scholarly journals Recurring Slow Slip Events and Earthquake Nucleation in the Source Region of the M  7 Ibaraki-Oki Earthquakes Revealed by Earthquake Swarm and Foreshock Activity

2018 ◽  
Vol 123 (9) ◽  
pp. 7950-7968 ◽  
Author(s):  
Tomoaki Nishikawa ◽  
Satoshi Ide
Keyword(s):  
Source Region ◽  
Earthquake Swarm ◽  
Slow Slip ◽  
Slow Slip Events ◽  
Earthquake Nucleation ◽  
Foreshock Activity

scholarly journals The Boso slow slip events in 2007 and 2011 as a driving process for the accompanying earthquake swarm

2014 ◽  
Vol 41 (8) ◽  
pp. 2778-2785 ◽  
Author(s):  
Hitoshi Hirose ◽  
Takanori Matsuzawa ◽  
Takeshi Kimura ◽  
Hisanori Kimura
Keyword(s):  
Earthquake Swarm ◽  
Slow Slip ◽  
Slow Slip Events

scholarly journals Do slow slip events trigger large and great megathrust earthquakes?

2018 ◽  
Vol 4 (10) ◽  
pp. eaat8472 ◽  
Author(s):  
N. Voss ◽  
T. H. Dixon ◽  
Z. Liu ◽  
R. Malservisi ◽  
M. Protti ◽  
...  
Keyword(s):  
Costa Rica ◽  
Power Law ◽  
Slip Rate ◽  
Failure Stress ◽  
Slow Slip ◽  
Short Term ◽  
Slow Slip Events ◽  
Megathrust Earthquakes ◽  
Coulomb Failure ◽  
Earthquake Nucleation

Slow slip events have been suggested to trigger subduction earthquakes. However, examples to date have been poorly recorded, occurring offshore, where data are sparse. Better understanding of slow slip events and their influence on subsequent earthquakes is critical for hazard forecasts. We analyze a well-recorded event beginning 6 months before the 2012 Mw (moment magnitude) 7.6 earthquake in Costa Rica. The event migrates to the eventual megathrust rupture. Peak slip rate reached a maximum of 5 mm/day, 43 days before the earthquake, remaining high until the earthquake. However, changes in Mohr-Coulomb failure stress at the hypocenter were small (0.1 bar). Our data contradict models of earthquake nucleation that involve power law acceleration of slip and foreshocks. Slow slip events may prove useful for short-term earthquake forecasts.

scholarly journals Slow slip source characterized by lithological and geometric heterogeneity

2020 ◽  
Vol 6 (13) ◽  
pp. eaay3314 ◽  
Author(s):  
Philip M. Barnes ◽  
Laura M. Wallace ◽  
Demian M. Saffer ◽  
Rebecca E. Bell ◽  
Michael B. Underwood ◽  
...  
Keyword(s):  
Subduction Zone ◽  
Subduction Zones ◽  
Source Region ◽  
Significant Proportion ◽  
Plate Motion ◽  
Direct Access ◽  
Slow Slip ◽  
Plate Interface ◽  
Slow Slip Events ◽  
Geophysical Imaging

Slow slip events (SSEs) accommodate a significant proportion of tectonic plate motion at subduction zones, yet little is known about the faults that actually host them. The shallow depth (<2 km) of well-documented SSEs at the Hikurangi subduction zone offshore New Zealand offers a unique opportunity to link geophysical imaging of the subduction zone with direct access to incoming material that represents the megathrust fault rocks hosting slow slip. Two recent International Ocean Discovery Program Expeditions sampled this incoming material before it is entrained immediately down-dip along the shallow plate interface. Drilling results, tied to regional seismic reflection images, reveal heterogeneous lithologies with highly variable physical properties entering the SSE source region. These observations suggest that SSEs and associated slow earthquake phenomena are promoted by lithological, mechanical, and frictional heterogeneity within the fault zone, enhanced by geometric complexity associated with subduction of rough crust.

scholarly journals Long-lived shallow slow-slip events on the Sunda megathrust

2021 ◽  
Author(s):  
Rishav Mallick ◽  
Aron J. Meltzner ◽  
Louisa L. H. Tsang ◽  
Eric O. Lindsey ◽  
Lujia Feng ◽  
...  
Keyword(s):  
Slow Slip ◽  
Slow Slip Events

scholarly journals Configuration and structure of the Philippine Sea Plate off Boso, Japan: constraints on the shallow subduction kinematics, seismicity, and slow slip events

2019 ◽  
Vol 71 (1) ◽  
Author(s):  
Aki Ito ◽  
Takashi Tonegawa ◽  
Naoki Uchida ◽  
Yojiro Yamamoto ◽  
Daisuke Suetsugu ◽  
...  
Keyword(s):  
Receiver Function ◽  
Function Analysis ◽  
Philippine Sea Plate ◽  
Slow Slip ◽  
Low Velocity ◽  
Slow Slip Events ◽  
Philippine Sea ◽  
Receiver Function Analysis ◽  
Eastern Edge ◽  
Upper Boundary

Abstract We applied tomographic inversion and receiver function analysis to seismic data from ocean-bottom seismometers and land-based stations to understand the structure and its relationship with slow slip events off Boso, Japan. First, we delineated the upper boundary of the Philippine Sea Plate based on both the velocity structure and the locations of the low-angle thrust-faulting earthquakes. The upper boundary of the Philippine Sea Plate is distorted upward by a few kilometers between 140.5 and 141.0°E. We also determined the eastern edge of the Philippine Sea Plate based on the delineated upper boundary and the results of the receiver function analysis. The eastern edge has a northwest–southeast trend between the triple junction and 141.6°E, which changes to a north–south trend north of 34.7°N. The change in the subduction direction at 1–3 Ma might have resulted in the inflection of the eastern edge of the subducted Philippine Sea Plate. Second, we compared the subduction zone structure and hypocenter locations and the area of the Boso slow slip events. Most of the low-angle thrust-faulting earthquakes identified in this study occurred outside the areas of recurrent Boso slow slip events, which indicates that the slow slip area and regular low-angle thrust earthquakes are spatially separated in the offshore area. In addition, the slow slip areas are located only at the contact zone between the crustal parts of the North American Plate and the subducting Philippine Sea Plate. The localization of the slow slip events in the crust–crust contact zone off Boso is examined for the first time in this study. Finally, we detected a relatively low-velocity region in the mantle of the Philippine Sea Plate. The low-velocity mantle can be interpreted as serpentinized peridotite, which is also found in the Philippine Sea Plate prior to subduction. The serpentinized peridotite zone remains after the subduction of the Philippine Sea Plate and is likely distributed over a wide area along the subducted slab.

Estimation of frictional properties and slip evolution on a long-term slow slip event fault with the ensemble Kalman filter: numerical experiments

2019 ◽  
Vol 219 (3) ◽  
pp. 2074-2096 ◽  
Author(s):  
Kazuro Hirahara ◽  
Kento Nishikiori
Keyword(s):  
Surface Displacement ◽  
Slip Rate ◽  
Slow Slip ◽  
Slow Slip Events ◽  
Actual Distribution ◽  
Frictional Properties ◽  
Data Analyses ◽  
Bungo Channel ◽  
Megathrust Faults ◽  
Gnss Data

Summary A variety of slow slip events at subduction zones have been observed. They can be stress meters for monitoring the stress state of megathrust faults during their earthquake cycles. In this study, we focus on long-term slow slip events (LSSEs) recurring at downdip portions of megathrust faults among such slow earthquakes. Data analyses and simulation studies of LSSEs have so far been executed independently. In atmosphere and ocean sciences, data assimilations that optimally combine data analyses and simulation studies have been developed. We develop a method for estimating frictional properties and monitoring slip evolution on an LSSE fault, with a sequential data assimilation method, the ensemble Kalman filter (EnKF). We executed numerical twin experiments for the Bungo Channel LSSE fault in southwest Japan to validate the method. First, based on a rate- and state-dependent friction law, we set a rate-weakening circular LSSE patch on the rate-strengthening flat plate interface, whose critical nucleation size is larger than that of the patch, and reproduced the observed Bungo Channel LSSEs with recurrence times of approximately 7 yr and slip durations of 1 yr. Then, we synthesized the observed data of surface displacement rates at uniformly distributed stations with noises from the simulated slip model. Using our EnKF method, we successfully estimated the frictional parameters and the slip rate evolution after a few cycles. Secondly, we considered the effect of the megathrust fault existing in the updip portion of the LSSE fault, as revealed by kinematic inversion studies of Global Navigation Satellite System (GNSS) data and added this locked region with a slip deficit rate in the model. We estimated the slip rate on the locked region only kinematically, but the quasi-dynamic equation of motion in each LSSE fault cell includes the stress term arising from the locked region. Based on this model, we synthesized the observed surface displacement rate data for the actual distribution of GNSS stations and executed EnKF estimations including the slip rate on the locked region. The slip rate on the locked region could be quickly retrieved. Even for the actual distribution of GNSS stations, we could successfully estimate frictional parameters and slip evolution on the LSSE fault. Thus, our twin numerical experiments showed the validity of our EnKF method, although we need further studies for actual GNSS data analyses.

scholarly journals Segmentation of Slow Slip Events in South Central Alaska Possibly Controlled by a Subducted Oceanic Plateau

2018 ◽  
Vol 123 (1) ◽  
pp. 418-436 ◽  
Author(s):  
Haotian Li ◽  
Meng Wei ◽  
Duo Li ◽  
Yajing Liu ◽  
YoungHee Kim ◽  
...  
Keyword(s):  
Slow Slip ◽  
Slow Slip Events ◽  
Oceanic Plateau ◽  
South Central

scholarly journals COEXISTENCE OF FAST AND SLOW SLIP EVENTS IN LABORATORY SEISMIC CYCLES

2020 ◽  
Author(s):  
Kseniya G. Morozova ◽  
Vadim K. Markov ◽  
Dmitry V. Pavlov ◽  
Maxim F. Popov ◽  
Alexey A. Ostapchuk
Keyword(s):  
Slow Slip ◽  
Slow Slip Events ◽  
Seismic Cycles

Slow slip events and megathrust coupling changes reveal the earthquake potential before the 2020 Mw 7.4 Huatulco, Mexico, event

2020 ◽  
Author(s):  
Carlos Villafuerte ◽  
Víctor M. Cruz-Atienza ◽  
Josué Tago ◽  
Darío Solano-Rojas ◽  
Sara Franco ◽  
...  
Keyword(s):  
Slow Slip ◽  
Slow Slip Events ◽  
Earthquake Potential
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