Linkage of deep lithospheric structures to intraplate earthquakes: A perspective from multi-source and multi-scale geophysical data in the South China Block

Di, Qingyun; Tian, Fei; Suo, Yanhui; Gao, Rui; Li, Sanzhong; Fu, Changmin; Wang, Guangzeng; Feng, Li; Tan, Yuyang

doi:10.1016/j.earscirev.2021.103504

Cited by 13 publications

(3 citation statements)

References 151 publications

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“…Both electrical and seismic reflection images show the typical chevron anticlines of the Huaying Mountain fold-and-thrust belt thin-skinned structures. The interested reader should refer to [ 41 ] for more details. This paper shall focus on the Biyang depression case study.…”

Section: Case Studiesmentioning

confidence: 99%

Insight into skywave theory and breakthrough applications in resource exploration

Xue

et al. 2021

National Science Review

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Skywave refers to the electromagnetic wave reflected or refracted from the ionosphere and propagate in the form of a guided wave between the ionosphere and the Earth's surface. Since the skywave can propagate over large distances, it has been widely used in long-distance communication. This paper explores and demonstrates the feasibility of skywave for deep resource and energy exploration at depths up to 10 km. Theoretical and technical advancements were accomplished in furthering the skywave applications. A new solution method based on Green's function has been developed to study skywave propagation in a fully coupled lithosphere-air-ionosphere full space model. The model allows one, for the first time, to study skywave distribution characteristics in the lithosphere containing inhomogeneity such as ore deposits or oil and gas reservoirs. This model also lays a foundation for skywave data processing and interpretation. On a parallel line, we have developed a multi-channel, broadband, low-noise, portable data acquisition system suitable for receiving skywave signals. Using the skywave field excited by a high-power fixed source located in the central China, actual field surveys have been carried out in some areas in China including the Biyang depression of Henan Province. The initial results appear encouraging – The interpreted resistivity models prove to be consistent with those of seismic exploration and known geological information, and the exploration cost is only about 1/4 to 1/10 of seismic surveys. These initial successful applications of the skywave theory lay a solid foundation for further verification of the new method.

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Section: Case Studiesmentioning

confidence: 99%

Insight into skywave theory and breakthrough applications in resource exploration

Xue

et al. 2021

National Science Review

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“…Extensive studies have been conducted to understand the seismogenic structure and physical causes of large intraplate earthquakes (e.g., Campbell, 1978; Di et al., 2021; Iio & Kobayashi, 2002; Johnston & Schweig, 1996; Stevenson et al., 2006; Talwani, 1988, 1999). Several studies proposed to link their occurrence with the presence of localized weak zones forming from either the intersections of faults (Dentith & Featherstone, 2003; Gangopadhyay & Talwani, 2003; Gangopadhyay et al., 2004; Johnston & Schweig, 1996; Talwani, 1988, 1999; Zhu et al., 2022), oriented ancient rifts (e.g., Kato et al., 2009; Zoback & Richardson, 1996), fluid‐related weakening zone (Craig et al., 2017; Gardonio et al., 2018; Lin et al., 2022; Pavan Kumar et al., 2017; Umeda et al., 2011), or vicinity of booming plutons (e.g., Stevenson et al., 2006).…”

Section: Introductionmentioning

confidence: 99%

Seismological Constraints on the Causes of Intraplate Earthquakes in Yangjiang Region, South China

Li,

Zhang,

Shen

et al. 2024

JGR Solid Earth

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Large earthquakes that occur away from plate boundaries (i.e., large intraplate earthquakes), though rare, could cause heavy damage. Understanding their causes could help with seismic hazard assessment. In this study, we image the seismogenic structure under the 1969 Ms6.4 Yangjiang intraplate earthquake within the stable South China Block with a high‐resolution three‐dimensional shear‐wave velocity model constructed from ambient noise tomography based on a dense nodal seismic array. The model images relatively low velocities at a fault intersection region from the surface to at least 13 km depth in the Yangjiang seismogenic zone. Given spatial links among the intersection zone of faults, surface seawater, and low velocities, we interpret the low velocities to reflect the presence of seawater‐filled, highly fractured rocks created by the intersection of faults. We infer that the seawater infiltration through densely‐fractures could have elevated pore pressure in the long term, as evidenced by low earthquake b values at 8–13 km depths. We hypothesize that this long‐term seawater infiltration could have lowered the stress threshold of earthquake occurrence and contributed to the generation of the 1969 Ms6.4 Yangjiang earthquake. We propose that the large intraplate earthquakes within stable plates tend to occur in regional weakening regions (e.g., fault intersections) favorable to stress buildup. Given sufficient tectonic stress accumulation, the long‐term hydrologically driven crustal stress variations could play an essential role in triggering large intraplate earthquakes. This study could potentially contribute to improving seismic hazard assessment in the Guangdong‐Hong Kong‐Macao‐Greater‐Bay‐Area, China.

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“…If the building did not collapse during the first (short) phase, then the damage is likely repairable [Dalle et al, 2021;Wang and Shen, 2020]. Therefore, when designing a building, it is very important to estimate the level of stress from the shock during its short phase in order to ensure the strength of the structure [Qingyun et al, 2021]. The present work aims to conduct a series of numerical tests to determine the sensitivity of nonlinear dynamic systems to seismic conditions.…”

Section: Introductionmentioning

confidence: 99%

Seismic assessment of high-rise buildings through dynamic nonlinear analysis

Wu¹,

Lin

2022

Annals of Geophysics

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This paper present a seismic assessment of high-rise buildings using dynamic nonlinear analysis. The work touches upon an urgent problem of ensuring the stability of high-rise buildings under seismic load and preventing their destruction. A mathematical model has been built to investigate the effect of seismic activity on high-rise buildings in the Sichuan province (China). Pearson’s test was used to compare the statistical dependence between variables in the study period. Values with a statistical significance of p ≤ 0.05 were considered statistically significant. The probability of earthquakes of 8 magnitude and above was found to be 5% with a frequency of recurrence of 3900 ± 400 yrs, p ≤ 0.001. The paper presents the technique of refractive geophysical research. The seismic reliability index was n = 3.2 at t = 5 s. The standard deviation was 2% and the χ2 statistic was 0.95. The overall (0.59, or 59%) and conditional (0.06, or 6%) risks of failure under seismic load were calculated for high-rise buildings with a service life of 100 years. The coefficients of seismic activity were as follows: 3.203 at the conditional risk level of 5%; 2.97 at the conditional risk level of 10%; and 2.523 at the conditional risk level of 30%.

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Linkage of deep lithospheric structures to intraplate earthquakes: A perspective from multi-source and multi-scale geophysical data in the South China Block

Cited by 13 publications

References 151 publications

Insight into skywave theory and breakthrough applications in resource exploration

Insight into skywave theory and breakthrough applications in resource exploration

Seismological Constraints on the Causes of Intraplate Earthquakes in Yangjiang Region, South China

Seismic assessment of high-rise buildings through dynamic nonlinear analysis

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