Global Volcanism Program | Image GVP-04792
Volcán Ubinas, seen here from the west, is Perú's most active volcano. A small, 1.2-km-wide caldera that cuts the top of Ubinas gives it a truncated appearance. The upper slopes of the stratovolcano steepen to nearly 45 degrees. The steep-walled, 150-m-deep caldera contains an ash cone with a 500-m-wide funnel-shaped vent that is 200-m deep. Holocene lava flows are visible on the volcano's flanks, but historical activity, documented since the 16th century, has consisted of intermittent minor explosive eruptions.
Photo by Norm Banks, 1988 (U.S. Geological Survey).