Hypocenter ≈ Hypocenter
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Source rupture processes of the foreshock and mainshock in the 2016 Kumamoto earthquake sequence estimated from the kinematic waveform inversion of strong motion data Open
The 2016 Kumamoto earthquake sequence started with an MJMA 6.5 foreshock occurring along the northern part of the Hinagu fault, central Kyushu, Japan, and the MJMA 7.3 mainshock occurred just 28 h after the foreshock. We analyzed the sourc…
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Slip heterogeneity and directivity of the <i>M<sub>L</sub></i> 6.0, 2016, Amatrice earthquake estimated with rapid finite‐fault inversion Open
On 24 August 2016 a magnitude M L 6.0 occurred in the Central Apennines (Italy) between Amatrice and Norcia causing nearly 300 fatalities. The main shock ruptured a NNW‐SSE striking, WSW dipping normal fault. We invert waveforms from 26 th…
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ISC‐EHB 1964–2016, an Improved Data Set for Studies of Earth Structure and Global Seismicity Open
A data set of earthquake hypocenters and associated traveltime residuals for seismic phases recorded by seismograph stations globally is an essential starting point for most studies of global seismicity and Earth structure. Such data sets …
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Detailed rupture imaging of the 25 April 2015 Nepal earthquake using teleseismic <i>P</i> waves Open
We analyze the rupture process of the 25 April 2015 Nepal earthquake with globally recorded teleseismic P waves. The rupture propagated east‐southeast from the hypocenter for about 160 km with a duration of ∼55 s. Backprojection of both hi…
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SeisBench—A Toolbox for Machine Learning in Seismology Open
Machine-learning (ML) methods have seen widespread adoption in seismology in recent years. The ability of these techniques to efficiently infer the statistical properties of large datasets often provides significant improvements over tradi…
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Seismicity Structure of the Northern Chile Forearc From >100,000 Double‐Difference Relocated Hypocenters Open
In this study, we present high‐resolution seismicity images of the northern Chile subduction zone forearc. We used 8 years of continuous seismic waveform data from the Integrated Plate Boundary Observatory Chile network and auxiliary stati…
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The 2015 Gorkha earthquake: A large event illuminating the Main Himalayan Thrust fault Open
The 2015 Gorkha earthquake sequence provides an outstanding opportunity to better characterize the geometry of the Main Himalayan Thrust (MHT). To overcome limitations due to unaccounted lateral heterogeneities, we perform Centroid Moment …
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Source rupture processes of the 2016 Kumamoto, Japan, earthquakes estimated from strong-motion waveforms Open
The detailed source rupture process of the M 7.3 event (April 16, 2016, 01:25, JST) of the 2016 Kumamoto, Japan, earthquakes was derived from strong-motion waveforms using multiple-time-window linear waveform inversion. Based on the observ…
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Coseismic and early postseismic deformation due to the 25 April 2015, <i>M<sub>w</sub></i> 7.8 Gorkha, Nepal, earthquake from InSAR and GPS measurements Open
Analysis of Interferometric Synthetic Aperture Radar (InSAR) and Global Positioning System (GPS) data reveals coseismic and early postseismic (4–88 days) surface displacements associated with the 25 April 2015, M w 7.8 Gorkha, Nepal, earth…
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Fluid‐faulting interactions: Fracture‐mesh and fault‐valve behavior in the February 2014 Mammoth Mountain, California, earthquake swarm Open
Faulting and fluid transport in the subsurface are highly coupled processes, which may manifest seismically as earthquake swarms. A swarm in February 2014 beneath densely monitored Mammoth Mountain, California, provides an opportunity to w…
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The Zagreb (Croatia) M5.5 Earthquake on 22 March 2020 Open
On 22 March 2020, Zagreb was struck by an M5.5 earthquake that had been expected for more than 100 years and revealed all the failures in the construction of residential buildings in the Croatian capital, especially those built in the firs…
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The 2016 Kumamoto–Oita earthquake sequence: aftershock seismicity gap and dynamic triggering in volcanic areas Open
The 2016 Kumamoto–Oita earthquake sequence involving three large events (M w ≥ 6) in the central Kyushu Island, southwest Japan, activated seismicities in two volcanic areas with unusual and puzzling spatial gaps after the largest earthqua…
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Foreshocks and Mainshock Nucleation of the 1999 <i>M</i><sub><i>w</i></sub> 7.1 Hector Mine, California, Earthquake Open
Foreshocks provide valuable information on the nucleation process of an upcoming large earthquake. We applied high‐resolution similar‐waveform techniques for earthquake detection, location, and source parameter estimation to understand the…
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Groundwater helium anomaly reflects strain change during the 2016 Kumamoto earthquake in Southwest Japan Open
Geochemical monitoring of groundwater and soil gas emission pointed out precursor and/or coseismic anomalies of noble gases associated with earthquakes, but there was lack of plausible physico-chemical basis. A laboratory experiment of roc…
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Effects of Low‐Velocity Fault Damage Zones on Long‐Term Earthquake Behaviors on Mature Strike‐Slip Faults Open
Mature strike‐slip faults are usually surrounded by a narrow zone of damaged rocks characterized by low seismic wave velocities. Observations of earthquakes along such faults indicate that seismicity is highly concentrated within this faul…
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Crustal structure beneath earthquake swarm in the Noto peninsula, Japan Open
We carried out seismic tomography study to reveal three-dimensional (3D) seismic velocity structures in the Noto peninsula, Japan, where swarm-like seismic activity started in December 2020. The obtained results reveal a highly heterogeneo…
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Slip-partitioned surface ruptures for the Mw 7.0 16 April 2016 Kumamoto, Japan, earthquake Open
An ENE-trending ~30-km-long surface rupture emerged during the Mw = 7.0 16 April 2016 Kumamoto earthquake along the previously mapped Futagawa and northern Hinagu faults. This included a previously unknown 5-km-long fault within the Aso Ca…
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Do slow slip events trigger large and great megathrust earthquakes? Open
A slow slip event in Costa Rica migrated toward the hypocenter of a large megathrust earthquake, possibly triggering the event.
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Machine‐Learning‐Based Analysis of the Guy‐Greenbrier, Arkansas Earthquakes: A Tale of Two Sequences Open
We revisited the June 2010 to October 2011 Guy‐Greenbrier earthquake sequence in central Arkansas using PhaseNet, a deep neural network trained to pick P and S arrival times. We applied PhaseNet to continuous waveform data and used phase a…
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Spatiotemporal Variation of Stress Drop During the 2008 Mogul, Nevada, Earthquake Swarm Open
We estimate stress drops for 148 shallow (<6 km) earthquakes in the complex 2008 Mogul, Nevada, swarm using empirical Green's function‐derived spectral ratios. Near‐source, temporary broadband seismometers deployed before the M w 4.9 main …
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Long‐Living Earthquake Swarm and Intermittent Seismicity in the Northeastern Tip of the Noto Peninsula, Japan Open
The factors controlling earthquake swarm duration are remain unclear, especially in the long‐living ones. A severe earthquake swarm struck the tip of the Noto peninsula, Japan. Ten M > 4.0 earthquakes occurred, and the sequence has continu…
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Years to weeks of seismic unrest and magmatic intrusions precede monogenetic eruptions Open
Seismic, deformation, and gas activity (unrest) typically precedes volcanic eruptions. Tracking the changes of this activity with monitoring data makes it increasingly possible to successfully forecast eruptions from stratovolcanoes. Howev…
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Earthquake early warning for the 2016 Kumamoto earthquake: performance evaluation of the current system and the next-generation methods of the Japan Meteorological Agency Open
The 2016 Kumamoto earthquake (Kumamoto earthquake sequence) is an extremely high-seismicity event that has been occurring across Kumamoto and Oita Prefectures in Japan since April 14, 2016 (JST). The earthquake early warning system of the …
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Hydraulic fracture propagation geometry and acoustic emission interpretation: A case study of Silurian Longmaxi Formation shale in Sichuan Basin, SW China Open
A series of laboratory fracturing experiments was performed on samples mined from an outcrop of the Silurian Longmaxi Formation shale in the Sichuan Basin, using a true triaxial fracturing simulation system. To reveal the characteristics o…
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Very low frequency earthquakes off the Pacific coast of Tohoku, Japan Open
We found very low frequency earthquakes (VLFEs) at a shallow subduction zone close to the Japan Trench off the Pacific coast of Tohoku, Japan. Centroid moment tensor solutions of VLFEs showed reverse fault mechanisms with a compression axi…
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Faulting structure above the Main Himalayan Thrust as shown by relocated aftershocks of the 2015 <i>M<sub>w</sub></i>7.8 Gorkha, Nepal, earthquake Open
The 25 April 2015, M w 7.8 Gorkha, Nepal, earthquake ruptured a shallow section of the Indian‐Eurasian plate boundary by reverse faulting with NNE‐SSW compression, consistent with the direction of current Indian‐Eurasian continental collis…
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Upward Earthquake Swarm Migration in the Northeastern Noto Peninsula, Japan, Initiated From a Deep Ring‐Shaped Cluster: Possibility of Fluid Leakage From a Hidden Magma System Open
This study describes an ongoing intense earthquake swarm in the crust of the northeastern Noto Peninsula, Japan, that began around the end of 2019. Fluid movement related to volcanic activity is often involved in earthquake swarms in the c…
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The 2018 Mw 7.5 Palu Earthquake: A Supershear Rupture Event Constrained by InSAR and Broadband Regional Seismograms Open
The 28 September 2018 Mw 7.5 Palu earthquake occurred at a triple junction zone where the Philippine Sea, Australian, and Sunda plates are convergent. Here, we utilized Advanced Land Observing Satellite-2 (ALOS-2) interferometry synthetic …
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Statistics of Earthquake Activity: Models and Methods for Earthquake Predictability Studies Open
Statistical methods and various models in time-space-magnitude parameter space of earthquakes are being developed to analyze seismic activity based on earthquake hypocenter catalogs that are routinely accumulated. Considering complex geoph…
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Adjoint‐State Traveltime Tomography: Eikonal Equation‐Based Methods and Application to the Anza Area in Southern California Open
Ray tracing is avoidable in seismic traveltime tomography. In this study, seismic traveltime tomography is reformulated as an eikonal equation‐constrained optimization problem solved by the ray‐free adjoint‐state method. The resultant appr…