Didicas

Geography & Climate

Didicas is located in Philippines, within the Luzon Volcanic Arc of the broader Western Pacific Volcanic Regions. Situated at 19.08° N, 122.20° E in the Northern Hemisphere, the volcano lies within a tropical climate zone. At just 228 meters above sea level, Didicas is a relatively low-elevation volcanic feature. Despite its modest height, it remains an active geological formation with the same underlying magmatic processes as its taller counterparts. The volcanic landform is characterized as a composite, which describes the physical shape and structure of the volcanic edifice as observed from the surface.

Geological Context

Didicas sits in a subduction zone, where one tectonic plate dives beneath another, creating intense heat and pressure that generates magma. Subduction zones are responsible for many of the world's most explosive volcanoes and deadliest eruptions. For communities in Philippines near Didicas, this tectonic setting means the volcano is capable of producing powerful explosive eruptions, pyroclastic flows, and lahars that can threaten populated areas within tens of kilometers of the summit. The dominant rock type is andesite / basaltic andesite, a dark, fine-grained volcanic rock that forms from rapidly cooling, low-viscosity lava. Basaltic eruptions tend to be less explosive and produce fluid lava flows that can travel long distances. While less immediately dangerous than explosive eruptions, basaltic lava flows can destroy structures and infrastructure in their path, and volcanic gases released during these eruptions can affect air quality over a wide area.

Eruption History Summary

Didicas has 6 recorded eruptions in the geological database, spanning from 1773 CE to 1978 CE. The most powerful recorded event was an explosive event producing ash plumes up to several kilometers in 1978 CE, reaching VEI 2 on the Volcanic Explosivity Index. This eruption frequency indicates a moderately active volcanic system with periodic reawakenings. The most recent eruption in 1978 CE places this volcano within the modern era of volcanological observation.

Significance

With 6 recorded eruptions on file, Didicas has enough documented activity to help scientists identify patterns in its eruptive behavior. Given its recent activity, Didicas is closely monitored by geological survey organizations to provide early warning of future unrest.

GVP Reference Summary

Didicas, 22 km NE of Camiguin Island in the Babuyanes Islands north of Luzon, was a submarine volcano prior to 1952, when a permanent island was formed. It now consists of an andesitic lava dome about 200 m above sea level and 1.4 km in longest exposed dimension. A 400-m-wide crater was formed during the 1952 eruption. The first certain submarine eruption began in 1856, building a subaerial cone that reached a height of over 200 m in 1860, but soon was eroded beneath the sea. Three rock masses up to 82 m high were left after an eruption in 1900. Two eruptions have occurred since 1952 at an explosion crater on the northern side of the island.

— Smithsonian Institution, Global Volcanism Program