Wednesday, November 22, 2006
Yellowstone is being monitored!
Jake Lowenstern, a USGS geologist and head of the Yellowstone Volcano Observatory, said the survey’s proposal is meant as a starting point for launching discussions about how best to monitor seismic activity in the park. “It’s our way of thinking through what sort of techniques would be useful, what we do and why, and then where do we fall short and how we might improve,” Lowenstern said.
The proposal suggests upgrading Yellowstone’s seismic network with more gauges to monitor streams and potentially dangerous gases, GPS stations that help predict ground-splitting explosions and even instruments hundreds of feet below the ground to monitor groundwater, magma and shifting rocks. “In terms of knowing whether an eruption is going to happen, we already have a pretty good system,” Lowenstern said.
But geologists say at least equal attention should be paid to hydrothermal explosions that, aside from earthquakes and landslides, pose the greatest threat. At least 20 large craters in the park were made by explosions over the last 15,000 years that erupted from boiling groundwater just below the surface. About 2,000 earthquakes also shake the park each year. Most of them are so small they are not even felt, but the magnitude 7.5 earthquake at Hebgen Lake in 1959 killed 28 people and caused extensive damage.
“All (of those) geologic events can occur again at Yellowstone and some likely will within the coming decades,” says the USGS plan. Yellowstone’s volcanic system was classified as a “high-threat” system by the federal government in a report last year that noted the park doesn’t have enough gauges and gadgets to keep track of it. Upgrading the system would help detect “subtle, precursory changes that are likely to occur before hazardous events” so people can be given plenty of notice, the USGS said in its proposal.
There are already 26 seismic stations in Yellowstone. Satellites, GPS stations and other Instruments also monitor its movements. One of the shortcomings of the current system is that in a large earthquake, the instruments might be so disrupted they couldn’t faithfully record what’s going on. Some of the technology is also outdated — much of it is analog, not digital — and the park doesn’t have a redundant system that would allow important geologic data to be relayed outside the park in the case of a large-scale event.
Any new instruments, including those buried in the ground, would need approval from the National Park Service. Though there has been talk of putting more devices in the backcountry, Lowenstern said USGS tries to be as unobtrusive as possible. “A lot of what we’ve done is try to put as many instruments as we can in places that are already developed,” he said.