stratigraphic optically stimulated luminescence ages. Four paleoearthquakes were identified in the middle of the northeastern segment, and occurred after 11.6 ± 0.7 ka and between 11.6 ± 0.7 to 6.9 ± 0.5, 6.9 ± 0.5 to 4.8 ± 0.6 and 4.8 ± 0.6 to 3.9 ± 0.7 ka, respectively. Three paleoearthquake events, one of which occurred at around 23.6 ± 1.6 ka, were identified at the northeastern end of the fault. According to the spatiotemporal distribution of the ruptured events on the YRF, the middle segment may be a long seismic gap (~8 ka), and combined with the status of tectonic stress concentration, this segment can be regarded as a zone of high seismic probability with the ability to produce a magnitude 7.2 earthquake. Furthermore, from the late Pleistocene to early Holocene, cascading ruptures may have occurred on the middle and northeastern segments of the YRF, with magnitudes approaching 7.3. In terms of tectonic relationships, we suggest that the YRF and the Langshan piedmont fault are two independent faults even though they are connected.
The Sertengshan Range-front Fault (SRF) and Langshan Range-front Fault (LRF) constitute a normal fault system on the northern boundary of the Linhe Depression in its northwest, and an investigation of the LRF–SRF is significant for understanding the seismic activities of normal faults. We set four trenches at three study sites to reveal paleo-earthquakes in the western segment of the SRF (W-SRF) in this system, and established 5 surface rupture events along W-SRF since the Late Pleistocene. By integrating paleoseismic data from 27 trenches on multiple fault segments, we reconstructed the paleoseismic sequence for the LRF–SRF region since 15 ka, and identified 10 paleoseismic events with corresponding rupture segments and magnitudes. The slip rates at the three study sites decreased gradually from the west to east on the W-SRF, by comparing with previous studies, further evidencing that the tectonic activities of the two faults have gradually synchronized. Besides, based on the timing of the latest paleoseismic event (1.88−2.03 ka BP), earthquakes of > M 8 surface ruptures of > 200 km can occur in the northwestern Ordos Block and its seismic behavior revealed the seismogenic possibility of normal faults triggering an M>8 earthquske.
