Gravity Changes Associated with Volcanism : Observation, Theory, and Analysis

Abstract

We describe in this paper recent development of gravity observation and theoretical works on gravity change that enable us to infer mass transport during volcanism with reasonable accuracy. Combined use of both absolute and relative gravity measurement, namely hybrid gravity measurement, gives us "absolute" gravity data on local to regional scales. The data merged with crustal movement can be inverted for physical models of volcanism. The strategy gives us invaluable information how underground masses were transported during the event of Miyake-jima eruption in 2000 and that of Mt. Asama in 2004.