Japan to revise geodetic data

The Japanese government is officially revising some geodetic measurements after tectonic changes caused by the March 11th earthquake.

The massive quake and ensuing aftershocks have shifted the ground across Japan, mainly in the northeast and central regions. In Miyagi Prefecture, the ground has shifted east more than 5 meters.

Japan's Geospatial Information Authority says about 45,000 control points for measuring longitude, latitude and elevation have moved.

The authority's new measurements show the origin points of longitude and latitude have moved 27 centimeters east in Tokyo's Minato Ward. In Chiyoda Ward, elevation has sunk 2.4 centimeters.

The geospatial authority is revising its data on Friday by government ordinance.

It will be resetting measurement control points across Japan and will release the new data on October 31st.

It is the first such change since 1928. Elevation was revised then to account for changes in the earth's crust caused by the Great Kanto Earthquake of 1923.

Wednesday, October 19, 2011 12:44 +0900 (JST)