Seismicity at the Eastern End of the 1944 Tonankai Earthquake Rupture Area

2009 ◽  
Vol 99 (1) ◽  
pp. 110-122 ◽  
Author(s):  
K. Obana ◽  
S. Kodaira ◽  
Y. Kaneda
2013 ◽  
Vol 470 ◽  
pp. 866-870
Author(s):  
Wei He ◽  
Yan Dong Liu ◽  
Guo Xing Wang

Based on the actual project example of high pressure gas pipeline crossing earthquake rupture area, the paper shows and explains the way to make stress analysis and strength checking calculation for the high pressure gas pipeline in the earthquake rupture area by the method of finite element.


Solid Earth ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 2467-2477
Author(s):  
Yueyang Xia ◽  
Jacob Geersen ◽  
Dirk Klaeschen ◽  
Bo Ma ◽  
Dietrich Lange ◽  
...  

Abstract. We resolve a previously unrecognized shallow subducting seamount from a re-processed multichannel seismic profile crossing the 1994 Mw 7.8 Java tsunami earthquake rupture area. Seamount subduction occurs where the overriding plate experiences uplift by lateral shortening and vertical thickening. Pronounced back-thrusting at the landward slope of the forearc high and the formation of splay faults branching off the landward flank of the subducting seamount are observed. The location of the seamount in relation to the 1994 earthquake hypocentre and its co-seismic slip model suggests that the seamount acted as a seismic barrier to the up-dip co-seismic rupture propagation of this moderate-size earthquake.


2019 ◽  
Vol 109 (5) ◽  
pp. 1701-1715 ◽  
Author(s):  
Clayton M. J. Brengman ◽  
William D. Barnhart ◽  
Emma H. Mankin ◽  
Cody N. Miller

Abstract Empirical earthquake scaling relationships describe expected relationships between moment magnitude and various spatial descriptors of the earthquake rupture (along‐strike length, down‐dip width, rupture area, and peak and mean slip). These scaling relationships play important roles in many seismological, geological, and hazards‐assessment applications. Historically, scaling relationships were defined from various seismological criteria, such as teleseismic finite‐fault models or aftershock distributions. The proliferation of earthquake slip distributions from geodetic observations presents an opportunity to reassess earthquake scaling relationships using observations that more directly sample the spatial characteristics of an earthquake than seismological observations. Here, we present a database of 111 earthquake slip distributions from 73 different earthquakes that were derived from geodetic observations. The earthquakes range in magnitude from Mw 5.3 to 9.1. We extract common spatial descriptors from these slip distributions in four different ways to account for biases introduced by inversion regularization, and we regress these spatial descriptors with moment magnitude to derive new empirical scaling relationships. We additionally assess the shape characteristics of the slip distributions and report the average earthquake shape. We find that our scaling relationships differ in important ways from previous studies, and we show that these differences originate from our use of a geodetic slip‐distribution database rather than from methods for extracting spatial descriptors. Notably, we find that geodetic slip distributions systematically predict smaller fault areas than seismically derived scaling relationships. Because geodetic source inversions are likely contaminated to some degree by aseismic afterslip, this relationship suggests that seismologically determined scaling relationships systematically overpredict earthquake dimensions. We find that fault length, fault width, peak slip, and mean slip differ from previous studies in ways that are more complex and magnitude dependent. Given the high‐model resolution afforded by geodetic observations, our earthquake scaling relationships derived from geodetic slip distributions provide improved constraints on empirical scaling relationships.


2021 ◽  
Author(s):  
David Kammer ◽  
Gregory McLaskey

<p>The energy dissipated during the friction weakening process at the front of an earthquake rupture, which is known as the fracture energy, is a key earthquake property. It directly affects the nucleation, propagation and arrest of earthquake ruptures, and, is therefore related to important questions, including the maximum possible size of earthquakes at a given fault section. However, estimating the fracture energy in the field is a difficult task and current approaches remain limited. In this work, we present near-fault strain measurements of large-scale laboratory earthquakes on a granite fault. The strain measurements present high-frequency fluctuations while the fault is sliding. These strain fluctuations are indicative of rupture fronts that propagate across the entire fault and occasionally reflect at the boundaries. Here, we will characterize these strain fluctuations by applying fracture-mechanics theory. We will demonstrate that the shape and time scales of the strain fluctuations are well described by the proposed analytical solution. We will further show that by fitting the amplitude of the theory to the experimental measurement, we can estimate the local fracture energy. We apply this process to determine the fracture energy for secondary rupture fronts, which appear within the sliding rupture area. The results are consistent with fracture energy estimates from laboratory-earthquake arrest experiments, but are orders of magnitude lower than reported values from small-scale rotary shear friction experiments. We will discuss the implications and potential of these observations.</p>


2016 ◽  
Author(s):  
Christie D. Rowe ◽  
◽  
W. Ashley Griffith ◽  
Catherine Ross ◽  
Benjamin Melosh ◽  
...  
Keyword(s):  

2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Yasuhira Aoyagi ◽  
Haruo Kimura ◽  
Kazuo Mizoguchi

Abstract The earthquake rupture termination mechanism and size of the ruptured area are crucial parameters for earthquake magnitude estimations and seismic hazard assessments. The 2016 Mw 7.0 Kumamoto Earthquake, central Kyushu, Japan, ruptured a 34-km-long area along previously recognized active faults, eastern part of the Futagawa fault zone and northernmost part of the Hinagu fault zone. Many researchers have suggested that a magma chamber under Aso Volcano terminated the eastward rupture. However, the termination mechanism of the southward rupture has remained unclear. Here, we conduct a local seismic tomographic inversion using a dense temporary seismic network to detail the seismic velocity structure around the southern termination of the rupture. The compressional-wave velocity (Vp) results and compressional- to shear-wave velocity (Vp/Vs) structure indicate several E–W- and ENE–WSW-trending zonal anomalies in the upper to middle crust. These zonal anomalies may reflect regional geological structures that follow the same trends as the Oita–Kumamoto Tectonic Line and Usuki–Yatsushiro Tectonic Line. While the 2016 Kumamoto Earthquake rupture mainly propagated through a low-Vp/Vs area (1.62–1.74) along the Hinagu fault zone, the southern termination of the earthquake at the focal depth of the mainshock is adjacent to a 3-km-diameter high-Vp/Vs body. There is a rapid 5-km step in the depth of the seismogenic layer across the E–W-trending velocity boundary between the low- and high-Vp/Vs areas that corresponds well with the Rokkoku Tectonic Line; this geological boundary is the likely cause of the dislocation of the seismogenic layer because it is intruded by serpentinite veins. A possible factor in the southern rupture termination of the 2016 Kumamoto Earthquake is the existence of a high-Vp/Vs body in the direction of southern rupture propagation. The provided details of this inhomogeneous barrier, which are inferred from the seismic velocity structures, may improve future seismic hazard assessments for a complex fault system composed of multiple segments.


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