1998 Eruption of axial volcano: Multibeam anomalies and seafloor observations

Abstract

Lava flows erupted during the January/February 1998 seismic swarm at Axial Volcano on the Juan de Fuca Ridge have been identified by differencing of pre- and post-event multibeam bathymetric surveys and by seafloor observations. A sheet flow more than 3 km in length and 500-800 m wide erupted from the uppermost south rift is the site of a robust hydrothermal system. 1998 lavas occur over about 9 km of the upper south rift zone, or about 20% of the along-axis length of the seismicity event (-50 km). The estimated volume of lava erupted is 18-76 × 106 m3 for the extrusion and 100-150 × 106 m3 for the intrusion. The total volume is consistent with the volume from modeling of seafloor strain measurements recorded during the event. Copyright 1999 by the American Geophysical Union.