Liquefaction Potential Map of Tokyo Revised 2024

１．Liquefaction Potential Map

1. This map shows the relative potential for liquefaction when the Tokyo metropolitan area underground is shaken at a consistent intensity. It does not indicate the potential for a specific earthquake, such as an earthquake directly hitting Tokyo.
2. The purpose of this map is to give a risk indication of ground surface liquefaction and is not intended to be a definitive guide of which places “will liquefy or will not liquefy.” Even sites that are “low potential for liquefaction,” the Tokyo Metropolitan Government does not guarantee that liquefaction will not occur.
3. If an assessment of liquefaction effects is required for land or building transactions, detailed surveys and studies shall be conducted at your responsibility.

1. The assessment is performed using collected borehole data and topographic maps, and does NOT consider the effects of liquefaction measures such as ground improvement.
2. In the borehole data assessment, artificial embankments with no description of soil material are set to be liquefaction-resistant materials. Even if an area is determined to have “low potential for liquefaction,” some embankment materials may have the potential to liquefy.
3. Some areas that are assessed as “low potential for liquefaction” may be unsuitable as foundation ground for buildings, such as with the case of soft clayey ground.
4. Since the potential of liquefaction effects is assessed by a 250 meter square grid, the potential may vary from one place to another even within the same grid square.

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2. Unauthorized modification of the contents of this website and the information contained herein, in whole or in part, is NOT permitted.
3. Information provided as open data is subject to a separate Creative Commons license.

1. The Tokyo Metropolitan Government shall NOT be liable for any direct or indirect loss or damage resulting from the use of this liquefaction potential map.

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