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Indonesia contains more active volcanoes than any country on Earth. Of the 130 active volcanoes in Indonesia, Merapi is the most active, and has had at least twelve eruptions that killed people. The name Merapi means "Mountain of Fire". The volcano is considered sacred and every year a priest climbs to the top to make an offering.
311 lava avalanches were recorded by the seismometers this week. Some of them travalled over a distance of 2.5 km. The Alert Level remains at 2.
This information was summarized from the GVP/USGS Weekly Volcanic Activity Report
Incandescent lava avalanches traveled predominately down Merapi's southwest flank into the upstream portions of the Sat, Lamat, and Senowo rivers during August 5-18.
This information was summarized from the GVP/USGS Weekly Volcanic Activity Report
Incandescent lava avalanches traveled predominately down Merapi's southwest flank into the upstream portions of the Sat, Lamat, Senowo, and Bebeng Rivers during July 29th-August 4th.
This information was summarized from the GVP/USGS Weekly Volcanic Activity Report
Observers noted 65 incandescent lava avalanches flowing predominately down the southwest flank into the upstream portions of the Sat, Lamat, and Senowo rivers during June 17-23.
This information was summarized from the GVP/USGS
Weekly Volcanic Activity Report
Last week, two pyroclastic flows and incandescent lava avalanches were visible at Merapi. The volcano remained at Alert level 2 (on scale of 1 to 4).
This information was summarized from the GVP/USGS Weekly Volcanic Activity Report
March 5, 2002
Again this week, several incandescent avalanches of lava blocks were observed. Three minor pyroclastic flows were produced on 25 February and as well as one on 3 March. The flows travelled SSW as far as 1 km to the upstream portion of the Bebeng River. Seismicity remained similar to the previous week. Merapi remained at Alert Level 2 (on a scale of 1-4).
This information was summarized from the GVP/USGS
Weekly Volcanic Activity Report
February 26, 2002
Last week, 67 incandescent lava avalanches were observed as well as one 2.2-km long pyroclastic flow. Merapi remained at Alert Level 2 (on a scale of 1-4).
This information was summarized from the GVP/USGS Weekly Volcanic Activity Report
This week, 65 incandescent lava avalanches were observed around Merapi. They were mainly flowing southeastward (max. 2.5 km). Furthermore, six minor pyroclastic flows travelled up to 2.5 km to the upstream portions of the Lamat and Senowo rivers. Merapi remained at Alert Level 2 (on a scale of 1-4).
This information was summarized from the GVP/USGS
Weekly Volcanic Activity Report
February 5, 2002
979 lava avalanches were reported during January 21-27. They traveled down the flanks of the volcano but predominately southwest toward the upstream portions of the Sat and Bebeng rivers, and partly to the west-southwest to the Lamat and Senowo rivers. The maximum run-out distance was approximately 2.75 kilometers. Several small pyroclastic flows travelled also 1.5 kilometers to the upstream portion of the Sat and Bebeng rivers: two on the 23rd, one on the 24th, and two on the 25th.
This information was summarized from the Smithsonian
Institution's Preliminary Notices of Volcanic Activity.
January 22, 2002
Lava avalanches continued to travel down the flanks of the volcano this week and there were five small pyroclastic flows on January 17th. They travelled 1.2 kilometers to the upstream portions of the Sat and Bebeng rivers.
This information was summarized from the Smithsonian Institution's Preliminary Notices of Volcanic Activity.
January 15, 2002
There was a small pyroclastic flow that travelled approximately 2 kilometers to the upstream portion of the Bebeng river on January 7th. Also, there were lava avalanches that continued to flow down the flanks of Merapi during January 7th - 13th.
This information was summarized from the Smithsonian
Institution's Preliminary Notices of Volcanic Activity.
March 21, 2001
Volcanic activity is continuing at the Merapi Volcano. Hot lava avalanches continue to enter the rivers in the area. Pyroclastic flows traveled ~2.75 km down several rivers. Superficial earthquakes dominated the seismicity. On 10 March, it was noted that high-pressure fumaroles appear on most of the dome's surface. Merapi remains at Alert Level 2.
This information was summarized from Smithsonian Institution's Preliminary Notices of Volcanic Activity.
On 10 February, the Merapi volcano erupted, and the status was changed to the maximum of Alert Level 4. The eruption produced a continuous major pyroclastic flow 7 km to the River Sat and 4.5 km to the River Lamat. The flow lasted ~2.5 hours, and the ash plume spread 60 km to the east. Instrumental monitoring is recording high seismicity.
This information was summarized from Smithsonian Institution's Preliminary Notices of Volcanic Activity.
On 28 January, the partial collapse of the lava dome created continuous pyroclastic flows and molten lava avalanches down the SW and W flanks for up to 4.5 km. Thick ash plumes rose to 2000 m above the summit of Merapi. The volcano continues to show an increase in activity.
This information was summarized from Smithsonian Institution's Preliminary Notices of Volcanic Activity.
The Merapi volcano continues its trend of increasing activity. The volcano is producing numerous pyroclastic flows, ash, glowing lava flows, and lava avalanches. In addition to heightened seismic levels, a new lava dome ("Lava Dome 2001") has formed on the summit in the remnants of Dome 1998. The volcano remains at Alert Level 3 (on a scale of 1-4).
This information was summarized from Smithsonian Institution's Preliminary Notices of Volcanic Activity.
On 11 January, Indonesian authorities issued evacuation alerts to residents living near the Merapi Volcano. The volcano had sent rock and ash 5,000 feet skyward during the previous week. On 15 January, lava began flowing from the western flanks of the volcano. The lava was reported to have burned everthing in its path within 10,000 feet of the crater. The Alert level was raised to level two. No evacuations orders have been issued at this time.
This information was summarized from Discovery Online.
During the week of November 15-21, the Merapi Volcano produced small explosions and white ash plumes rose ~530 m above the summit. The volcano remains at Alert Level 2. Deep and shallow volcanic earthquakes have been recorded.
This information was summarized from Discovery Online.
Lava flowed down the slopes of Merapi on October 18. Over 2,000 residents were forced to evacuate the area. Most of the evacuees have returned home, but future eruptions are still possible.
This information was summarized from Discovery Online.
July 20, 1998
Merapi erupted again on Monday, July 20, forcing 2,100 people to flee their homes. A huge column of black ash was sent towering above the island, and lava flowed down the flanks of the volcano, destroying many acres of plantations in the surrounding area. Mudslides are a huge concern now, as heavy rains could fall over the fresh volcanic debris, sending the mix into populated areas with little warning.
This information was summarized from a report on Discovery Online.
July 13, 1998
Merapi has continued to erupt over the weekend of July 11-12. Lava fountains spilled down the slopes of the volcano, and ash plumes reached heights of 2 miles (3.2 km) into the sky. Ash from these plumes fell on villages up to 38 miles (61 km) away. The highest state of warning has been given to the volcano. Residents have been alerted and readied for evacuation with little or no warning. Concrete barriers are being built to channel any lava flows away from settlements.
This information was summarized from a report by Discovery Online.
July 10, 1998
Merapi has entered a new eruptive phase. Lava is currently overflowing from the summit of the volcano. The Directorate of Vulcanology issued its highest warning status for the volcano. Nearby residents have been put on alert. More than 6,000 people may have to be evacuated from the area if activity increases.
This information was summarized from Boris Behnke's Latest News page and Discovery Online.
January 9, 1998
A large amount of lava was spotted on top of Merapi on Friday January 9. Experts have warned nearby residents that they may have to evacuate quickly as hot gas clouds could descend from the volcano. Rain could also send the lava towards nearby villages.
This information was summarized from a Washington Post/AP article.
The current eruption started on 22 November 1994 when a plume of ash shot up 10 kilometers above the volcano. A rocky dome that had blocked the volcano's crater had collapsed, releasing the cloud. Pieces of the dome tumbled violently down the south flank of Merapi. Super-hot flows of gas, boulders and ash - called Nuees Ardentes or glowing avalanche - swept down the mountain, destroying and killing everything they touched. Nuees continued for hours. They usually flow down river valleys; one nuee traveled 6 km (~3.5 miles) down the Boyong River.
At last report, rescuers had found 37 bodies of farmers and villagers who were burned, buried, or asphixiated (died from a lack of air). Eighty-five other people were injured and are in hospitals. Many people need plastic surgery to repair bured areas of their skin. The Japanese government has sent a team of medical medical advisors to help. Because of the massive amounts of volcanic ash and other deposits, the actual number of casualties may never be known. More than 6000 people have been evacuated from their homes because of the danger.
Like most of the volcanoes in Indonesia, Merapi is stratovolcano. It is tall (2.8 km or 1.7 miles high) and has steep slopes. The top of the volcano sometimes has a normal crater, but usually a broad mound of pasty lava -- called a dome -- fills the crater. The dome plugs up the volcano, making it difficult for other lava and ash to escape. A broad gouge funnels lava and ash flows from the top of Merapi to the south slopes of the volcano. The top of the mountain has no vegetation because erupted ash often falls there. Dense vegetation covers the flanks of the volcano. Many farmers live in villages around the volcano. The volcanic ash makes rich soil for growing crops, but it is a dangerous place to live.
Like all volcanoes, Merapi has eruptions of different sizes. Small eruptions happen every 2-3 years, bigger ones every 10-15 years, and very large ones every 50-60 years. The biggest eruptions occurred in the years 1006, 1786, 1822, 1872 and 1930. The eruption of 1006 spread ash all over the central part of the island of Java. The destruction was so bad that the existing Hindu kingdom was destroyed and the island was taken over by Muslims.
A large eruption of Merapi commenced on Thursday, October 31, 1996, according to the West Australia, a Perth-based newspaper. Ash is falling on houses on the flank of the volcano and at least 300 people have been evacuated. The eruption may have been triggered by collapse of a part of the lava dome in the volcano's crater. Little information is available about this eruption.
Information Sources:
Global Volcanism Network electronic reports, 23 & 28 Nov., (Smithsonian Institution); email address: gvn@volcano.si.edu
Disaster Information Report, 29 Nov. 1994 (VITA, Geneva, Switzerland).
G. Boudon, G. Camus, A. Gourgaud and J. Lajoie (1993) The 1984 nuee-ardente deposits of Merapi volcano, Central Java... Bulletin of Volcanology 55, 327-342.
M. Kraft (1993) Volcanoes: Fire from the Earth. Henry A. Abrams Inc, New York; 208 pp.
Questions:
Here is a graph that shows how many eruptions of Merapi are known during the
last 500 years.
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