Typical Riedel shear structures of the coseismic surface rupture zone produced by the 2021 Mw 7.3 Maduo earthquake, Qinghai, China, and the implications for seismic hazards in the block interior

Abstract. Mechanism of fluids in modifying mineralogy and geochemistry of the fault zone and the role of rock-fluid interaction in the faulting weakening is still debatable. Through analyzing mineralogical compositions, major elements as well as micro-structural characteristics of outcrop samples including wall rocks, low damage zone, high damage zone and oriented fault gouge samples from principal slip zone gouges, mineralogical and geochemical variations of the fault-rocks is observed from Shaba outcrop of Beichuan-Yingxiu surface rupture zone of the Mw 7.9 Wenchuan earthquake, China. The element enrichment/depletion pattern of fault rock shows excellent consistency with the variation pattern of minerals in terms of the notable feldspar alteration and decomposition, decarbonization, coseismic illitization, and chloritization that occurs in the fault zone. The Isocon analysis indicates that the overall mass loss amount of the Shaba fault zone is ranked as low damage zone

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Structure of the 1906 near-surface rupture zone of the San Andreas Fault, San Francisco Peninsula segment, near Woodside, California

Open-File Report ◽

10.3133/ofr20161063 ◽

2016 ◽

Author(s):

C.M. Rosa ◽

R.D. Catchings ◽

M.J. Rymer ◽

Karen Grove ◽

M.R. Goldman

Keyword(s):

San Francisco ◽

San Andreas Fault ◽

Rupture Zone ◽

Surface Rupture ◽

Near Surface ◽

San Andreas ◽

Surface Rupture Zone

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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 ◽

10.1130/l1113.1 ◽

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.

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Analysis of Permanent Deformation Scale of the Overlying Soil Caused by Earthquake Fault

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.243-249.3848 ◽

2011 ◽

Vol 243-249 ◽

pp. 3848-3853 ◽

Cited By ~ 2

Author(s):

Lei Zhao ◽

Jin Hua Wang ◽

Ji Sheng Zhao

Keyword(s):

Shear Wave ◽

Permanent Deformation ◽

Rupture Zone ◽

Physical Parameters ◽

Kinetic Characteristics ◽

Key Factors ◽

Observation Station ◽

Surface Rupture ◽

Surface Rupture Zone ◽

Setback Distance

Characteristics of the permanent deformation and surface rupture caused by fault dislocation in 512 Wenchuan earthquake are analyzed in this paper. On the basis of the data from surveying reports and engineering geological reports of some observation station, three kinds of overlying soil model are established and analyzed, the physical parameters coming from clay and sand: thickness 30m and 50m model of the clay, thickness 30m model of the sand and thickness 50m model of the clay containing sand interlayer. Results show: The thickness of the overlying soil is same, but fault dislocation changed, the permanent deformation scale of overlying soil with velocity of shear wave from 250m/s to 500m/s is almost same, but the surface rupture zone is different: shear wave velocity of the soil is low, surface rupture zone becme wide. With thickness of the soil increassing, the rupture zone become wide too. Influence of sand interlayer is small. Considering the setback distance determination, the geometric and kinetic characteristics of faults, regional seismic activity, material properties and thickness of the overlying soil are key factors.

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