About Ranau
Ranau is a caldera rising to 1,854 meters (6,083 feet) in Indonesia's Sunda-Banda Volcanic Regions. No historical eruptions have been recorded, though the volcano is classified based on geological evidence of past activity. The volcano has produced 2 recorded eruptions.
Geography & Climate
Ranau is located in Indonesia, within the Sunda Volcanic Arc of the broader Sunda-Banda Volcanic Regions. Situated at 4.87° S, 103.92° E in the Southern Hemisphere, the volcano lies within a tropical climate zone. With a summit elevation of 1,854 meters above sea level, Ranau is a moderately sized peak that remains accessible to hikers and researchers for much of the year. The volcanic landform is characterized as a caldera, which describes the physical shape and structure of the volcanic edifice as observed from the surface.
Geological Context
Ranau 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 Ranau, 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 dacite, an intermediate to silica-rich volcanic rock. This composition typically produces more viscous magma, leading to more explosive eruptions with ash columns and pyroclastic flows. Andesitic and dacitic magmas build pressure before erupting, which is why volcanoes with this rock chemistry are often associated with Plinian-style eruptions that can send ash tens of kilometers into the atmosphere and disrupt aviation across entire regions.
Eruption History Summary
Ranau has 2 recorded eruptions in the geological database, spanning from 1887 CE to 1903 CE. These eruptions span roughly 16 years of volcanic history. The most recent eruption in 1903 CE places this volcano within the modern era of volcanological observation.
GVP Reference Summary
Ranau is an 8 x 13 km Pleistocene caldera partially filled by the crescent-shaped Lake Ranau. The caldera lies along the Great Sumatran Fault that extends the length of Sumatra. Incremental formation of the caldera culminated in the eruption of the voluminous Ranau Tuff about 0.55 million years ago. A morphologically young post-caldera stratovolcano, Gunung Semuning, was constructed within the SE side of the caldera to a height of more than 1,200 m above the lake surface. The volcano has not been mapped in sufficient detail to determine the age of its latest eruptions, although fish kills and sulfur smells in the late 19th and early 20th centuries may be related to volcanism.
— Smithsonian Institution, Global Volcanism Program
2 Recorded Eruptions
| Year | VEI | Type | Area |
|---|---|---|---|
| 1903 | — | Uncertain Eruption | — |
| 1887 | — | Uncertain Eruption | — |
Real-Time Data
USGS Alert Level
Thermal Anomalies
Frequently Asked Questions About Ranau
Is Ranau an active volcano?+
Ranau is not currently classified as active. Its activity evidence is listed as "Evidence Uncertain." No recorded eruptions have been documented. However, no volcano is ever considered permanently extinct.
When did Ranau last erupt?+
The most recent recorded eruption of Ranau occurred in 1903 CE. The eruption was classified as a "Uncertain Eruption." Ranau has 2 recorded eruptions in total.
How high is Ranau?+
Ranau has a summit elevation of 1,854 meters (6,083 feet) above sea level. At 1,854 meters, it is a moderately sized volcanic peak, roughly comparable to Mount Vesuvius (1,281m).
What type of volcano is Ranau?+
Ranau is classified as a Caldera. Calderas are large volcanic depressions formed when a volcano erupts so powerfully that its magma chamber collapses, creating a basin that can be kilometers wide. They are often sites of some of Earth's largest eruptions.
Where is Ranau located?+
Ranau is located in Indonesia, in the Sunda-Banda Volcanic Regions. More specifically, it lies within the Sunda Volcanic Arc. Its exact coordinates are -4.871° latitude, 103.925° longitude.
Is it safe to visit Ranau?+
Ranau can generally be visited, but as with any volcano, visitors should check local conditions and any advisory notices before traveling. Indonesia may have specific regulations for accessing volcanic areas. Guided tours are often the safest and most informative way to experience a volcano.
