HOME > Research Results > Research Highlights, Completed at Last! 3D Geological Map of Central Tokyo

Research Highlights, Completed at Last! 3D Geological Map of Central Tokyo

Geological Survey of Japan

Completed at Last! 3D Geological Map
of Central Tokyo

NAKAZAWA Tsutomu, NONOGAKI Susumu
Research Institute of Geology and Geoinformation

Released: May 21, 2021

3D visualization of subsurface geological structures of central Tokyo

We created a detailed visualization of the subsurface geological structures beneath central Tokyo based on drilling survey data from 50,000 locations. By the 3D analysis of the stratal distribution, soft strata were also found in places considered hard ground until now. It is expected to be utilized in earthquake hazard maps of the capital, Tokyo, and for the development of urban infrastructure.

Three-dimensional analysis method of subsurface geological structures
(partially modified from AIST press release materials on March 29, 2018)

Clarifying subsurface geological structures can help reduce seismic damage and promote urban infrastructure development

During the Great East Japan Earthquake in 2011, a large amount of damage from liquefaction occurred in the Greater Tokyo Metropolitan Area as well, mainly in the bay area. Since it was widely confirmed there was damage to buildings and houses caused by the shaking from the earthquake, attention has been drawn to the geological characteristics of the shallow subsurface, which greatly affects the earthquake damage. In addition, geological information is important for proceeding with infrastructure developments efficiently. However, since urban areas are undergoing development and it is not easy to directly observe strata, it is difficult to obtain accurate subsurface geological information. The details of the distribution of subsurface geological structures were also unclear in central Tokyo.

We analyzed a large number of drilling survey data to visualize the subsurface geological structures of central Tokyo in three dimensions

The three-dimensional morphology of the stratum was clarified by drilling survey data from civil engineering and construction work provided by the Tokyo Metropolitan Government and original drilling surveys by AIST. On the AIST website "Urban Geological Map", anyone can easily view subsurface geological structures of central Tokyo in three dimensions on a computer screen. In addition to the three-dimensional view, it is also possible to display a geological cross-sectional view of any location—this could not be done with a conventional two-dimensional geological map. In addition, in the geological plan view, the area of interest can be enlarged and viewed in detail. Subsurface geological information can be used for earthquake hazard maps and for urban infrastructure development.

Preparing 3D subsurface information of the main metropolitan area

We plan to develop 3D subsurface geological information covering the main areas of the Tokyo metropolitan area, such as the southeastern part of Saitama Prefecture, the central part of Chiba Prefecture, and the eastern part of Kanagawa Prefecture. By providing easy-to-understand and easy-to-use geological information, it will contribute to urban earthquake disaster prevention and infrastructure development.

Contact for inquiries related to this theme

Geoinformatics Research Group, Research Institute of Geology and Geoinformation,
Geological Survey of Japan

NONOGAKI Susumu, Senior Researcher

AIST Tsukuba Central 7, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8567 Japan

E-mail: igg-webmaster-ml*aist.go.jp (Please convert "*" to "@".)

Web: https://unit.aist.go.jp/igg/cie/

▲ ページトップへ