Lokon-Empung Volcano (Tompaluan crater)


Lokon-Empung is a twin volcano lying on the rim of the Tondano Caldera in northern Sulawesi, Indonesia. In addition to Lokon-Empung, the volcanoes Mahawu, Sopotan and Sempu are located along the perimeter of the 20x30 km wide caldera which was formed by a massive eruption in the Late Miocene or Early Pliocene period. Nested within Tondano lies the more recent 3.5x5 km Pangolombian caldera and several subsequently formed volcanic edifices. The North Sulawesi-Sangihe Islands magmatic arc which encompasses the volcanoes around Tondano, including Lokon-Empung, is related to subduction of oceanic crust of the Molucca plate in a westward direction (thus sliding under Northern Sulawesi). The nearby Halmahera arc is associated with eastward subduction of the Molucca plate.

Powerful ash eruption from Lokon-Empung volcano, Kawah Tompaluan crater, 6th December 2012 Powerful ash eruption from Lokon-Empung volcano, Kawah Tompaluan crater, 6th December 2012, portrait orientation Powerful ash eruption from Lokon-Empung volcano, Kawah Tompaluan crater, 6th December 2012

Powerful ash eruption, evening 06.12.2012


Map of Molucca Sea Region with Collision Zone and Volcanic Arcs indicated.

Based on data from Google Maps, MacPherson et al. 2003 (Geol. Soc. London, Special Publ. 219, p.207-220), Siahaan et al. 2005 (Proc. World Geol. Congress, 5pp).

Note: Only selected extinct volcanoes have been included in the map, many others exist in the Arcs.


The active crater of the Lokon-Empung complex, Kawah Tompaluan (1140m), lies on the saddle connecting Lokon and Empung volcanoes. No historical activity has been documented at Lokon (1579m), whilst moderate explosive eruptions occurred at Empung (1340m) around 1375 and 1775 (exact dates not known). Activity has since only been observed at Kawah Tompaluan. The first eruption at Tompaluan was recorded in 1829, with further eruptions in 1893-94, 1930, 1942, 1949, 1951-53, 1958-59, 1962-66, 1969-71, 1973-80, 1984, 1986-88, 1991-92, 2000-2003 and 2011-2012 (list last updated 2012). The 1991 eruptive phase produced particularly powerful eruptions. On 19. September, volcanic bombs falling in a radius of 500m of the crater set fire to nearby plantations. On 24-25 October significant ash emission occurred, sometimes associated with short pyroclastic flows. Up to one meter of ash fell around the crater and 2.5 cm in Kinilow, 4 km east of Tompaluan. About 10000 people were evacuated, particularly from Kinilow, about 3 square km of clove tree and coconut plantations were damaged, as well as nearly 1900 buildings (although presumably not badly). The eruption accounted for one fatality, a swiss volcanologist, who ventured too close to the crater on 24 October and was sadly killed by volcanic bombs before being buried in ash. Manado airport was closed due to volcanic ash for several days. The data in this text is largely derived from the Smithsonian GVP, as only few publications on Lokon exist. The documented visit occurred from 05.12-10.12, 2012. A week beforehand eruptions were occuring almost daily although activity was approximately at 3-day intervals at the time of the visit.

Powerful ash eruption from Lokon-Empung volcano, Kawah Tompaluan crater, 6th December 2012 Powerful ash eruption from Lokon-Empung volcano, Kawah Tompaluan crater, 6th December 2012 Powerful ash eruption from Lokon-Empung volcano, Kawah Tompaluan crater, wide-angle view, 6th December 2012

Powerful ash eruption, evening 06.12.2012


Towering ash cloud from Lokon-Empung volcano, Kawah Tompaluan crater, 6th December 2012 Powerful ash eruption from Lokon-Empung volcano, Kawah Tompaluan crater, 6th December 2012 Towering ash cloud rising from Lokon-Empung volcano, Kawah Tompaluan crater, 6th December 2012

Powerful ash eruption, evening 06.12.2012


Sustained ash eruption from Lokon-Empung volcano, Kawah Tompaluan crater, 6th December 2012 Ash cloud from eruption of Lokon-Empung volcano being tipped by wind, Kawah Tompaluan crater, 6th December 2012 Ash raining from eruption cloud of Lokon-Empung volcano, Kawah Tompaluan crater, 6th December 2012

Powerful ash eruption, evening 06.12.2012


View toward Kawah Tompaluan crater and eroded flank of Lokon volcano Lokon volcano degassing

View toward Kawah Tompaluan crater and eroded flank of Lokon

Degassing between eruptions


Lokon volcano degassing between eruptions Weak ash emissions from Lokon volcano hours after large eruption

Degassing 09.12.2012

Weak ash venting on morning of 10.12.2012 following nighttime eruption


The 2011-2012 eruption period has involved numerous explosive eruptive episodes. In July 2011 nearly 5000 residents were evacuated but most returned to their homes relatively soon. A 3km exclusion zone has been in place since and those with homes therein have remained in temporary shelters. On 26. October 2011, volcanic bombs were thrown to a distance of 800 meters from Tompaluan. During the period of the visit, two eruptions occurred at Lokon-Empung, the first in the evening of 6. Dec. 2012. Both were relatively typical and involved a succession of overlapping explosions resulting in sustained ash emission and the production of a towering ash cloud. which is documented in detail, the second early in the morning on 10. Dec, for which only subsequent degassing was documented. According to Darwin VAAC, the eruptions produced ash clouds reaching 3.4 and 4.3 km in altitude, respectively.

Quarrying volcanic materials, Lokon-Empung volcano Ash deposits near Lokon-Empung volcano Quarrying volcanic materials, Lokon-Empung volcano, Indonesia

Facility processing volcanic materials

Ash deposits

Facility processing volcanic materials, Empung behind


Digging volcanic ashes, Lokon volcano Agriculture at foot of Lokon volcano Farming at foot of Lokon volcano

Collecting ash

Fertile land at base of volcano in agricultural use

Farming near foot of Lokon volcano


Lokon lavas are largely andesitic or dacitic and thought to be derived from the magma chambers associated with Tondano caldera, in contrast to the basaltic lavas from Soputan, which are attributed to an independent source (Kushendratno et al. 2012. Bull. Volcanol. 74, p.1581-1609).


Visitor Information


Lokon-Empung volcanic complex lies in northern Sulawesi, about an hours drive from Manado airport. The volcano is best viewed from the resort town of Kinilow, which lies close to the city of Tomohon. The Highland Resort hotel offers a good view of the volcano and friendly staff, others use the Boutique hotel which has a more expansive although maybe less photogenic view.

Watching Lokon volcano from Highland Resort Farmland at foot of Lokon-Empung

View from front of Highland Resort

View from near Boutique Hotel


Evacuation sign near Lokon volcano Vegetated flanks of Lokon volcano

Sign indicating evacuation path for population

Dense vegetation on slopes with Lokon


Kinilow town at foot of Lokon-Empung volcano Kinilow town at foot of Lokon-Empung volcano

Kinilow town at foot of Lokon-Empung

Kinilow town at foot of Lokon-Empung


The KKVO Volcano Observatory on the outskirts of Kinilow. The observatory is responsible not only for Lokon-Empung, but also for monitoring a number of other volcanoes in northern Sulawesi, including several on islands extending off the northern coast. The staff are friendly and will show interested visitors the monitoring equipment. Information panels showing the monitored volcanoes are also available.


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