Volcanoes, which spit ash, ooze lava and create darkness in the middle of the day, are impressive displays of nature's restlessness. They are also life-threatening: more than 28,500 people died from eruptions during the 1980s. They can cause millions of dollars in property damage and bring industrial activity to a grinding halt. New technology to improve the accuracy of eruption forecasts is helping to minimise the devastation volcanoes can cause. After the Nevado del Ruiz eruption killed nearly 25,000 people in Colombia in 1986, the US government began taking volcanic forecasting seriously. The US Geological Survey, which tracks volcanic activity around the world, was infused with new funds to create a detailed database and update its techniques. The new technology will not only help to save thousands of lives, it may also save millions of dollars. According to the Aviation Safety Journal, more than 60 aircraft have been damaged by drifting clouds of volcanic ash since 1980. The repair of a 747 aircraft damaged during the 1989 eruption from Redoubt Volcano in Alaska cost Dollars 80m (Pounds 53m). The continuous eruption of Hawaii's Kilauea since 1983 has caused more than Dollars 5m in damage, much of it to properties and crops affected by the acid-bearing volcanic pollutants. Mount St Helens in Washington state wiped out thousands of acres of productive timberland. Losses from interrupted economic activity are harder to quantify, but may be more devastating. Redoubt's eruption, for instance, caused a valuable oil storage terminal to close for several weeks and halted most flights into and out of the region. Tourism often takes the hardest hit of all. When US geologists issued eruption warnings in California's Long Valley in 1982, the resort area turned into a ghost town almost overnight. And the tourist-based economy of Guadeloupe neared collapse in 1976 after an international group of volcanologists forecast the eruption of La Soufriere. The Long Valley and Guadeloupe incidents are tinged with bitterness since the predicted disasters never happened. Guadeloupe evacuated 72,000 people and tourists stayed away. Yet the only crisis that hit the Caribbean island was in the economic sphere. Scientists blame these fiascos on insufficient data. 'The identification of fresh volcanic glass in the erupted ash - which seemed to indicate that the volcano was about to erupt violently - was a mistake,' wrote Richard Fiske, a volcanologist at the Smithsonian Institution, about the incident. Volcanologists today use more sophisticated techniques. Detailed databases are maintained on all life-threatening volcanoes around the world. High-frequency monitors to measure debris flows are now in place. Earthquakes - often the first warning of volcanic activity - are tracked with increasing accuracy. And changes in gas composition, electrical conductivity and other clues are carefully monitored. As a result, volcanic activity can now be forecast with substantial accuracy, often pinpointing the eruption to within days or even hours of its actual occurrence. When Redoubt erupted in Alaska in 1989 and Pinatubo blew its top in the Philippines in 1991, volcanologists provided important information, not only about the timing of the events, but also about the direction of debris flows and ash blooms - vast clouds formed when tiny pieces of lava or rock are thrown into the air. 'We used information on the ash blooms (during the Redoubt eruption) to know which areas to stay away from, and which were safe to fly through,' says Greg Witter, a spokesman for Alaska Air. Companies can also take advantage of eruption forecasts to move valuable equipment out of the way, and evacuate employees from the area. 'Businesses with sensitive electronics may want to shut down their air filtration system during an ash bloom,' says Steven Brantley, public information scientist with the US Geological Survey. Since ash blooms often drift for many miles, they can wreak havoc on property well beyond the life-threatening zone of eruption. Volcanology can also be used for future planning. After much of its timber was wiped out during the eruption of Mount St Helens, the paper group Weyerhaeuser consulted experts to decide which areas should be replanted and which avoided as too high-risk. Not all businesses welcome the interference of volcanologists, however. In Long Valley developers have refused to heed warnings in land use planning. 'We've had mixed results, because we can't force people to follow our advice,' says Daniel Miller, a geologist with the US Geological Survey. 'We've had a very negative and unpleasant response from businesses in Long Valley. They just don't believe that they might be in a risk zone and insist on building things anywhere they please.' Developers in the region complain that the volcanologists' warnings have resulted in higher insurance rates, limited areas of potential development and stoked the fears of tourists. The relationship between active volcanoes and the communities that surround them is not always confrontational. Kilauea has become a leading Hawaiian tourist attraction. It is considered the ideal volcano. Because the eruption is continuous, it is seldom life-threatening and ash blooms are rare. Instead, the volcano throws up a scenic display of colourful lava, which attracts hikers by day and creates a natural light show at night. Scientists have gleaned much useful information from the decade-long eruption. 'The resorts look to us to provide information on best viewing times, which they pass on to the tourists,' says David Clague, scientist in charge of the Hawaii Volcano Observatory at Kilauea. 'It's generally pretty tame as far as volcano eruptions go, but it's spectacular at night because it's iridescent.'
Over 28,500 people died from eruptions in the 1980s, most in Colombia's 1986 Nevado del Ruiz eruption, prompting the US Geological Survey to improve forecasting. They predicted the eruptions of Alaska's Redoubt Volcano in 1989 and the Philippines' Pinatubo in 1991. In Hawaii, resorts ask the USGS for best viewing times for Kilauea, which has erupted continuously since 1983 and become a tourist attraction. After Washington's Mount St. Helens wiped out timberland, Weyerhaueuser consulted experts on where to replant. But after California's Long Valley and Guadeloupe's tourist economies suffered from false alarms, Long Valley residents refuse to heed land use warnings.