scholarly journals Co-seismic slip, post-seismic slip, and aftershocks associated with two large earthquakes in 1996 in Hyuga-nada, Japan

2001 ◽  
Vol 53 (8) ◽  
pp. 793-803 ◽  
Author(s):  
Yuji Yagi ◽  
Masayuki Kikuchi ◽  
Takeshi Sagiya
Keyword(s):  
Seismic Slip ◽  
Large Earthquakes

Role of the creeping segment in the synchronization of earthquake cycles on oceanic transform faults revealed by numerical simulations in the framework of rate-and-state friction

2020 ◽  
Author(s):  
Meng Wei ◽  
Pengcheng Shi
Keyword(s):  
Seismic Data ◽  
Numerical Models ◽  
General Idea ◽  
Partial Rupture ◽  
Transform Faults ◽  
Seismic Slip ◽  
Rate And State Friction ◽  
Large Earthquakes ◽  
Earthquake Cycles

<p>Synchronization behavior of large earthquakes, rupture of nearby faults close in time for many cycles, has been reported in many fault systems. The general idea is that the faults in the system have similar repeating interval and are positively coupled through stress interaction. However, many details of such synchronization remain unknown. Here, we built numerical models in the framework of rate-and-state friction to simulate earthquake cycles on the west Gofar fault, an oceanic transform fault in the East Pacific Rise. Our model is consisted of two seismic segments, separated by a creeping segment, for which the size and location is constrained by seismic data. The parameters in the seismic segments were set to reproduce M6 earthquakes every 5 years, to be consistent with observation. We varied the parameters in the creeping segment to understand its role on earthquake synchronization. We found that the width and the strength of the creeping segment will determine the synchronization of earthquake cycles on the two seismic segments. When the creeping segment is relatively narrow or weak, the system will become synchronized quickly and the synchronization remains for many cycles. When it is relatively wide or strong, the earthquake cycles on the two segments are not related but could be synchronized by chance. In both cases, earthquakes tend to rupture the entire seismic segment. Between these two end-member situations, the system fluctuated between synchronization and non-synchronization on the time scale of 5-10 cycles. The switch always happens when the partial rupture of the seismic segment occurs, resulting in moderate size earthquakes (M4-5) and earthquake cycle shift, which is likely caused by stress interaction through the creeping segment. Here, we conclude that the co-seismic slip and aseismic after slip in the creeping segment could promote the synchronization of earthquake cycles on oceanic transform faults, and likely in other tectonic systems. In addition, the average seismic ratio of the entire fault can be quite low, ranging between 0.2-0.4 because of the barrier segment. We suggest that the existence of creep segments contributed significantly to the well-observed low seismic ratio on oceanic transform faults.</p>

Decadal Seismicity Prior to Great Earthquakes at Subduction and Transform-Fault Plate Boundaries

2021 ◽  
Author(s):  
Lynn Sykes
Keyword(s):  
Subduction Zones ◽  
Tide Gauge ◽  
Plate Boundaries ◽  
Transform Faults ◽  
Slow Slip Events ◽  
Seismic Slip ◽  
Great Earthquakes ◽  
Shallow Earthquakes ◽  
Plate Coupling ◽  
Large Earthquakes

<p>Decadal forerunning seismic activity is used to map great asperities that subsequently ruptured in very large, shallow earthquakes at subduction zones and transform faults. The distribution of forerunning shocks of magnitude Mw>5.0 is examined for 50 mainshocks of Mw 7.5 to 9.1 from 1993 to 2020. The zones of large slip in many great earthquakes were nearly quiescent beforehand and are identified as the sites of great asperities. Much forerunning activity occurred at smaller asperities along the peripheries of the rupture zones of great and giant mainshocks. Asperities are strong, well-coupled portions of plate interfaces. Sizes of great asperities as ascertained from forerunning activity generally agree with the areas of high seismic slip as determined by others using geodetic and tide-gauge data and finite-source seismic modeling. Different patterns of forerunning activity on time scales of about 5 to 45 years are attributed to the sizes and spacing of asperities. This permits many great asperities to be mapped decades before they rupture in great and giant shocks. Rupture zones of many large earthquakes are bordered either along strike, updip, or downdip by zones of low plate coupling. Several bordering regions were sites of forerunning activity, aftershocks and slow-slip events. Several poorly coupled subduction zones, however, are characterized by few great earthquakes and little forerunning activity. The detection of forerunning and precursory activities of various kinds should be sought on the peripheries of great asperities. The manuscript can be found at <strong>http://www.ldeo.columbia.edu/~sykes</strong></p><p> </p>

scholarly journals Repeating earthquakes record fault weakening and healing in areas of megathrust postseismic slip

2020 ◽  
Vol 6 (32) ◽  
pp. eaaz9317 ◽  
Author(s):  
E. J. Chaves ◽  
S. Y. Schwartz ◽  
R. E. Abercrombie
Keyword(s):  
Loading Rate ◽  
Temporal Variations ◽  
Earthquake Cycle ◽  
Repeating Earthquakes ◽  
Seismic Slip ◽  
Rupture Area ◽  
Recurrence Intervals ◽  
Large Earthquakes ◽  
Constant Moment ◽  
Postseismic Slip

Repeating earthquakes (REs) rupture the same fault patches at different times allowing temporal variations in the mechanical behavior of specific areas of the fault to be interrogated over the earthquake cycle. We study REs that reveal fault weakening after a large megathrust earthquake in Costa Rica, followed by fault recovery. We find shorter RE recurrence intervals and larger slip areas immediately following the mainshock that both gradually return to pre-earthquake values. RE seismic moments remain nearly constant throughout the earthquake cycle. This implies a balance between fault weakening (reducing slip) and transient embrittlement (increasing rupture area by converting regions from aseismic to seismic slip), induced by the increased loading rate following the mainshock. This interpretation is consistent with positive, negative, and constant moment versus RE recurrence interval trends reported in other studies following large earthquakes and with experimental work showing slip amplitudes and stress drop decrease with loading rate.

scholarly journals Forecasting the Locations of Future Large Earthquakes: An Analysis and Verification

2010 ◽  
Vol 167 (6-7) ◽  
pp. 743-749 ◽  
Author(s):  
Robert Shcherbakov ◽  
Donald L. Turcotte ◽  
John B. Rundle ◽  
Kristy F. Tiampo ◽  
James R. Holliday
Keyword(s):  
Large Earthquakes

scholarly journals Observation evidences of atmospheric Gravity Waves induced by seismic activity from analysis of subionospheric LF signal spectra

2007 ◽  
Vol 7 (5) ◽  
pp. 625-628 ◽  
Author(s):  
A. Rozhnoi ◽  
M. Solovieva ◽  
O. Molchanov ◽  
P.-F. Biagi ◽  
M. Hayakawa
Keyword(s):  
Gravity Waves ◽  
Fresnel Zone ◽  
Signal Amplitude ◽  
Magnetic Storms ◽  
Frequency Range ◽  
Atmospheric Gravity Waves ◽  
Period Range ◽  
Before And After ◽  
Atmospheric Gravity ◽  
Large Earthquakes

Abstract. We analyze variations of the LF subionospheric signal amplitude and phase from JJY transmitter in Japan (F=40 kHz) received in Petropavlovsk-Kamchatsky station during seismically quiet and active periods including also periods of magnetic storms. After 20 s averaging, the frequency range of the analysis is 0.28–15 mHz that corresponds to the period range from 1 to 60 min. Changes in spectra of the LF signal perturbations are found several days before and after three large earthquakes, which happened in November 2004 (M=7.1), August 2005 (M=7.2) and November 2006 (M=8.2) inside the Fresnel zone of the Japan-Kamchatka wavepath. Comparing the perturbed and background spectra we have found the evident increase in spectral range 10–25 min that is in the compliance with theoretical estimations on lithosphere-ionosphere coupling by the Atmospheric Gravity Waves (T>6 min). Similar changes are not found for the periods of magnetic storms.

scholarly journals Investigation of Pre-Earthquake Ionospheric and Atmospheric Disturbances for Three Large Earthquakes in Mexico

Geosciences ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 16
Author(s):  
Christina Oikonomou ◽  
Haris Haralambous ◽  
Sergey Pulinets ◽  
Aakriti Khadka ◽  
Shukra R. Paudel ◽  
...  
Keyword(s):  
Chemical Potential ◽  
Atmospheric Model ◽  
Satellite System ◽  
Seismic Events ◽  
Electron Content ◽  
Total Electron ◽  
Atmospheric Disturbances ◽  
Global Ionospheric Maps ◽  
Global Navigation Satellite ◽  
Large Earthquakes

The purpose of the present study is to investigate simultaneously pre-earthquake ionospheric and atmospheric disturbances by the application of different methodologies, with the ultimate aim to detect their possible link with the impending seismic event. Three large earthquakes in Mexico are selected (8.2 Mw, 7.1 Mw and 6.6 Mw during 8 and 19 September 2017 and 21 January 2016 respectively), while ionospheric variations during the entire year 2017 prior to 37 earthquakes are also examined. In particular, Total Electron Content (TEC) retrieved from Global Navigation Satellite System (GNSS) networks and Atmospheric Chemical Potential (ACP) variations extracted from an atmospheric model are analyzed by performing statistical and spectral analysis on TEC measurements with the aid of Global Ionospheric Maps (GIMs), Ionospheric Precursor Mask (IPM) methodology and time series and regional maps of ACP. It is found that both large and short scale ionospheric anomalies occurring from few hours to a few days prior to the seismic events may be linked to the forthcoming events and most of them are nearly concurrent with atmospheric anomalies happening during the same day. This analysis also highlights that even in low-latitude areas it is possible to discern pre-earthquake ionospheric disturbances possibly linked with the imminent seismic events.

Meso- to nano-scale evidence of fluid-assisted co-seismic slip along the normal Mt. Morrone Fault, Italy: Implications for earthquake hydrogeochemical precursors

2021 ◽  
Vol 568 ◽  
pp. 117010
Author(s):  
Martina Coppola ◽  
Alessandra Correale ◽  
Marino Domenico Barberio ◽  
Andrea Billi ◽  
Andrea Cavallo ◽  
...  
Keyword(s):  
Seismic Slip ◽  
Nano Scale ◽  
Hydrogeochemical Precursors

scholarly journals Stress relaxation arrested the mainshock rupture of the 2016 Central Tottori earthquake

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Yoshihisa Iio ◽  
Satoshi Matsumoto ◽  
Yusuke Yamashita ◽  
Shin’ichi Sakai ◽  
Kazuhide Tomisaka ◽  
...  
Keyword(s):  
Stress Relaxation ◽  
Focal Mechanism ◽  
Large Earthquake ◽  
Static Stress ◽  
Focal Mechanism Solutions ◽  
Large Earthquakes

AbstractAfter a large earthquake, many small earthquakes, called aftershocks, ensue. Additional large earthquakes typically do not occur, despite the fact that the large static stress near the edges of the fault is expected to trigger further large earthquakes at these locations. Here we analyse ~10,000 highly accurate focal mechanism solutions of aftershocks of the 2016 Mw 6.2 Central Tottori earthquake in Japan. We determine the location of the horizontal edges of the mainshock fault relative to the aftershock hypocentres, with an accuracy of approximately 200 m. We find that aftershocks rarely occur near the horizontal edges and extensions of the fault. We propose that the mainshock rupture was arrested within areas characterised by substantial stress relaxation prior to the main earthquake. This stress relaxation along fault edges could explain why mainshocks are rarely followed by further large earthquakes.

scholarly journals Coseismic and early post-seismic slip associated with the 1999 Izmit earthquake (Turkey), from SAR interferometry and tectonic field observations

2003 ◽  
Vol 155 (1) ◽  
pp. 93-110 ◽  
Author(s):  
Ziyadin Çakir ◽  
Jean-Bernard de Chabalier ◽  
Rolando Armijo ◽  
Bertrand Meyer ◽  
Aykut Barka ◽  
...  
Keyword(s):  
Sar Interferometry ◽  
Field Observations ◽  
Seismic Slip ◽  
Izmit Earthquake
Sign in / Sign up

Export Citation Format

Share Document