Variable opening of dike-fed eruptive fissures determined from geodetic data: the 1971 and 1983 rift-zone eruptions of Kilauea Volcano, Hawaii

The variable amount of opening across a dike-fed eruptive fissure can be determined by inversion of geodetic data. We have developed an inverse method based on a gradient algorithm that uses analytic expressions for surface displacement and that requires non-negative tensile displacement perpendicular to the dike. The inversion method has been applied to dikes that fed the 1971 and 1983 rift-zone eruptions of Kilauea Volcano. III both cases, the dikes did not extend below about 4 km and a large variation occurred in the amount of dike opening with depth and along the length of each dike. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.