Lokon-Empung (Indonesia): Recorded Eruptions and Historical Activity

Lokon-Empung is a stratovolcano complex located in Indonesia, standing at an elevation of 1,580 meters within a subduction zone and continental crust tectonic setting (greater than 25 km). Managed in historical records by the Smithsonian Global Volcanism Program, the volcano features two distinct main peaks, Lokon and Empung, with eruptive activity distributed across specific local areas such as Tompaluan and Empung.

Official records document 30 confirmed eruptions for the volcano. The earliest recorded eruption occurred in 1375 CE (with a start year uncertainty of 25 years), and the latest confirmed eruption began on August 30, 2015, concluding on September 28, 2015.

Chronological Distribution of Eruptions

Historical observation of Lokon-Empung spans multiple centuries, with the frequency of recorded events increasing significantly in the modern era. Across the 30 confirmed eruptions, recorded events are distributed across centuries as follows:

• 14th century CE: 1 eruption (starting around 1375 CE)
• 18th century CE: 1 eruption
• 19th century CE: 2 eruptions
• 20th century CE: 18 eruptions
• 21st century CE: 8 eruptions (up to the 2015 activity)

The Volcanic Explosivity Index (VEI) values associated with the recorded eruptions reach a maximum size of 3.0. For instance, the earliest recorded event in 1375 CE had a VEI of 3.0, as did the 1951–1953 activity and the single-day eruption on September 12, 2003. Other events, such as the 1969–1970 activity and the 2015 eruption, registered a VEI of 2.0.

Selected Historical Eruption Examples

The official record contains numerous documented eruptive phases involving different parts of the volcanic complex. Selected representative entries from the official catalog illustrate the historical record:

• 1375 CE (Empung): Reported activity starting around 1375 CE with a 25-year uncertainty window and a VEI of 3.0.
• 1951–1953 (Tompaluan): A reported eruption in the Tompaluan activity area beginning July 2, 1951, and ending March 16, 1953, with a VEI of 3.0.
• 1969–1970 (Tompaluan): Activity at Tompaluan starting November 27, 1969, and ending December 26, 1970, with a VEI of 2.0.
• 2003 (Tompaluan): A brief reported eruption on September 12, 2003, with a VEI of 3.0.
• 2015 (Tompaluan): An eruption beginning August 30, 2015, and ending September 28, 2015, with a VEI of 2.0.