MERAPI VOLCANO

MERAPI VOLCANO

Mount Merapi (25 kilometers north of Yogyakarta, near Borobudur) is the most active of Indonesia's 127 active volcanos. Located north of Central Java's capital of Yogyakarta, it is a 2968 meter-high (9,737 foot-high) stratovolcano with steep slopes and an almost perfect cone shape. According to volcanodiscovery.com: “It erupts on average every five to ten years and is feared for its deadly pyroclastic flows - avalanches of hot rocks and gas that are generated when parts of new lava domes constructed during eruptions in the summit crater collapse and slide down the mountain's steep flanks.” The name "Merapi" comes from the old Javanese language and means "the one making fire". It is a popular name for volcanoes: another volcano with the same name Merapi is in the Ijen Massif in East Java and similarly called volcano "Marapi" lies on Sumatra Island.

The United Nations cites Merapi as one of 16 volcanoes worldwide that pose especially serious threats because of their activity and vicinity to major population centers. Despite its frequent eruptions many people continue to live on the volcano’s flanks and farm the fertile soil. Merapi dominates the landscape immediately north of the city of Yogyakarta in one of the world's most densely populated areas. Despite its frequent eruptions, Mt. Merapi is very central to the lives of the Javanese people and kings. For through its eruptions Merapi spews lava, ash and minerals to the surrounding areas. These provide nutrients for the soil.

Merapi has determined the lives of kings and kingdoms. In the early 11th century, the once mighty ancient empire of Mataram mysteriously disappeared, and power suddenly shifted to East Java. Scientists surmise that a violent eruption of Merapi in A.D. 1006 was behind the change. This massive eruption also buried the nearby Borobudur temple .

Every year, the Sultan of Yogyakarta makes an offering of his hair and fingernail clippings to Merapi. The volcano plays an important part in the accepted cosmos of the Javanese sultans. The Kraton of Yogyakarta faces the mountain in one direct line. Merapi is also guarded by spiritual “guards” who give offerings to the mountain. Annually, on the anniversary of the Sultan’s coronation, offerings (labuhan) are brought from the kraton of Yogyakarta to Mt. Merapi, together with similar offerings carried to the Indian Ocean to the south, to appease the spirits of the mountain and the sea, in order to bring welfare to the inhabitants of Java.

Merapi is continuously monitored from the Merapi Volcano Observatory (MVO) in Yogyakarta. There are a number of earthquake posts and monitoring stations. Inhabitants are warned of impending eruptions. Despite frequently giving out smoke, Merapi still attracts hikers and climbers. Sometimes tourists are allow to hike to the crater. It is a 5,000 foot climb to the top mountain. Inside the crater are glowing red fissures of lava. Scientists monitor the volcano for signs of activity and local residents annually climbs to the crater's edge to make offerings. Selo is the main trailhead . The trail can be steep and the ascent takes about four hours. Treks are organized in Yogyakarta. Many begin at 1:30am to catch the sunrise. But the mountain is often closed. There are good views of Merapi form the hill station of Kaliurung.

Merapi Geology

According to volcanodiscovery.com: “Merapi is the youngest and southernmost of a volcanic chain extending NNW to Ungaran volcano. The steep-sided modern Merapi edifice, its upper part unvegetated due to frequent eruptive activity, was constructed to the SW of an arcuate scarp cutting the eroded older Batulawang volcano. Pyroclastic flows and lahars accompanying growth and collapse of the steep-sided active summit lava dome have devastated cultivated lands on the volcano's western-to-southern flanks and caused many fatalities during historical time. Since 1953, activity has been characterized by extrusion of lava into the summit crater, with periodic lava dome collapse and nuée ardente formation. Summit lava dome growth has continued since the 1969 gas explosion.

F. Beauducel wrote: “Merapi volcano is situated above the subduction zone between the Eurasian and Indo-Australian tectonic plates. This subduction extends for about 2000 kilometers from Sumatra to the Lesser Sunda Islands. In the Java-Bali sector, subduction occurs between an oceanic plate 10- kilometers in thickness (Indo-Australian) and an intermediate plate of 20- kilometers thickness (Eurasian). This Mesozoic subduction has formed a trench of 6 to 7 kilometers deep. Merapi volcano was born in period of late Pleistocene - Early Holocene. It is situated at the intersection between two main volcanic alignments Ungaran-Telomoyo - Merbabu - Merapi (N164E) and Lawu - Merapi -Sumbing-Sindoro-Slamet or between two main quartenary faults, Semarang fault (north south) and Solo fault (east west). Among them, Merapi volcano is the youngest one. Merapi volcano has suffered an evolution. The early stage of its growth, it had a basaltic magma with effusive eruptions. The characteristics of magma then change to more silicic and more viscous. Lava extrusion, thus, may be effusive or explosive. Recently, magma is quite viscous so that it extrudes and accumulates at the crater surface as a lava dome. Since magma is poor in gas, eruption is usually less than 3 in VEI-scale. [Source: F. Beauducel pages, ipgp.fr +++]

Merapi Eruptions

Since the 1820s, Merapi has erupted with deadly force at least two dozen times. In 1930 a pyroclastic flow incinerated and suffocated 1,300 people. In 1960, pyroclastic flows raced down the mountain’s southwest side, killing 60 and injured 300. In 1969 there was another major eruption. This one was predicted and the large cloud of ignited gas resulted in few casualties. In 1994 Merapi erupted violently again, killing 60 people. It has been very active in recent years. In June 1998, pyroclastic flows raced down the western flank, destroying farmland. In January 2001, there were a number of earthquakes and scientists predicted a major eruption that didn’t occur. After a five year period of relative calm, a new eruption started in April 2006. Tens of thousands of people were evacuated during the peak of the eruption in late May-mid June. A particularly powerful pyroclastic flow killed two workers trapped inside a shelter that was overrun by a flow. In 2010, Merapi roared to life again, killing 324 people over two months.

Typical eruption style: Highly explosive, with growth of lava domes and pyroclastic flows, sometimes with associated flank collapse. Large Plinian eruptions occur every few 1000 of years (the last ones were about 1000 years ago and 2000 years ago). Typically, small eruptions occur every two to three years, and larger ones every ten to 15 years or so. Notable eruptions, often causing many deaths, have occurred in 1006, 1786, 1822, 1872, and 1930—when thirteen villages were destroyed and 1400 people killed by pyroclastic flows. A very large eruption in 1006 is claimed to have covered all of central Java with ash. The volcanic devastation is also claimed to have led to the collapse of the Hindu Kingdom of Mataram, however there is insufficient evidence from that era to be substantiate the claim.

Merapi volcano eruptions: 1548, 1554, 1560, 1584, 1586(?), 1587, 1658, 1663, 1672, 1678, 1745, 1752, 1755, 1768, 1791, 1797, 1807, 1810, 1812-22, 1822-23, 1828, 1832-36, 1837-38, 1840, 1846, 1848(?), 1849, 1854(?), 1861, 1862-64, 1865-71, 1872 (large vulcanian-subplinian eruption VEI:4) , 1872-73, 1878-79, 1883-84, 1885-87, 1888, 1889, 1891-92, 1893, 1894, 1897, 1902, 1902-04, 1905, 1906-07, 1908, 1909-13, 1915, 1918, 1920-21, 1922, 1923(?), 1924, 1930-31, 1932, 1933-35, 1939-40, 1942-45, 1948, 1953-58, 1961, 1967-1970, 1971(?), 1972-85, 1986-90, 1992-2002, April-July 2006, Oct 2010- Feb 2011. [Source: volcanodiscovery.com]

Describing activity on Merapi in April 2014, Ben Otto wrote in the Wall Street Journal, “Scientists raised the alert status of Mount Merapi to level II on a 4-point scale amid an uptick in small quakes and avalanches. Since April 20, the mountain has experienced 29 avalanches and dozens of low-frequency quakes that show “an increase in the fluid contained in the volcanic gas,” which indicates an increased likelihood of eruption, Sutopo Purwo Nugroho, spokesman for the country’s national disaster agency, said. The mountain is still considered safe under the current alert level, and no one has been ordered to evacuate. Climbing the mountain – typically a popular tourist activity – has been prohibited. [Source: Ben Otto, Wall Street Journal, April 30, 2014]

Large Merapi Eruptions in 1930, 1872 and 1822

In 1930 pyroclastic flows from Merapi killed more than 1,300 people. Preliminary phases consisted of appearance of tremors recorded at Maron, 9 kilometers from the volcano using Bosch-Omori seismograph installed in February 1924. Tremor occurred at almost all along 1930. A strong tremor preceded the first lava flow in November 21, 1930. Lava appeared at 2700m elevation, 250m below the summit. The paroxysmal phenomena occurred in December 18 and 19, 1930 in a form of strong explosions and pyroclastic flows. The strongest pyroclastic flow reached a distance of 15 kilometers along Blongkeng river. About 20 square kilometers of area was burned. Thirteen (13) villages were swept completely, 23 were partially. About 1369 persons were killed, and 2000 animals died. A huge depression was created in the west part of the summit. It has about a length of 850 meters in a east-west orientation and a maximum depth of 850 m. The depression extended from the summit to an elevation of 2150 m, thus about 700 meters of altitude difference. In January 1931, a effusive phase started. Lava came out from the most upper part of the depression. Due to the morphology of the depression, lava built a dome of "coulee" type while producing glowing avalanches. The avalanches increase in the number in June and July. Eruptive activity stopped in the middle of September 1931. [Source: F. Beauducel pages, ipgp.fr +++]

In April 15, 1872 the biggest explosion ever known started. There was no preliminary phase and eruption began with a series of strong explosions. A big crater "Mesjidanlama" formed with three breaches: Blongkeng, Woro, Gendol. Pyroclastic flows came out from these three breaches. Some pyroclastic flows passed also in Apu, Trising and Senowo rivers. All villages 1000 meters altitude were destroyed by pyroclastic falls. Explosive phase lasted in five days. In November 3 and 4, 1872, some new explosions generated ashfalls. +++

The large in 1822-1823 eruption was preceded by a big earthquake felt at several places in Java. The first explosion occurred in December 27, 1822 at 09.00, which led to a paroxysm in two and three days later. A strong explosion destroyed the west part of the summit. Ashfall happened at Boyolali, Muntilan and Magelang. A new crater of 600 meters wide formed, opened in three directions: Apu, Blongkeng and Woro. Pyroclastic flows swept Apu, Lamat, Blongkeng, Batang, Gendol and Woro rivers. The explosion ceased in January 10, 1823. Several days after, rain triggered lahars which transferred hot material from pyroclastic flows. At mid of January 1823, a new dome started to form inside the crater while created lava flow through the breach of Blongke. +++

Analysis of Merapi Eruption

F. Beauducel wrote: “Merapi activity is characterized by a very frequent eruption ranging from 1 to 5 years of time duration, weak explosion, and low gas pressure. Eruption is usually accompanied by pyroclastic flows, or "awan panas" in local term or a familiar term "wedhus gembel". There are two types of awan panas: awan panas guguran and awan panas letusan. Awan panas "guguran" results from collapse of lava domes in the crater of the volcano. Occasionally, a dome might grow so large that it becomes unstable and collapses into several drainage catchments. The distance traveled by the flow and its extent depend strongly upon the volume of the destroyed lava, gas pressure and the slope angle of the flank. Awan panas "letusan" results from collapse of debris that is erupted vertically. Flow direction depends to some extent on the summit morphology. [Source: F. Beauducel pages, ipgp.fr +++]

“Most of the Merapi eruption has low explosivity and the awan panas usually reaches about 6 to 7 kilometers from the summit. Some awan panas have traveled as far as 13 kilometers from the summit, such as the deposit generated during the 1969 eruption. Velocity of pyroclastic flow can reach up to 110 kilometers/hour. Infrared spectrometry of carbonized woods sampled from pyroclastic deposits indicates that awan panas have a temperature range of about 300 - 400 degrees C. +++

“Some eruptive activities at of the Merapi are characterized by dome formation. A slow upflow of andesitic magma leads to an extrusion of viscous magma, which accumulate and construct a dome in the crater. Magma is almost completely degassed and flows out of the conduit with a rate of up to 20.000 cubic meters/day a normal dome formation. The shape and evolution of the dome depend on The 1994 dome stays in a slope of about 35 degrees in the horseshoe shaped crater open to the southwest. The core of the dome is viscous and incandescent (looks glowing at night), while the dome crust is solid. +++

“Several studies on geochemistry and mineralogy of Merapi lava and pyroclastic flow indicate that there are three magmatic processes occur within the volcano, which are magmatic differentiation, magma mixing and sediment contamination. Magmatic differentiation or fractionated crystallization is showed by a progressive evolution of magma from basic, about 50 percent of SiO2, to more acid, 60 percent of SiO2. The lack of a great difference in volcanic product indicates that the fractionated crystallization is very limited which may be caused by a frequent supply or injection of deep magma to the system. Chemical composition of certain rocks is related to the stage of lava differentiation. The Merapi basalt flow, at Turgo for instance, in general has a higher Ca than the other lavas of Merapi. +++

“However, the cyclic evolution of SiO2 of Merapi lava does not come from fractionated crystallization. The abrupt change in chemical composition of lava may be explained by the process of a new magma supply. A glass analysis of the two facies, dark and white, in the 1984 eruption product shows that they are chemically different. The dark component has a higher silica content than the white one. It was inferred that a mixing between magma from shallow pocket with more-acid magma from deeper chamber may have played a role during the 1984 eruption. The influence of sedimentary contamination in magma was concluded from isotope analysis. There are carbonate contaminations, which may originated from the subduction plate or from shallow crust, from around the magma chamber for instance.” +++

Mount Merapi Erupts in 2010

In 2010, Merapi erupted violently in a once every "100-year" event, releasing poisonous gases, producing deadly pyroclastic flows and blanketed a region, populated by millions of people, with a layer of ash. A total of 324 people were killed over a two month period and hundreds of thousands were displaced. Gunungmerapi.weebly.com reported: “Volcanic activity at Mount Merapi in 2010 was the largest observed since the eruption of 1872. It was the worst volcanic disaster in the region in nearly 80 years and resulted in 322 deaths, and the displacement of one third of a million people (Surono et al., 2012). On October 26 Merapi began to erupt after four years quiescence. Although the sight of volcanic ash extruding from the volcano is just another day for many of the local inhabitants, the behavior of this eruption was to be dramatically different to the eruptions that had preceded it in recent times. [Source: gunungmerapi.weebly.com/history /*\]

“For nearly two months prior to the eruption, enhanced seismic activity and deformation was observed at the volcano (Gertisser et al., 2011). On October 24 several villages within 10 kilometers of Merapi were evacuated, after a sharp increase in earthquakes and summit deformation gave a slight indication of the events that would surpass. Not all villagers evacuated, however, and on October 26 a series of pyroclastic flows enveloped the village of Kinarejo, some 5 kilometers from the summit, resulting in the death of 34 people. For the next few days "glowing avalanches" traveled 12 kilometers from the summit, and on November 4 a 7 kilometers-high eruption plume transported ash 10s of kilometers from source (Gertisser et al., 2011). “November 5 marked the climax of the eruption. On this day, an unusually large pyroclastic flow traveled 15 kilometers south of Merapi along Gendol Valley. Villages just outside the valley were enveloped by ash-cloud surges. The villages were almost completely destroyed, and hundreds of fatalities resulted. /*\

In late October 2010, AFP reported: “Indonesia's Mount Merapi has erupted three times, emitting searing clouds and volcanic ash, spewing lava down its southern and south-eastern slopes, and sending villagers fleeing. "We heard three explosions around 6:00 pm (local time) spewing volcanic material as high as 1.5 kilometres and sending heat clouds down the slopes," government vulcanologist Surono said. Before the latest eruption people living in the shadow of Indonesia's most active volcano had been warned to evacuate or risk being killed. Authorities put an area of 10 kilometres around the crater on red alert on Monday, ordering 19,000 people to flee. "This eruption is certainly bigger than the 2006 eruption during which the heat clouds occurred for only seven minutes after the eruption," Surono said. "Today's eruption released heat clouds of gas and ash down the slopes for about two hours. Television footage showed thousands of people fleeing the eruptions in panic, some covered in white ash, as officials with loudhailers tried to help them escape the area. [Source: AFP, abc.net.au, October 27, 2010]

A week later, Associated Press reported: “A deadly Indonesian volcano spewing lava and smoke for more than a week erupted today with its biggest blast yet, shooting searing ash miles into the air as soldiers hastily evacuated villages and emergency shelters. Women screamed and children cried as they were loaded into trucks while rocks and debris rained from the sky. Several abandoned homes were set ablaze and the carcasses of incinerated cattle littered the scorched slopes. No new casualties were reported immediately after the booming explosion that lasted more than an hour. "This is an extraordinary eruption, triple times the first on 26 October," said a state volcanologist. Tens of thousands of villagers have been evacuated from Mount Merapi, one of the most active volcanoes in the world, since it began erupting just over a week ago, killing 38 people, most dying from severe burns. The last eruption has raised Merapi's status to "crisis" condition, said Andi Arief, a staff member at the presidential office dealing with disaster and social assistance.” [Source: Associated Press, The Guardian, November 3, 2010]

“The volcano's initial blast occurred less than 24 hours after a towering tsunami slammed into remote islands on the western end of the country, sweeping entire villages out to sea and killing at least 428 people. More than 800 miles west of the volcano, helicopters and boats were delivering aid to tsunami survivors in the most distant Mentawai islands, which lie almost directly over the fault that spawned the 2004 Indian Ocean monster quake and wave. “ [Ibid]

Survivors and People Refuse to Leave as Mount Merapi Erupts in 2010

More than 100,000 people living on Merapi were evacuated to crowded emergency shelters, many by force. Some returned to their villages during lulls in activity, however, to tend to their livestock. The government also announced an $11 million program to buy the cows on the mountain to keep farmers off its slopes, and to provide compensation for animals lost in the eruptions.

One week before Merapi produced its most deadly pyroclastic flow, AFP reported: “Before the latest eruption, officials said nearly 15,000 people had ignored evacuation orders despite several minor eruptions that sent lava spewing down Merapi's southern slopes. Many people sleeping in camps returned to their homes during the day to work and tend to their cattle. Some men refused to leave altogether, confident they would be able to escape. Field coordinator Widi Sutikno, of the Sleman district on the southern slopes of the 2,914 metre mountain, said only about 3,700 people out of 11,400 in his area had sought shelter in makeshift refuges. "We have evacuated many women, pregnant women, sick people, elderly people and children," he said. "We let some people return to their fields for their daily activity. But they need to go back to the camps and not their houses." [Source: AFP, abc.net.au, October 27, 2010]

“Sukamto, 50, a farmer, said his family had been evacuated but he still needed to tend his cows. "It's still fine for me to work, as I can see when the volcano will erupt from here. I work at around eight kilometres from the top of Merapi and I think it's still safe," he said. "However, I still have to be really careful here." [Ibid]

In mid November 2010, about a month after the eruption started, AFP reported: Merapi “has claimed the lives of 240 people since it began erupting, sending almost 400,000 fleeing into makeshift camps, an official said yesterday. The authorities have warned people living in the temporary shelters not to return to their homes as Mount Merapi, remained highly active and unpredictable. “We don’t know and cannot predict the next big eruptions, so refugees still have to stay in makeshift camps until further evaluations,” government volcanologist Subandrio said. “Merapi activity is still high and it still has an alert status.” A disaster management official said the death toll had now reached 240 after rescuers recovered more bodies from the disaster zone, while about 390,000 people have fled their homes. [Source: AFP, November 14, 2010]

Merapi’s 2010 Eruptions Burns Entire Villages

In early November 2010, after a deadly pyroclastic flow reached 15 kilometers from Merapi’s crater, NBC News reported: “A surge of searing gas raced down the sides of Mount Merapi, smothering houses, cattle and villagers in its path. The death toll after the volcano's largest eruption in a century soared to 122. The worst hit village of Bronggang lay nine miles (15 kilometers) from the fiery crater, just on the perimeter of the government-delineated "danger zone." Crumpled roofs, charred carcasses of cattle and broken chairs — all layered in white ash and soot — dotted the smoldering landscape. The zone has since been expanded to a ring 12 miles (20 kilometers) from the peak, bringing it to the edge of the ancient royal capital of Yogyakarta, which has been put on its highest alert. [Source: NBC News, Reuters, Associated Press, November 5, 2010 *=*]

“Merapi's latest round of eruptions began Oct. 26, followed by more than a dozen other powerful blasts and thousands of tremors. With each new eruption, scientists and officials have steadily pushed the villagers who live along Merapi's fertile slopes farther from the crater. But after initially predicting earlier eruptions would ease pressure under the magma dome, experts who have spent a lifetime studying the volcano now say the don't know what to expect. Scientists can study the patterns of volcanoes, but their eruptions are essentially unpredictable, as Merapi's increasingly intense blasts have proved. *=*

“The eruption released 1,765 million cubic feet (50 million cubic meters) of volcanic material, making it "the biggest in at least a century," said state volcanologist Gede Swantika as plumes of smoke continued to shoot up more than 30,000 feet (10,000 meters). Towering plumes of ash rained dust on windshields of cars 300 miles (480 kilometers) away, although a rain near the mountain in the afternoon turned much of it to sludge. Bursts of hot clouds occasionally interrupted aid efforts, with rescuers screaming, "Watch out! Hot cloud!" *=*

“Soldiers pulled at least 78 bodies from homes and streets blanketed by ash up to a foot (30 centimeters) deep Friday, raising the overall toll to 122, according to the National Disaster Management Agency. With bodies found in front of houses and in streets, it appeared that many of the villagers died from the blistering gas while trying to escape, said Col. Tjiptono, a deputy police chief.” *=*

Survivors and People Killed by Merapi’s 2010 Pyroclastic Flows

NBC News reported: “Sri Sucirathasri said her family had stayed in their Bronggang home because they hadn't been told to leave. They awoke in the dark as the mountain let out thunderous claps and tried desperately to outrun the flows, which reached speeds of 60 mph (100 kph), on a motorbike. Her mother, father and 12-year-old sister, Prisca, left first, but with gray ash blocking out any light, they mistakenly drove into — rather than away from — the volcano's dangerous discharge.[Source: NBC News, Reuters, Associated Press, November 5, 2010 *=*]

“The 18-year-old Sri went looking for them when she heard her mother's screams, leaving at home an older sister, who died when the house became engulfed in flames. "It was a safe place. There were no signs to evacuate," said Sri, a vacant gaze fixed on Prisca, whose neck and face are burned a shiny ebony, her features nearly melted away. Their mother is still missing. Their father, whose feet and ankles are burned, is being treated in another ward "I don't know what to say," she whispers when asked if she blames officials for not warning the family. "Angry at who? I'm just sad. And very sick." *=*

“The living — with clothes, blankets and even mattresses fused to their skin by the 1,400-degree Fahrenheit (750-degree Celsius) heat — were carried away on stretchers following the first big explosion just before midnight. "The heat surrounded us and there was white smoke everywhere," said Niti Raharjo, 47, who was thrown from his motorbike along with his 19-year-old son while trying to flee. "There was an explosion ... and it got worse, the ash and debris raining down," he said from a hospital. *=*

“More than 150 injured people — with burns, respiratory problems, broken bones and cuts — waited to be treated at the tiny Sardjito hospital, where the bodies piled up in its morgue, and two other hospitals. Despite being at the foot of Indonesia's deadliest volcano, Yogyakarta has only one burn unit — at Sardjito. The facility is limited to 10 beds, though, and so turns away any patient without facial burns or whose body is burned less than 40 percent, according to Sigit Priohutomo, a senior official at Sardjito. "We're totally overwhelmed here!" hospital spokesman Heru Nogroho said. *=*

“Two days before the deadly pyroclastic flow, Associated Press reported: “The danger zone was widened today from 10kms (six miles) from the glowing crater to 15kms (9 miles) because of the heightened threat. "I [didn't] think of anything else except to save my wife and son. We left my house and everything," said Tentrem Wahono, 50, who lives in Kaliurang village, about six miles from the peak. He and his family fled on a motorbike, "racing with the explosive sounds as the searing ash chased us from behind". [Source: Associated Press, The Guardian, November 3, 2010]

Merapi Impact on Obama and Local Farmers

In mid November 2010, the Jakarta Post reported: “The ongoing eruption of Mount Merapi in Yogyakarta forced US President Barack Obama to cut short his whirlwind Indonesian and depart several hours ahead of schedule. After speaking to students at the University of Indonesia, Obama directly went to Halim Perdanakusuma Airport and left for Seoul, South Korea. Obama cancelled a planned visit with President Susilo Bambang Yudhoyono to Kalibata Heroes Cemetery to commemorate National Heroes Day. Mt. Merapi has spewed massive clouds of ash and gas for more than two weeks, killing over 150 people, causing travel chaos and forcing the intermittent closure nearby Adisucipto International Airport in Yogyakarta. Ash concerns also led several international carriers to again cancel flights into and out of the Jakarta, including Cathay Pacific, Value Air, Qantas and Malaysia Air. [Source: Jakarta Post, November 10 2010]

A few days later, AFP reported: “Indonesian farmer Ari Sutikno was a month away from harvesting his rice crop when Mount Merapi buried it — and his family’s income — under a layer of hot ash. Like thousands of other poor farmers across central Java, the 65-year-old father of three has lost everything to the destructive power of nature. His paddy field in Sanggrahan village, about 22 kilometers northwest of the fuming crater, is now dead and he does not know when he will be able to plant again. In the meantime, his family will have to depend on the charity of friends and relatives, and the meager support of the state. “My paddy was our only source of income but it’s all gone,” he told reporters as the volcano continued to spew ash and hot gas a week after its last deadly eruption. “I’m waiting now for rain to soften the mud so I can salvage the paddy, otherwise it’s the end.”[Source: AFP, November 14, 2010 ^^]

“Farmers around Merapi would normally expect three harvests a year. However, that natural richness sometimes extracts a high price. Vast tracts of countryside that usually glow a verdant green now wear a gray mask of ash and volcanic mud known as lahar. In Banyudono village, rice farmer Pertimah was desperately trying to save what she could from her ruined crop. Relatives were helping to carefully separate the paddy from the heavy mud. “I’ve tried to save as much as I can, but that’s all I can do. I put everything in God’s hands. It’s part of his scheme,” she said. She had been five days away from harvest when the ash rained down. ^^

“People like Sutikno and Pertimah think of Merapi as a living thing, one which wakes and sleeps and, at times, bursts with intemperate anger. “It’s like someone who has a serious illness and there’s no sign of a recovery,” Sutikno said. “It’s almost impossible to predict. I’ve often thought that it would go back to sleep but it has come back to life again and again. It’s never-ending misery for us, I’m so frustrated.” ^^

“Pertimah said the failed harvest had cost her about US$2,500, a fortune for poor farmers like her. All the money I invested here has gone. I don’t know what’s going to happen tomorrow. I don’t have any idea where can I find money to start over again,” she said. The government has said it will replace all the livestock killed on the slopes of Merapi since Oct. 26, but for arable farmers like Pertimah, there have been no such guarantees. “I hope Merapi stops erupting soon. Otherwise it’s a pity for all the villagers here,” she said. Officials said that despite the devastation around Merapi, the eruptions would have almost no effect on Indonesia’s total rice output.” ^^

Merapi Eruptions in 2006

After five year period of relative calm, Merapi erupted in April 2006. A new lava dome was built on top of the lava dome of 1998-2001, powerful pyroclastic flows descended the southwest, south and southeast flanks in late May and June. Tens of thousands of people were evacuated during the peak of the eruption in late May-mid June. A particularly powerful pyroclastic flow killed two workers trapped inside a shelter that was overrun by the flow. In the middle of the eruption, on May 27, 2006 a magnitude 6.3 tectonic earthquake struck near Yogyakarta causing 5750 fatalities, around 40,000 injuries and destroyed large sections of Yogyakarta and surrounding towns, leaving more than 600,000 people homeless. The earthquake was caused by the collision of the Australian and Sunda tectonic plates, forming a subduction zone west of the coast of Java. [Source: volcanodiscovery.com]

According to gunungmerapi.weebly.com: “Although the eruption occurred in 2006, activity began in June 2005, when an increased number of volcanic earthquakes and deformation on the summit area was observed (Charbonnier and Gertisser, 2008). Extrusion of a new lava dome began in March 2006. Dome growth increased from April onwards and was accompanied by systematic rock fall and pyroclastic flows during May and June. In the earliest stages (May 5-27), rock fall and pyroclastic flows were concentrated within an area around five kilometers southwest of the summit. During this time, the alert level at the volcano was raised to 4 and up to 22,000 residents in the hazardous zone seven kilometers from the volcano were evacuated. After the May 27 earthquake lava extrusion rates on Merapi increased and the dome reached a height 116 meters above the summit by June 4. Pyroclastic flows became more voluminous and began to flow south of the volcano. On June 14, the longest traveled flows reached distances offive to seven kilometers from the volcano down the Gendol valley, resulting in 2 fatalities. [Source: gunungmerapi.weebly.com/history ]

Villagers Flee Pyroclastic Flows from the Merapi Eruptions in 2006

In June 2010, The Guardian reported: “Mount Merapi today spewed a spectacular rolling cloud of hot gas and ash down its southern slope in what an Indonesian government expert said was its biggest eruption yet. More than 15,000 villagers ran to safety or piled into cars and trucks as dark grey clouds poured three miles down the mountainside, officials said. Mt Merapi has been venting steam and ash for weeks, but today's burst was its largest yet, Sugiono, an Indonesian government vulcanologist, said. It was one of a series of powerful explosions, but hundreds of villagers living on the volcano's fertile slopes refused to leave, saying they wanted to tend livestock or crops. "Of course we're worried," one resident, Supriatun, said by mobile phone, adding that her small dairy farming community was so far untouched. "But as long as the hot clouds do not reach us, we won't go." [Source: theguardian.com, news agencies, June 8. 2006 <<<]

“Some scientists say a powerful earthquake on May 27, which killed more than 5,700 people in an area 25 miles south of Mt Merapi, could have contributed to the volcano's volatility in recent weeks. The rumbling mountain's lava dome has swelled, raising concerns that it could suddenly collapse and send scalding clouds of fast-moving gas, lava and rocks into areas yet to be evacuated. <<<

“Sutomo, a government official at the scene, told the Associated Press that 3,500 people had fled Sleman district on Mt Merapi's southern side. Another 12,000 people fled their villages in the Magelang district on the mountain's west side. Farmers carrying piles of grass on their heads ran down the mountain as others clambered on to motorcycles. "We saw the hot cloud spilling down the mountain and ran as fast as we could," Judi Sutrisono, a father of five, said, adding that ash had covered rooftops in Jrakah, a village four miles from the crater. <<<

“Sutrisono was among hundreds of people seeking refuge in a makeshift camp set up in a field dotted with Red Cross tents. As he spoke, a truck carrying 30 men, women and children arrived. Roads leading to the mountain peak had been closed, Sunarto, another government official, said. Earlier, authorities had urged residents to evacuate the danger zone on the mountain's fertile slopes. Around 20,000 people left, but thousands more stayed behind, some complaining of boredom at shelters set up in schools, mosques and at government offices. <<<

“Authorities said another big, deadly eruption would severely strain ongoing earthquake relief operations in the nearby Bantul and Klaten districts. More than half a million people were displaced in last month's tremor, many living in makeshift shelters with no toilets or running water. Hundreds of local and international relief workers have poured into the region to help, providing food, tents and medical supplies. <<<

“Mark Snelling, the information officer for the British Red Cross, who is in Yogyakarta with the charity's logistics team, said: "There was a strong smell of sulphur in the air and a light ash fall where we were." One farmer, Mardi, who is staying at the Dompol camp with his family, said "the ground started shaking, stones were falling down the hill and there was lots of ash in the air" when he returned to his farm near Mt Merapi today. "The volcano has been like this for many days, but this was the biggest it has been," he added. <<<

Villagers Make Offerings Rather Than Evacuate as Merapi Erupts in 2006

In May 2006, Indonesian officials evacuated tens of thousands of villagers from around Mount Merapi volcano, as lava and superheated clouds of gas poured down its upper slopes. The government of Magelang district mobilised more than 40 trucks and cars to evacuate about 11,000 villagers from three subdistricts near the foot of the mountain to temporary shelters, including school buildings. Thousands more refused to evacuate.

Chris Brummitt of Associated Press wrote: “Villagers burned incense and floated offerings to the spirits Sunday, hoping to ward off an eruption of Mount Merapi, while a scientist warned that a growing lava dome could collapse and shoot deadly, red-hot gases down the sides of the volcano. Despite a government evacuation order, many farmers were in the fields to tend animals and crops on the volcano's fertile slopes, ignoring black clouds billowing into the sky and fresh scars scorched by lava flows on the mountain's western flank. "I cannot force them," said Widi Sutikno, the official coordinating the government's emergency operation. "All I can do is tell them to keep looking up at the mountain and have a motorbike ready." [Source: Chris Brummitt, Associated Press May 15 2006 |=|]

“More than 4,500 people living in villages closest to the crater or next to rivers that could provide paths for hot lava had been evacuated a day after scientists raised the alert status for Merapi to the highest warning after weeks of volcanic activity. Sutikno said 18,000 others who live lower down the slopes were not considered in immediate danger and had not been ordered to leave their homes on the 9,800-foot mountain that rises from the plains of Indonesia's densely populated Java Island. |=|

“In one of the villages in the shadow of Merapi, holy men and hundreds of people lit incense and set rice, fruit and vegetables floating down a river in a ceremony they believed would appease the spirits and prevent an eruption. "It's bound to help," Parsi, a villager who like many Indonesians using only one name, said after the ceremony. "Everyone around here believes in this. It is in our blood." Although most Indonesians are Muslim, many also worship ancient spirits, especially in Central Java province. "All the things we are doing here are to try to make us safe," said Assize Asyhori, an Islamic preacher who took part in the ceremony. "Only Allah knows if Merapi will explode." |=|

“Police at roadblocks prevented vehicles from getting within five miles of the volcano's crater, but allowed evacuated villagers to walk in, advising them to leave again by nightfall. "My feeling is it will not blow at this time," a 30-year-old farmer, Budi, said as he returned to cut grass to feed his cows. Scientists, however, feared an eruption could be imminent. The deadly clouds, which contain a mix of hot ash, rock fragments and volcanic gas, are a big worry, said Sugiono, one of the scientists on a team monitoring the volcano 24 hours a day. He said a glowing dome of lava being formed by magma forced to the surface was poised to collapse and could send searing clouds down the mountain at several hundred miles an hour.

"Hot clouds keep appearing all the time," Sugiono said. "If you get stuck in them, then you have no chance." |=|

Merapi Eruptions in the Eary 2000s

January-February 2001 activity with a major dome collapse on February 10: Activity increased in January 2001, lava effusion rates were at high levels and feeding frequent pyroclastic flows. On 31 January pyroclastic flows occurred continuously, reaching up to 3.5 kilometers from the summit, flowing mainly to the south-southwest, but started also to descend on the southwest and W flanks of the mountain into the Senowo and Bebeng Rivers. On 10 February 2001, a large section of the 1998 lava dome collapsed and triggered a serious of pyroclastic flows that reached 7 kilometers distance from the crater, travelling south-southwest into the Sat River. Significant ash fall from the eruption occured up to 60 kilometers E of the volcano. After this event, activity decreased sharply, but continued at lower levels through much of 2001. [Source: volcanodiscovery.com ~~]

December 2000- January 2001 eruption with pyroclastic flows: Eruptive activity increased steeply during the period of 26 December 2000-22 January 2001. On 14 January, 29 pyroclastic flows traveled down the volcano's south-southwest and southwest flanks and reached up to 4 kilometers from their source. During the week, lava avalanches and pyroclastic flows occurred with an average interval of 0.5-1 hours. ~~

Merapi Eruptions in the Late 1990s

1998-2000 activity: glowing rockfalls. Seismic activity and rockfalls from the lava dome at the summit increased again in June 1998 and peaked between 11-19 July when 128 rock avalanches and pyroclastic flows were recorded descending the Lamat, Krasak/Bebeng and Boyong rivers on the southwest and south-southwest flanks of the volcano. Activity decreased, but the volcano remained active through 1999 and 2000, when intense degassing, minor explosions, intermittend glow at the summit and occasional rockfalls were recorded. [Source: volcanodiscovery.com ~~]

1996 eruptions: contining lava dome growth and pyroclastic flows. The activity that had started in 1994 continued through 1995 and increased again starting from August 1996, when explosions and pyroclastic flows became more frequent and large. On 9 August, a pyroclastic flow traveled 3.5 kilometers from the summit down the south-southwest flank and reached the upper parts of the Krasak and Boyong rivers. No casualties were reported. An explosion on 13 September created an ash cloud of ca. 4 kilometers height above the summit. Activity peaked on 31 October when 17 pyroclastic flows were recorded. They reached a maximum of 3 kilometers distance and touched the upper valleys of Bebeng, Krasak, Boyong, and Kuning rivers on the south-southwest and southwest flanks. Pyroclastic flows decreased on 1st November and the eruption ended on 2nd November. ~~

60 People Killed in 1994 Merapi Eruption

In 1994 Merapi erupted violently again, killing 60 people. A major collapse of the growing lava dome on November 22 1994 produced a large pyroclastic flow that ran 7.5 kilometers on the south flank, overrunning Kaliurang village and killed at least 41 people. 6000 people were evacuated. A new eruption started around 14h00 on 16 July 1994, when an explosion and pyroclastic flow was triggered following a period of strong inflation. The eruption started to built a lava dome and peaked in November. Particularly powerful pyroclastic flows on 22 November killed at least 41 people on the SSW flank, despite the fact that the population living in the affected areas had been warned constantly about the risk during the preceding months. The glowing avalanche on 22 November was triggered by collapse of the active summit dome producing pyroclastic block-and-ash flows and glowing surges that traveled SSW up to 7.5 kilometers from the summit. By 28 November, 41 people had died and another 43 were at hospitals in serious condition. All of the victims lived near the banks of the Boyong River on Marapi's S flank. (Source: GVP) [Source: volcanodiscovery.com ~~]

The activity in 1994 can be distinguished in five successive steps. 1) Creep of lava block in the upper part of the 1992 dome: About 90.000 cubic meters of lava crept to south-southwest with a lateral speed of 0.18 m/day in December 1993. In January 1994 it accelerated to 0.5 m/day. 2) Birth of the 1994 dome: In February 1994, a new lava was observed located in the top of 1992 dome in the fracture separating the active block from the stable part of 1992 dome. The new lava pushed the active block so that some small pyroclastic flows formed from the collapse of the block from March 9 to April 8, 1994. They traveled mostly in Bebeng river up to 1.7 kilometers. Until May 1994, the rate of the new lava was about 6500 cubic meters/day.[Source: F. Beauducel pages, ipgp.fr +++]

3) High Activity: From May to June 1994, the lava flux increased to 17.000 cubic meters/day in average. In the period of July-August 1994 the dome formation continued with a rather small rate than that in June 1994. It was found then, that the dome had reached the eastern rim of crater, and some of then cascaded to the Gendol solfatara field. In the end of September 1994, the dome’s volume was about 2.5 million cubic meters. The dome became stable during three months which was indicated by disappearance of Guguran (rockfalls or avalanches). Even though there were several MP events, the morphology of the dome did not show any changes. Fourth: collapse of the 1994 dome. Almost the whole of the dome collapsed in November 22, 1994, producing pyroclastic flow along Boyong river up to 6 kilometers from the summit. the village of Turgo was burned by the hot cloud. The village had never been touched by any pyroclastic since hundreds of years.

1992-1993 eruption: new lava dome growth A new lava dome grew in late January and early February 1992 and generated pyroclastic flows travelling up to 4 kilometers to the southwest flank. A new eruption began on 20 January 1992 when glowing rockfalls were first seen and a new lava dome started to grow in the SW section of the summit crater. Around midnight of 21 January 1992 an ash explosion occured. Pyroclastic flows increased through the end of January and peaked on 2 February, when 33 flows extending up to 4 kilometers to the SW occured. Activity declined in mid February. During the rest of 1992, the lava dome continued to grow at lower rates and produced intermittend glowing rockfalls and smaller pyroclastic flows. Activity resumed again a higher intensity Dec 1992-Feb 1993. Some rockfall avalanches flowed into the Bedog and Boyong rivers on the S flank. On 3 February, the longest pyroclastic flow of this period travelled 4 kilometers WNW down the Senowo and Sat rivers on the SSW flank. After March 1993, activity decreased to low levels. ~~

Large Merapi Eruptions in the Past

In 1930 pyroclastic flows from Merapi killed more than 1,300 people. Preliminary phases consisted of appearance of tremors recorded at Maron, 9 kilometers from the volcano using Bosch-Omori seismograph installed in February 1924. Tremor occurred at almost all along 1930. A strong tremor preceded the first lava flow in November 21, 1930. Lava appeared at 2700m elevation, 250m below the summit. The paroxysmal phenomena occurred in December 18 and 19, 1930 in a form of strong explosions and pyroclastic flows. The strongest pyroclastic flow reached a distance of 15 kilometers along Blongkeng river. About 20 square kilometers of area was burned. Thirteen (13) villages were swept completely, 23 were partially. About 1369 persons were killed, and 2000 animals died. A huge depression was created in the west part of the summit. It has about a length of 850 meters in a east-west orientation and a maximum depth of 850 m. The depression extended from the summit to an elevation of 2150 m, thus about 700 meters of altitude difference. In January 1931, a effusive phase started. Lava came out from the most upper part of the depression. Due to the morphology of the depression, lava built a dome of "coulee" type while producing glowing avalanches. The avalanches increase in the number in June and July. Eruptive activity stopped in the middle of September 1931. [Source: F. Beauducel pages, ipgp.fr +++]

In April 15, 1872 the biggest explosion ever known started. There was no preliminary phase and eruption began with a series of strong explosions. A big crater "Mesjidanlama" formed with three breaches: Blongkeng, Woro, Gendol. Pyroclastic flows came out from these three breaches. Some pyroclastic flows passed also in Apu, Trising and Senowo rivers. All villages 1000 meters altitude were destroyed by pyroclastic falls. Explosive phase lasted in five days. In November 3 and 4, 1872, some new explosions generated ashfalls. +++

The large in 1822-1823 was preceded by a big earthquake felt at several places in Java. The first explosion occurred in December 27, 1822 at 09.00, which led to a paroxysm in two and three days later. A strong explosion destroyed the west part of the summit. Ashfall happened at Boyolali, Muntilan and Magelang. A new crater of 600 meters wide formed, opened in three directions: Apu, Blongkeng and Woro. Pyroclastic flows swept Apu, Lamat, Blongkeng, Batang, Gendol and Woro rivers. The explosion ceased in January 10, 1823. Several days after, rain triggered lahars which transferred hot material from pyroclastic flows. At mid of January 1823, a new dome started to form inside the crater while created lava flow through the breach of Blongke. +++

Image Sources:

Text Sources: New York Times, Washington Post, Los Angeles Times, Times of London, Lonely Planet Guides, Library of Congress, Compton’s Encyclopedia, The Guardian, National Geographic, Smithsonian magazine, The New Yorker, Time, Newsweek, Reuters, AP, AFP, Wall Street Journal, The Atlantic Monthly, The Economist, Global Viewpoint (Christian Science Monitor), Foreign Policy, Wikipedia, BBC, CNN, and various books, websites and other publications.

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© 2008 Jeffrey Hays

Last updated June 2015

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