2012 Survival Guide: A practical planner for the worst case scenario

Are the Yellowstone and Long Valley Calderas About to Blow?

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Porkchop Geyser, in the Norris Geyser Basin in Yellowstone, formed by a hydrothermal explosion in 1989. Blocks of silica sinter thrown from the geyser's throat form a berm around the new crater. Photo: Jim Peaco/NPS

In Apocalypse 2012, Joseph interviews University of Utah geologist Robert B. Smith, who has studied the caldera in the park for decades. Paraphrasing the scientist, Joseph writes, "This supervolcano's topographical distortion is so pronounced that Yellowstone Lake, which sits atop the caldera, is now actually tilting because of the bulge. Water is draining out at the south end, inundating trees that just a few years earlier grew normally out of the soil along the shore".

According to the 2005 BBC documentary, a key indicator of magma pushing towards the surface would be an increase in the number and frequency of earthquakes above the magma chamber. Environmental activists also remain wary about continued oil drilling in areas adjacent to the park. Over 5,000 wells have been drilled to date, with another 10,000 approved during the course the Bush Administration, Joseph reports. Every time a mining company pokes a hole in the crust, it facilitates another escape route for this modern-day equivalent of Pandora's box.

USGS photo: Chris Farrar

Because of stepped up volcanic activity, the U.S. Forest Service closed parts of the Hot Creek Geologic Site in Long Valley to visitors in 2007.


In California, the Long Valley Caldera was hit by a series of strong quakes in the late 1970's. "Unrest in the area persists today," the USGS explains in a fact sheet, with frequent earthquakes occurring in the 1.0 to 3.0 range. The supervolcano last blew its top 760,000 years ago, and the lava flow covered 1,500 square miles. Today you can find massive amounts of pumice and obsidian fused together in the area of the blast, along with cinder cones, craters and a resurgent dome. The caldera is located near Mammoth Mountain and Mono Lake, less than 20 miles from Yosemite.

(Hill, 2006)

A satellite image of the Southern Çalifornia-Nevada border. The Long Valley Caldera is indicated in red with the desgination "LVC". Just above the "C" is where Mammoth Mountain is located. Yosemite is to the left and below the "L". Interestingly, you'll find the highest peak in the lower 48 states, Mount Whitney (14,497 ft.), in the Sierras about 70 miles south of the caldera, as well as the lowest point, in Death Valley (282 ft. below sea level), which is southeast of Owens Valley. In the Bristlecone Pine Forest, located in the White Mountains (far right of the "LVC"), stands one of the world's oldest trees, "Methuselah", at 4,700 yrs. old.

In 1980, the Mammoth Mountain ski resort area was temporarily evacuated when four strong quakes struck in a vertical series, suggesting magma might be plowing toward the surface. However, no eruption followed, and the local chamber of commerce filed a lawsuit against USGS in hopes of recouping tourism revenues. Although the businessmen lost in court, it remains to be seen whether USGS officials will continue to err on the side of caution if the same scenario unfolds again.


According to a fact sheet on the Long Valley Caldera, "High concentrations of carbon dioxide (CO2) in soil gas are killing trees on the flanks of Mammoth Mountain. First noted in 1990, the areas of tree kill now total 170 acres in six general areas, including Horseshoe Lake on the south side of Mammoth Mountain. The soil gas there is composed of 20 to 90 percent CO2." As a result, overnight camping is no longer permitted.


Horseshoe Lakes, with Mammoth Mountain in the background. Notice the whitish areas of tree-kill caused by CO2 gas emissions.

As if two supervolcanoes weren’t enough to keep westerners on their toes, there are a few others. The 175-square-mile Valles Caldera near Santa Fe, New Mexico, had its last big bang over a million years ago, sending ash as far as Iowa. Meanwhile, Idaho is home to the Island Park and La Garita calderas, both residing along the Snake River Plain.

Volcano Survival 101

While lava and mud flows (lahars) present life-threatening risks with any volcano, less talked about are the fast-moving pyroclastic flows. These dark plumes combine hot rock, gases and ash heated up to 1,300 degrees, moving at breakneck speeds in excess of 100 miles an hour across land and water. Nothing can outrun them. Forests are leveled by these flows. The best evasive action is to get as far below ground as possible, or take cover inside a very deep cave, or a sealed, concrete building. Wherever you take refuge, cover up any opening (doors and windows), and keep your face to the ground.

Mt. Saint Helens on 5/18/80

To predict the volatility of a typical cone-shaped, stratovolcano, geologists keep an eye on the "lava bombs" thrown out from the spout over time. If the hardened rock is a dark color, the threat is considered much less than if it were whitish. When the volcano is spewing lava, its viscosity (thickness) also reveals how much pressure there is below ground. Runny lava, as in the case of most Hawaiin volcanoes, indicates that the magma has a relatively easy time rising to the surface. Conversely, when the lava is thick like peanut butter, which volcanologists call "blocky lava", the lava inside the mountain is having to battle its way to the surface.

A second indicator of the destructive capacity of a coming eruption are the fumaroles in a volcanic crater. Sulfur dioxide, CO2 and other gases seep out of these vents, often visible to the eye. By collecting samples of the gases, then examining their composition and temperature, geologists think they can forecast the next big blast. In Italy, for instance, Mt. Vesuvious is meticulously monitored in this manner.

In the case of supervolcanoes, it's the geysers, hot springs and CO2 emissions (as evidenced in dead trees and foilage) that generate similar data. Earthquakes offer another sign that magma is rising and an eruption may be imminent. In the worst case scenario, a bottleneck in a volcano or caldera prevents gases from seeping out and causes an intense amount of pressure to build up. When the situation reaches critical mass, a Krakatoa-like eruption follows, hurling ash and gases for tens of miles in every direction. With Yellowstone and Long Valley, scientists think the outer perimeter of their large calderas will unzip like a seam. (This is how Emmerich showed the Yellowstone eruption in his film.)

Other threats associated with volcanoes include inhaling high concentrations of sulphuric acid and carbon dioxide. While the smell of sulphur is easily detectable, CO2 is an odorless gas. You can fall asleep in your sleeping bag and never wake up if you're unlucky enough to bed down near a leak.

Meanwhile, volcanic ash spreading across hundreds of miles can disrupt vehicle operation and cause respiratory problems. More than three or four inches of wet ash accumulation on a roof of a house or other small building may be sufficient to cause its collapse.

As for lahars (mud flows), they'll follow the path of least resistance downhill, particularly river valleys and canyons. This was amply demonstrated in the dramatic footage captured after the Mt. Saint Helen's blast in 1980. Just remember, the more snow and ice piled up on a volcano, the greater the impact of the lahar. With a volcano like Vesuvious, this is less of an issue. Instead, lava flows pouring down from the sprout would likely to destroy entire towns on their path to the sea.

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Next topic: The Sunspot Cycle vs. Power Grid

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More Resources

DVDs and TV Programs

History Channel: Mega-Disaster series: Volcanic Winter. How the Earth Was Made Series: Yellowstone, Vesuvius and Mt. Saint Helens.

DVD - NOVA: Mystery of the Mega-Volcano (2006) PBS.

BBC Documentary: "Supervolcano: The Truth about Yellowstone". (Here's a transcript via ABC News.)

Clip from a History Channel program on the Yellowstone supervolcano. YouTube.

Yellowstone Caldera eruption dramatiziation. YouTube.

New at The City Edition:
Welders Universe


Apocalypse 2012: A Scientific Investigation Into Civilization's End (2007) by Lawrence E. Joseph.

Supervolcano (2007) by John Savino and Marie D. Jones

Volcanoes in Human History: The Far-Reaching Effects of Major Eruptions by Jelle Zeilinga de Boer, Donald Theodore Sanders and Robert D. Ballard.

The Unthinkable - Who Survives When Disaster Strikes (2008) by Amanda Ripley

What Everyone Should Know About the Future of Our Planet: And What We Can Do About It (2008) by Bill McGuire.

Articles of Interest

"Hundreds of Quakes Are Rattling Yellowstone." New York Times 1/31/10

"Multiple earthquakes rattle Yellowstone." Denver Post 1/3/09

"The Dangerous and Dynamic Thermal Springs in California’s Long Valley Caldera." U.S.G.S. Fact Sheet 2007

"Volcanic Unrest and Seismicity in Long Valley and Mammoth Lakes, California." By Elizabeth Sherrill.

"Yellowstone's Sister Volcanoes." Discovery Channel.

"A supervolcano eruption could put a tsunami in the shade." By Bill McGuire. The Guardian, U.K. 3/10/05


Info about 2010 Yellowstone earthquake swarm

Yellowstone Supervolcano threat

Yellowstone Volcano Observatory. and daily seismic readings University of Utah.

Long Valley Volcano Observatory and daily quake updates.

Disaster monitoring site in Budapest.

Geotripper Blog

Volcanic eruption guidelines

Volcanic ash/sulfur dioxide hazards

Respirator Fact Sheet NIOSH

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