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The Real Truth about Yellowstone "Supervolcano"

I am a Wyoming native and a forty-year veteran of Yellowstone National Park vacations, classes and general geological interest. I have met many of the geologists studying in the Park and have taken classes from some of them. I would like to correct some of the gross misinformation in your reprinted letter "Earthquake Activity Seen Worldwide!"

The first fallacy is that the Yellowstone "supervolcano" is the "only known supervolcano on Earth." The caldera eruptions caused by the hot spot presently beneath YNP are not the only supervolcanic eruptions known. Lake Toba on the island of Sumatra occupies the caldera of a supervolcano, one that according to some theories nearly obliterated human life at around 75,000 years ago.

Volcanic eruptions are quantified by the VEI, or volcanic explosivity index, as set forth by IAVCEI, the International Association of Volcanology and Chemistry of the Earth's Interior. Supervolcanoes are those that after close scrutiny and study are found to have a VEI of 7 to 8. Among those volcanoes that have erupted to this magnitude are Indonesia's Tambora, Valles Caldera in New Mexico, Mt. Aso in Japan, California's Long Valley Caldera, Whakamaru and Lake Taupo in New Zealand, and Kikai on the Ryukyu Islands. All of these volcanoes are considered to be active.

The article goes on to say that "the ground has swelled more in the past three (3) years than it has in the past hundred years.." this is simply prepostrous. The areas of ground swelling in YNP have actually been receding in the past decade. The only location within the Park's boundaries that "breathes" with any regularity is the newly mapped area beneath Yellowstone Lake, quite close to the loci of the present seismic swarm.

Which brings me to this point: Seismic swarms are very common in the Park. Swarms of this magnitude and constancy are less common, but since records only go back sixty years, there is no way of knowing the intensity of swarms noted by exploratory expeditions, trappers, native peoples and early Park scientists. We do know one detail, however; one that because of its non-sensational nature seems to completely vanish from Chicken Little articles such as yours. Please look at a well-detailed map of YNP. Look specifically at the northern and northeastern areas of the Lake.

Find Mary Bay, Turbid Lake, West Thumb, Steamboat Point and Indian Pond on your map. Mark them in red ink. Then go up to Midway Geyser Basin, just a bit northwest of the Old Faithful area. Note the features labelled Twin Buttes and Pocket Basin in red ink also.

ALL OF THESE FEATURES have formed from hydrothermal explosions. That's geological code for steam boom-booms. Within recorded history in the Park, Excelsior and Porkchop Geysers have exploded, leaving steaming holes behind. In short, when hot water migrates at shallow depth within altered rhyolite, it causes seismic swarms. Sometimes the ground, she go BOOM! Sometimes she doesn't. The seismic activity that is now slowing beneath the lake in YNP has the very typical seismic signature of *hydrothermal* migration with none of the kind of accompanying features of *magma* migration.

If you knew anything about geology you would know this, as you would if you understood anything about Aleutian volcanics. The volcanoes of the Aleutians are the second most active group of volcanoes in the world. The chances of at least two of them erupting at the same time are so good that most of them are at least at color code yellow most of the time.

As far as the breathless tinfoil hattery regarding where soon-to-be-ex-president Bush is moving to, one of the world's biggest aquifers does not, in fact, underlie any land in Paraguay. Paraguay has extradition agreements with both the United States and the Netherlands, which might stop anyone from the U.S. Government from immigrating there. The present government of Paraguay also despises the USA. Google Earth and Maps has no current images of this portion of South America just like it has no current and clear images of parts of Iceland, Wyoming and Iowa - because it has yet to update its images of some places on the Earth's surface.

What this planet needs is a good old-fashioned supervolcano eruption to wipe out most human life, but unfortunately that is not going to happen anytime soon. But don't worry - when it becomes inevitable, someone who understands SCIENCE will be getting back to you with real information instead of the silly speculation and paranoid drivel in that letter.

Cindy Rose