Zoomify images of earthquake-hit areas
Ground subsidence of liquefied landfills in Urayasu
The March 11th 2011 East-Japan Earthquake has caused sand-liquefaction
over a long stretch of landfills along the coast of Tokyo Bay. An attempt was made to detect
soil subsidence from airborne LiDAR (Light Detection and Ranging) images before and after
the earthquake. To cancel out deep-seated tectonic displacements and systematic errors of
LiDAR, the template matching technique is used for the end-bearing pile-supported buildings
chosen as the template in the source image of the target area of Urayasu. The obtained
subsidence map on Zoomify HTML5 allows you high-quality image viewing and zoom-and-pan interactivity.
Ground subsidence of landfills along the eastern shore line of Tokyo Bay
The map below on Zoomify HTML5 covers the entire stretch of the eastern shore line from Ichikawa to Chiba City.
Change in elevation caused by shallow subsurface soil movements in the 2004 Mid-Niigata Prefecture Earthquake
The October 23rd, 2004 Mid-Niigata Prefecture Earthquake triggered thousands of landslides in the Mid-Niigata Mountain terrain.
Digital elevation models (DEM hereafter) before (1975-1976) and after (Oct. 28, 2004) the earthquake were first compared.
Then changes in elevation in Eulerian description for DEM were converted to Lagrangian displacements,
and the obtained Lagrangian ground displacements were further resolved into shallow and deep seated displacement components (Refs. [6], [7] and [8]).
The change in elevation caused by only shallow subsurface soil displacements shown in the figure below highlights the locations of large landslides
such as (a) Dainichi-yama landslide, (b) Higashi-Takezawa landslide, and (c) the increased river bed of Imokawa blocked by the Higashi-Takezawa landslide mass.