Salak

Geography & Climate

Salak is located in Indonesia, within the Sunda Volcanic Arc of the broader Sunda-Banda Volcanic Regions. Situated at 6.72° S, 106.73° E in the Southern Hemisphere, the volcano lies within a tropical climate zone. At 2,218 meters above sea level, Salak rises above the surrounding terrain into montane or subalpine conditions. The elevation creates distinct ecological zones along its flanks, from forested lower slopes to exposed rocky terrain near the summit. 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

Salak 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 Indonesia near Salak, 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

Salak has 6 recorded eruptions in the geological database, spanning from 1699 CE to 1938 CE. The most powerful recorded event was an explosive event producing ash plumes up to several kilometers in 1938 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 1938 CE places this volcano within the modern era of volcanological observation.

Significance

With 6 recorded eruptions on file, Salak has enough documented activity to help scientists identify patterns in its eruptive behavior.

GVP Reference Summary

The forested Salak volcano was constructed at the NE end of an eroded volcanic range. Satellitic cones occur on the SW flank and at the northern foot, and two large breached craters truncate the summit. One crater is breached to the NE and the westernmost crater was the source of a debris-avalanche deposit that extends 10 km WNW of the summit. Phreatic explosions have been recorded from a solfataric area at 1,400 m on the western flank. Salak volcano has been the site of extensive geothermal exploration.

— Smithsonian Institution, Global Volcanism Program