The surface rupture zone and paleoseismic evidence on the seismogenic fault of the 1976 Ms 7.8 Tangshan earthquake, China

Geomorphology ◽  
2019 ◽  
Vol 327 ◽  
pp. 297-306 ◽  
Author(s):  
Hui Guo ◽  
Junxiang Zhao
Keyword(s):  
Rupture Zone ◽  
Seismogenic Fault ◽  
Tangshan Earthquake ◽  
Surface Rupture ◽  
Surface Rupture Zone

scholarly journals Soil gas distribution in the main coseismic surface rupture zone of the 1980, M s  = 6.9, Irpinia earthquake (southern Italy)

2014 ◽  
Vol 119 (3) ◽  
pp. 2440-2461 ◽  
Author(s):  
Giancarlo Ciotoli ◽  
Sabina Bigi ◽  
Chiara Tartarello ◽  
Pietro Sacco ◽  
Salvatore Lombardi ◽  
...  
Keyword(s):  
Southern Italy ◽  
Soil Gas ◽  
Rupture Zone ◽  
Gas Distribution ◽  
Surface Rupture ◽  
Surface Rupture Zone

scholarly journals Coseismic fluid–rock interactions in the Beichuan-Yingxiu surface rupture zone of the Mw 7.9 Wenchuan earthquake and its implication for the fault zone transformation

2020 ◽  
Author(s):  
Yangyang Wang ◽  
Xiaoqi Gao ◽  
Sijia Li ◽  
Shiyuan Wang ◽  
Deyang Shi ◽  
...  
Keyword(s):  
Wenchuan Earthquake ◽  
Fault Zone ◽  
Structural Characteristics ◽  
Damage Zone ◽  
Major Elements ◽  
Rupture Zone ◽  
Surface Rupture ◽  
Fault Rock ◽  
Surface Rupture Zone ◽  
Geochemical Variations

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 

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.

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

2011 ◽  
Vol 243-249 ◽  
pp. 3848-3853 ◽  
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.

scholarly journals Surface Fault Rupture and Slip Distribution of the Jordan-Kekerengu-Needles Fault Network during the 2016 Mw 7.8 Kaikōura Earthquake, New Zealand

2021 ◽  
Author(s):  
◽  
Jesse Kearse
Keyword(s):  
Ground Surface ◽  
Strike Slip ◽  
Airborne Lidar ◽  
Rupture Zone ◽  
Fault Rupture ◽  
Slip Direction ◽  
Surface Rupture ◽  
Linear Features ◽  
Surface Rupture Zone ◽  
Kaikoura Earthquake

<p>During the 2016, Mw 7.8 Kaikōura earthquake the Kekerengu fault ruptured the ground surface producing a maximum of ~12 m of net displacement (dextral-slip with minor reverse- slip), one of the largest five co-seismic surface rupture displacements so far observed globally. This thesis presents the first combined onshore to offshore dataset of co-seismic ground-surface and vertical seabed displacements along a near-continuous ~83 km long strike-slip dominated earthquake surface rupture of large slip magnitude. Onshore on the Kekerengu, Jordan Thrust, Upper Kowhai, and Manakau faults, we measured the displacement of 117 cultural and natural markers in the field and using airborne LiDAR data. Offshore on the dextral-reverse Needles fault, multibeam bathymetric and high-resolution seismic reflection data image a throw of the seabed of up to 3.5±0.2 m. Mean net slip on the total ~83 km rupture was 5.5±1 m, this is an unusually large mean slip for the rupture length compared to global strike-slip surface ruptures. Surveyed linear features that extend across the entire surface rupture zone show that it varies in width from 13 to 122 m. These cultural features also reveal the across-strike distribution of lateral displacement, 80% of which is, on average, concentrated within the central 43% of the rupture zone. Combining the near-field measurements of fault offset with published, far-field InSAR, continuous GPS, and coastal deformation data, suggests partitioning of oblique plate convergence, with a significant portion of co-seismic contractional deformation (and uplift) being accommodated off-fault in the hanging-wall crust to the northwest of the main rupturing faults.  This thesis also documents in detail the onshore extent of surface fault rupture on the Kekerengu, Jordan Thrust, Upper Kowhai and Manakau faults. I present large-scale maps (up to 1:3,000) and documentary field photographs of this 53 km-long onshore surface rupture zone utilizing field data, post-earthquake LiDAR-derived Digital Elevation Models (DEMs), and post-earthquake ortho-rectified aerial photography. Ground deformation data is most detailed near the Marlborough coast where the 2016 rupture trace is well-exposed on agricultural grassland on the Kekerengu fault. In the southwest, where surface fault rupture traversed the alpine slopes of the Seaward Kaikoura ranges, fault mapping relied heavily on the LiDAR-derived DEMs.   At 24 sites along the Kekerengu fault, I document co-seismic wear striae that were formed during the earthquake and were preserved on free face fault exposures. Nearly all of these striae were distinctly curved along their length, demonstrating that the direction of near-surface fault slip changed with time during rupture of the Kekerengu fault. Co-seismic displacement on the Kekerengu fault initiated as oblique-dextral (mainly dextral-reverse), and subsequently rotated to become nearly-pure dextral slip. These slip trajectories agree with directions of net displacements derived from offset linear features at nearby sites. Temporal rotation of the slip direction may suggest a state of low shear stress on the Kekerengu fault before the earthquake, and a near-complete reduction in stress during the earthquake, as has been inferred for other historic earthquakes that show evidence for changing slip direction with time.</p>

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