Interseismic Deformation and Earthquake Hazard along the Southernmost Longitudinal Valley Fault, Eastern Taiwan

Chuang, R. Y.; Miller, M. Meghan; Chen, Yue‐Gau; Chen, Horng-Yue; Ôta, Yôko; Yu, Shui-Beih; Rubin, Charles M.; Sieh, Kerry; Chung, Lap-Loi

doi:10.1785/0120110262

Cited by 7 publications

(3 citation statements)

References 29 publications

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“…This model highlights the distinction between sections of the fault that are creeping and the ones that remain locked. As previously recognized, the southern portion of the fault is creeping near the surface [ Angelier et al , ; Lee et al , , , , ; Hsu and Burgmann , ; Lee et al , ; Chang et al , ; Cheng et al , ; Hsu et al , ; Huang et al , ; Peyret et al , ; Champenois et al , ; Chen et al , ; Chuang et al , ]. Our study highlights that, on the contrary, the northern part is mostly locked.…”

Section: Secular Interseismic Modelsupporting

confidence: 80%

Spatiotemporal evolution of seismic and aseismic slip on the Longitudinal Valley Fault, Taiwan

et al. 2014

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The Longitudinal Valley Fault (LVF) in eastern Taiwan is a high slip rate fault (about 5 cm/yr), which exhibits both seismic and aseismic slip. Deformation of anthropogenic features shows that aseismic creep accounts for a significant fraction of fault slip near the surface, whereas a fraction of the slip is also seismic, since this fault has produced large earthquakes with five Mw>6.8 events in 1951 and 2003. In this study, we analyze a dense set of geodetic and seismological data around the LVF, including campaign mode Global Positioning System(GPS) measurements, time series of daily solutions for continuous GPS stations (cGPS), leveling data, and accelerometric records of the 2003 Chenkung earthquake. To enhance the spatial resolution provided by these data, we complement them with interferometric synthetic aperture radar (InSAR) measurements produced from a series of Advanced Land Observing Satellite images processed using a persistent scatterer technique. The combined data set covers the entire LVF and spans the period from 1992 to 2010. We invert this data to infer the temporal evolution of fault slip at depth using the Principal Component Analysis‐based Inversion Method. This technique allows the joint inversion of diverse data, taking the advantage of the spatial resolution given by the InSAR measurements and the temporal resolution afforded by the cGPS data. We find that (1) seismic slip during the 2003 Chengkung earthquake occurred on a fault patch which had remained partially locked in the interseismic period, (2) the seismic rupture propagated partially into a zone of shallow aseismic interseismic creep but failed to reach the surface, and (3) that aseismic afterslip occurred around the area that ruptured seismically. We find consistency between geodetic and seismological constraints on the partitioning between seismic and aseismic creep. About 80–90% of slip on the southern section of LVF in the 0–26 km, seismogenic depth range, is actually aseismic. We infer that the clay‐rich Lichi Mélange is the key factor promoting aseismic creep at shallow depth.

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Section: Secular Interseismic Modelsupporting

confidence: 80%

Spatiotemporal evolution of seismic and aseismic slip on the Longitudinal Valley Fault, Taiwan

et al. 2014

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“…According to GPS velocity data from 2001 to 2003, the Pingting Terrace is moving at an approximate rate of 28.6 mm/yr in the northwest direction (ERPN station). There's a significant velocity difference on both sides of the fault (approximately 16.9 mm/yr), suggesting a slight left-lateral oblique motion (Chuang et al, 2012). The MT-InSAR results from ALOS images taken between 2007 and 2010 show a reverse slip velocity of about 7 mm/yr for the Lichi Fault (PTF1) in the LOS direction, while the Chihshang Fault (PTF2) of the 2nd Terrace has a reverse activity rate of 20 mm/yr in the LOS direction (Deffontaines et al, 2017).…”

Section: Geological Backgroundmentioning

confidence: 99%

“…Strike-slip components are also observed in the fault activity. Previous studies have also indicated the presence of strike-slip components within the Pingting Terrace based on topographic features and geodetic monitoring (Shyu et al, 2008;Chuang et al, 2012). Accordingly, our research team employed the Riedel shear structures model to analyze the geometric relationships, regional stress, and principal shear directions of the surface ruptures within the Pingting Terrace.…”

Section: Riedel Shear Structure Analysismentioning

confidence: 99%

Investigating the Structure under the Pingting Terrace from the Co-Seismic Deformation of the 2022 Guanshan Earthquake

Hsu,

Chang,

Yen

et al. 2023

Preprint

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On September 17th and 18th, 2022, shallow earthquakes with magnitudes of 6.6 (ML) and 6.8 (ML) occurred in the eastern Taiwan Longitudinal Valley, which marks the collision zone between the Philippine Sea plate and the Eurasian plate, and led to noticeable surface deformation and ruptures within 70 km. This study primarily focuses on the southernmost section of the rupture zone - the Pingting Terrace. Surface rupture locations and behaviors correspond to changes in topography, providing mutual confirmation that the deformation behavior of Pingting Terrace is complex. Based on the distribution of surface ruptures and topography changes, this study roughly divides the Pingting Terrace into northern and southern segments, using the central concave feature as a boundary. The Riedel shear model analysis results show that the principal shear directions in the northern and southern segments are N-S trending and azimuth 20°, respectively. The maximum principal stress orientations are around 135° for the northern and 155° for the southern segments. These findings align with the fault mechanical investigation of the Lichi Mélange in the northern Muken River area of the Pingting Terrace. This suggests spatial changes in shear zone orientations within the Lichi Mélange, which contribute to developing pressure ridges due to transpressional forces. As a result, the Pingting Terrace experiences rapid uplift, causing the Luliao River to migrate southward into the Beinan River, while the eastern Beinan River turns to the eastward edge of the Pingting Terrace.

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Investigating the structure under the Pingting Terrace from the co-seismic surface rupture of the 2022 Guanshan earthquake

Hsu,

Chang,

Yen

et al. 2024

Terr Atmos Ocean Sci

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On September 17th and 18th, 2022, shallow earthquakes with magnitudes of 6.6 (ML) and 6.8 (ML) occurred in the eastern Taiwan Longitudinal Valley, which marks the collision zone between the Philippine Sea plate and the Eurasian plate, and led to noticeable surface deformation and ruptures within 70 km. This study primarily focuses on the southernmost section of the rupture zone—the Pingting Terrace. Surface rupture locations and behaviors correspond to changes in topography, providing mutual confirmation that the deformation behavior of Pingting Terrace is complex. Based on the distribution of surface ruptures and topography changes, this study roughly divides the Pingting Terrace into northern and southern segments, using the central concave feature as a boundary. The Riedel shear model analysis results show that the principal shear directions in the northern and southern segments are N–S trending and azimuth 20°, respectively. The maximum principal stress orientations are around 135° for the northern and 155° for the southern segments. These findings align with the fault mechanical investigation of the Lichi Mélange in the northern Muken River area of the Pingting Terrace. This suggests spatial changes in shear zone orientations within the Lichi Mélange, which contribute to developing pressure ridges due to transpressional forces. As a result, the Pingting Terrace experiences rapid uplift, causing the Luliao River to migrate southward into the Beinan River, while the eastern Beinan River turns to the eastward edge of the Pingting Terrace.

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Interseismic Deformation and Earthquake Hazard along the Southernmost Longitudinal Valley Fault, Eastern Taiwan

Abstract: About half of the 8 cm=yr of oblique convergence across the active con-

Cited by 7 publications

References 29 publications

Spatiotemporal evolution of seismic and aseismic slip on the Longitudinal Valley Fault, Taiwan

Spatiotemporal evolution of seismic and aseismic slip on the Longitudinal Valley Fault, Taiwan

Investigating the Structure under the Pingting Terrace from the Co-Seismic Deformation of the 2022 Guanshan Earthquake

Investigating the structure under the Pingting Terrace from the co-seismic surface rupture of the 2022 Guanshan earthquake

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