Una Una Volcano

Updated: May 21, 2025 13:46 GMT - refresh

stratovolcano

Sulawesi & Sangihe Islands (Indonesia), -0.17°S / 121.61°E

+Local time:

Sunrise:

Sunset:

Moonrise:

Moonset:

Summit height: 507 m / 1,663 ft

Current status: normal or dormant (1 out of 5)

Last update: 27 Jan 2025

Fumarole field at Una Una volcano in Jan 2025 (image: T Heuer)

Una Una (also known as Colo) is an isolated volcano in the Gulf of Tomni, offshore central Sulawesi. It is the site of sulfur extraction.

[smaller] [larger]

News/Updates | Earthquakes | Images

Typical eruption style: Explosive
Una Una volcano eruptions: 1983, 1938, 1898-1900 (?)

Latest nearby earthquakes

Date and Time	Mag / Depth	Distance / Location
May 10, 11:08 pm (Universal Time)	2.2 16 km	29 km (18 mi) to the NW	Minahassa Peninsula, Sulawesi	Info

View recent quakes

Background

Una Una volcano is a broad, low volcano containing a 2-km-wide caldera with a small central cone. Only 3 eruptions are known in historic time, but 2 of them caused extensive damage over much of the island. The last eruption of Una Una was in 1983 and produced pyroclastic flows that swept over most of the island shortly after all residents had been evacuated.

Una Una Volcano Photos

To get to the rim of Marum, we first have to circle it and descend a bit again, following a ridge in a moon-like landscape of ash, erosion gullies and (fortunately not re...

An impressive steam plume is rising from Kamokuna sea entry at Kilauea volcano, Hawai'i.
The lava erupts to the surface at the volcano's eastern rift zone at the Pu...

Mauna Kea volcano, partly in clouds, Big Island, Hawaii (Photo: Janka)

Wide angle view of the caldera with the concentric terraces and the lava lake during the day. The 1977 high level of the lake correspond to the discontinuous narrow terra...

More photos

Significant volcanic eruptions: Una Una volcano

In the past 10,000 years, Una Una has had at least 3 confirmed eruptions, all documented by historical records or observations.

The table below lists all known eruptions (date in bold face) of Una Una volcano in historic times and during the past 10,000 years. Updates on the most recent volcanic activity of Una Una can be found on the news page of Una Una volcano.

Date	Note	VEI	Damage
1983 Jul 18 - Dec 16 ±15 d.	Gunung Colo Historical obs./docs.	4
1983 Jul 23 (eruption 1983 Jul 18 - Dec 16 ±15 d.)	Historical obs./docs.	4	moderate	Info
1983 Jul 23: An explosive eruption produced pyroclastic flows that destroyed most homes, vegetation, and animal life on 40 km2 Una Una Island and probably injected tephra into the stratosphere. Initial activity prompted evacuation of everyone on the island before the devastating explosions. Almost all houses and buildings in the eight villages near the volcano were destroyed and nearly half of the residents of the island had been evacuated. All had left by the time of a major explosion on 21 July at 1623 that subjected 80% of the island to temperatures of up to 200°C. Tephra as large as 5-10 cm in diameter fell near a VSI observation vessel and the monitoring team reported flames on parts of the island. A government geologist estimated that all 700,000 coconut trees and all livestock on the island must have been burned, probably by pyroclastic flows. Ash darkened much of the region. People in Falu, 250 km away, were forced to protect themselves from ashfall until late 23 July. A VSI field party arriving on the island 22 July at 0100 felt ten earthquakes during their 15-hour stay and observed a 1.5-km eruption column at 1649. Cited references #9255 Smithsonian Institution (1983): Colo (Una Una). Scientific Event Alert Network (SEAN) Bulletin, v. 8, no. 7. Source: NOAA National Centers for Environmental Information (NCEI), Global Significant Earthquake Database. doi:10.7289/V5TD9V7K
1938 ±10 y.	Gunung Colo Historical obs./docs.	1
1898 May 2 - 1900 ?	Gunung Colo Historical obs./docs.	3?

Remark:

Our list of volcanic eruptions closely follows the database of eruptions of the Smithsonian's Global Volcanism Project (GVP), the internationally most recognized data source for volcanic eruptions, but also includes significant eruptive episodes or related volcano events. "Volcanic eruptions" are usually to be understood as sequences of individual eruptive episodes that can follow each other, or even overlap (if several vents are involved), and can last many years, decades or even longer. For example, the current activity of Stromboli volcano is understood as a single eruption that has been ongoing since 1934.

Sources: NOAA National Centers for Environmental Information (NCEI), Global Significant Volcanic Eruptions Database. doi:10.7289/V5TD9V7K | Global Volcanism Project / Smithsonian Institution

Una Una Volcano FAQ

+When was the last eruption of Una Una volcano?

The last confirmed eruption of Una Una occurred in 1983.

+How often does Una Una volcano erupt?

Since 1898, Una Una volcano has had at least 3 historically documented eruptions. This means that it erupts on average every 42 years.
Many eruptions of Una Una have lasted more than one year. In total, the volcano has been in eruption during 5 out of 127 years until now. In other words, Una Una has been active at least one in 25.4 years on average. Note that this value is likely an underestimate, because the known history of eruptions from Una Una is likely incomplete, especially further back in time.

+How active is Una Una volcano at present?

Una Una volcano is occasionally active: Since 1900, it has had 3 eruptions, and been active during 3 years out of 126 as of now. This means, Una Una has been in eruption one in 42 years on average. The last eruption was in 1983 and ended 41 years ago.

+When was the largest eruption of Una Una volcano?

The largest eruption of Una Una volcano in historic times occurred in 1983. It ranks as a sub-plinian eruption with a magnitude 4 on the VEI (Volcanic Explosivity Index) scale.

Latest satellite images

See also: Sentinel hub | Landsat 8 | NASA FIRMS

Latest satellite images

Una Una Volcano Maps

Below is a selection of maps showing the location and surroundings of the volcano at various resolutions based on aerial-imagery / terrain maps. Feel free to use them for non-commercial purposes on your blog or website as long as you credit them with a link back to this page (click to copy it).