11 April 2014
Added a new function superimposing seamless geological information on Google Maps in the On-Demand version.
16 July 2013
An automatic, daily, data-update system has been added to the "detailed hypocenter plot options" in the On-Demand version.
20 June 2013
The URL has been changed.
Updated the hypocenter data.
17 November 2011
Released the English version of the Visualization System for Subsurface Structures.
22 April 2011
Revised the "detailed hypocenter plot options" in the On-Demand version; added new plot features; added and updated data. In accordance with this, the plots in the Simple version have also been renewed totally. The specifics are as follows:
  1. Revision of the "detailed hypocenter plot options"
    1. With the "All-Japan hypocenter catalog by the JMA," we used to offer an option to specify an integer, 1 or greater, as the "minimum number of receivers used to determine the hypocenters." When that option was selected, our system did not plot data for which the "minimum number of receivers used to determine the hypocenters" was unavailable, assigning a zero value to this parameter in such cases. As a result, we used to have a problem where very few data from 1994 or earlier years were ever plotted. We have resolved this problem by creating a new option, "Plot data for which the number of receivers is unavailable?"
    2. We have remodeled the system so that the number of hypocenters extracted and the latitude/longitude/depth ranges are outputted on the parameters output screen when the "detailed hypocenter plot options" are used.
    3. We have added/modified/deleted the following options.
      1. "Minimum depth/Maximum depth" (added)
      2. The minimum "magnitude" option was changed to -2. The increments were changed to 0.5 above M5.
      3. Option "Plot data for which the magnitude is unavailable?" (Added)
      4. Option "Plot hypocenters which were determined with the depth fixed or by grid search?" (Added)
      5. "Hypocenter type" Artificial events (Deleted)
      6. "Minimum value for the largest JMA seismic intensity" (Deleted)
      7. Option "Plot data for which the number of receivers is unavailable?" (Added)
  2. Addition of new hypocenter plot features
    1. In the option "Plot all of the 2007 all-Japan hypocenter catalog by the JMA", we enabled the choice of any year, 1923 at the earliest.
    2. We created a new option to use different hypocenter plot sizes depending on the magnitude.
  3. Addition of other new plot features
    1. We have added the following features to the "Settings on how to plot the map (horizontal section)."
      1. Added "Plot ocean trenches."
      2. In "Plot Quaternary volcanoes," the triangular symbols appeared too outsized on large-scale maps, so we remodeled the system to adjust the plot size automatically according to the map scale.
      3. In "Plot topography," the bathymetry of areas greater than 3,000 m in depth used to be painted in magenta color which was unfriendly to the eye. We have adjusted the color palette to realize more natural coloring.
      4. Added new features to plot iso-depth contours of the Pacific plate and the Philippine Sea plate.
    2. We have added the following features to the "Settings on how to plot the vertical section."
      1. We have enabled the plot of vertical sections of terrestrial topography and bathymetry under the option "Plot topography."
      2. Added an option to set "Maximum elevation of the plot area/Maximum depth of the plot area."
  4. Renewal and addition of data
    1. "Superposition on Google Maps"
      1. Added the anticipated source areas of the Tokai/Tonankai/Nankai earthquakes.
      2. Added three sets of iso-depth contours each for the Pacific plate and the Philippine Sea plate.
    2. Hypocenter data
      1. Added data up to 31 August 2010 at the latest to the "All-Japan hypocenter catalog by the JMA" in "Use detailed settings on the hypocenter data."
    3. Detailed plot options
      1. Added the anticipated source areas of the Tokai/Tonankai/Nankai earthquakes.
      2. Added and renewed data on the Pacific plate and the Philippine Sea plate.
22 October 2010
Updated the plot menu "All-Japan hypocenter catalog by the JMA." The "All-Japan hypocenter catalog by the JMA" used to cover data from 14 January 1923, 14:51, to 1 March 2009, 0:00, although this was not specifically noted. With the present update, it now covers data up to 1 June 2010. 0:00. We also made sure that an error is returned if hypocenter data falling out of the coverage period are requested.
7 October 2010
Updated the data for the superposition menu "Offshore Geologic Structures Database" in the On-Demand version.
20 August 2010
Applied the revisions in the On-Demand version, dated 2 August 2010 (2) and 9 August 2010 (1) and (2), to the Simple version as well. In updating the images for the Simple version, we used Katsumata (2010) to plot depths of the Conrad and the Moho, and Nakajima et al. (2009) to plot depths of the upper surface of the Philippine Sea plate
9 August 2010 (1)
Fixed a problem, where data falling out of the range of the color palette (legends) were drawn either white or black, making the plots unfriendly to the eye (looked dirty). More specifically, we made sure that data falling out of the color palette's range were colored in smooth transition from data within the range. We also appended triangles at both ends of the legends to indicate that there are data falling out of the range.
9 August 2010 (2)
Fixed a typo in the title of the visualization image for the "All-Japan tomography data by Nishida et al. (2008)" (it used to appear as Nishida et al. (2007)). The correction was applied to the On-Demand version alone, although both the On-Demand and Simple versions contained the typo.
9 August 2010 (3)
Altered the Japanese transliteration of the word "Poisson's ratio."
2 August 2010 (1)
Fixed a problem, where no plot was created when you chose "Use detailed settings on the hypocenter data" in the On-Demand version and chose "All-Japan hypocenter catalog by the JMA."
2 August 2010 (2)
Fixed an error in the data visualization results for the All-Japan tomography data by Nishida et al. (2008). The latitudes indicated in the digital data were geocentric latitudes, but we had misconstrued them as geographic latitudes during visualization. A geographical latitude phi' and a geocentric latitude phi are approximately related by: phi' = phi + 11.55/60.*sin(2*phi/360*2*pi). As a result, the plots used to be shifted by about 0.18° to the south of their true latitudes. The correction was applied to the On-Demand version alone, although both the On-Demand and Simple versions contained the error.
2 August 2010 (3)
Fixed an error in the explanation of the grid point allocation depths in the All-Japan tomography data by Nakamura et al. (2008). (20 km intervals down to 40 km in depth -> Grid points allocated at depths of 2 km, 5 km, 10 km, 20 km, 30 km and 40 km. 20 km intervals for depths greater than 40 km.)
21 July 2010
Released the Visualization System for Subsurface Structures.