American scientists, it seems, once again prophesied end of the world. Well, maybe not the whole world, but only one part of it, briefly referred to as the United States. According to calculations by volcanologists giant ancient volcano, the ruins of which is now Yellowstone National Park, once again begins to show signs of activity. This is evidenced by the fact that the measuring device rate of uplift of ground in the vicinity of the ancient fire-breathing monster in the last three years has tripled.
But seismologists are somewhat suspicious of surveying colleagues and hasten to reassure frightened locals. According to them, afraid of a new eruption is not necessary, because the seismic activity, by contrast, fell. So, what is called, Diamond cut diamond — the volcano while keeping silent, and representatives of two related scientific disciplines are ready shlestnutsya each other. Who in the end is right — monitors volcanoes or earthquakes predictors?
In fact, the accuracy of forecasts of both, rather doubtful. The fact that the study of the underlying processes in the interior of the Earth's crust and mantle, on which the "sleep" or "wake-up" Volcanoes are still being exclusively using seismic measurements. Sensitive instruments record every slightest hesitation, the scientists begin to wrestle with the question: what does it mean? In the end, the same result of the seismograph can be interpreted in very different ways.
In addition, such a thing as a prediction of a geological event, most often done on the basis of building a computer model of the processes. Well, and the accuracy of these models — you know what, after all, even the most powerful computers are able to analyze the impact on two or three factors, but in fact there are dozens, if not hundreds. A similar analysis with no computer can handle.
However, let's look at the picture painted by volcanologists. Many years of measurements show that the rate of uplift giant volcanic caldera (depressions formed at the site destroyed by the volcanic eruption) in Yellowstone National Park in mid-2004 began to increase sharply. These data were published in the latest issue of the journal Science, and immediately caused panic among nonspecialists.
By the way, the data collection was very thorough. In their studies, researchers used data from Utah global satellite navigation system GPS, and radar measurements from aboard one of Europe's satellite mapping. According to them, the rate of uplift of soil has now reached seven centimeters a year, more than three times the average.
In addition, computer simulation disturbance source allows scientists to suggest a gradual expansion of the base in the underground supervolcano, is now about 1,200 square kilometers. Interestingly, this bottom section, located at a depth of ten kilometers, equal to magmennoy cavity (vug filled with hot magma) in the earth's crust, discovered using seismic measurements. According to the calculations of American experts, the volume of hot material at the base increased at a rate of about 0.1 cubic kilometers a year. This is consistent with counting the number of magma required to recharge the troubled area of seismic warmth.
Based on this, the researchers believe that the main driving force for raising the earth's crust in a given location is the natural circulation of hot and cold layers of lava. However, one can not exclude the possibility of increasing the power flow of hot magma, fueled volcanic zone. Similar phenomena have often said that in the near future volcano can awaken.
Volcanologists joke that currently follow the Yellowstone — all like being in a cage with a sleeping tiger, every new movement which makes tremble. However, in this case, they realize the causes of these strange natural phenomena. In their view, the acceleration of the earth's crust caused by the raising of the changes that have occurred in the deep structure, the so-called hot spots — fixed portion of the mantle (the layer that lies beneath the earth's crust), in which the rise of hot magma. And it often happens before awakening the fire-breathing monster.
It should be noted that the volcano attracts the attention of scientists for a long time. Detailed studies of the Yellowstone Park, famous primarily for its geysers, began in the mid-twentieth century. Even then, scientists have come to the conclusion that his giant caldera (70 to 30 kilometers) is clearly of volcanic origin. Of course, the mind refused to believe in the existence of volcanoes such size needed so many years of research and theoretical developments, before operating model was developed Yellowstone giant.
In the course they became known that the last three of the giant eruption occurred two million years ago, 1.3 million years ago and 630,000 years ago. Thus, we can conclude that they are more or less periodic and the period is about 650,000 years. This means that before the next eruption left quite a bit of time (say, the geological clock) — only some … 20,000 years.
And geologists have found that the last eruption of Yellowstone supervolcano has gone quite rapidly. The explosion released the 250 cubic kilometers of dust, rocks and ash that covered most of the western slope of the mountain in a layer thickness of 20 meters, and left a crater, which these days is a huge lake of Yellowstone. The total area of the geological tumors exceeded 2,400 square kilometers.
Not surprisingly, the predictions about what will happen to the U.S. as a result of the eruption of a new, very disappointing. Scientists say that the events will unfold as the explosion of a huge bomb. In just a few minutes instead of the park formed a huge crater and die hundreds of thousands of people, many suffocated by a cloud of poisonous gas, which will fly to the surface with lava. In the atmosphere would break a few thousand cubic miles of ash and ash, which for a couple of hours cover the entire western United States. In addition, a half meter layer of ground pumice hide under a street in Los Angeles and San Francisco. As a result, all traffic stops, a part of the country is cut off from the outside world.
However, experts believe that the most ruinous to the people will be released into the atmosphere of the smallest particles. Mass of ash blocks the sunlight. This threatens the so-called "volcanic winter" — climate change, for which the average temperature at the Earth's surface will not exceed -25 ° C. And though this winter will last a maximum of one and a half years, according to environmentalists, it can lead to a drastic reduction in the number of plants (which can not photosynthesize) and, accordingly, the loss of hunger eating their animals and people.
However, this scenario is actually also nothing more than a model. In fact, humanity has never seen this disaster, so to say exactly what will happen, no one can. Similarly, it is not clear when should wait awakening volcano.
Mathematics on the basis of new data with the help of computers found that the eruption should be expected in 2075. But after a while it became clear that things are moving much faster. The result had to be adjusted, and the terrible date approached. It turns out that the volcano wakes up between 2012, and 2016, the first digit, according to analysts, it looks likely.
However, many seismologists believe that all these conclusions are subjective and hasty. Some even say that this is an example of unscrupulous research which aims specifically to spread panic among the people, in order to knock out of the budget in new grants "prevent disaster" (according to the scenario of the notorious "2000 Problem"). According to them, at the present time there are no seismic eruption premises. In fact, the number of tremors in the valley cut by half: Scientists have recorded at least a thousand concussions last year, but usually there are more than two thousand.
According to David Hill of the U.S. Geological Survey, itself accelerated swelling of land is not a reason for concern. He gives the example of a situation with another sleeping giant volcano whose activity at the time formed the California Valley Long Valley. Observations of them has been going on for years, as well as for his fellow Yellowstone. For the six months of 1997, the soil in the crater up to ten centimeters, which was accompanied by a mass of earthquakes, but then the situation has stabilized, and so far the volcano is calm.
So, who is right — seismologists or volcanologists? Unfortunately, the exact answer to this question can only give time. However, the "warring parties" agree on one thing — the study of Yellowstone supervolcano should continue. Because they can help to understand the processes that control the highly active seismic zones in the Earth's surface.