Only next time, the death toll could be much higher, because Indonesia's population has soared to around 210 million. In 1921, Indonesia's former Dutch colonial rulers established the first volcanic monitoring stations in an effort to forecast eruptions and reduce death tolls. Observation posts now operate at 60 of Indonesia's most dangerous volcanoes. Their eruption warnings have saved countless lives. On Merapi, a team of 63 volcanologists works around the clock.
Seismographs flicker back and forth measuring tremors deep inside the mountain.
Scientists scan its crater rim with binoculars as clouds of noxious gases spew out. Two-way radios crackle with reports from outposts. Last year, two Indonesian volcanologists were killed and an Israeli and three American scientists were injured during an eruption at Mount Semeru on Java. In an effort to slow and deflect lava flows from Merapi, authorities have built steel-reinforced concrete dams in valleys leading toward heavily populated areas, including Yogyakarta, a city of 1 million people 18 miles to the south. Sirens have been set up in vulnerable villages.