A super-eruption in North America - a threat to the United States or a catastrophe on a terrestrial scale, promising a disaster for the entire northern hemisphere?
Viral news that "we are all about to die" from the eruption of the Yellowstone supervolcano shakes the World Wide Web every few years. However, as a more balanced analysis of geologists suggests, in reality this is almost always a false alarm. Today it is impossible to say confidently that a supervolcano may explode at any particular time. Only recently have geologists discovered "heavy breathing," a slight fluctuation in the level of the Yellowstone Caldera (volcano basin). There is still debate about the significance of this phenomenon: can it be used to predict the activity of a volcano? Modern monitoring methods are still making their first steps even in the field of predicting ordinary earthquakes. Super-eruptions of the Yellowstone type are fundamentally stronger and less frequent. Therefore, humanity simply does not have the experience of observing them live. The first people who survived many such eruptions were illiterate and did not leave any seismological observations. So what is the correct answer to the question "When will Yellowstone explode?" there will be not “Tomorrow or in a year”, but “We do not know” and “At any moment”.
Catastrophe
What could be the consequences of the awakening of the Yellowstone supervolcano? For a better understanding of the scale of such an event, it is worth looking at the latest super-eruption in the region. It is known as "Lava Creek" and happened 630,000 years ago. According to modern data, emissions then reached at least 1000 cubic kilometers (many billions of tons) of ash and an unknown amount of sulfur dioxide.
Solid emissions have covered an area from the Gulf of Mexico in the east to the Pacific Ocean in the west. And the ashes lay from the south of modern Canada to the north of Mexico. It is easy to see that this is the main part of the territory of today's USA, which in a future eruption will automatically take the first and most powerful blow. The release of ash can be very dangerous - its thickness after "Lava Creek" on the surface of the earth reached 180-200 meters. Although this was not the case everywhere, nevertheless the layer was thick enough to destroy all life at least in an area of hundreds of thousands of square kilometers. At the same time, the ash did not fall out at lightning speed: according to modern views, "black snow" after a super-eruption can go for a whole day. However, any living being must sometimes stop to sleep. Often such a stop in conditions of constantly falling ash from above can be his last.
The last danger? Not yet: near the Yellowstone Caldera, all the above problems will not bother anyone. The American Geological Survey claims that an eruption of this kind will be accompanied by a large-scale release of lava. The only question is whether the lava will spread 10 or 30 kilometers away from the caldera. Individual spills of the last hundreds of thousands of years covered up to 340 square kilometers at a time (the area of Moscow is just over 2500). In the zone of lava fields, everything and everyone will simply burn out, so ash and other things there will not be a relevant threat at all. American researchers console: the ash will most likely slightly affect California and Florida and thus spare two important centers of US agricultural production. One trouble - if the main part of the country is covered with many meters of ash deposits,feeding them with a couple of granary states will be very difficult. And even if something grows there, there is a chance that the food will not reach anywhere. Ash blocks railways and highways, and air transport will not be able to fly in the above-mentioned region for a long time.
Promotional video:
Judging by the experience of the incomparably smaller volcano Eyjafjallajökull, ash easily destroys the turbines of airliners, and all air routes near the active volcano will be closed for a long time. This alone will create a transport collapse unimaginable for the modern world. Today, in the event of a disaster like the New Orleans (Hurricane Katrina), you can send the army and the National Guard with military vehicles - but in the event of the Yellowstone aftermath, such an opportunity will simply be absent. Neither evacuating nor delivering food and water to disaster sites, as a rule, will simply work.
It is easy to understand the scale of the disaster by just one comparison. Calculations show that during a nuclear war, up to 5 tons of dust and soot will enter the atmosphere per ton of TNT. This means that even with the full expenditure of all nuclear warheads, less will rise into the air than Yellowstone raised 630,000 years ago.
What are those Poles to us?
Of course, you can console yourself with the fact that lava (for sure) and ash (with some probability) will not reach the territory of Russia. Although the ashes of the supervolcano Toba (Indonesia) at one time even reached the lakes of East Africa, where its traces were recently discovered by geologists. So the echo from the American ashes may well reach Russia. However, he is unlikely to bother any of its inhabitants. After all, they will have more urgent reasons to think.
Geophysicist Viktor Bokov from the Russian State Hydrometeorological University, in a comment to Life, noted that after such an event, billions of tons of raised ash will inevitably rise into the stratosphere. There, as the scientist notes, jet streams blow at speeds up to 200 kilometers per hour. In the atmosphere over the northern hemisphere, westerly transport prevails, so some of the emissions from Yellowstone is quite capable of reaching a number of regions of our country.
More importantly, the aerosols generated by the ash (as well as sulfur dioxide) will reflect a significant percentage of solar radiation, causing a global cooling. Without knowing the strength of the future super-eruption, it is impossible to predict the scale of a volcanic winter for sure. For Russia, it will be about reducing the average annual temperature by several degrees. At first glance, this is not much. However, upon closer examination, it becomes clear that for us the possible disaster will be colossal in scale. In Moscow (now there is an average annual + 4.1 degrees Celsius) or Penza, the climate for years will be the same as in Murmansk (+0.2). Not only the middle zone, but also the main part of the Chernozem region in terms of temperatures will become similar to the forest tundra of the Kola Peninsula. Of courseagriculture in the usual sense of the word will simply stop here - potatoes and wheat do not grow in the tundra. Plants will not have enough heat to grow.
According to Viktor Bokov, the ancient Russian chronicles have already recorded similar isolated climatic problems in the past of our country - up to the XII century. Then they were accompanied by a catastrophic famine. However, the Yellowstone scenario is especially grave because volcanic aerosols will not leave the atmosphere in a year or two. Depending on the strength of the Yellowstone super-eruption, they will spend several years or even a decade there. A drop in temperature in terrestrial conditions will lead to a significant decrease in evaporation - and rainfall. Even where it will be slightly warmer than now in Murmansk, a prolonged drought may occur.
All this means that crop failures will not only be total, but also long-term. Something can grow only in regions like Crimea and Kuban (unless, of course, precipitation disappears there). But these will not be food crops that are usual for these places, but those that usually grow hundreds and thousands of kilometers to the north. And it won't be so easy to feed the whole country from the Kuban patch. Due to the global nature of the catastrophe, one should not rely on international assistance - the whole world will be faced with the prospect of hunger. There are simply no countries on the planet that have food reserves equal to 5-10 years of their own consumption. It is far from the fact that many will be able to avoid depopulation as a result of starvation.
About good
However, both domestic and American scientists insist that the scope of the future catastrophe will still be relatively moderate. The extinction of the human species as a whole from one super-eruption certainly does not threaten us. As noted by Jamie Farrell, renowned Yellowstone scholar at the University of Utah, “We almost certainly won't die out entirely from [future] Yellowstone eruptions. There have been super-eruptions over the past couple of million years, but we are still here. " Indeed, this supervolcano 630,000 years ago did not kill our elder relatives, Homo erectus.
At the same time, the resort is still not worth waiting for. The super-eruption of Toba volcano 70,000 years ago coincides in time with the sudden extinction of all Homo sapiens who managed to reach Asia. They survived only in Africa, but their number dropped tenfold. 40 thousand years ago, a super-eruption in the Phlegraean Fields (Italy) temporarily covered the space from modern Naples to Donbass with ash. For a long time, all traces of both humans and Neanderthals disappeared in this part of Europe. And at the same time, on a global scale, complete extinction did not happen - just a sharp decline in numbers. If hunters and gatherers dressed in skins were able to survive despite the sharp deterioration of the climate and the mass death of animals, then we, their descendants, also have some chances of survival.
When will the thunder break out?
Is it possible to find out exactly when to dig a cellar in the yard and get ready to speculate with stew? Alas, the current state of volcanology does not allow making an accurate forecast of this kind. According to Viktor Bokov, popular attempts to designate the frequency of super-eruptions have little to do with science. “When they say that super-eruptions happen every 50,000-100,000 years, we are talking about extremely rough assumptions,” he notes. The only thing is true, the scientist concludes, that the longer this or that supervolcano has not erupted, the higher the probability of its super-eruption in the future.
Sometimes American experts allow themselves to make more confident statements. Peter Cervelli of the US Department of Internal Affairs' Geology, Survey and Cartography Service believes the Yellowstone super-eruption will not happen "in the next 10,000 years." True, and he immediately makes a reservation: "We are always ready for surprises [in this regard] and do not declare that we fully understand everything connected with this." However, geologists from the area of a future earthquake often tend to make politically motivated reassuring statements, which then turn out to be overly optimistic. Similar forecasts by Italian geologists in 2009 led to an increase in the number of victims of the earthquake in L'Aquila. In our country, most experts doubt the idea of a possible in advance accurate prediction of how long we will have to wait for the next event of this kind.
True, Viktor Bokov notes, volcanology can indicate a situation in which the likelihood of a super-eruption will increase significantly. In Yellowstone's case, nuclear war may well be its trigger. As you know, the United States is a priority target for a significant number of nuclear warheads. One of them can explode near the Yellowstone Caldera and accidentally provoke the beginning of such a catastrophe. Moreover, as mentioned above, the cooling effect of Yellowstone for the planetary climate itself may not be weaker than that of a nuclear war. Thus, humanity in this case will face a catastrophe of double dimensions.
At the same time, Viktor Bokov notes, attempts to deliberately provoke supervolcanoes with nuclear weapons are in themselves ineffective. Indeed, in order to guarantee the launch of an eruption, it is necessary to understand exactly how shock waves from nuclear explosions will propagate in the upper layers of the mantle and where exactly they will come. And our planet is a non-stationary object, it changes slightly all the time, its crust is subject to constant small movements, the geophysicist states. It is impossible to accurately predict the consequences of a hypothetical provocative nuclear strike. Therefore, it is impossible to blow up Yellowstone as planned - only by accident.
To summarize: although the American volcano seems far from the problems of our country, in fact, its muzzle is set to the head of humanity as a whole. And even if it is beyond his powers to inflict a mortal wound, this threat is comparable in severity to a nuclear war. The situation is aggravated by the fact that if the government of a number of countries is at least theoretically preparing for the latter, then the supervolcano does not affect state planning and the accumulation of reserves in case of an emergency. Without any major breakthrough in volcanology, all that scientists can say so far about the timing of this event is that sooner or later it will inevitably happen. And given the absence of a specific timeframe to take preventive measures, we may be completely defenseless in front of him.
