it is probably a little unfair to describe their relationship as a feud, although Williams is on record as saying that he and Chouet ‘never really got along’. The two men are volcano experts, men whose driving ambition has been to work out how to predict an eruption. They differed sharply on their answers to this question, differences reflected in the ways they have approached their topic and in their views of what constitutes a ‘real’ volcanologist. These differences would be brutally and tragically highlighted in 1993, when Williams led a group of scientists and others into a volcanic crater, only for it to erupt, killing nine and severely injuring Williams himself.
Desk jockeys vs volcano jocks
Arguably, the world of volcanologists can be divided into jocks and nerds. The nerds work in laboratories and behind computers, poring over graphs, statistics and computer models. The jocks climb active volcanoes and get up close and personal with them. Williams has claimed that ‘the best work ... comes from those of us who walk into the crater’, so it is probably fair to describe him as a volcano jock. In the words of Dr Larry Malinconico of Lafayette College in Pennsylvania, ‘Stan’s a very aggressive scientist.’
Williams undertakes dangerous ventures into the volcano’s mouth, partly in order to study and collect samples of the noxious gases issuing from vents known as fumaroles. He believes that the make-up and volume of these emissions can be used to determine how close to an eruption the volcano is. Bernard Chouet, who trained as an engineer and rocket scientist before becoming a volcanologist, concentrates more on studying the seismology of volcanoes; he can be classed as one of the nerds. It was while studying seismographs in the early 1980s that he identified a hitherto unrecognized component of the vibrations produced by pre-eruption volcanoes: ‘It stared you in the face. “Wow, this is obviously different.” Embedded in the record among all these ... earthquakes were classic-looking quasi-monochromatic harmonic signatures, beautiful textbook examples.’
The ‘harmonic signatures’ were what is more commonly known as long-period events (LPEs), known in Spanish as tornillos (screws) because of their characteristic corkscrew shape. They are resonant frequencies produced by bottled-up lava and gas vibrating inside volcanic fissures like air in an organ pipe, and Chouet realized that their presence signalled an imminent eruption. He described his revelation as ‘a defining moment ... suddenly you realize the volcano is speaking to you and you understand the language.’
Bernard Chouet. Swiss geophysicist and seismologist who originally studied astronautics, making him, literally, a rocket scientist. Chouet is now best known for his pioneering research on Long Period Events.
Under the volcano
The pressing need for a reliable way to predict an eruption was driven home in 1985, when the Colombian volcano Nevado del Ruiz became highly active. Local volcanologists feared that when it erupted it would trigger catastrophic floods and mudslides that could threaten the nearby town of Armero, but without precise knowledge of when such an event might occur the authorities would not agree to evacuate over 20,000 people for an indefinite period. On 13 November the mountain blew, drowning Armero in a vast tide of mud, water and rubble that claimed 24,000 lives. Williams and Chouet continued work on their respective theories, hoping to prevent the next catastrophe.
In 1989, Chouet’s LPE model proved itself when he was able to issue warnings to evacuate workers from an oil facility near the Alaskan volcano Mount Redoubt just two hours before it erupted. News of this feat was slow to percolate through the world of volcanology, but soon another dangerous volcano in Colombia was to become a test for both men’s theories. In 1991, Mount Galeras became active, drawing attention from around the world. In 1992, both Chouet and Williams were studying the volcano closely, and in July both men began to predict an eruption. Williams had noted increased rates of emission of sulphur dioxide and other gases, and Chouet and his team had noted the appearance of tornillos on their seismographs. On 16 July, a small eruption destroyed observation posts round the rim of the crater; both men felt vindicated.
In January 1993, Williams secured UN funding to host an international conference for volcanologists in Pasto, near Galeras. He managed to attract many distinguished experts from around the globe, although Chouet and his team were not able to attend. Williams, something of a showman, planned for the highlight of the conference to be a field trip into the crater, led by himself. He had checked emissions from fumaroles in the crater and was convinced there was no imminent danger of an eruption because sulphur dioxide levels were relatively low. But other volcanologists had begun to detect telltale tornillos since 23 December and questions were raised about the safety of the expedition.
On the eve of the expedition there was a meeting but accounts of the ensuing discussion differ. Colombian volcanologist Fernando Gil, who had previously worked with Chouet, was alarmed: ‘We were concerned by these long-period events and what had happened when we’d seen them before.’ But Williams and his colleagues, who were not seismologists, did not really understand what the problem was. Williams’ associate John Stix admits, ‘There was a concern, but we didn’t really understand what those [long-period] events were telling us.’ Williams claims that there was no consensus about the predictive value of LPEs: ‘... there was no such understanding [that tornillos might presage an eruption]. In the days before our trip into the crater, no one brought the tornillos to my attention or warned that the volcano might be poised to blow ... Based on all available evidence, the consensus at the observatory was that Galeras was safe.’
Cross section through a volcano. Heat and pressure from rising magma forces steam and gas through cracks and vents in the rock known as fumaroles.
TIMELINE
Why was he not aware of the potential significance of Chouet’s work? ‘Unfortunately, Chouet – with whom I did not get along – never sent me a copy of his report,’ he wrote in Surviving Galeras, his 2001 account of the disaster. Would it have made any difference? ‘If I had been down there at the time and I had seen the long-period events I would certainly have voiced my opinion that it was not an appropriate time to go into the crater. But I couldn’t have just jumped in front of them and said, “Over my dead body!” so I don’t know what the outcome would have been,’ points out Chouet.
Into the valley of death
The next morning, 14 January 1993, Williams led a party of nine scientists and three hikers up the mountain and into the caldera, the wide crater atop the volcano within which sits the volcanic cone itself. For several hours they took readings and gathered samples; other scientists watched from the caldera rim. At 1.30pm the volcano blew its top, blasting thousands of tons of rock into the air to rain down on those in and around the crater. Nine people were killed almost instantly, blown away or smashed by falling rocks. Williams himself was horribly injured, his leg mangled and slivers of skull driven into his brain.
Whether Williams was at fault for going ahead with the field trip is debatable but his behaviour after the disaster damned him in the eyes of many. He compounded bouts of apparent memory loss and fantasising with arrogance and contempt for others, in what science journalist Victoria Bruce, author of No Apparent Danger: The True Story of Volcanic Disaster at Galeras and Nevado del Ruiz and one of Williams’ most trenchant critics, called ‘a flagrant grab for fame at the expense of dead colleagues’.
