Lightning strikes during the 1982 eruption of Galunggung
Elevation : 2,168 m (7,113 ft )
Location : WestJava, Indonesia
Coordinates : 7°15′24″S - 108°04′37″E
Geology Type : Strato volcano
Last eruption : 1982
Mount Galunggung (Indonesian: Gunung Galunggung, formerly spelled Galoen-gong) is an active stratovolcano in West Java,Indonesia, around 80 km (50 mi) southeast of the West Java provincial capital, Bandung (or around 10 km to the north of the West Java town of Tasikmalaya). Mount Galunggung is part of the Sunda Arc extending through Sumatra, Java and Bali, which has resulted from the subduction of the Australian plate beneath the Eurasian plate.For the first time since 1921 after eruptions finished and conditions seemed normal, on February 12, 2012 the status was upgraded to Alert based on changes in conditions.On 28 May 2012 it was lowered from 7 back to 6 (On a scale of 1-4)
The first historic eruption of Galunggung was in 1822. Since then the volcano has erupted four times, most recently in 1984. This photo shows a column of ash rising above the summit during the large (VEI=4)Vulcanian-type eruption. Eruption columns at Galunggung reached heights as great as 15 miles (24 km). Photo by Jack Lockwood, U.S. Geological Survey, August 16, 1982.
Two eruptions at Galunggung have caused fatalities. During the 1822 eruption (VEI=5), nuee ardentes and mudflows killed 4,011 people and destroyed 114 villages. The nuee ardentes extended up to 6 miles (10 km) away from the volcano. During the 1982 eruption (VEI=4) about 68 people died, mostly from indirect causes (traffic accidents, old age, cold, and lack of food). Estimated damage was $15 million and 22 villages were left uninhabitable. The 1984 eruption was phreatic and lasted about two weeks. This photo shows lightning above the summit and glowing pyroclasts on the flank of Galunggung. Photo by Jack Lockwood, U.S. Geological Survey, September 16, 1982.
The April 1982-January 1983 eruption destroyed the 1918 lava dome and produced a new cinder cone in a new crater. The crater was about 2,000 feet (600m) across and about 1,000 feet (300 m) deep. The cone grew to 250 feet (75 m) and was 650 feet (200 m) in diameter. Photo by Jack Lockwood, U.S. Geological Survey, July 31, 1982.
View of new cinder cone. As the 1982-1983 eruption waned a crater lake began to form. The presence of the lake, high rainfall, and the large volume of exposed pyroclastic material on the volcano have made the hazard associated with secondary lahars very high. The lahar deposits have been revegitated and a lahar warning system has been established.
During the 1982 eruption two jumbo jets entered the ash clouds at an altitude of about 6 miles (10 km). Their engines stalled and windshields were abraded. Fortunately, the pilots were able to restart the engines.
Hazardous eruption of 1982 :
A lahar from the 1982 eruption of Galunggung.The last major eruption on Galunggung was in 1982, which had a Volcanic Explosivity Index of 4 and killed 72 people. This eruption also brought the dangers of volcanic ash to aviation to worldwide attention, after two Boeing 747 passenger jets flying downwind of the eruption suffered temporary engine failures and damage to exterior surfaces, both planes being forced to make emergency landings atJakarta airport.One, a British Airways aircraft carrying 240 passengers, accidentally entered the ash cloud during night time in June 1982 150 km (93 mi) downwind of the volcano. All four engines failed due to the buildup of volcanic ash, and the aircraft descended for 16 minutes, losing 7,500 m (24,606 ft) of its 11,500 m (37,730 ft) altitude, until the crew managed to restart the engines.The following month a Singapore Airlines aeroplane with approximately 230 passengers aboard also inadvertently entered the cloud at night, and three of its four engines stopped. The crew succeeded in restarting one of the engines after descending 2,400 m (7,874 ft). Both aircraft suffered serious damage to their engines and exterior surfaces.
Historical avalanche deposit :
A hummocky deposit known as the Ten Thousand Hills of Tasikmalaya attracted the attention of early 20th century geologists. Houses were built on the hummocks since they provided good defence against hostile people, and being above the paddy fields were free ofmosquitoes and rats.Originally, it was thought that either it had been formed by a lahar caused by the release of the waters of the crater lake, or that it was man-made; composed of rocks and boulders dumped there after being cleared from paddy fields.However, in the light of the Mount St. Helens eruption of 1980 and from examination of the Mount Shasta deposits it has become clear that the hummocks are a debris-avalanche deposit. Like these mountains, Galunggung has a horseshoe-shaped crater indicating a massive landslide, and examination of shattered lava blocks revealed them to be similar to deposits on the other two volcanoes. According to radiocarbon dating of samples taken from a lava flow the landslide happened within the last 23,000 years.
"Sejak 1982, Baru Kali ini Galunggung Berstatus Waspada (in Indonesian)". February 14, 2012.Suwarni, Yuli Tri (February 13, 2012), "Mt. Galunggung status raised to alert", The Jakarta Post"
