17 Result(s)
within
Takashi Kunugi
Geology
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Article
Open AccessEstimation of source, path, and site factors of S waves recorded at the S-net sites in the Japan Trench area using the spectral inversion technique
S-net is a large-scale ocean bottom (OB) network in the Japan Trench area, consisting of inline-type 150 observatories equipped with seismometers and pressure gauges. Among them, 41 observatories have been bur...
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Open AccessDetermination of the source parameters of the 2011 Tohoku-Oki earthquake from three-component pre-P gravity signals recorded by dense arrays in Japan
Dynamic earthquake rupture causes mass redistribution around the fault, and the emitted propagating seismic waves are accompanied by bulk density perturbations. Both processes cause transient gravity changes p...
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Open AccessMOWLAS: NIED observation network for earthquake, tsunami and volcano
National Research Institute for Earth Science and Disaster Resilience (NIED) integrated the land observation networks established since the 1995 Kobe earthquake with the seafloor observation networks establish...
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Open AccessReply to comment by Vallée et al. on “Earthquake-induced prompt gravity signals identified in dense array data in Japan”
Density perturbations accompanying seismic waves are expected to generate prompt gravity perturbations preceding the arrival of P-waves. Vallée et al. (Science 358:1164–1168, 2017, https://doi.org/10.1126/scie...
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Open AccessPeak ground motions and characteristics of nonlinear site response during the 2018 Mw 6.6 Hokkaido eastern Iburi earthquake
The observed peak ground accelerations and peak ground velocities (PGVs) of the 2018 Mw 6.6 Hokkaido eastern Iburi earthquake generally followed the median values from ground motion prediction equations with r...
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Earthquake-induced prompt gravity signals identified in dense array data in Japan
Earthquake ruptures cause mass redistribution, which is expected to induce transient gravity perturbations simultaneously at all distances from the source before the arrival of P-waves. A recent research paper...
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Open AccessEvidence of strong long-period ground motions of engineering importance for Nankai Trough plate boundary earthquakes: comparison of ground motions of two moderate-magnitude earthquakes
We analyzed strong-motion and broadband recordings of two moderate-magnitude earthquakes that occurred in the Nankai Trough. The first event was the 2004 Mw 6.5 southeast off-Kii peninsula earthquake, an after...
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Open AccessSurface wave group velocity in the Osaka sedimentary basin, Japan, estimated using ambient noise cross-correlation functions
Inter-station cross-correlation functions estimated using continuous ambient noise or microtremor records were used to extract the seismic wave propagation characteristics of the Osaka sedimentary basin, Japan...
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Open AccessAssessment of nonlinear site response at ocean bottom seismograph sites based on S-wave horizontal-to-vertical spectral ratios: a study at the Sagami Bay area K-NET sites in Japan
We analyzed S-wave horizontal-to-vertical (S-H/V) spectral ratios at six ocean bottom seismograph (OBS) sites of K-NET located in the Sagami Bay area of Japan for nonlinear site responses. The degree of nonlin...
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Open AccessStrong motions observed by K-NET and KiK-net during the 2016 Kumamoto earthquake sequence
The nationwide strong-motion seismograph network of K-NET and KiK-net in Japan successfully recorded the strong ground motions of the 2016 Kumamoto earthquake sequence, which show the several notable character...
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Article
Open AccessMulti-index method using offshore ocean-bottom pressure data for real-time tsunami forecast
We developed a real-time tsunami forecast method using only pressure data collected from the bottom of the ocean via a dense offshore observation network. The key feature of the method is rapid matching betwee...
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Open AccessAnalysis of strong ground motions and site effects at Kantipath, Kathmandu, from 2015 Mw 7.8 Gorkha, Nepal, earthquake and its aftershocks
Strong ground motions from the 2015 Mw 7.8 Gorkha, Nepal, earthquake and its eight aftershocks recorded by a strong-motion seismograph at Kantipath (KATNP), Kathmandu, were analyzed to assess the ground-motion...
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Open AccessEstimation of the source process of the 2015 Gorkha, Nepal, earthquake and simulation of long-period ground motions in the Kathmandu basin using a one-dimensional basin structure model
The source rupture process of the 2015 Gorkha, Nepal, earthquake was estimated by the joint kinematic source inversion with near-field waveforms, teleseismic waveforms, and geodetic data. The estimated seismic...
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Open AccessSource process of the 2007 Niigata-ken Chuetsu-oki earthquake derived from near-fault strong motion data
The 2007 Niigata-ken Chuetsu-oki earthquake generated strong ground motions in Kashiwazaki and Kariwa, where the world largest nuclear power plant was in operation. Due to the complexity of the aftershock dist...
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Open AccessRupture process of the 2005 West Off Fukuoka Prefecture earthquake obtained from strong motion data of K-NET and KiK-net
We have investigated the rupture process of the 2005 West Off Fukuoka Prefecture earthquake by the multitime- window linear waveform inversion method using the strong ground motion data recorded at 11 K-NET an...
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Erratum to: Ground motion and rupture process of the 2003 Tokachi-oki earthquake obtained from strong motion data of K-NET and KiK-net
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Article
Ground motion and rupture process of the 2003 Tokachi-oki earthquake obtained from strong motion data of K-NET and KiK-net
A great earthquake, named the 2003 Tokachi-oki earthquake, occurred in the southern Kuril subduction zone on 26th September 2003,4:50 JST (41.7797°N, 144.0795°E, 42 km depth; Japan Meteorological Agency). Its ...
