Global Volcanism Program | Image GVP-01657
A volcanologist from the Rabaul Volcano Observatory beside an instrument used to make electronic distance measurements (EDM) across Rabaul caldera. Repeated precise measurements of the distance to stations on opposite sides of the caldera are used for monitoring the slow decade-long deformation that preceded a major eruption in 1994. Two pre-caldera peaks, Mount Kombiu (left) and Mount Turanguna (right) are located near the NE caldera rim.
Photo by Norm Banks, 1983 (U.S. Geological Survey).