FAMOUS VOLCANOES ON JAVA: KELUD, BROMO, SEMERU AND SULFUR ON IJEN VOLCANO

KELUD

Mt. Kelud (also spelled Kelut) is a 1731-meter-high (5,679 feet-high) stratovolcano in East Java. It erupted in the 1920s killing more than 5,000 people. The disaster led to the founding of the Direktorat Vulkunologi in Indonesia. Kelud volcanic lake was drained by drilling a hole in the crater wall after the lake was deemed a flood threat that could kill hundreds of people. A similar strategy was tried on a lake in the crater of Pinatabu in the Philippines.

Kelud is about 200 kilometers east of Yogyakarta and 600 kilometers east of Jakarta. In February 2014, Mt. Kelud spewed ash and sand over a 10-kilometer radius, grounding flights and affecting 200,000 people. Major tourist attractions in Yogyakarta and Central Java, including Borobudur, Prambanan and Ratu Boko, were closed after being severely affected by the volcanic ash from the eruption of Kelud, which is located around 200 kilometers east of Yogyakarta. Noise from the eruption could be heard as far away as Yogyakarta. Kelud's last major eruption before that was in 1990, when it kicked out searing fumes and lava that killed more than 30 people and injured hundreds. In 1919, a powerful explosion that reportedly could be heard hundreds of kilometers away killed at least 5,160 people.

Relatively inconspicuous, Kelud volcano is one of East Java's most active volcanoes. The volcano has a spectacular large crater that contains a lake, which was a popular weekend destination but also the origin of devastating mud flows (lahars). In 2007, a new lava dome grew within the lake to form an island, replacing most of the water. A cluster of summit lava domes cut by numerous craters has given the summit a very irregular profile. Satellitic cones and lava domes are also located low on the eastern, western, and south-southwest flanks. [Source: Volcano Discovery]

Kelud' has a reputation of being a mountain that blows its top dramatically but then quickly settles down for another 10 years or so. But when it erupts it presents a serious danger as water from its crater, along with rain, can bring deadly landslides and lahars river beds into villages and valleys.

See Separate Article on Merapi

Kelud Eruptions

Kelut is notorious among Indonesia's volcanoes for its violent, and often deadly explosive eruptions. Over the past six centuries Kelud has erupted at least thirty times and has been responsible for approximately 15,000 fatalities. On May 19, 1919 it was the site of one of the deadliest volcanic eruptions of the twentieth century, killing over 5160 people when water was ejected from its large crater lake formed lethal lahars that travelled nearly 40 kilometres and destroyed more than 100 villages. An eruption in 1586 is believed to have caused even more than 10,000 fatalities. Typical eruption style: Explosive. Lava domes, pyroclastic flows. Presence of extensive crater lake at low elevation, generating destructive lahars. [Source: Volcano Discovery ~~, Volcanism blog]

More than 30 eruptions have been recorded from Gunung Kelud since A.D. 1000. Kelud volcano eruptions: 1500, 1548, 1586 (sub-Plinian eruption, 1641 (sub-Plininan eruption), 1716, 1752, 1756, 1771, 1776, 1785, 1811, 1825, 1826, 1835, 1848, 1849, 1864, 1901, 1919, 1920, 1951, 1966, 1967, 1990, Oct-Nov 2007, 13 Feb 2014. ~~

Eruptive activity has in general migrated in a clockwise direction around the summit vent complex. The ejection of water from the crater lake during Kelud's typically short, but violent eruptions has created pyroclastic flows and lahars that have caused widespread fatalities and destruction. ~~

After more than 5000 persons were killed during an eruption in 1919, an ambitious engineering project sought to drain the crater lake. This initial effort lowered the lake by more than 50 meters, but the 1951 eruption deepened the crater by 70 meters, leaving 50 million cubic meters of water after repair of the damaged drainage tunnels. After more than 200 deaths in the 1966 eruption, a new deeper tunnel was constructed, and the lake's volume before the 1990 eruption was only about 1 million cubic meters. ~~

Kelud Eruption in 2014 Kills Four Forces 100,000 to Evacuate

In February 2104, an explosive volcanic eruption from Kelud ejected ash and debris 20 kilometers into the air, killing four people—including a 97-year-old woman when the roofs of their homes caved in under the weight of ash—and forcing authorities to evacuate more than 100,000 people to temporary shelters and close seven airports. The overnight eruption could be heard in Yogyakarta, 200 kilometers away, "The eruption sounded like thousands of bombs exploding," Ratno Pramono, a 35-year-old farmer, told Associated Press after returning from an evacuation center to check on his property in the village of Sugihwaras, around three miles from the crater. "I thought doomsday was upon us. Women and children were screaming and crying." [Source: Associated Press, February 14, 2014]

Associated Press reported: “A 60-year-old man and a 65-year-old woman were killed in the village of Pandansari near the mountain when the roofs of their homes collapsed under the weight of the ash and volcanic debris unleashed during the eruption, the disaster agency said. A 70-year-old man died after being hit by a collapsed wall while waiting to be evacuated from the same village, where the volcanic ash reached 8 inches deep in some places.

Ash and grit fell to earth in towns and cities across the region, including Surabaya, Indonesia's second-largest city after Jakarta, with a population of about 3 million. It also fell even farther afield in Yogyakarta, where motorists switched on headlights in daylight, and lay two inches deep in some places. The large international airport in Surabaya and airports in the cities of Yogyakarta, Solo, Bandung, Semarang and Cilacap were closed due to reduced visibility and the dangers posed to aircraft engines by ash, Transport Ministry spokesman Bambang Ervan said. Virgin Australia said it had canceled its Friday flights from Australia to several locations due to the eruption, including the resort islands of Bali in Indonesia and Phuket in Thailand.

The 5,680-foot-high Mount Kelud had been rumbling for several weeks and was under close observation. Muhammad Hendrasto, head of Indonesia's volcano monitoring agency, said the mountain erupted violently about 90 minutes after authorities raised its alert status to the highest level. The disaster agency said it had spewed millions of cubic meters of debris into the atmosphere. The disaster agency said tremors were still wracking the volcano, but that scientists didn't expect another major eruption. It said all villages within 10 kilometers of Kelud - more than 100,000 people - had been evacuated to temporary shelters, but that some villagers were returning to their homes to begin cleaning up.

Kediri, a normally bustling town about 19 miles from the mountain, was largely deserted as residents stayed indoors to avoid the choking ash. "The smell of sulfur and ash hung so thickly in the air that breathing was painful," said Kediri resident Insaf Wibowo. Some residents were shoveling the ash and grit into sacks to use for the construction of buildings or to fertilize crops. One collector said that middlemen had already told him they would pay up to $56 for a small truck filled with the debris.

After the imminent danger was over Associated Press reported: Army troops enforced a ban on people returning to houses within 10 kilometers (6 miles) of the volcano, but many people sneaked back to check on livestock and clean up. Authorities were finding it hard to prevent people from returning, given the money farmers stand to lose by staying away, and said about 56,000 people remained in 89 shelters."Our cows need to be milked. If they aren't, they can get sick and die," said Marjito, who was riding on a motorbike with his wife to his village around 5 kilometers (3 miles) from the crater. "We have so much work to do, including running and hiding from security officers," said his wife, Dinayah. A massive cleanup was underway in the region, where millions of homes received ash fall. Police and soldiers used water cannons to clear roads that in places were covered in up to 10 centimeters (4 inches) of white ash. Supporters of political parties campaigning for April elections, wearing party colors, also chipped in and gave out food, seeking to win votes on the back of their assistance. Many people were wearing face masks to protect against the dust that remained in the air. [Source: Niniek Karmini, Associated Press, February 15, 2014]

Lava Dome Activity at Kelud in 2007

In November 2007, Kelud spat out fresh clouds of smoke as scientists warned a major eruption was imminent News agencies reported: “Kelud has been on the highest alert level for more than two weeks, but since Friday scientists have been warning an eruption may be imminent based on the frequency of tremors shaking the mountain and the temperature of it lake. The temperature of the crater lake on Mount Kelud was so great that nearby monitoring equipment was no longer working, said Surono, one of 16 volcanologists watching over the peak 24 hours a day. Despite the threat, there was little sense of panic on Kelud's slopes, witnesses said. [Source: Agencies, November 6, 2007]

“While several thousand people have fled to government shelters, authorities said that around 25,000 others were ignoring evacuation orders and remained in the danger zone around Kelud. Officials have made no attempts to prevent people from traveling inside a 10-kilometer (6-mile) zone around the peak that the local government say is off-limits. "I feel it is OK to stay here," said Sukirno, who was tending papaya plants some 7 kilometers (4 miles) from the peak. "No one can guarantee our safety apart from ourselves."

"If it goes this time, it will be much larger than in 1990," said Surono, basing his prediction on the number of tremors and the lake temperature -- both of which have been way higher than in the days preceding the earlier blast. The team monitoring the volcano have also said an eruption may be small or gradual -- or might not happen at all given the unpredictable nature of the 5,679-foot mountain. Around 70 kilometers (40 miles) southeast of Kelud, Mount Semeru was also putting on a display, sending out ash clouds high into the air, witnesses said. The peak was on the second highest alert, meaning no evacuations are ordered. Anak Krakatoa off the northern tip of Java island was spitting out hot stones and lava as well as rolling clouds of ash, television footage showed. It was also on the second highest alert.

In the end nothing major happened. Peter Gelling wrote in the New York Times, “Scientists had feared the worst because a layer of cooled lava had formed over the bubbling magma beneath the volcano’s crater, trapping a tremendous amount of pressure. But that layer had since cracked and was beginning to release the pressure. “Anyone more than three kilometers from the crater is allowed to return,” said Pak Surono, chief volcanologist for Mount Kelud. “The mountain is erupting slowly. There will be no explosive eruption that could threaten those living nearby.” [Source: Peter Gelling, New York Times, November 10, 2007]

Living in the Shadow of Kelud

Reporting from Kali Bladar, near Kelud, Peter Gelling wrote in the New York Times, “For about a month, Ibu Suwarni’s life has been interrupted by Mount Kelud. The mountain was giving every indication that a major eruption was imminent, with clouds of white smoke billowing as the temperature of its crater lake spiked as high as 169 degrees. The water around the volcano was so hot by mid-October that Ms. Suwarni and the hundreds of others in this town on eastern Java who make their living mining for sand and rocks from nearby rivers had to stop working. Then, when scientists recorded an intense series of volcanic tremors, residents were ordered to evacuate. [Source: Peter Gelling, New York Times, November 10, 2007 ^/^]

“Her family of four, along with about 600 other people, moved into a government refugee camp six miles from the steaming crater lake. They joined thousands of others who had already been living in refugee camps in the vicinity since Kelud began amassing energy deep within its belly a few weeks earlier. Thousands of others defied the order, refusing to leave their homes and crops, while in Ms. Suwarni’s camp, nearly a hundred people crowded a single tent every night and children played in ankle-deep mud outside, inevitably chased back inside by deafening thunder, nearby lightning and torrents of rain. “I want to go back; I want my life back,” Ms. Suwarni said earlier this week as the electricity flickered on and off. “We’ve been waiting for so long.” Her wait ended when scientists reduced the alert at Kelud from its highest level and allowed most villagers to go back to their homes.” ^/^

“Even those who have gone back to their homes cannot return to the work that provided them with a meager 80 cents a day. The mountain rivers they mined for valuable rocks and sand are still scalding hot, and noxious gas continues to spew from Kelud. It is anyone’s guess when Kelud will start amassing energy again. Refugee tents remain, and search and rescue teams stay ready. Volcanologists have raised and reduced the alert level here so many times in the past month that residents are bewildered. “It is frustrating and confusing,” said Budi Rianto, the town’s mayor. “All you can do is wait and hope we make the right decision.” ^/^

“Many of those who evacuated did so after they saw the warnings on television. “This is the first time there has ever been an evacuation,” Ibu Misyen, a 40-year-old grandmother who has lived through three eruptions, told the New York Times. “We could see the signs: the smell of sulfur, the warm air and hot water. But we wouldn’t have left if the government didn’t tell us to.” Some villagers release live swans into its rivers to help appease what they believe is a love-scorned prince living within. ^/^

“When the police announced through a bullhorn on Thursday that Ms. Suwarni and the others could return to their homes, the camp leaped with activity. Ms. Suwarni stuffed her few belongings into a bag, collected her children and began the walk back seemingly in one motion. The camp was empty in less than an hour. “I am so happy to go back,” she said, the hot river still steaming beside her, a cloud of poisonous gas still obscuring the mountain’s top. “It is always dangerous living here, but it’s better than starting over someplace else.” ^/^

For many of the millions of people affected by the 2014 Kelud eruption, the event provided a means for making money and fertilizer for their crops. "This is a blessing of the disaster," Imam Choiri, a farmer who was scraping up the ash from the road to use as fertilizer on his small vegetable plot a few kilometers from the crater of the rumbling mountain, told Associated Press. Choiri said locals believe the ash helps drive away pests from crops. Volcanic ash and debris are also prized in the building industry because they make especially strong cement, and sand diggers can charge almost twice as much per load than they can for regular sand. Scores of diggers were collecting the fresh, easy-to-dig sand, packing the windfall into bags or onto trucks. "Kelud is a valuable source of livelihood to me and my family," Harjito Huda, a sand miner from Ngancar village, said. [Source: Niniek Karmini, Associated Press, February 15, 2014]

Kelud’s Catastrophic 1919 Eruption

On 19 May 1919 Kelud was the site of one of the deadliest volcanic eruptions of the twentieth century, killing over 5100 people when water ejected from the crater lake formed lethal lahars that travelled nearly 40 kilometres and destroyed more than 100 villages. The powerful explosion reportedly could be heard hundreds of kilometers away. According to Volcanism blog: “The 1919 eruption is interesting not only for itself but for the response it generated. At the time Java was under Dutch colonial rule, and the Dutch authorities reacted to the disaster both institutionally, by establishing the forerunner of today’s Indonesian volcanological authority, and technologically, by creating a drainage system intended to manage the hazard posed by the crater lake. [Source: Volcanism blog]

The presence of a substantial crater lake has been the main reason why Kelud is a very lahar-prone volcano, but also significant are its deeply eroded flanks and abundance of loose sediment. During the May 1919 eruption 38 million cubic metres of water was expelled from the crater lake, radiating out through the deep drainage channels and accumulating vast quantities of sediment and volcanic material to produce fast-moving lahars that inundated over 30 square kilometres of the surrounding countryside.

Even before the 1919 catastrophe the colonial authorities recognized the danger Kelud posed and had, in 1905, constructed a dyke intended to protect the nearby city of Blitar. The 1919 lahars, however, overwhelmed this construction. The Dutch response was to abandon the mitigation of lahars and concentrate instead on preventing them developing by enabling the drainage of the crater lake. The work took until 1926 to complete: a system of seven drainage tunnels was constructed, which reduced the volume of the lake by more than 2 million cubic metres, lowering the level by 50 metres.

In 1951 the volcano erupted again, but the successful operation of the drainage system meant that little water was present in the crater and no lahars resulted. A second catastrophe had been averted. The eruption itself, however, deepened the lake and destroyed the drainage tunnels. Only after another deadly eruption in 1966, in which more than 200 people died, was a new deeper tunnel excavated. The most recent large-scale eruption, in 1990, would certainly have been much more destructive to life and property had the crater lake not been largely drained. The autumn 2007 eruption built a lava dome that fills the crater lake site and has overwhelmed the drainage inlets. Volcanic lake specialists at the Université Libre de Bruxelles, Belgium are currently collaborating with the Volcanological Survey of Indonesia in monitoring Kelud. Le volcan Kelud – account of the 1919 eruption and a detailed history, with illustrations, of the various drainage systems built since to drain the crater lake (in French).

Bromo Tengger Semeru National Park

The Bromo Tengger Semeru National Park covers a massive area of 800 square kilometers in the center of East Java, the largest volcanic region in the province. Here you can see plumes of smoke coming from Mt. Semeru, an active volcano which rises 3676 meters above sea level, and experience the remarkable Tengger Caldera, Java's largest, with its 10 kilometers barren desert-like sea of sand. Within the caldera rise the deeply fissured volcanic cones of Batok and Bromo, the latter is still active with a cavernous crater from which smoke blows skyward. Temperatures at the top of Mount Bromo range about 5 to 18 degrees Celsius. To the south of the park is a rolling upland plateau dissected by valleys and dotted with several small scenic lakes.

The 16-kilometer-wide Tengger caldera is located at the northern end of a volcanic massif extending from Semeru volcano. The massive Tengger volcanic complex dates back to about 820,000 years ago and consists of five overlapping stratovolcanoes, each truncated by a caldera. Lava domes, pyroclastic cones, and a maar occupy the flanks of the massif. The Ngadisari caldera at the northeast end of the complex formed about 150,000 years ago and is now drained through the Sapikerep Valley. The most recent of the Tengger calderas is the 9 x 10 kilometers wide Sandsea Caldera at the southwest end of the complex, which formed incrementally during the late Pleistocene and early Holocene. An overlapping cluster of post-caldera cones was constructed on the floor of the Sandsea Caldera within the last several thousand years. The youngest of these is Bromo, one of Java's most active and most frequently visited volcanoes. [Source: Volcano Discovery]

The Tengger sandy area has been protected since 1919. This is believed to be the only conservation area in Indonesia, and possibly the world which possesses a unique sand sea at the attitude of about 2000 meters above sea level. There are several peaks inside the caldera: Mt Watangan (2,661 meters). Mt Batok (2,470 meters), Mt Kursi (2,581), Mt Watangan (2,661 meters), and Mt Widadaren (2,650 meters).

Many hikers take in the spectacular view of the sun rising over volcanic peaks with an early morning trip to Mt Bromo. From the lookout point at Penanjakan there is a spectacular vista. Cross the desert on a pony, climb the steep stairs right up to Mt. Bromo’s crater rim, then watch the sun spectacularly rise over the horizon. Mount Semeru is the highest peak in Java. This mountain, also known as the Great Mountain, is regarded by Indonesian Hindus as their most sacred mountain. Getting to the peak is a tough three day trek. Mt Semeru is one of the most active volcanoes on Java and regularly explodes. These gases and belching lava make Semeru dangerous, so stay well away from the vent.

On the fourteenth day of the Hindu month Kasada — usually around November or September — the native people of the area, the Tenggerese, gather at the rim of Mount Bromo's active crater to present offerings of rice, fruit, vegetables, flowers, livestock and other local produce to the God of the Mountain. The Tenggerese are adherents of a religion which combines elements of Hinduism and Mahayana Buddhism. In this Kasada ceremony the Tenggerese ask for blessing from the supreme God, Sang Hyang Widi Wasa.

Bromo Tengger Semeru can be reached by private and public vehicle from Surabaya or Malang in East Java. Sriwijaya Air flies twice daily to Malang from Jakarta. There are multiple ways to get into the park. Visitors can come from Probolinggo, in the north west arrive through the village of Ngadisari. Or take the north east approach via Pasuruan and the village of Tosari. The third, the more difficult approach is via Ngadas, which is best travelled on the way down. The Probolinggo approach is the easiest and by far the most popular route, especially if travelling by public bus. Wonokitri is the closest and the easiest approach if you are coming by private vehicle from Surabaya (5 hours journey). To get closer to Mt. Bromo you must rent 4x4 vehicles (there are many 4x4 vehicles available for rent there).Most tour groups from Surabaya stay overnight at Tretes, where there are a number hotels, as there are in Malang, which has the added advantage of having an airport. Alternatively, you can contact a travel agency to arrange your trip.

Mt. Bromo

Mount Bromo (near the town of Probolinggo, two hours from Surabaya) is a 2,329-meter-high (7,641 foot-high),very active volcanic peak. One of Java’s most popular tourist destinations, it lies at the top of a massive volcano known as Tengger with other volcanic peaks inside a "Sea of Sand”—a huge 5½ miles long and 4½ miles wide caldera filled with fine black volcanic debris. Although Bromo doesn't erupt with the deadly force that Mt. Merapti does it is still dangerous.

Mt. Bromo (meaning "The Fire") is a 650-foot-high cone striped with yellow sulphur deposits. Smoke is constantly spilling out of the crater. Periodically it erupts small amounts of ash and debris. Bromo is one of three major craters and many more minor ones that emerge from the Sea of Sand. One is called Bataok ("The Bride"). It is 2,440 meters high. The quiescent one with the perfect cone is Kursi ("The Cup"). It is 2,581 meters high.

Bromo is a stratovolcano and an active cone inside the giant Tengger caldera, one of Indonesia's most scenic locations destination in East Java, famous for its magnificient sunrise views and the panorama over the caldera with Semeru volcano in the background.

Mt. Bromo is sacred to the Tenggerese people of eastern Java, many of whom live on Tengger’s slopes. During the Kasada Festival they make offerings of animals, meat, money and vegetables to encourage the volcano to keep it calm (See Festivals). When the volcano starts to rumble, the local population doesn't try to escape, instead they go to the top to make offerings to placate the volcano God.

The Tenggerese and other people in the region have attached a number of myths to the mountain. According to one Tenggerese story the caldera was created by an ogre—in love with a princess—who dug out the whole thing with half of a coconut shell. The Tenggerese believe that the childless rulers of a small kingdom—King Joko Seger and Queen Roro—asked the god of the volcano. He fulfilled the request with 25 children but demanded that the youngest and most handsome one, Dian Kesuma, be offered as a sacrifice. When the queen refused to go along, Dian bravely offered himself to save the kingdom.

Climbing Mt. Bromo

Mt. Bromo is popular with tourists who try to reach the peak at sunrise before the clouds set in. The crater can be quite crowded at this time especially when school groups make the trek. Some suggest getting a good night’ sleep, reaching the crater when the crowds have thinned and the visibility is still generally good. Javanese make the trek during August or October to make offerings during the Kasada festival. Westerners generally make the hike in the dry season from April to October.

There are a number of different routes to the top. The most popular is via Probolinggo and the village of Ngadisari, where it possible to hike by foot or take a pony trek to the top of the mountain. Probolinggo is two hours from Surabaya and eight hours from Yogyakarta). The next town, Sukapura, us 28 kilometers further and 14 kilometers up Ngadisari and an another three kilometers to Cemero Lawang, which is situated at the edge of the caldera. Trips can be arranged from Yogyakarta. Public transportation is available almost all the way, with regular minibuses running to Cemero Lawan.

From Cemero Lawang it is a three kilometers walk down the caldera across to the Sea of Sand to the 250-step climb up Bromo. Many venture on up 2777-meter-high Gunung Penanjakan, where there is a spectacular view of Bromo, with Semeru smoking the background. For information in some of the other routes check the Lonely Planet Book.

Mt. Bromo Eruptions

When at the crater of Mt. Bromo it is probably wise to keep your distance. In June 2004, two hikers, including a boy from Singapore, were killed and seven other were injured by rocks expelled from the crater during an eruption that sent smoke rising 3,000 meters into the air. Rescue teams were sent to look for hikers who might have been trapped.

Typical eruption style: Explosive. Frequent small, phreatic eruptions at Bromo cinder cone on the bottom of the caldera. Bromo volcano eruptions: 1804, 1815, 1820, 1822, 1825, 1829, 1830, 1835, 1842, 1843, 1844, 1856, 1857, 1858, 1858, 1859, 1860, 1865, 1865, 1866, 1867-68, 1877, 1885, 1885-86, 1886, 1886-87, 1888(?), 1890, 1893, 1896, 1906-07, 1907, 1907-08, 1909, 1910, 1915-16, 1921, 1922, 1928, 1930, 1935, 1939, 1940, 1948, 1950, 1955, 1956, 1972, 1980, 1983(?), 1983, 1984, 1995 (March-May), 1995 (Sep-Dec), 2000 (Nov)-20001 (Jan), 2004 (June), Dec 2010 - 2011. [Source: Volcano Discovery]

On the 2004 eruption that killed the two hikers, the BBC reported: “The two men - one Indonesian and the other from Singapore - were hit by hot rocks expelled from Mount Bromo. An eyewitness on Mount Bromo told the BBC she was forced to scramble down from the crater when the volcano began spewing rocks and dark smoke. Few people live in the immediate vicinity of the volcano, but visitors to the region often climb its slopes to watch the sunrise.

Semeru Volcano

Gugung Semeru (a few kilometers from Bromo) is the highest mountain in Java at 3,676 meters high. It is often puffing out smoke and regarded as one of one of the most dangerous volcanos in Indonesia. Hindus call it Mahameru, a reference to Mt. Meru, the center of the Hindu universe. It is also regarded as the father of Gunung Agung in Bali. Semeru’s first recorded eruption was in 1818. In 1981, an eruption killed 250 people. In March 2002, two pyroclastic flows traveled 2½ kilometers down the mountainside and access to the crater was closed. In the early 2000s it was erupting about every 30 minutes, sending out smoke, gas and molten rock.

Semeru is a stratovolcano that has been erupting in almost continuously since 1967. It lies at the southern end of a volcanic massif extending north to the Tengger caldera. Semeru, a favourite mountain trekking destination. It is known for its regular ash explosions that typically occur at intervals of 10-30 minutes. The steep-sided volcano rises abruptly to 3676 meters above coastal plains to the south. Gunung Semeru was constructed south of the overlapping Ajek-ajek and Jambangan calderas. A line of lake-filled maars was constructed along a N-S trend cutting through the summit, and cinder cones and lava domes occupy the eastern and northeast flanks. Summit topography is complicated by the shifting of craters from northwest to southeast. Frequent 19th and 20th century eruptions were dominated by small-to-moderate explosions from the summit crater, with occasional lava flows and larger explosive eruptions accompanied by pyroclastic flows that have reached the lower flanks of the volcano. [Source: Volcano Discovery ~~]

Typical eruption style: Explosive. Near constant strombolian activity, occasionally stronger explosions, lava flows and pyroclastic flows. Semeru volcano eruptions: 1818, 1829, 1830, 1832, 1836, 1838, 1842, 1844, 1845, 1848, 1849, 1851, 1856, 1857, 1865, 1866, 1887, 1887, 1888, 1889-91, 1892, 1893, 1893-94, 1895, 1896, 1897, 1899, 1899, 1900, 1901, 1903, 1904, 1905, 1907, 1908, 1909-10, 1910-11, 1911, 1912, 1913, 1941-42, 1945, 1946, 1946-47, 1950-64, 1967-ongoing (as of 2013). ~~

Byron Spice wrote in the Post-Gazette, “Semeru has erupted at least 55 times since 1818, sometimes producing lava flows, pyroclastic flows -- swiftly moving, deadly clouds of hot gas and rock fragments -- and mudflows that have killed hundreds of people over the years. For several decades, however, Semeru has been a "popper," sending up 1,000-foot plumes of steam and ash every 20 minutes or so. Molten magma isn't visible from the crater, but water seeps down through the crust of rocks and ash at the bottom of the crater until it hits hot rock. The water flashes to steam, building up pressure under the crust until an explosion occurs. "It's just this big pit and every so often it blows," scientist Michael Ramsey said. A national park surrounds the mountain and, despite the dangers, the crater has become a popular hiking destination. The crater at the top is inactive; the steam-and-ash explosions occur in a smaller crater that is about 200 to 300 feet below the summit and connected to the summit by a curved ridge. [Source: Byron Spice, Science Editor, Post-Gazette, August 27, 2000 <<<]

Climbing Semeru

When Semeru is open the crater can be reached via a rough three day trek from Tumpang, where you travel by jeep to Ranu Pani, for the start of the trek. Alternatively you can hike 12 kilometers from Ngadas to Jemplan and then another six kilometers to Ramu Pani. At Ramu Pani there is a homestay where you can get a guide or directions for the hike.

According to the Jakarta Post: “The scenery around Mt. Semeru was strikingly beautiful, yet the challenge to reach the summit was so demanding that it seemed some divine spirit had forbade humans to ascend to the mountain’s top, promising severe punishment for those who disobeyed. Hikers can enjoy heavenly vistas even without climbing to the mountain’s summit, as the surrounding area boasts Ranu Kumbolo Lake, which is famous for its turquoise blue water and the stunning green hills that surround it. Only a 15-minute walk from the lake is a breathtaking view of the Oro Oro Ombo meadow, a 100-hectare savanna. [Source: Jakarta Post, September 28 2013]

“A two-hour walk from the meadow takes hikers to the Jambangan field, which is blanketed by countless edelweiss flowers. But for those that choose to climb, it is not only leg ache that you must contend with. Hikers need to avoid the poisonous gas regularly emitted from the volcano and, as such, hikers must reach the summit before noon as the change of wind direction wafts the poisonous gas onto the climbing route.

“As the climb to the summit from the lowest camp takes roughly seven hours, hikers performing the so-called “summit attack” must start ascending at midnight, in the face of strong winds and minus-zero temperatures. The seven-hour climb was painstaking as a 60-degree climb on sandy terrain offers unstable footing, which is energy-sapping, as well as the constant fear of falling rocks from above. Still, the reward from watching sunrise from the summit of Mt. Semeru was worth the pain, with Java’s coastline, the nearby mountains, cities and the crater all joining to create a panoramic, picture-perfect view above the clouds.

Small But Deadly Semeru Eruption

On a small Semeru eruption that killed two Indonesian volcanologists and injured three American scientists who were in the wrong place at the wrong time, Byron Spice wrote in the Post-Gazette, “As molten rocks the size of softballs rained down around him, geologist Michael Ramsey concentrated on advice he had heard from a survivor of a volcanic eruption seven years before. Falling face down on a ridge that shielded him from the direct blast of the 12,000-foot volcano in Indonesia, the 33-year-old volcanologist from the University of Pittsburgh held his camera bag across the back of his head and tried to flick away the hot, glassy pebbles that pelted him and melted into his parka. [Source: Byron Spice, Science Editor, Post-Gazette, August 27, 2000 <<<]

“The July 26 eruption of the Semeru volcano in eastern Java had caught Ramsey and a small group of fellow volcanologists by surprise. It lasted just 40 or 45 seconds and was by most standards a minor volcanic event, little more than a hissy fit of Nature. Yet when Ramsey stood and surveyed the aftermath, he was aghast at the power Semeru had just displayed. Two Indonesian colleagues lay dead. An American scientist was unconscious, bleeding and seriously burned. Ramsey and another American were both injured. And, as they learned as they made their way off the mountain, this was only the beginning of their ordeal. <<<

“At Mt. Semeru, the American scientists were accompanying Volcanological Survey staff members on a routine, weekly monitoring tour. On July 25, Ramsey and the rest of the group drove to a small village near the mountain and hiked 12 to 13 miles into the park, setting up camp about 1,000 feet above the tree line and 1,000 feet below the summit. They rose at 2 a.m. the next day to begin their climb, planning to reach the crater by dawn, take some photos, make some measurements, and, after a couple of hours, make their way back to camp. Ramsey, a former Grand Canyon river guide with training in field medicine, usually carries a first aid kit, but he tossed it back in his tent before leaving, figuring he could do without the extra 2 pounds on the short trek. Then he thought better of it and retrieved the kit. <<<

“About 20 people were at the summit at sunrise, including Ramsey, the two Smithsonian volcanologists, an Israeli student and four scientists from the Indonesian agency, as well as a couple of porters and a Dutch tourist. After watching three or four eruptions, the group decided to venture down the ridge to get a closer view. The summit was cloudy that morning and the fog became thicker as they reached the active crater. Ramsey, Kimberly and the Dutch hiker got discouraged and headed back up the ridge. About halfway up, the clouds rapidly dissipated. Someone at the crater called out a good-natured taunt to the departing trio: "Thanks for leaving, guys -- now we've got a clear shot." Kimberly took the hint and began running back to the crater, perhaps 100 feet away. <<<

“Ramsey stayed in place fiddling with the telephoto lens on his camera. He felt a tremor beneath his feet. "That's when I got a little nervous because we hadn't felt that before." That low vibrational motion most likely was caused by fresh magma pushing up through the rock, cracking it. Unlike the usual steam-and-ash eruptions, which are caused by water seeping down from above, this movement originated deep within the volcano, maybe a mile beneath the volcanologists' feet. Perhaps a new batch of gas-rich magma had flowed into the chamber below Semeru; when it mixed with the existing magma, its gas would decompress and begin rising like bubbles in a glass of champagne. The sudden dissipation of the fog, Ramsey realized later, may have been caused by the heat of the hot magma as it pushed to the surface.” <<<

Deaths and Injuries from the Small Semeru Eruption

Byron Spice wrote in the Post-Gazette, “But none of that was evident before it was too late. Looking back toward the crater through his camera, Ramsey saw a wall of rock and ash shoot straight up toward the group gathered at the crater. "I immediately knew we were in big trouble," Ramsey said. The Dutch hiker started to scream. Ramsey shoved him toward a rock outcrop about 20 feet away down the side of the ridge opposite the crater. Rocks were starting to fall. The rocks -- molten when they hit the air -- were nearly 1,300 degrees Fahrenheit, and Ramsey knew it was important to remain conscious so that he could extricate himself from any scalding masses that struck him. He threw himself to the ground and positioned his camera bag behind his head. Small gobs of glassy stone pelted him, sticking to his clothes until he could flick them off. Something big hit the camera bag, knocking it off his head and out of his hands. Something hit his left boot, melting all its rivets. [Source: Byron Spice, Science Editor, Post-Gazette, August 27, 2000 <<<]

“And within 40 or 45 seconds -- 60 seconds at most -- it was over. A minute later, Ramsey clambered to his feet. Ten feet away lay a smoldering rock the size of a basketball. He found his camera case, which was melted in one corner. "That's when I started hearing the screaming and wailing," he said. Kimberly had been knocked unconscious. Unable to protect himself from the nearly molten projectiles, he suffered third-degree burns to his arms and legs. Making his way to the crater's edge, Ramsey found the two senior Indonesian volcanologists, who had been caught in the direct blast of the eruption. He barely knew them. The man he knew as Willie, named Asep Wildan, and his colleague, named Mukti, were both dead, killed instantly from blows to their heads. <<<

“Amit Mushkin, the Israeli student, was largely unscathed, but Siebert, the other Smithsonian scientist, was bleeding from his head and had a large chunk of skin missing between the thumb and forefinger of his right hand. Ramsey and the other survivors helped get Kimberly to his feet and back to the summit, where two other Indonesian scientists had remained. The Indonesians radioed for help. <<<

“Within a half-hour, Kimberly became coherent again and Ramsey assessed his injuries. He had a broken arm and a smashed hand. His pants had burned off and he had third-degree burns on the tops of both thighs. He was bleeding from a rip in the upper left arm of his jacket; closer inspection showed a hole almost the size of a half dollar that continued down to his fractured collarbone. "I wanted to get him off the summit," Ramsey said, so they headed down the mountain, past their tents to a base camp 2,000 feet below the summit, where there was a small hut and room for a helicopter to land. <<<

“As they waited to be evacuated, Ramsey took out two suture kits from the first aid kit he had almost left behind and began to stitch up the gaping wound on Kimberly's shoulder. "I had learned to do sutures on a big slab of roast beef," he said, but had never done it on a live human being before. "About halfway through, Paul said, 'Are you going to begin soon?' so I guess I wasn't too bad." By 5 p.m., it was obvious that no helicopter would be coming that day. "None of us got much sleep that night," Ramsey said. <<<

“The next morning, word came that a helicopter rescue had been approved, but that clouds and rain would make it impossible. So villagers, who had hiked up with supplies through the night, constructed a gurney for Kimberly and suspended it by ropes to a single pole supported on the shoulders of two men. The village men were small, skinny and usually barefoot, but they expertly moved Kimberly down the hill, with replacements taking over as each set of porters tired. <<<

“Ramsey, his left foot swollen from the impact of the flying rock, limped along in the procession, a tree limb serving as a makeshift crutch. Siebert, who had worked in Indonesia before, took the lead in communicating with the Indonesians and Mushkin aided with Kimberly's transport. "All of us were kind of the walking wounded," Ramsey recalled, "so we didn't have much energy." <<<

“It was about 9:30 p.m. on July 27 before they arrived in the trailhead village of Ranupane, where Kimberly, Siebert, Ramsey and Mushkin piled into an ambulance headed for the next major city, Lumajong. When they arrived about 2:30 a.m., almost two days after the eruption, 30 or 40 reporters greeted them. Siebert and Kimberly were flown to a hospital in Singapore. Siebert, now back at work at the National Museum of Natural History, declined to be interviewed for this story, explaining, "This tragedy is still much too close at hand for me." Randall Kremer, spokesman for the museum in Washington, D.C., said Kimberly continues to undergo treatment for his burns and is expected to make a full recovery. Ramsey said doctors in Lumajong found nothing wrong with his bruised foot, though it still bothers him a month later. Covered in bruises, he returned with Mushkin to Semeru to gather up the camping gear. Ramsey then returned to the United States.” <<<

Collecting Sulfur on Ijen Volcano

Kawah Ijen (near Bondowoso, which is two hours from Probolinggo, and four hours from Surabaya) is a 2148-meter-high (7,500-foot-high) volcanic lake in eastern Java. Inside the kilometer-wide crater is a turquoise lake made of sulfuric acid, one of the largest hot acidic crater lakes in the world. Great plums of acrid smoke rise from the lake and vents in the earth around it.

The Ijen Plateau ("Kawah Ijen") is situated on a once active caldera that covers 134 square kilometers. On this plateau are there three major volcanos: 2368-meter-high Ijen, 2800-meter-high Merapi and 3332-meter-high Raung. Ijen erupted violently in 1936 and has erupted with plums of smoke and ash periodically since 1952. The lake bubbles when the volcano is especially active. Much of the western part of the plateau is covered by coffee plantations.

Inside the crater of Kawah Ijen volcano on Java, hundreds of miners collect sulfur by hand amid noxious sulfuric fumes. The use a process widely used in the 19th century but regarded as obsolete today. Ceramic pots collect the volcanic gas and condense it into an amber liquid that dries and forms large stalactites of pure, yellow sulfur. Miners break up the stalgtites with long metal rods and load the sulfur into whicker baskets connected by bamboo shoulder poles. The sulfur is used in refining sugar, processing natural rubber and as an ingredient in pesticides and medications. It is also a natural source of sulfuric acid, in great demand in the oil-refining business and in the production of fertilizers. Around the places the miners work are amorphous blue flames from sulfur fires.

Miners carry 40-kilogram loads balanced on one shoulder in baskets from a quarry on the lakes edge under the shadow of the sheer walls of the crater—a vertical distance of 200 meters— out of the crater to an unloading station on the crater’s edge. The miners have strong back muscles and huge callouses on their shoulders. They typically carry two loads a day and make a few dollars per load. The miners protect themselves form the fumes with handkerchiefs. Some have worked more than 10 years and show no ill affects. The biggest danger for them is an eruption or a sudden overpowering release of gas. [Source: Justin Guariglia, Smithsonian]

Mount Inje Crater can be reached by a five kilometers walk up to the rim of the crater and then down to the lake along the same route the sulfur collectors use. The fumes by the lake can be overwhelming and dangerous. The trail can be a little dodgy as well. In 1997, a French tourist died when he fell into the steaming lake. It also possible to hike around the rim of the crater. The starting point is the PHKA post in Pos Paltuding, which is usually reached from Bondowoso—64 kilometers away on a mostly good road which takes two hours to traverse—but can also be reached by Banyuwangi—which is closer but the roads connecting it to Pos Paltuding are in much worse condition. Bondowoso in turn can reached by bus from Probolinggo or Surabaya. Trips are organized in Yogyakarta

Ijen and Merapi lie on the northeastern edge of the Plateau, and Raung is situated on the southwest corner. The magnificent turquoise sulfur lake of Kawah Ijen lies at 2148 meters above sea level and is surrounded by sheer crater walls. The sulfur collectors make the trek up to the crater and down to the lake every day. They generally hike up in the morning and return around 1 pm when the clouds roll in. The sulphur at Kawah Ijen is very pure.

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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