Nationwide 7.5-Arc-Second Japan Engineering Geomorphologic Classification Map and Vs30 Zoning

Local geological and ground conditions play important roles in characterizing and estimating hazards in seismic hazard assessment. The authors recently constructed the Japan Engineering Geomorphologic Classification Map (JEGM), which is a systematically standardized GIS-based ground-condition map containing attributes of geomorphologic classification in grid cells of 7.5 arc-seconds in latitude x 11.25 arc-seconds in longitude for Japan nationwide. This paper introduces the concept of developing the 7.5-arc-second JEGM, and presents sample JEGM images. As an example of the database's application in estimating hazards, the average shear velocity of the ground in the upper 30m, Vs30 is estimated and mapped for Japan nationwide. Other applications being released include seismic hazard maps of Japan, seismic risk analysis by Central Disaster Prevention Council and local governments, and a Quick Estimation System for Earthquake Maps Triggered by Observation Records (QuiQuake).