A5091909223- earthquake and tectonic studies
- Seismology and Earthquake Studies
- Earthquake Detection and Analysis
- High-pressure geophysics and materials
- Geological and Geochemical Analysis
- Seismic Waves and Analysis
- Seismic Imaging and Inversion Techniques
- Landslides and related hazards
- Geophysics and Sensor Technology
- Geological Modeling and Analysis
- Geological and Tectonic Studies in Latin America
- Neurological disorders and treatments
- Reservoir Engineering and Simulation Methods
- Atomic and Subatomic Physics Research
- Advanced MRI Techniques and Applications
- CO2 Sequestration and Geologic Interactions
- Geological and Geophysical Studies Worldwide
- Earthquake and Disaster Impact Studies
- Geology and Paleoclimatology Research
- Seismic Performance and Analysis
- Time Series Analysis and Forecasting
- Geomagnetism and Paleomagnetism Studies
- Neurological and metabolic disorders
- Glycogen Storage Diseases and Myoclonus
- Mineral Processing and Grinding
Geologic Hazards Science Center
2020-2025
United States Geological Survey
2016-2025
Volcano Science Center
2013-2018
Cascades Volcano Observatory
2015-2018
Menlo School
2009-2016
Georgia Institute of Technology
2012
Pacific Island Ecosystems Research Center
2009
ATUM (United States)
2009
University of California, Berkeley
2008
Stanford University
2003-2007
We study the mechanism of low frequency earthquakes (LFEs) in Nankai Trough western Shikoku, Japan. Precise locations have previously suggested that they represent shear slip on plate boundary. In this paper we examine these events. Due to signal‐to‐noise ratio, analyze stacked LFE waveforms and compare them with nearby known within subducting Philippine Sea Plate. Analysis both focal using P ‐wave first‐motions moment tensor S indicates LFEs a low‐angle thrust fault dipping northwest,...
Abstract An extended earthquake swarm occurred beneath southeastern Long Valley Caldera between May and November 2014, culminating in three magnitude 3.5 earthquakes 1145 cataloged events on 26 September alone. The produced the most prolific seismicity caldera since a major unrest episode 1997–1998. To gain insight into physics controlling evolution, we used large‐scale cross correlation waveforms of continuous data, producing precise locations for 8494 events, more than 2.5 times routine...
Abstract I use template matching and precise relative relocation techniques to develop a high-resolution earthquake catalog for the initial portion of 2019 Ridgecrest sequence, from 4 16 July, encompassing foreshock sequence first 10+ days aftershocks following Mw 7.1 mainshock. Using 13,525 routinely cataloged events as waveform templates, detect precisely locate total 34,091 events. Precisely located earthquakes reveal numerous crosscutting fault structures with dominantly perpendicular...
Abstract The 6 February 2023 Mw 7.8 Pazarcık and subsequent 7.5 Elbistan earthquakes generated strong ground shaking that resulted in catastrophic human economic loss across south-central Türkiye northwest Syria. rapid characterization of the earthquakes, including their location, size, fault geometries, slip kinematics, is critical to estimate impact significant seismic events. U.S. Geological Survey National Earthquake Information Center (NEIC) provides real-time monitoring globally,...
Abstract Earthquake swarms are most commonly composed of small‐magnitude earthquakes. However, a recent study by Yoshida, Uchida, et al. (2023, https://doi.org/10.1029/2023GL106023 ) analyzed swarm beneath the Noto Peninsula in Japan that, after more than two years moderate‐magnitude seismicity, triggered moment magnitude ( M w 6.2 Suzu mainshock May 2023. Based on high‐precision earthquake locations and slip inversion mainshock, these authors found that occurred updip extension fault was...
Transient slip events, which occur more slowly than traditional earthquakes, are increasingly being recognized as important components of strain release on faults and may substantially impact the earthquake cycle. Surface‐based geodetic instruments provide estimates overall distribution in larger transients but unable to capture detailed evolution such slip, either time or space. Accompanying some these is a relatively weak, extended duration seismic signal, known nonvolcanic tremor, has...
Deep tremor under Shikoku, Japan, consists primarily, and perhaps entirely, of swarms low‐frequency earthquakes (LFEs) that occur as shear slip on the plate interface . Although is observed at other boundaries, lack cataloged has precluded a similar conclusion about in those locales. We use network autocorrelation approach to detect locate LFEs within recorded three subduction zones characterized by different thermal structures levels interplate seismicity: southwest northern Cascadia, Costa...
Abstract Over the past several decades, Yellowstone caldera has experienced frequent earthquake swarms and repeated cycles of uplift subsidence, reflecting dynamic volcanic tectonic processes. Here we examine detailed spatial‐temporal evolution 2010 Madison Plateau swarm, which occurred near northwest boundary caldera. To fully explore integrated procedures for seismic waveform‐based detection with precise double‐difference relative relocation. Using cross correlation continuous data...
We precisely locate 88 tremor families along the central San Andreas Fault using a 3D velocity model and numerous P S wave arrival times estimated from seismogram stacks of up to 400 events per family. Maximum amplitudes vary fault by at least factor 7, with far strongest sources 25 km section southeast Parkfield. also identify many weaker families, which have largely escaped prior detection. Together, these extend 150 fault, beneath creeping, transitional, locked sections upper crustal...
Studies of nonvolcanic tremor (NVT) have established the significant impact small stress perturbations on NVT generation. Here we analyze influence solid earth and ocean tides a catalog ∼550,000 low frequency earthquakes (LFEs) distributed along 150 km section San Andreas Fault centered at Parkfield. LFE families are identified in data basis waveform similarity thought to represent small, effectively co‐located occurring brittle asperities an otherwise aseismic fault depths 16 30 km. We...
Abstract We present the first evidence of low‐frequency earthquakes (LFEs) associated with deep extension transpressional Alpine Fault beneath central Southern Alps New Zealand. Our database comprises a temporally continuous 36 month‐long catalog 8760 LFEs within 14 families. To generate this catalog, we identify primary template known periods seismic tremor and use these templates to detect similar events in an iterative stacking cross‐correlation routine. The hypocentres 12 LFE families...
The Mendocino triple junction-the intersection of the Pacific, North American, and Gorda plates-activates a collection disparate faults that reconcile Cascadia subduction with San Andreas transform motion. 20 December 2022
Research Article| April 01, 2004 High-resolution subducting-slab structure beneath northern Honshu, Japan, revealed by double-difference tomography Haijiang Zhang; Zhang 1Department of Geology and Geophysics, University Wisconsin, Madison, Wisconsin 53706, USA Search for other works this author on: GSW Google Scholar Clifford H. Thurber; Thurber David Shelly; Shelly 2Department Stanford University, Stanford, California 94305, Satoshi Ide; Ide 3Department Earth Planetary Science, Tokyo, Tokyo...
Recently observed unusual seismic events: deep low frequency earthquakes and tremor, very earthquakes, slow slip events form a family of that are governed by scaling law different from ordinary earthquakes. Guided this law, we have previously unknown events, with source duration 20–200 s moment magnitude 3–4, under the Kii Peninsula in western Japan. These radiate energy 2–8 Hz band direct proportion to their moment‐rate, though constant proportionality is 4–5 orders smaller than for Slow...
Recent studies have shown that deep tremor in the Nankai Trough under western Shikoku consists of a swarm low frequency earthquakes (LFEs) occur as slow shear slip on down‐dip extension primary seismogenic zone plate interface. The similarity other locations suggests similar mechanism, but absence cataloged prevents analysis. In this study, we develop method for identifying LFEs within tremor. employs matched‐filter algorithm, to technique used infer parts is comprised LFEs; however, case do...
We examine a 24‐hour period of active San Andreas Fault (SAF) tremor and show that this is largely composed repeated similar events. Utilizing similarity, we locate the subset with waveforms to an identified low frequency earthquake (LFE) “master template,” located using P S wave arrivals be ∼26 km deep. To compensate for signal‐to‐noise, estimate event‐pair differential times at “clusters” nearby stations rather than single stations. find locations form near‐linear structure in map view,...
Earthquake predictability depends, in part, on the degree to which sudden slip is preceded by slow aseismic slip. Recently, observations of deep tremor have enabled inferences even when detection other means not possible, but these data are limited certain areas and mostly last decade. The region near Parkfield, California, provides a unique convergence several years high‐quality bracketing moderate earthquake, 2004 magnitude 6.0 event. Here, I present detailed tectonic from mid‐2001 through...