Cosmic catastrophes may be even catastrophic

Widely known picture of the dinosaurs, from the fall of a large asteroid or comet to Earth near the Yucatan Peninsula in Central America (the photo does not it). Explosion, tsunami, fires and other amenities of a global catastrophe that is so fond of Hollywood. What do much rarer is that at about the same geological time, on the opposite side of the Earth begins catastrophic eruption of the volcano.

The eruption was the power with explosions disparate historical epoch. If "normal" eruption of a volcano, or generates a small island, the eruption 65 million years ago has given rise to a whole plateau, which now occupies about a third of the Indian subcontinent - Деканское.



Geological dating is always relative, so that "at about the same time" can be interpreted as ± 1 million years. And geologists are in no hurry to link these two events: a blow from space and the eruption on the back side of the planet. Usually say that killed the dinosaurs did not actually an asteroid, and climate change, which were caused by the eruption and the fall and.

UPD. The comments in LiveJournal indicated , that still Deccan Traps began to erupt before the fall of the asteroid on the other side Earth. i>

Examples of connection of heavy cosmic collisions and powerful eruptions can be found not only in the days of the dinosaurs, and not only on Earth. And recently, there were the first experimental confirmation.

To begin with examples.
At present, the largest asteroid crater confirmed - called astrobleme - the world is the African Вредефорт. Its diameter is about 300 km and can be considered even guglokartah.



So, diametrically opposite Vredefort object on the surface of the Earth is a chain of volcanoes in Hawaii.



There is still need to digress into the theory of volcanology. Today we know the two reasons for the formation of volcanoes: субдукция and mantle plume.

Subduction - a meeting of tectonic plates. They are heated by friction and melted rock looking for a way to the surface. Since forming, for example volcanoes of the Pacific Ring of Fire: Indonesia, Filipino, Japanese, Kuril Islands, Kamchatka.



The second reason: the so-called "Mantle plume" or "hot spot." Under this term refers to a hot jet of mantle material, which breaks up almost from the very core of the planet. In this case, the jet has one point, and if over her moving continental plates of the earth's crust, it formed a whole chain of volcanoes, which differ from each other by their age. Thus, at the time Hawaii became evidence of continental drift. I've seen research that such a chain of volcanoes was once in Karelia, but almost wiped out after so many years. There was one Girvas . The truth now appear hypothesis that the very hot spot can also "travel", while opposition Vredefort / Hawaii is random.

Supervolcanoes Mars, unrivaled throughout the solar system, there were just over a hot spot. By the time of their formation on Mars there was no movement of the continents, so hot spots found only one way out, and formed many kilometers stratovolcano.



It can be found on Mars, the most convincing hypothesis of the occurrence of hot spots in the opposite direction from the asteroid impact site.

The most obvious example - Tharsis volcanic plateau, which is directly opposite the largest astrobleme solar system - Valley Hellas. Diameter of Hellas about 2, 5 thousand. Km, 9 km depth. It is possible that this large-scale strike and was involved in the formation of Valles Marineris, which is adjacent to the Tharsis.

Another notable pair crater / volcano - a valley Argir, which is opposed to the volcanic highlands of Elysium. There, too: the second largest crater of Mars, and the second largest Highlands, even though it is much smaller Hellas.



All of the above - known, in principle, a fact that many have noticed, but to bring them under a rigorous mathematical justification nobody could. Therefore, major communication astroblems and mantle plumes is still a guess, no convincing scientific argumentation.

Only recently have additional evidence for the hypothesis. American scientists have modeled hitting small but fast body for the larger.



At the stand of NASA Ames Vertical Gun Range glass pellet dispersed up to speed about 7 km / s (up to 10 times faster than a bullet, but 2 times slower than the average of the asteroid). The shot struck transparent acrylic sphere, and scientists have been studying the damage.

In general, this study focused on the physics of the formation of relief planetoid Vesta, so scientists were limited to a homogeneous sphere. The planet will be much harder on the device - for reliable modeling will have to add the core and crust. But even in a plastic bowl, with a powerful blow, much distortion of the structure in the opposite area from the point of impact. Even though the pellet that flew at an angle 47 degrees (direction indicated by the arrow).



large size .

Further numerical modeling allowed us to obtain a mathematical model of the impact, the most appropriate to the experimental results.



It seems that a powerful blow to the area forms the back of the dynamic effects of the response zone. The shock wave radiating from the crater, converges on the opposite side of the planet. There is increased pressure that can warm mantle material, and it fixed up, breaking the volcano.

Thus, it appears that the risk of falling from a large body of space can lead to much more serious consequences than a single Badabum. On the other hand, if the hypothesis is true, then we can relax a little in anticipation of catastrophic eruptions Yellowstone caldera and the like. If the reverse side will not come anything speed and massive, the danger of the destruction of human civilization declines. The main thing to look around and do not miss the bus the next visitor from outer space.

Source: geektimes.ru/post/245220/