This is an extract of the article, with small photos. You will find the complete article with full-sized photos in my e-book View America: West Mountain - Part 1
In the travel series View America, West Mountain - Part 1 covers Montana and Wyoming. It is not a traditional travelogue, but a non-commercial and more or less objective chronicle of an in-depth exploration of these states. Each state is described with its own brief historical background and its main sights, tourist attractions and points of interest.
My book does not describe lodgings, restaurants or entertainment, except where these may interact with the narrative. It is illustrated with more than 150 full-sized photos.
In 1971 a paleontologist accidentally discovered the fossil bones of a large herd in Nebraska. The remains were dated to 10 million years ago and the animals were in the prime of their lives, so it was assumed that a natural phenomenon had been responsible for their death. All of the bones were affected by a disease, which according to further investigation was associated with volcanic ash.
However, the area of the discovery wasn't volcanic and no known volcano was situated in the immediate vicinity. Normally a volcano spews lava and ash during an eruption, and with violent outbursts this ash can be spread over a few hundred miles. Further investigation revealed that the only volcanic eruption around that time had been the Bruno Drawbridge, located in northern Idaho. But that location is about 1,000 miles (1,600 km) to the west.
Nevertheless this eruption and location were examined more intensively, and samples of soil and ash from all over America were compared. The astonishing results were that after this explosion about half of America had been covered with on average 6.5 feet (2 m) of ash!
Such a violent eruption was hundreds of times more violent than a "normal" volcanic eruption, and never had one been seen or recorded. A name for such an appalling phenomenon was soon found; this was a Supervolcano!
In a typical volcano magma pushes itself to the surface through a "chimney", usually after a landslide. Lava flows from the crater and gradually forms the volcano's typical conical mountain. At the same time volcanic ashes are thrown up by the gases from the magma, and escape in the air. With the Super Volcano everything is different.
Magma is still pushed to the surface through a chimney, but along the way it piles up in a huge chamber, deep under the surface. This "bubble" is gradually filled with liquid magma and super-hot gases. The "boiler" gradually reaches enormous pressure, and it slowly pushes up the mile-thick layer of earth above it.
After a break occurs in the earth layer, usually through an earthquake or a landslide, a rift is formed along which the entire contents of the chamber are explosively spewed out.
After the explosion there is no typical volcanic mountain left, but rather a major depression or subsidence of land, because the now empty chamber collapses under the weight of the overlying mass. Such a depression is called a Caldera.
Scientists now started investigating the entire earth's surface and they found traces of another "recent" Supervolcano, mount Toba in Sumatra, that exploded about 74,000 years ago.
In 1973 a geologist discovered that parts of Yellowstone National Park came under water, whereas previously they had been dry. This led to extensive measurements and these were compared with previous measurements from 1923. This in turn led to the discovery that one side of the lake had been pushed up for more than 2.5 feet (74 cm), which caused the lake to move and flood new sections.
This observation could be an indication that a magma chamber was being formed deep below the surface. In Yellowstone Park scientists now searched for the caldera that would have been formed after a previous eruption, but they only found it after the NASA provided special aircraft that took high-altitude photos of the area. Then the reason became immediately apparent why no caldera had ever been discovered. The elliptical depression of the caldera was 43.5 miles long by 18.6 miles wide (70 km by 30 km), or almost as large as the entire Yellowstone Park!
Samples of the ash layers in the soil were taken to date the eruption. To their great surprise the scientists found traces of not one but three super eruptions; respectively 2 million, 1.2 million, and 600,000 years ago. The eruptions at this location seemed to occur with a certain regularity at intervals of 600,000 to 800,000 years. And the last eruption dated from 600,000 years ago...
Several seismographs were installed and the shock waves from mild earthquakes were thoroughly examined. They effectively revealed the existence of a magma chamber at 5 miles (8 km) below the Earth's surface. Now things started to look grim and the entire area was re-examined meticulously with 22 seismographs, to obtain more information about this chamber.
Eventually its exact size could be determined: 31 miles long by 13.6 miles wide and 6.2 miles high (50 km long by 22 km wide and 10 km high)! This represents a tremendously powerful time bomb, with a content of more than 2,400 cubic miles (10,000 cubic km), located under about one third of the park.
By now the scientists were in shock, and they tried to calculate the potential power and impact of an eventual eruption. They visited the Greek island of Santarini where 3,500 years ago an eruption occurred, not really a supervolcano, but still with a small magma chamber. The pumice of this eruption included heavy boulders weighing dozens of tons, that had been blown away like pebbles...
In a laboratory in the U.K. a super eruption was imitated on a scale of one billionth. Volumes of acetone and pine resin were mixed in a flask, put under pressure and strongly heated. Acetone actually possesses many of the properties of volcanic gas, and pine resin shows a strong resemblance to magma.
When the mixture was heated the situation remained pretty much unchanged until the acetone suddenly ignited. It then worked as a detonator for the pine resin, which explosively expanded to a near-gas and caused a large mini eruption.
Armed with these scientific data they re-examined the supervolcano Toba in Sumatra to verify the effects of the eruption. The caldera that was formed after the eruption is 62 miles wide by 41 miles long (100 km wide by 67 km long). It was calculated that about 720 cubic miles (3,000 cubic km) of material were thrown up, and soil samples were found in the Indian Ocean with 1 foot (35 cm) of ash from this eruption, more than 1,500 miles away (2,500 km)!...
The eruption also propelled large quantities of sulfur dioxide in the atmosphere, which in turn caused a volcanic winter, and global temperatures dropped by five degrees Celsius!
By coincidence the results of this research came to the ears of any other scientific team that examines DNA worldwide and studies the changes through the generations. They specialize their research on the Mitochondria, the engines in our cells, that exist alongside the individual DNA. These Mitochondria are only passed on by the mother and they have their own genetic structure. The mutations of these genes are statistically very predictable and they can therefore display a sort of "time line" of the entire human race.
Oddly enough, this team had reached the strange conclusion that a gap existed in the diversity of these genes. Between 70,000 and 80,000 years ago the number of different genes had been reduced enormously, insofar that of the entire worldwide race of Homo Erectus during this period only 5,000 to 10,000 members remained.
Therefore there had to have been a natural disaster, which had nearly exterminated the entire human race. The two theories were combined in a startling statement, namely that the eruption of a supervolcano had nearly wiped out all human life! These are of course matters for scientific controversy.
Another team tried to mathematically calculate the effects of a super explosion of the Yellowstone magma bubble, based on the geological data. They reached the conservative conclusion that the explosion would spew out gas and ash between 24 and 31 miles high (40 and 50 km), and more than 620 miles (1,000 km) away.
Fortunately the area itself is sparsely populated, but still, tens of thousands of people would be killed by the eruption. Even worse news is that the extremely fertile Great Plains, which are not only North America's bread basket but also the rest of the world's basket, would entirely be covered with ashes, which would instantly kill all agricultural crops.
Furthermore, the enormous volume of ash in the atmosphere would cause a volcanic winter around the globe, and large parts of Europe would become infertile. The number of victims of such an enormous natural cataclysm cannot even approximately be estimated, especially since there are no scientific observations of such a phenomenon to base comparisons on.
The scientific teams gloomily came to the conclusion that a supervolcano eruption in Yellowstone is not a question of IF, but rather of WHEN...