Preliminary results of a high-resolution aeromagnetic survey over Usu Volcano, Hokkaido, Japan.

摘要

A helicopter-borne high-resolution aeromagnetic survey was conducted to better understand the subsurface structure of Usu Volcano, Hokkaido, Japan, with a special reference to an eruption, which started on March 31, 2000. The survey was flown at an altitude of 150 m above terrain along north-south survey lines and east-west tie lines, spaced 200 m and 1000 m apart, respectively. Aeromagnetic anomalies were reduced onto a smoothed observed surface and some filtered maps were created. The characteristics of the distribution of magnetic anomalies will be discussed in this report.