[FONT=Arial, Helvetica, sans-serif]Reasons to Worry?[/FONT]
Scientists have known about Yellowstone's explosive history for quite some time, but events in the fall of 2003 suddenly had people concerned about the possibility of another massive explosion.
In August of 2003 a new high-resolution sonar map of the bottom of Yellowstone Lake showed a bulge, or "inflated plain" there that was 2000 feet long and 100 feet high. Was it being pushed up by hydrothermal or even volcanic forces?
At about the same time there were some unusual changes at Norris Geyser basin some 20 miles north of the lake. Areas formally dry suddenly had hot springs. Other hot springs dried up. A long dormant geyser became active and forced the closing of some of the trails through the basin.
Rumors also spread that the land near the center of the Yellowstone caldera has been rising, perhaps a sign that the humongous magma chamber below was about to blow.
Some amateur geologists connected these events with the history of the Yellowstone volcano and came to some troubling conclusions: The catastrophic caldera making eruptions have occurred. at 2.1 million, 1.3 million and 650,000 years ago. Was another one about to happen? Was the next explosion overdue?
Interest in these developments quickly mounted. Several Internet sites sprang up predicting another explosion very soon and suggesting that the only way to avoid such a disaster was to drill holes into the magma chamber to release the pressure.
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Conditions Normal[/FONT]
As fascinating as the history of Yellowstone volcano is, however, most professional geologists who study the site are not concerned that the park is on the brink of a catastrophic eruption. The bulge on the bottom of the lake may have been there for thousands of years, but not noticed until the recent survey. Changes in the geyser activity is not unusual. New geysers have appeared throughout the history of the park, while others go dormant. Rangers often shut down parts of trails or alter them as needed.
The land near the center of the caldera did rise more than three feet between 1923 and 1985. However, between 1985 and 1992 it actually subsided six inches. Studies of the shorelines of Yellowstone Lake have led scientists to believe this is a regular phenomenon. The caldera floor has risen and fallen at least three times in the last 10,000 years, moving as far as 65 feet.
The idea that Yellowstone may be "overdue" is also faulty. With only three catastrophic eruptions and two intervals between to go on there is not enough data to say that another one should be occurring in the near future.
Even if there was, there is little mankind could do about it. Drilling into the magma chamber to release pressure, as some have suggested, would be impractical and ineffective. The material in the chamber has the consistency of a sponge and any "hole" opened up to the surface would quickly seal as the molten rock crept up and cooled.
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The Sleeping Dragon[/FONT]
That doesn't mean that there isn't (as one scientist put it) a proverbial giant dragon sleeping under Yellowstone. It may well one day awake and lay waste to much of the western United States. The Yellowstone Volcano Observatory, however, watches the park carefully and analyzes the continuous geological changes occurring in the region. It is likely that the imminent threat of another catastrophic explosion would not go unnoticed by their modern instruments. So far, however, activity is business-as-usual at the park.
Still, the super volcano at Yellowstone, and its kin around the world are a credible threat to man. Even the United States Geological Survey, usually conservative about such matters, admits that should a major eruption occur the results would have "global consequences that are beyond human experience and impossible to anticipate fully."