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Are the Yellowstone and Long Valley Calderas About to Blow?
The City Edition ^ | March 11, 2011

Posted on 03/13/2011 1:24:04 AM PST by 2ndDivisionVet

As good a read as it is throughout, Lawrence Joseph's book, Apocalypse 2012: An Investigation into Civilization's End devotes a spine-tingling chapter to two ticking bombs in our own backyard — Yellowstone National Park and California's Long Valley Caldera. Both locations are home to massive supervolcanoes. Geologists say these submerged magma chambers fill up over the course of several hundred thousand years, then shoot their wads skyward in climate-changing events. And both are due for their periodic eruption.

The last supervolcano to erupt on the planet was Mount Toba in Sumatra — 74,000 years ago. Incredibly, both Yellowstone and Long Valley are considered a thousand times more explosive than Toba. A major blast would produce a lava field extending at least four hundred miles to the south and east. Moreover, the accompanying ash cloud may blanket much of the world for months, if not years. That would trigger worldwide crop failures and radically alter weather patterns.

Between January 17 and February 11, 2010, Yellowstone experienced its second largest swarm of earthquakes on record. Some of the over 1,800 tremors included two measuring 3.7 and 3.8 on the Richter Scale, with a total of 14 at 3.0 or more in magnitude. (For comparison, a 5.1 earthquake accompanied the 1980 Mt. St. Helens eruption.)

The previous year, a similar earthquake swarm occurred at the same location. In both cases, no evacuation orders or volcano warnings were issued. The U.S. Geological Suvey insists the latest activity was concentrated along known faultlines, with no direct connection to the caldera. Regardless, scientists continue to monitor more than two dozen seismograph stations. They also routinely sample sulphur and carbon dioxide levels at geysers and other hot spots around the park. Tilt meters have been installed to measure deformity of the land as the magma chamber inches slowly toward the surface.

To put the situation in context, a typical, cone-shaped stratovolcano gets its magma from seawater melting rocks along subterrainean subduction zones (i.e. where tectonic plates collide). However, the Yellowstone and Long Valley Calderas are thought to get their magma directly from the Earth's molten mantle via a "plume". This chimney-like shaft climbs to the surface through many miles of the crust. In the 1990's, satellite imaging revealed that both supervolcanoes were packing far more firepower than previously estimated.

In Yellowstone's case, the caldera is about three times the size of Manhattan. British geologist Bill McGuire first sounded the alarm publicly in a 2005 documentary produced by the BBC in London. That's when the USGS set up its 26 seismic stations, which are monitored by the Yellowstone Volcano Observatory in Utah. Even so, some experts question the equipment's ability to forecast an eruption in sufficient time to evacuate people for hundreds of miles.

In Apocalypse 2012, Joseph interviews University of Utah geologist Robert B. Smith, who has studied the Yellowstone caldera 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 BBC documentary, a key indicator of magma pushing towards the surface would be an increase in the number and frequency of earthquakes above the 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.

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.

In 1980, the Mammoth Lakes 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, leading the local chamber of commerce to file a lawsuit over the loss of 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.

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 two calderas along the Snake River Plain, known as Island Park and La Garita.

Volcano Survival 101 While lava and mud flows (called lahars) present life-threatening risks with any volcano, less talked about are the fast-moving pyroclastic flows. These dark plumes combine hot gases and solids heated to 1,300 degrees, moving at breakneck speeds in excess of 100 miles an hour across land and water. Nothing can outrun them, so the best evasive action is to get underground. In addition, river valleys and canyons provide a natural highway for mud flows, as evidenced in the dramatic footage of the Mt. Saint Helen's blast in 1980. Climbing up in elevation is critical to surviving these flows.

To predict the volatility of a typical cone-shaped, stratovolcano, geologists keep tabs on "lava bombs" thrown out from the spout in recent weeks or months. 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) offers another tell-tale clue about the disaster that may lie ahead. Runny lava, for instance, is common to Hawaiian volcanoes and indicates that the magma below the surface has a relatively easy time rising to the surface. Conversely, when the lava is thick like peanut butter -- volcanologists call it "blocky lava" -- it suggests that the lava inside the mountaing is getting plugged up near the surface. When such intense pressure reaches critical mass, the volcano will erupt in a huge, Krakatoa-like blast, hurling ash and gases for tens of miles in every direction.

Other threats associated with volcanoes (both super and strato) include inhaling high concentrations of sulphuric acid and carbon dioxide. While the smell the sulphur is easily detectable, CO2 is an odorless gas. Less lethal but still worrisome, 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 also be sufficient to cause its collapse.


TOPICS: Local News; Science; Weather; Weird Stuff
KEYWORDS: disaster; earthquakes; volcanoes; yellowstone
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To: spankalib

Sacrifice Viryins, why yes we can, my seester she viryin seex times already.........


61 posted on 04/13/2011 11:48:58 AM PDT by sniper63 (Endeavor to persevere, then go to war with 'em.....)
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To: 2ndDivisionVet

Article makes reference to New Mexico’s 175-square mile Valles Caldera and states that it is near Santa Fe. The truth is, it’s closer to Los Alamos with all it’s nuclear issues — past and present. Well — why not build the world’s biggest bomb factory atop a volcano?


62 posted on 04/13/2011 11:50:12 PM PDT by TiaS
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To: bt_dooftlook

The trees die because of oxygen starvation caused by higher levels of CO2.


63 posted on 04/13/2011 11:57:00 PM PDT by TiaS
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To: TiaS; All

Thanks for the response but I still need a better explanation. Trees consume CO2 and produce oxygen (in the process called photsynthesis); the carbon is used to build the cell walls of a growing tree. Can you tell me how something that doesn’t consume oxygen can be oxygen-starved? Thanks!


64 posted on 04/14/2011 10:19:14 AM PDT by bt_dooftlook (Democrats - the party of Amnesty, Abortion, and Adolescence)
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To: bt_dooftlook

The air we breathe is made up of several different gases. Two of those being, oxygen and CO2. It is the ratio of these gases in parts per million (PPM) that determines whether the CO2 is good for us or bad. When CO2 increases in relation to the other gases in the air we breath it creates the problem. The CO2, being a heavier gas, displaces the oxygen — people have been killed because of this. This is only my opinion and I have no scientific background, just an interest in the subject.


65 posted on 04/14/2011 10:38:36 AM PDT by TiaS
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