Mount Ruang, also known as Gunung Ruang, is an intriguing and active stratovolcano located in the Sangihe Islands of North Sulawesi, Indonesia. It is particularly notable for its geological activity and the picturesque landscapes it contributes to the region.

Mount Ruang Volcano Eruptions | Times of India Travel (

Geographic Location

Mount Ruang is situated within the Pacific Ring of Fire, which is renowned for its high concentration of volcanoes and seismic activity. The volcano forms part of the Sangihe volcanic arc, which includes several other active volcanoes. It sits between the Celebes Sea to the west and the Molucca Sea to the east, making it a prominent geographic feature in this island chain.


The significance of Mount Ruang extends beyond its immediate geographical location. It plays a crucial role in the local ecosystem and biodiversity. The volcanic soils around Mount Ruang are fertile and support diverse plant and animal life, which is typical of Indonesian volcanic regions. Additionally, the volcano’s periodic eruptions have shaped the landscape over millennia, creating unique geological formations and contributing to the island’s topographical diversity.

Furthermore, Mount Ruang is of interest to geologists and volcanologists who study its patterns of activity to gain insights into volcanic behavior. Its eruptions are also significant for local communities, influencing agricultural practices due to the fertility of the soil, which is periodically enriched by volcanic ash.

Overall, Mount Ruang is a striking natural feature with considerable influence on its environment and the people who live in its vicinity.

Geological Description

A ship from Indonesia’s National Search and Rescue Agency (BASARNAS) is anchored at the port on Tagulandang island in Sitaro, North Sulawesi on April 19, 2024, as the Mount Ruang volcano is seen in the background spewing smoke. (Photo by Ronny Adolof BUOL / AFP)

Mount Ruang, as a stratovolcano, exhibits characteristics typical of this type of volcano, which includes a layered structure composed of alternating layers of hardened lava, tephra, and volcanic ash. These features are formed from periodic explosive eruptions followed by quieter eruptions that produce lava flows. Stratovolcanoes are known for their steep profiles and periodic, explosive eruptions.

Composition and Structure

The composition of Mount Ruang largely consists of andesite and dacite, which are intermediate volcanic rocks containing a higher silica content than basalt. This higher silica content makes the magma more viscous, contributing to the explosive nature of eruptions. The structure of Mount Ruang includes a central vent, which is the primary outlet for magma during an eruption. This vent is surrounded by a crater, which may be filled with a lava dome formed from slower, oozing lava that cools and accumulates around the vent.

Historical Eruptions and Recent Activity

Mount Ruang in Sitaro Islands, North Sulawesi, spewing volcanic ash as seen on Friday, April 19, 2024. (ANTARA/HO-Basarnas/aa/rst) Mt. Ruang eruption damages 498 houses, public facilities: BNPB – ANTARA News

Mount Ruang has a documented history of eruptions that have impacted the surrounding areas. Historical eruptions have been characterized by explosive activity that ejects significant amounts of ash and tephra into the atmosphere, often disrupting local communities and ecosystems. For instance, its eruption in 2002 was particularly noteworthy, featuring a substantial ash plume that caused disruptions in air travel and deposited ash on nearby islands.

Mount Ruang boasts a long history of fiery outbursts. Records indicate at least 16 eruptions since 1808, with some leaving a significant mark:

  • Early 19th Century: The first documented eruption occurred in 1808.
  • 1871: A particularly destructive eruption triggered a tsunami that devastated a nearby island village, tragically claiming hundreds of lives [ English].
  • 20th & 21st Centuries: Major eruptions continued throughout the 20th and 21st centuries, with significant events in 1904, 1956, 2002, and most recently in April 2024 [NASA Earth Observatory].

Recent Activity (April 2024):

In April 2024, Mount Ruang rumbled back to life, prompting concern. The eruption caused ashfall and potential hazards, leading to evacuations for residents on the northern side of Sulawesi Island. Thankfully, no casualties were reported [EXO Travel Blog].

The eruptive history and recent activity of Mount Ruang underscore its status as one of Indonesia’s most active and potentially dangerous volcanoes. The historical record, combined with recent events, highlights the serious natural hazards associated with this volcano.

Mt Ruang eruption: Volcanic ash in Kota Kinabalu FIR affects multiple air routes, airports | ADQIT NEWS

Historical Eruptions

Mount Ruang has a documented history of major explosive eruptions, with significant events recorded in:

  • 1634, 1670, 1843, 1871, 1904, 1956, and 2002: Each of these eruptions was characterized by substantial explosive activity. The 1871 eruption was particularly devastating, as it triggered a tsunami that resulted in extensive damage and loss of life on a nearby island.

2024 Eruption and Current Risks

The recent eruption in 2024 has again brought to light the dangers posed by Mount Ruang:

  • Lahars and Tsunami Risks: The interaction of volcanic ash with rain has created conditions ripe for lahars—destructive mudflows that can sweep down the slopes of the volcano, devastating everything in their path. The geological dynamics of the eruption also raised concerns about the possibility of tsunamis, especially if significant volcanic material entered the sea. Although multiple tsunami warnings were issued, thankfully, no significant tsunamis have occurred so far.
  • Evacuation and Safety Measures: The Indonesian authorities, specifically the PVMBG (Center for Volcanology and Geological Hazard Mitigation) and the BNPB (National Board for Disaster Management), have taken proactive measures by evacuating over 16,000 people from areas deemed most at risk. These areas include zones likely to be affected by pyroclastic flows, ash falls, and potential tsunamis. The effective management of this situation has so far prevented any deaths or injuries since the eruption began.

Monitoring and Response

The ongoing monitoring efforts by PVMBG and coordination by BNPB are critical in managing the risks associated with Mount Ruang. The use of seismic data, satellite imagery, and ground-based observations ensures that authorities can quickly respond to changes in the volcano’s activity. This comprehensive monitoring network, coupled with public education and evacuation protocols, is vital in minimizing the impact of eruptions and safeguarding the lives of those living in proximity to this powerful and unpredictable volcano.

Monitoring Efforts and Volcanic Warning Systems

Mount Ruang is monitored by the Indonesian Center for Volcanology and Geological Hazard Mitigation (CVGHM), which employs a variety of techniques to track and predict volcanic activity:

  • Seismic Monitoring: Networks of seismographs around the volcano measure earthquakes that occur as magma moves through the Earth’s crust. Increases in seismic activity can indicate that an eruption may be imminent.
  • Gas Emissions: The analysis of gases released by the volcano provides insights into the movement of magma beneath the surface. Changes in the quantity and type of gases can signal changes in activity levels.
  • Visual and Satellite Observations: Regular visual monitoring and satellite imagery help detect changes in the shape of the volcano (deformation), thermal anomalies, and ash emissions.

The CVGHM works in conjunction with local and national disaster response agencies to disseminate information and warnings to the public. Warning systems include community education, sirens, and evacuation drills to ensure that residents are prepared to act quickly in the event of an eruption.

Through these efforts, the monitoring of Mount Ruang is comprehensive, aiming to mitigate the impact of eruptions and safeguard the communities living in proximity to the volcano.