"All Japan by Matsubara et al. (2011)" (Vp, Vs, P (Poisson's ratio), dVp and dVs plottable

Geographical extent

All Japan including Hokkaido and Okinawa

Grid spacings

In the latitudinal and longitudinal directions, 0.1º intervals. In the depth direction, 2.5 km (down to 10 km in depth), 5 km (< 40 km), 10 km (< 60 km), 15 km (< 180 km), 20 km (< 300 km) and 25 km (more than 300 km) intervals.

Reference velocity structures for dVp and dVs

The spatial averages of Vp and Vs at each depth were taken as the reference velocities (only Vp and Vs data that satisfied conflim ≤ 0.8 were used to calculate the averages).

Confidence indicator

The values contained in the distributed data file, titled "reliability (value derived from the difference between the assumed perturbations and the obtained perturbations in the 12 surrounding grid elements in the checkerboard test. The confidence is high if this value is smaller than 0.8)," were used as the conflim. The default value is 0.8.

Citation

Matsubara, M. and K. Obara, 2011, The 2011 Off the Pacific coast of Tohoku earthquake related to a strong velocity gradient with the Pacific plate, Earth Planets Space, 63, 663-667, doi:10.5047/eps.2011.05.018.

Note

Digital data and dedicated plotting software are downloadable from the National Research Institute for Earth Science and Disaster Prevention Website. The page contains descriptions of the data and the resolution.

"All Japan by Matsubara et al. (2008)" (Vp, Vs, P (Poisson's ratio), dVp and dVs plottable

Geographical extent

All Japan

Grid spacings

In the latitudinal and longitudinal directions, 0.1º intervals. In the depth direction, 2.5 km (down to 10 km in depth), 5 km (< 40 km), 10 km (< 60 km), 15 km (< 180 km), 20 km (< 300 km) and 25 km (more than 300 km) intervals.

Reference velocity structures for dVp and dVs

The spatial averages of Vp and Vs at each depth were taken as the reference velocities (only Vp and Vs data that satisfied conflim ≤ 0.8 were used to calculate the averages).

Confidence indicator

The values contained in the distributed data file, titled "reliability (value derived from the difference between the assumed perturbations and the obtained perturbations in the 12 surrounding grid elements in the checkerboard test. The confidence is high if this value is smaller than 0.8)," were used as the conflim. The default value is 0.8.

Citation

Matsubara, M., K. Obara, and K. Kasahara, 2008, Three-dimensional P- and S-velocity structures beneath the Japan Islands obtained by high-density seismic stations by seismic tomography, Tectonophysics, 454, 86-103, doi:10.1016/j.tecto.2008.04.016

# "All-Japan by Nakamura et al. (2008)" (Vp, Vs, P, dVp and dVs plottable)

Geographical extent

All Japan

Grid spacings

In the latitudinal and longitudinal directions, 0.1º intervals beneath land and 0.2º intervals beneath the sea (note that, for convenience, our system plots plus symbols at 0.1º intervals in all areas). In the depth direction, grid points are allocated at 2 km, 5 km, 10 km, 20 km, 30 km and 40 km in depth. The intervals are 20 km below 40 km in depth.

Reference velocity structures for dVp and dVs

Velocity structures standard.p and standard.s, included in the distributed data, were used as the reference.

Confidence indicator

None

Citation

Nakamura M., Y. Yoshida, D. Zhao, H. Takayama, K. Obana, H. Katao, J. Kasahara, T. Kanazawa, S. Kodaira, T. Sato, H. Shiobara, M. Shinohara, H. Shimamura, N. Takahashi, A. Nakanishi, R. Hino, Y. Murai, and K. Mochizuki, 2008, Three-dimensional P- and S-wave velocity structures beneath Japan, Phys. Earth Planet. Inter., 168, 49-70.

Note

Digital data are downloadable from the Earthquake Research Institute Website.

# "All-Japan by Abdelwahed and Zhao (2007)" (Vp and dVp plottable)

Geographical extent

All Japan

Grid spacings

In the latitudinal and longitudinal directions, 0.4º intervals. In the depth direction, 20 km (< 100 km), 40 km (100-300 km) and 60 km (300-700 km) intervals.

Reference velocity structures for dVp and dVs:

The distributed data contained dVp (dVs) values, so there was no need to designate "reference velocity structures" in our system (we used the dVp and dVs values just as they were in the distributed data).

Confidence indicatore

None

Citation

Abdelwahed, M. F. and D. Zhao, 2007, Deep structure of the Japan subduction zone, Phys. Earth Planet. Inter. 162, 32-52.

Note

Digital data are downloadable from the Earthquake Research Institute Website.

# "All-Japan by Nishida et al. (2008)" (Vs and dVs plottable)

Geographical extent

All Japan

Grid spacings

In the latitudinal and longitudinal directions, 0.1º intervals. In the depth direction, 1 km intervals.

Reference velocity structures for dVp and dVs

Spatial averages at individual depths were used as the reference velocities.

Confidence indicator

None

Citation

Nishida, K., Kawakatsu, H., and K. Obara, 2008, Three-dimensional crustal S wave velocity structure in Japan using microseismic data recorded by Hi-net tiltmeters, J. Geophys. Res., 113, B10302, doi:10.1029/2007JB005395.

Note

Surface-wave tomography using pulsations of the Earth. Digital data are downloadable from the Earthquake Research Institute Website.

# "All Tohoku by Nakajima et al. (2001)" (Vp, Vs, P, dVp and dVs plottable)

Geographical extent

Area covering the whole Tohoku District, spanning from the Oshima Peninsula to northern Kanto District (range: 36.0ºN-42.0ºN, 138.5ºE-142.25ºE)

Grid spacings

In the latitudinal and longitudinal directions, 0.25º intervals. In the depth direction, 10-30 km intervals (more specifically, grid points were allocated at 0, 10, 25, 40, 65, 90, 120 and 150 km in depth).

Reference velocity structures for dVp and dVs

"Deviations from the average velocities" as indicated in the distributed data file were used as dVp and dVs.

Confidence indicator

None

Citation

Nakajima, J., T. Matsuzawa, A. Hasegawa and D. Zhao, 2001, Three-dimensional structure of Vp, Vs, and Vp/Vs beneath northeastern Japan: Implications for arc magmatism and fluids, J. Geophys. Res., 106, 21,843-21,857.

Note

Digital data are downloadable from the Earthquake Research Institute Website.

"Chuetsu area of Niigata Prefecture by Kato et al. (2006)" (Vp, Vs, P, dVp and dVs plottable)

Geographical extent

Rectangular area, 60 x 60 km in size, centered on the source area of the 2004 Niigata-ken Chuetsu earthquake (37.3ºN, 138.9ºE)

Grid spacings

In the horizontal directions, about 3 km in the source area. More specifically, grid points were set at locations -30, -18, -12, -9, -6, -3, 0, 3, 6, 9, 12, 18 and 30 km in the N125ºE direction, and -30, -24, -18, -15,-12,-9,-6,-3, 0, 3, 6, 9, 12, 15, 18, 24 and 30 km in the N35ºE direction, with the origin at (37.3ºN, 138.9ºE). In the depth direction, grid points were allocated at 0, 3, 6, 9, 12, 15 and 20 km.

Reference velocity structures for dVp and dVs

Spatial averages of Vp and Vs at individual depths were used as the reference velocities (only Vp and Vs data that satisfied conflim ≤ 0.05 in each case were used to calculate the averages).

Confidence indicator

The inverse of dws was used as the conflim. The default value is 0.05.

Citation

Kato, A., S. Sakai, N. Hirata, E. Kurashimo, T. Iidaka, T. Iwasaki, and T. Kanazawa, 2006, Imaging the seismic structure and stress field in the source region of the 2004 mid-Niigata prefecture earthquake: Structural zones of weakness and seismogenic stress concentration by ductile flow, J. Geophys. Res. 111, B08308, doi:10.1029/2005JB004016.

"Chuetsu area of Niigata Prefecture by Takeda et al. (2005)" (Vp, Vs, P, dVp and dVs plottable)

Geographical extent

Rectangular area, 80 x 100 km in size, centered on the southern part of the 2004 Niigata-ken Chuetsu earthquake source area (37.1ºN, 138.8ºE)

Grid spacings

In the N30ºE direction, 8-12 km intervals. In the N120ºE direction, 10-15 km intervals. In the depth direction, 3 km intervals (down to 18 km in depth).

Reference velocity structures for dVp and dVs

Spatial averages of Vp and Vs at individual depths were used as the reference velocities (only Vp and Vs data that satisfied conflim ≤ 0.05 in each case were used to calculate the averages).

Confidence indicator

The inverse of dws was used as the conflim. The default value is 0.05.

Citation

Takeda, T., Y. Kuwahara, K. Imanishi, and Y. Haryu, 2005, Crustal structure in southern area of the 2004 Mid-Niigata earthquake by Double-Difference Tomography method, Abstracts, Japan Earth Planet. Sci. Joint Meeting (CD-ROM), S101-007.

# "Niigata-Kobe Tectonic Zone by Nakajima and Hasegawa (2007)" (Vp, Vs, P, dVp and dVs plottable)

Geographical extent

Area centered on the zone of strain concentration (from Niigata to Kobe) (range: 33.4ºN-38.0ºN and 134.0ºE-140.0ºE)

Grid spacings

In the latitudinal and longitudinal directions, 0.2º intervals. In the depth direction, 5-15 km (0-40 km in depth), 20 km (40-120 km in depth) and 30 km (more than 120 km in depth) intervals.

Reference velocity structures for dVp and dVs

"Deviations from the average velocities" as indicated in the distributed data file were used as dVp and dVs.

Confidence indicator

The inverse of the "P wave (S wave) hit count", as indicated in the distributed data file, was used as the conflim. The default value is 0.00001.

Citation

Nakajima, J. and A. Hasegawa, 2007, Deep crustal structure along the Niigata-Kobe Tectonic Zone, Japan: Its origin and segmentation, Earth, Planets and Space, 59, e5-e8.

Note

Digital data are downloadable from the Earthquake Research Institute Website.

"Itoigawa-Shizuoka Tectonic Line and its surroundings by Kasahara et al. (2006)" (Vp, Vs, P, dVp and dVs plottable)

Geographical extent

Rectangular area, 80 x 220 km in size, along the Itoigawa-Shizuoka Tectonic Line

Grid spacings

In the N20ºW and N70ºE directions, 10 km intervals each. In the depth direction, 3 km (down to 15 km in depth) and 10-15 km (15-40 km) intervals.

Reference velocity structures for dVp and dVs

Spatial averages of Vp and Vs at individual depths were used as the reference velocities (only Vp and Vs data that satisfied conflim ≤ 0.05 in each case were used to calculate the averages).

Confidence indicator

The inverse of dws was used as the conflim. The default value is 0.05.

Citation

Kasahara, K., Y. Asano, T. Takeda, S. Hori, K. Obara, K. Shiomi, S. Sekine, M. Matsubara, and Y. Ito, 2006, Observation of natural earthquakes in the neighborhood of the fault zone (long-term mobile observation), in Achievement Report for Fiscal 2005, Priority Survey and Observation in the Itoigawa-Shizuoka Tectonic Line Fault Zone, pp. 34-52, Research and Development Bureau of the Ministry of Education, Culture, Sports, Science and Technology, Geospatial Information Authority of Japan of the Ministry of Land, Infrastructure, Transport and Tourism, and the Earthquake Research Institute of the University of Tokyo (in Japanese).

"Kobe (Kinki District) by Zhao et al. (1996)" (Vp, Vs, P, dVp and dVs plottable)

Geographical extent

Neighborhood of Kobe (Kinki District) (range: 33-36ºN and 134-137ºE)

Grid spacings

In the north-south and east-west directions, 0.05-0.2º. In the depth direction, 3-6 km (down to 35 km in depth).

Reference velocity structures for dVp and dVs

The distributed data contained dVp (dVs) values, so there was no need to designate "reference velocity structures" in our system (we used the dVp and dVs values just as they were in the distributed data).

Confidence indicator

None

Citation

Zhao, D., H. Kanamori, H. Negishi, and D. Wiens, 1996, Tomography of the source area of the 1995 Kobe earthquake: Evidence for fluids at the hypocenter?, Science, 274, 1891-1894.

# "Kii Peninsula and the Chugoku/Shikoku Districts by Nakajima et al. (2007EPSL)" (Vp, Vs, P, dVp and dVs plottable)

Geographical extent

Area covering southwestern Japan from eastern Kyushu to the Chubu District (range: 32ºN-35.5ºN and 131ºE-137ºE)

Grid spacings

In the latitudinal and longitudinal directions, 0.3º intervals. In the depth direction, 10-50 km intervals (more specifically, grid points were allocated at depths of 0, 10, 25, 40, 60, 80, 100, 120, 140, 160, 180, 210, 240, 270, 300, 350, 400 and 450 km).

Reference velocity structures for dVp and dVs

"Deviations from the average velocities" as indicated in the distributed data file were used as dVp and dVs.

Confidence indicator

The inverse of the "P wave (S wave) hit count", as indicated in the distributed data file, was used as the conflim. The default value is 0.00001.

Citation

Nakajima, J. and A. Hasegawa, 2007, Tomographic evidence for the mantle upwelling beneath southwestern Japan and its implications for arc magmatism: Earth and Planetary Science Letters, 254, 90-105.

Note

Digital data are downloadable from the Earthquake Research Institute Website.

# "Southwestern Japan by Nakajima et al. (2007JGR)" (Vp, Vs, P, dVp and dVs plottable)

Geographical extent

Area covering southwestern Japan from Kyushu to northern Kanto

Grid spacings

In the Chugoku and Shikoku Districts, 0.3º intervals in the north-south direction and 0.4º intervals in the east-west direction. In the other districts, 0.25º intervals in the north-south direction and 0.3º intervals in the east-west direction. In the depth direction, 10-15 km (down to 60 km in depth) and 20-40 km (more than 60 km in depth) intervals.

Reference velocity structures for dVp and dVs

"Deviations from the average velocities" as indicated in the distributed data file were used as dVp and dVs.

Confidence indicator

The inverse of the "P wave (S wave) hit count", as indicated in the distributed data file, was used as the conflim. The default value is 0.00001.

Citation

Nakajima, J. and A. Hasegawa, 2007, Subduction of the Philippine Sea plate beneath southwestern Japan: Slab geometry and its relationship to arc magmatism: J. Geophys. Res., 112, B08306, doi:10.1029/2006JB004770.

Note

Digital data are downloadable from the Earthquake Research Institute Website.

Hypocenters

"All-Japan hypocenter catalog by the JMA"

Japan Meteorological Agency, since 14-Jan-1923, Annual Earthquake Report CD-ROM.

Note

The whole body of the annual catalog is included by selecting "Plot all of the 20XX all-Japan hypocenter catalog by the JMA" in the basic selection menu. In the meantime, only the data with the hypocenter determination flag "K" (good accuracy) are picked up by selecting "All-Japan hypocenter catalog by the JMA" under "Use detailed settings on the hypocenter data." The standard deviation for the depth was set at 999 km if the hypocenter was determined with its depth fixed. The JMA magnitude I was selected as the magnitude value.

"Precise determination of hypocenters along the ISTL by Obara et al. (2008)"

Obara, K., T. Takeda, Y. Asano, Y. Yukutake, K. Shiomi, M. Matsubara, S. Sekine, and S. Hori, 2008, Observation of natural earthquakes in the neighborhood of the fault zone (long-term mobile observation), in Achievement Report for Fiscal 2007, Priority Survey and Observation in the Itoigawa-Shizuoka Tectonic Line Fault Zone, pp. 33-48, Research and Development Bureau of the Ministry of Education, Culture, Sports, Science and Technology, Geospatial Information Authority of Japan of the Ministry of Land, Infrastructure, Transport and Tourism, and the Earthquake Research Institute of the University of Tokyo (in Japanese).

"Seismicity surrounding the 1995 Hyogo-ken Nambu earthquake by Zhao et al. (1996)"

Zhao, D., H. Kanamori, H. Negishi, and D. Wiens, 1996, Tomography of the source area of the 1995 Kobe earthquake: Evidence for fluids at the hypocenter?, Science, 274, 1891-1894.

"2004 Chuetsu earthquake aftershock distribution by Kato et al. (2006)"

Kato, A., S. Sakai, N. Hirata, E. Kurashimo, T. Iidaka, T. Iwasaki, and T. Kanazawa, 2006, Imaging the seismic structure and stress field in the source region of the 2004 mid-Niigata prefecture earthquake: Structural zones of weakness and seismogenic stress concentration by ductile flow, J. Geophys. Res. 111, B08308, doi:10.1029/2005JB004016.

Tectonic line

"Conrad and Moho depths"

"Zhao et al. (1992)"

Zhao, D., S. Horiuchi and A. Hasegawa, 1992, Seismic velocity structure of the crust beneath the Japan Islands, Tectonophysics, 212, 289-301.

"Katsumata (2010)"

Katsumata, A., 2010, Depth of the Moho discontinuity beneath the Japanese islands estimated by traveltime analysis, J. Geophys. Res., 115, B04303, doi:10.1029/2008JB005864.

"Depths of the upper surface of the Pacific plate"

"Zhao et al. (1993)"

Zhao, D., and A. Hasegawa, 1993, P wave tomographic imaging of the crust and upper mantle beneath the Japan Islands, J. Geophys. Res., 98, 4333-4353.

"Fujiwara et al. 2009; J-SHIS, NIED"

Fujiwara, H., S. Kawai, S. Aoi, N. Morikawa, S. Senna, N. Kudo, M. Ooi, K. X.-S. Hao, K. Wakamatsu, Y. Ishikawa, T. Okumura, T. Ishii, S. Matsushima, Y. Hayakawa, N. Toyama, and A. Narita, 2009, A study on "National Seismic Hazard Maps for Japan", Technical Note of the National Research Institute for Earth Science and Disaster Prevention, No. 336 (in Japanese).

Note

Numerical data (P-Y2010-PRM-PLATE_SHP_PSE_CPCF.csv, downloaded on 09-Jan-2011) downloaded from (the Japan Seismic Hazard Information Station (J-SHIS) of the National Research Institute for Earth Science and Disaster Prevention (NIED) are published here under permission by the NIED. The user should obey the terms and conditions of J-SHIS when publishing plot results.

"KNHN compiled by Hirose"

Data compiled by Dr Fuyuki Hirose of the Meteorological Research Institute are published here under his and his co-authors' permission. (Digital data are downloadable from Dr Hirose's Website. The data in our system were downloaded from his Website on 04-Feb-2011.) When publishing plot results, the user should cite the original paper(s) corresponding to the study region [Kita et al. (2010) for Hokkaido and northern Tohoku; Nakajima and Hasegawa (2006) for northern and southern Tohoku; Nakajima et al. (2009) for Kanto and northern Izu Arc].

Nakajima, J., and A. Hasegawa, 2006, Anomalous low-velocity zone and linear alignment of seismicity along it in the subducted Pacific slab beneath Kanto, Japan: Reactivation of subducted fracture zone?, Geophys. Res. Lett., 33, L16309, doi: 10.1029/2006GL026773.

Nakajima, J., F. Hirose, and A. Hasegawa, 2009, Seismotectonics beneath the Tokyo metropolitan area, Japan: Effect of slab-slab contact and overlap on seismicity, J. Geophys. Res., 114, B08309, doi:10.1029/2008JB006101.

Kita, S., T. Okada, A. Hasegawa, J. Nakajima, and T. Matsuzawa, 2010, Anomalous deepening of a seismic belt in the upper-plane of the double seismic zone in the Pacific slab beneath the Hokkaido corner: Possible evidence for thermal shielding caused by subducted forearc crust materials, Earth Planet. Sci. Lett., 290, 415-426.

"Depths of the upper surface of the Philippine Sea plate"

"Nakamura and Kaneshiro (2000)"

Nakamura, M., and S. Kaneshiro, 2000, Determination of subducted Philippine Sea Plate in the Nansei islands deduced from hypocenter data, Bull. Fac. Sci., Univ. Ryukyus, 70, 73-82 (in Japanese with English abstract).

Note

Numerical data in Table 1 of the cited article are used.

"Fujiwara et al. 2009; J-SHIS, NIED"

Fujiwara, H., S. Kawai, S. Aoi, N. Morikawa, S. Senna, N. Kudo, M. Ooi, K. X.-S. Hao, K. Wakamatsu, Y. Ishikawa, T. Okumura, T. Ishii, S. Matsushima, Y. Hayakawa, N. Toyama, and A. Narita, 2009, A study on "National Seismic Hazard Maps for Japan", Technical Note of the National Research Institute for Earth Science and Disaster Prevention, No. 336 (in Japanese).

Note

Numerical data (P-Y2010-PRM-PLATE_SHP_PSE_CPHL.csv, downloaded on 09-Jan-2011) downloaded from the Japan Seismic Hazard Information Station (J-SHIS) of the National Research Institute for Earth Science and Disaster Prevention (http://www.j-shis.bosai.go.jp/?lang=en) are used. The user should obey the terms and conditions of J-SHIS when publishing plot results.

"BNHHHN compiled by Hirose"

Data compiled by Dr Fuyuki Hirose of the Meteorological Research Institute are published here under his and his co-authors' permission. (Digital data are downloadable from Dr Hirose's Website. The data in our system were downloaded from his Website on 04-Feb-2011.) In regions where iso-depth contours are interrupted midway, we represented, for convenience, the upper surface of the Philippine Sea plate by a single, smoothly curving surface (in vertical section plots in our Visualization System, iso-depth contours are represented by solid and dashed curves, respectively, in regions where they are drawn and not drawn).

When publishing plot results, the user should cite the original paper(s) corresponding to the study region [Baba et al. (2002), Nakajima and Hasegawa (2007) and Hirose et al. (2008) for southwestern Japan; Hirose et al. (2008) for Kanto; Nakajima et al. (2009) for the northern extension of Izu].

Baba, T., Y. Tanioka, P. R. Cummins, and K. Uhira (2002), The slip distribution of the 1946 Nankai earthquake estimated from tsunami inversion using a new plate model, Phys. Earth Planet. Inter., 132, 59-73.

Hirose, F., J. Nakajima, and A. Hasegawa (2008), Three-dimensional seismic velocity structure and configuration of the Philippine Sea slab in southwestern Japan estimated by double-difference tomography, J. Geophys. Res., 113, B09315, doi:10.1029/2007JB005274.

Hirose, F., J. Nakajima, and A. Hasegawa, 2008, Three-dimensional velocity structure and configuration of the Philippine Sea slab beneath Kanto district, central Japan, estimated by double-difference tomography, Zisin J. Seismol. Soc. Japan, Second Series, 60, 123-138 (in Japanese with English abstract).

Nakajima, J., and A. Hasegawa (2007), Subduction of the Philippine Sea plate beneath southwestern Japan: Slab geometry and its relationship to arc magmatism, J. Geophys. Res., 112, B08306, doi:10.1029/2006JB004770.

Nakajima, J., F. Hirose, and A. Hasegawa, 2009, Seismotectonics beneath the Tokyo metropolitan area, Japan: Effect of slab-slab contact and overlap on seismicity, J. Geophys. Res., 114, B08309, doi:10.1029/2008JB006101.

"Active faults"

National Institute of Advanced Industrial Science and Technology, 2013, Active Fault Database of Japan, July 23, 2013 Version. Research Information Database DB095, National Institute of Advanced Industrial Science and Technology. https://gbank.gsj.jp/activefault/index_e_gmap.html