Mount Lokon
The Gunung Lokon
Plume of the crater Tompaluan 10 July 2011
Lokon and Empung of Manado seen around 1900 - 1925bdep2
The Lokon - Empung is a twin volcano on the Indonesian island of Sulawesi. It is located around 15 kilometers south of the city of Manado west of Tomohon in Minahasa district of North Sulawesi province and is one of the most active volcanoes on the island.
Construction
The two composite volcanoes occur on the northern edge of the Tondano caldera. With a height of 1580 meters is the Lokon, the higher and also older of the two mountains. The Lokon has no crater; Eruptions in historical time are not known. It consists of pyroclastic sediments and lava flows, which are composed of basalt and olivine. Later, the two kilometers to the north- northeast lying 1340 meters high Empung arose. He broke 1350-1800 frequently. At the southern foot of Mount Lokon is the Irang, an existing rhyolite lava dome of, of which is not known whether it was before or after the Empung. Since the 19th century, all the volcanic eruptions were originated from the crater Tompaluan, which is located at about 1140 meters in the saddle between the Lokon and the Empung. The Tompaluan contains a crater lake at times.
Outbreaks
The volcanic eruptions in historical times were mostly small to moderate explosive eruptions with a Vulkanexplosivitätsindex ( VEI ) of one to three. Occasionally, lava domes formed or led to pyroclastic flows.
During an eruption of the volcano in 1986, in which an approximately 1,000 -meter-high cloud of black smoke was blown into the air, there were no casualties.
On September 19, 1991, the Tompaluan broke out and came across a half-mile high cloud of smoke into the sky. Glowing tephra continued the fields of seven nearby villages on fire. With stronger eruptions from October 25 about 1,900 houses and about 3 km ² plantations were damaged; about 10,000 people were evacuated. Other outbreaks in November led to panic among residents who were temporarily returned to their homes. Since the outbreak of 25 October, the Swiss volcanologist Viviane Clavel is missing. According to witnesses, she was struck by ejected blocks and buried under ash.
Due to frequent earthquakes and increased gas leaks about 5000 people have been evacuated from the vicinity of Lokon - Empung in July 2011. In mid-July, there were several eruptions in which eruption columns up to 3.5 km ascended high. The end of July were able to return to their homes, most evacuees; an area three kilometers radius around the crater Tompaluan was still locked. The Tompaluan remained active with other eruptions until 2013.