The ancient Chicxulub meteorite crater was discovered by accident in 1978 during a geophysical expedition organized by Pemex (Petroleum Mexicana) to search for oil deposits at the bottom of the Gulf of Mexico. Geophysicists Antonio Camargo and Glen Penfield first discovered an incredibly symmetrical 70-kilometer underwater arc, then examined a gravity map of the area and found a continuation of the arc on land - near the village of Chicxulub (“tick demon” in the Mayan language) in the northwestern part of the peninsula. Having closed, these arcs formed a circle with a diameter of about 180 km. Penfield immediately hypothesized the impact origin of this unique geological structure: this idea was suggested by the gravitational anomaly inside the crater, the samples he discovered of “impact quartz” with a compressed molecular structure and glassy tektites, which form only under extreme temperatures and pressures. Alan Hildebrant, a professor at the Department of Earth Sciences at the University of Calgary, managed to scientifically prove that a meteorite with a diameter of at least 10 km fell in this place in 1980.
In parallel, the question of the supposed fall of a giant meteorite to Earth at the Cretaceous-Paleozoic boundary (about 65 million years ago) was studied by Nobel laureate in physics Luis Alvarez and his son geologist Walter Alvarez from the University of California, who, based on the presence of an abnormally high content of iridium in the soil layer of that period ( extraterrestrial origin) suggested that the fall of such a meteorite could have caused the extinction of the dinosaurs. This version is not generally accepted, but is considered quite probable. During that period, rich in natural disasters, the Earth was subjected to a series of meteorite impacts (including the meteorite that left the 24-kilometer Boltysh crater in Ukraine), but Chicxulub seemed to surpass all others in scale and consequences. The fall of the Chicxulub meteorite affected life on Earth more seriously than any of the strongest volcanic eruptions known today. The destructive force of its impact was millions of times greater than the force of the atomic bomb explosion over Hiroshima. A column of dust, rock fragments, and soot shot up into the sky (the forests were burning), hiding the sun for a long time; the shock wave circled the planet several times, causing a series of earthquakes, volcanic eruptions and tsunamis 50-100 m high. The nuclear winter with acid rain, destructive for almost half of the species diversity, lasted several years... Before this global catastrophe, dinosaurs, marine plesiosaurs, and mosasaurs reigned on our planet and flying pterosaurs, and then - not immediately, but in a short time, almost all of them became extinct (Cretaceous-Paleogene crisis), freeing up an ecological niche for mammals and birds.
Before the discovery in 1978, the area around the Mexican village of Chicxulub in the northwest of the Yucatan Peninsula was famous only for its abundance of ticks. The fact that it is here that a 180-kilometer meteorite crater lies half on land and half under the water of the bay is completely impossible to determine by eye. Nevertheless, the results of chemical analyzes of the soil under the sedimentary rocks, the gravitational anomaly of the place and detailed photography from space leave no doubt: a huge meteorite fell here.
Now the Chicxulub crater is being intensively studied by scientists from literally all sides, that is, from above - from space, and from below - using deep drilling.
On a gravity map, the impact zone of the Chicxulub meteorite appears broadly as two yellow-red rings on a blue-green background. On such maps, a gradation from cold to warm colors means an increase in the force of gravity: green and blue show areas with reduced gravity, yellow and red - areas with increased gravity. The smaller ring is the epicenter of the impact, which occurred in the vicinity of the current village of Chicxulub, and the larger ring, covering not only the north-west of the Yucatan Peninsula, but also the bottom within a radius of 90 km, is the edge of the meteorite crater. It is noteworthy that a strip of cenotes (sinkholes with underground freshwater lakes) in the north-west of Yucatan almost coincides with the explosion, with the largest accumulation in the eastern part of the circle and individual cenotes outside. Geologically, this can be explained by the filling of the crater with limestone deposits up to a kilometer thick. The processes of destruction and erosion of limestone rocks caused the formation of voids and drainage wells with fresh underground lakes at the bottom. The cenotes on the outside of the ring probably arose from the impact of meteorite fragments thrown outside the crater by the explosion during the fall. Cenotes (not counting the rains, this is the only source of drinking water on the peninsula, so Mayan-Toltec cities later grew up near them) are conventionally designated as white dots on the gravity map. But there are no more blank spots left on the map of Yucatan: in 2003, the results of space photography of the crater surface, taken by the Endeavor shuttle back in February 2000, were published (American astronauts were interested not only in Yucatan: in addition to the volumetric space survey of Chicxulub from the shuttle in During NASA's 11-day radar topography mission, 80% of the earth's surface was surveyed).
In photographs taken from space, the boundary of the Chicxulub crater is clearly visible. For this purpose, the images underwent special computer processing, which “cleaned off” the surface layers of sediment. The space image even shows a trace of the fall in the form of a “tail,” from which it was determined that the meteorite approached the Earth at a low angle from the southeast, moving at a speed of approximately 30 km/sec. At a distance of up to 150 km from the epicenter, secondary craters are visible. Probably, immediately after the meteorite fell, a ring-shaped ridge several kilometers high rose up around the main crater, but the ridge quickly collapsed, causing strong earthquakes, and this led to the formation of secondary craters.
In addition to space exploration, scientists have begun in-depth research of the Chicxulub crater: it is planned to drill three wells with a depth of 700 m to 1.5 km. This will make it possible to restore the original geometry of the crater, and chemical analysis of rock samples taken at the depth of the wells will make it possible to determine the scale of that distant environmental disaster.
general information
Ancient meteorite crater.Location: in the northwest of the Yucatan Peninsula and at the bottom of the Gulf of Mexico.
Date of meteorite fall: 65 million years ago.
Administrative affiliation of the crater: Yucatan state, Mexico.
The largest settlement on the crater territory: state capital city - 1,955,577 people. (2010).
Languages: Spanish (official), Mayan (language of the Mayan Indians).
Ethnic composition: Mayan Indians and mestizos.
Religion: Catholicism (majority).
Currency unit: Mexican Peso.
Water sources: natural wells cenotes (water from an underground karst lake).
Nearest airport: Manuel Cressencio Rejon International Airport, Merida.
Numbers
Crater diameter: 180 km.Meteorite diameter: 10-11 km.
Crater depth: not exactly clear, presumably up to 16 km.
Impact energy: 5×10 23 joules or 100 teratons of TNT equivalent.
Tsunami wave height(estimated): 50-100 m.
Climate and weather
Tropical.Dry, very hot, woodlands and xerophytic shrubs predominate.
Average January temperature: +23°С.
Average temperature in July: +28°С.
Average annual precipitation: 1500-1800 mm.
Economy
Industry: forestry (cedar), food, tobacco, textile.Agriculture: farms grow henequin agave, corn, citrus fruits and other fruits and vegetables; Breeding cattle; beekeeping.
Fishing.
Service sector: financial, trade, tourism.
Attractions
■ Natural: Cenote area.■ Cultural-historical: ruins of Mayan-Toltec cities in the cenote zone: Mayapan, Uxmal, Itzmal, etc. (Merida is a modern city on the ruins of an ancient one).
Curious facts
■ The ancient cities of the Mayans and the Toltecs who conquered them were built near the cenotes. It is known that some of these cenotes (the most important one in Chichen Itza) were sacred to the Maya-Toltec civilization. Through the “eye of god” the Indian priests communicated with the gods, and they threw human sacrifices into it.■ Even before the discovery of the Chicxulub meteorite crater, the scientific community in the late 1970s was developing a theory about the extraterrestrial (meteorite) origin of the Cretaceous-Paleogene crisis, which led to the death of the dinosaurs. Thus, father and son Alvarez (physicist and geologist), successively analyzing the composition of the soil in an archaeological section taken in Mexico, discovered in a clay layer aged 65 million years an abnormally increased (15 times) concentration of iridium - a rare element for the Earth, typical of a certain species asteroids. After the discovery of the Chicxulub crater, it would seem that their guesses were confirmed. However, similar studies of soil sections in Italy, Denmark and New Zealand showed that in a layer of the same age the iridium concentration also exceeds the nominal one - 30, 160 and 20 times, respectively! This proves that perhaps a meteor shower occurred over the Earth at that time.
■ In the first week after the meteorite fell, scientists believe that the fewest and most vulnerable species, already in danger of extinction, died out - the last of the giant sauropods and apex predators. Due to acid rain and lack of light, some plant species began to die out, the photosynthesis process of the remaining ones slowed down, as a result there was a lack of oxygen and a second wave of extinction began... It took thousands of years for the ecological balance to be restored.
Our beloved blue planet is constantly being hit by space debris, but due to the fact that most space objects burn up or fall apart in the atmosphere, this most often does not pose any serious problems. Even if an object reaches the surface of the planet, it is most often small, and the damage it causes is insignificant.
However, of course, there are very rare cases when something very large flies through the atmosphere, and in this case very significant damage is caused. Fortunately, such falls are extremely rare, but it’s worth knowing about them, if only to remember that there are forces in the Universe that can disrupt people’s everyday lives in a couple of minutes. Where and when did these monsters fall to Earth? Let's look at the geological records and find out:
10. Barringer Crater, Arizona, USA
Arizona apparently couldn't get enough of the Grand Canyon, so about 50,000 years ago it added another tourist attraction when a 50-meter meteorite landed in the northern desert, leaving behind a crater 1,200 meters in diameter and deep. at 180 meters. Scientists believe that the meteorite that created the crater flew at a speed of about 55 thousand kilometers per hour, and caused an explosion about 150 times more powerful than the atomic bomb dropped on Hiroshima. Some scientists initially doubted that the crater was formed by a meteorite, since there is no meteorite itself, but according to modern scientists, the stone simply melted during the explosion, spreading molten nickel and iron throughout the surrounding area.
Although its diameter is not that large, its lack of erosion makes it an impressive sight. Moreover, it is one of the few meteorite craters that look true to its origin, making it a top-notch tourist destination - just as the Universe intended.
9. Lake Bosumtwi Crater, Ghana 
When someone discovers a natural lake whose outline is almost perfectly round, it is quite suspicious. This is exactly what Lake Bosumtwi is, with a diameter of about 10 kilometers and located 30 kilometers southeast of Kumasi, Ghana. The crater was formed by a collision with a meteorite with a diameter of about 500 meters, which fell to Earth about 1.3 million years ago. Attempts to study the crater in detail are quite difficult, since the lake is difficult to reach, it is surrounded by dense forest, and the local Ashanti people consider it a holy place (they believe that touching the water with iron or using metal boats is prohibited, making access to nickel at the bottom of the lake is problematic). Still, this is one of the best-preserved craters on the planet today, and a good example of the destructive power of megarocks from space.
8. Mistastin Lake, Labrador, Canada 
The Mistatin impact crater, located in the Labrador province of Canada, is an impressive 17 by 11 kilometer depression in the earth that formed approximately 38 million years ago. The crater was likely originally much larger, but has shrunk over time due to the erosion it has suffered from the many glaciers that have passed through Canada over the past millions of years. This crater is unique in that, unlike most impact craters, it is elliptical in shape rather than circular, indicating that the meteorite fell at an acute angle rather than flat, as is the case with most meteorite impacts. Even more unusual is the fact that in the middle of the lake there is a small island that may be the central rise of the complex structure of the crater.
7. Gosses Bluff, Northern Territory, Australia
This 142-million-year-old crater with a diameter of 22 kilometers, located in the center of Australia, is an impressive sight from both the air and the ground. The crater was formed by the impact of an asteroid with a diameter of 22 kilometers, which crashed into the Earth's surface at a speed of 65,000 kilometers per hour and created a crater almost 5 kilometers deep. The energy of the collision was approximately 10 to the twentieth power of Joules, so life on the continent faced great problems after this collision. The highly deformed crater is one of the most significant impact craters in the world and never lets us forget the power of one large rock.
6. Clearwater Lakes, Quebec, Canada 
Finding one impact crater is cool, but finding two impact craters next to each other is doubly cool. That's what happened when the asteroid broke into two pieces as it entered Earth's atmosphere 290 million years ago, creating two impact craters on the eastern shore of Hudson Bay. Since then, erosion and glaciers have greatly eroded the original craters, but what remains is still an impressive sight. The diameter of one lake is 36 kilometers, and the second is about 26 kilometers. Considering that the craters were formed 290 million years ago and were subject to severe erosion, one can only imagine how large they were originally.
5. Tunguska meteorite, Siberia, Russia
This is a controversial point, since no parts of the hypothetical meteorite remain, and what exactly fell into Siberia 105 years ago is not entirely clear. The only thing that can be said with certainty is that something large and moving at high speed exploded near the Tunguska River in June 1908, leaving behind fallen trees over an area of 2000 square kilometers. The explosion was so strong that it was recorded by instruments even in the UK.
Because no pieces of meteorite were found, some believe that the object may not have been a meteorite at all, but a small part of a comet (which, if true, would explain the lack of meteorite debris). Conspiracy fans believe that an alien spaceship actually exploded here. Although this theory is completely unfounded and pure speculation, we must admit that it sounds interesting.
4. Manicouagan Crater, Canada 
Manicouagan Reservoir, also known as the "Eye of Quebec", is located in a crater formed 212 million years ago when an asteroid with a diameter of 5 kilometers fell to Earth. The crater with an area of 100 kilometers, which remained after the fall, was destroyed by glaciers and other erosive processes, but at the moment it remains an impressive sight. What is unique about this crater is that nature did not fill it with water, forming an almost perfectly round lake - the crater basically remained dry land, surrounded by a ring of water. A great place to build a castle here.
3. Sudbury Crater, Ontario, Canada 
Apparently, Canada and impact craters are very fond of each other. Singer Alanis Morrisette's birthplace is a favorite place for meteorite impacts - the largest meteorite crater in Canada is located near Sudbury, Ontario. This crater is already 1.85 billion years old, and its dimensions are 65 kilometers long, 25 wide and 14 deep - it is home to 162 thousand people, and is also home to many mining enterprises, which discovered a century ago that the crater is very rich in nickel. for a fallen asteroid. The crater is so rich in this element that about 10% of the world's nickel production comes from here.
2. Chicxulub Crater, Mexico
The impact of this meteorite may have caused the extinction of the dinosaurs, but it is certainly the most powerful asteroid collision in the entire history of the Earth. The impact occurred approximately 65 million years ago when an asteroid the size of a small city crashed into Earth with an energy of 100 teratons of TNT. For those who like precise data, this is approximately 1 billion kilotons. Compare this energy to the atomic bomb dropped on Hiroshima, with a yield of 20 kilotons, and the impact of this collision becomes clearer.
The impact not only created a crater 168 kilometers in diameter, but also caused megatsunamis, earthquakes and volcanic eruptions across the Earth, greatly altering the environment and dooming the dinosaurs (and apparently many other creatures). This vast crater, located on the Yucatan Peninsula near the village of Chicxulub (from which the crater gets its name), can only be seen from space, which is why scientists discovered it relatively recently.
1. Vredefort Dome, South Africa
Although the Chicxulub crater is better known, compared to the 300-kilometer-wide Vredefort Crater in South Africa, it is an ordinary pothole. Vredefort is currently the largest impact crater on Earth. Fortunately, the meteorite/asteroid that fell 2 billion years ago (its diameter was about 10 kilometers) did not cause significant harm to life on Earth, since multicellular organisms did not yet exist at that time. The collision undoubtedly greatly changed the Earth's climate, but no one noticed it.
At the moment, the original crater is heavily eroded, but from space its remains look impressive and are a great visual example of how scary the Universe can be.
Location of Chicxulub - Yucotan, Mexico. The largest historical asteroid crater on Earth.
Researchers from the University of Glasgow examined soil samples and determined its age at 66,038,000 ± 11,000 years. Today it is the largest known crater. This period coincides with the period of extinction of dinosaurs, but it is still premature to say 100% that dinosaurs became extinct only due to the effects of the consequences of an asteroid collision with the Earth, since there are theories that claim that dinosaurs by species began to decline even before the asteroid collision, although the consequences collisions became a powerful factor in changing all life on Earth.
The crater was discovered by geophysicist Antonio Camargo and Glend Penfield while they were searching for oil in the Yucatan Peninsula in the late 1970s.
Penfield was unable to prove that the geological feature was an asteroid crater and abandoned further research in this area.
In 1990, Penfield obtained soil samples that proved that there was external influence at this site. Evidence of the impact origin of the crater includes altered quartz with a gravity anomaly, as well as tektites in the surrounding areas.
Traces of the visible boundaries of the crater have not been preserved to this day. If you look at the gravitational map, there are anomalies in the form of a ring, which is one of the proofs of external influence.
In 1978, geophysicists Antonio Camargo and Glen Penfield, working for the Mexican state oil company, discovered a huge underwater arc with “extraordinary symmetry” - a ring 70 km across.
Glen Penfield evaluated a gravity map of Yucatan made in the 1960s. Ten years ago, Robert Baltosser reported to his employer about possible external influence in the Yucatan, but was prohibited from publishing his opinion on corporate policy at the time.
Penfield found another arc on the peninsula itself, the ends of which continued north. Comparing the two maps, he discovered that the individual arcs formed a circle, 180 km wide, centered near the Yucatan village of Chicxulub.
He was sure that such a shape was created by a catastrophic event in the geological history of the Earth.
Penfield and Antonio Camargo presented their research results in 1981 at a conference of geophysicists.
Coincidentally, many experts in the field of impact craters were present at this conference.
Artist's reconstruction of the crater
The oil producing company Pemex has drilled exploration wells in the region. In 1951, they were described as drilling into a thick layer of andesite about 1.3 kilometers deep.
This layer may be the result of intense heat generation as a result of impact pressure.
Penfield tried to collect samples of drills, but as the company said, they were lost.
Penfield abandoned his research, published his findings, and returned to his job at Pemex.
In 1980, scientist Luis Alvarez put forward his hypothesis that a large extraterrestrial body collided with the Earth. In 1981, unaware of Penfield's discovery, at Arizona State University, graduate student Alan R. Hildebrand and faculty member William W. Boynton published a theory of an asteroid impact with Earth and began searching for the crater.
Their evidence included greenish-brown clay with excess iridium containing quartz grains and small glass inclusions that looked like tektites.
More recent evidence suggests that the actual crater is 300 km across and has another ring inside with a diameter of 180 km.
Asteroid Chicxulub
The Chicxulub meteorite is estimated to have had a diameter of 10 km or more.
Upon impact with the ground, energy was released (4.2 × 1023 J), comparable to more than a billion atomic explosions in Hiroshima and Nagasaki.
The largest known volcanic eruption (La Garita Caldera), released an equivalent explosion energy of approximately 240 gigatons of TNT (1.0 × 1021 J), which is only 0.1% of the energy of the Chicxulub impact.
As a result of the impact, almost 200,000 cubic kilometers of material, including water and earth rock, were lifted into the atmosphere.
The shock wave spread over thousands of kilometers, and for hundreds of kilometers around everything was incinerated by the thermal effect. Colossal shock waves caused global earthquakes throughout the Earth, as well as massive volcanic eruptions. Almost all over the Earth, forest fires blazed from the consequences of the impact.
The emission of dust and particles covered the entire surface of the Earth for several years, perhaps decades. There was a large amount of dust and smog in the atmosphere.
Carbon dioxide released from the depths by the destruction of carbonate rocks led to a sudden greenhouse effect.
Sunlight was stopped by dust particles in the atmosphere, and a sharp cooling of the Earth's surface occurred. Plant photosynthesis was also interrupted, affecting the entire food chain.
In February 2008, a team of researchers led by Sean Gulich at the University of Texas at Austin-Jackson used seismic images of the crater to determine its depth.
They suggested that the deeper crater could have led to more sulfate aerosols in the atmosphere.
Sulfate aerosols in the upper atmosphere can have a cooling effect and generate acid rain.
Astronomical origin of the asteroid
There is no single theory about the origin of the asteroid, but there are many contradictory theories. Considering that there are a number of large craters on Earth, including one of them on the territory of Ukraine. In terms of time, they appeared at approximately the same period, this may mean that Chicxulub had satellites or fragments that collided with the Earth at the same time as it.
Chicxulub and the mass extinction
Chicxulub may have had a significant impact on the extinction of numerous animal and plant groups, including dinosaurs.
In March 2010, 41 experts from various countries reviewed the available evidence.
They concluded that the impact of the Chicxulub meteorite triggered the mass extinction.
A 2013 study compared isotopes in rock exposed to the Chicxulub impact with the same isotopes in the extinction boundary layer.
It was concluded that the impact was dated at 66,038 ± 0.049 Ma, and the rupture layer in the geological and paleontological rock at 66,019 ± 0.021 Ma, that is, the two dates are within 19,000 years of each other, or almost coincident within experimental errors.
This theory is now widely accepted by the scientific community. Some critics, including paleontologist Robert Bakker, argue that such exposure would have killed frogs and dinosaurs together, but frogs survived the dinosaur extinction period.
Hertha Keller of Princeton University argues that the latest core samples from the Chicxulub crater indicate that the impact occurred about 300,000 years before the mass extinction, and thus cannot be a causal factor.
However, this conclusion is not supported by radioactive dating and lithology.
Repeated exposure - hypotheses
In recent years, several other craters of approximately the same age have been discovered, such as Chicxulub (Silverpit) in the North Sea and the Boltyshsky crater in Ukraine.
The collision of Comet Shoemaker-Levy 9 with Jupiter in 1994 showed that gravitational interactions can fragment comets.
It is possible, but not proven, that the above craters are the result of a collision of Chicxulub fragments.
Future Research
In April and May 2016, the exploration team will obtain the first offshore core samples from the peak ring, in the central zone of the crater, to determine what the total impact energy was. Chicxulub is the only known crater on Earth with a remaining peak impact ring.
But it is under 600 m of sedimentary rocks. The target depth is 1500 m below the ocean floor. The main conclusions will be drawn after studying the core in Bremen, Germany.
CHICXULUB CRATER(CHICXULUB) IN MEXICO
As a result of research conducted by an international group of scientists, it turned out that about 160 million years ago, one huge asteroid with a diameter of about 170 kilometers collided with another smaller asteroid, about 60 kilometers in diameter, and fell apart into many small fragments.And about 65 million years ago, one fragment (about 10 kilometers in diameter) reached the surface of the Earth.
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This collision created the Chicxulub crater on the Yucatan Peninsula in Mexico.
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Another fragment fell on the Moon, forming the Tycho crater(about 85 kilometers in diameter).
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The fate of the remaining fragments is unknown.
This is how scientists model this impact.
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And this is what they think the Chicxulub crater looked like after the disaster.
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The impact energy is estimated at approximately 100 thousand gigatons of TNT equivalent.For comparison, the largest thermonuclear device had a power of about only 0.05 gigatons.The impact caused a tsunami up to 100 meters high and climate change,The raised particles covered the Earth's surface from direct sunlight for several years.
Presumably, as a result of this particular catastrophe, more than 70% of the plant and animal species that inhabited the Earth at that time, including dinosaurs, disappeared.
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In general, about 175 meteorite craters are known on Earth. Although, of course, throughout the history of its existence, the Earth has suffered significantly more impacts. Simply due to the processes of change occurring in the soil, many traces of impacts are not preserved. And besides, for a considerable time, some craters could not be detected using the imperfect technology that scientists had at their disposal.
Most of Earth's meteorite craters have been discovered in the last fifty years using satellite images.
The Chicxulub crater, the third largest in the world, has a diameter of 180 kilometers and a depth of about 900 meters.
P After millions of years of erosion and deposition of rock, almost no visible traces of the crater remain on the surface.After the disaster, the entire peninsula was submerged in 100 meters of water. In subsequent years of soil formation, the crater was filled with marine calcareous sediment and its border was almost level with the surface.
The only thing that might indicate the presence of a crater in the flat landscape is a giant ring of underground lakes, located mostly in the south of the crater. The northern part of the crater generally lies in the sea.
That is why space research was decisive here and made it possible to identify what could not be determined from the surface - the thin, but still unmistakably guessable outer boundary of the crater: a semicircular trench 3 - 5 meters deep and 5 kilometers wide.
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The white spot in the bottom image indicates the center of the crater.
The collision centered on the Caribbean coast in Yucatan. The impact destroyed subsurface rock layers, making them unstable. Because of this instability, the collapse of numerous limestone rocks has created sinkholes, which appear as small round depressions, often filled with water.
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Initially, the discovery of the crater happened by accident. In 1952, a Mexican oil company explored the Yucatan Peninsula near Merida in search of oil. During the drilling process, they came across porous rock, similar in structure to rock of volcanic origin. The company's engineers concluded that there was a volcano beneath the surface and stopped searching for oil in the area.
They returned to the study of the Yucatan Peninsula only 20 years later, that is, in the 70s. And the reason for this was the conviction of one of the scientists that there cannot be underground volcanoes in Yucatan. They conducted research of the area. Measurements have shown that a magnetic field exists in this area.
The presence of a magnetic field is due to the large amount of iron contained in the rock, as well as the structure of the rock itself. In addition, iridium was found in the rock. The shape of the magnetic field, the composition and structure of the rock allowed scientists to conclude that they are dealing with a crater formed as a result of a large object hitting the Earth’s surface from a great distance, because only very high pressure and temperature cause such changes in the rocks.
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The existence of the crater was first substantiated in 1980.
In the 1990s, satellite data and ground-based researchcompletely confirmed the existence of the crater, data obtained using the latest instruments allowed scientists to clarify its entire structure and identify new features, A a map of magnetic anomalies made it possible to completely recreate its appearance.
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Later, NASA's Shuttle Radar Topography Mission (SRTM) provided scientists with convincing visual evidence - a clearly visible crater.
Thanks to these data, scientists have gained a detailed understanding of the internal structure of the crater.
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In 2008, the NASA aerospace agency invited Mexico to build a special research center in the crater. Studying the crater will help answer many questions regarding meteorite collisions with our planet, and explore the possible consequences of these collisions. After all, they can be as sad for the existing structure of the world as those that led to the formation of Chicxulub and the extinction of the dinosaurs.
The crater is of great value from the point of view of study, because the Yucatan Peninsula is located on a tectonically stable area. This is the only such example in the world. The structure of other craters may change as a result of some kind of soil movements, so it is not so convenient to study them, and their study cannot answer many questions, so their historical value is not as great as the value of Chicxulub.
In addition, using the example of Chicculub, scientists from such a research center will be able to study the nature of another famous crater, recently discovered on Mars and which is currently the largest meteorite crater known to science.
“By studying the Chicxulub crater, we will be able to understand what happened on Mars 2-3 billion years ago,” say geologists from NASA.
By the way, scientist Luis Alvarez and his son Walter became Nobel Prize laureates for their research into the disaster.
| Countries of the world |
The Chicxulub crater (pronounced Chicxulub) in Mexico is widely known as the site of the asteroid impact that supposedly killed the dinosaurs. Scientists are now preparing to extract new ideas from it about the formation of craters and the study of the mechanisms of mass extinction.
Researchers are reexamining the crater formed by the asteroid that may have killed the dinosaurs. The photo shows a crater covering the land and part of the sea of the Yucatan Peninsula.
In 1978, Antonio Camargo and Glen Penfield, geophysical engineers, conducted aeromagnetic tests over the Gulf of Mexico. Their goal was to determine the likelihood of finding oil deposits for their employer, the Mexican state oil company. What they found there, however, had far-reaching consequences.
To display the magnetic field, the aircraft was equipped with sensitive magnetometers. Scientists looked for local changes in the Earth's magnetic field to gain clues about rocks buried under thick layers of sediment.
The data showed some arcs at a depth of 600-1000 m, which, when compared with a map of gravity measurements from the 1950s on the Yucatan Peninsula, formed a huge 200-kilometer-diameter structure covering the ground and the bottom of the bay. Camargo and Penfield suggested that they had found either an ancient volcanic caldera or an impact crater centered on the city of Puerto Chicxulub.
The researchers announced their findings in a small ceremony at a meeting of the Society of Geophysicists in 1981. Around the same time, another conference was held at which the hypothesis of the extinction of dinosaurs due to the impact of an asteroid was discussed. This idea was put forward by physicists, Nobel Prize winner Luis Alvarez and his son Walter Alvarez. They believed that a 10-kilometer asteroid was a strong reason for the mass extinction of both the dinosaurs and another 75% of all species at the end of the Cretaceous period - about 65 million years ago. At first, the hypothesis was practically ridiculed. Perhaps the fact that Louis himself was a physicist and not a paleontologist prevented him and his theory from being accepted. But over the next years, the question gradually began to be discussed: where is the crater itself?
In 1991, after nearly a decade, Camargo and Penfield, in collaboration with Canadian geophysicist Alan Hildebrand, finally brought the two stories together. Today, most scientists agree that the Chicxulub structure is the site of an asteroid that struck the earth at the end of the Cretaceous period and killed the dinosaurs.
As is often the case in scientific circles, consensus was not immediately reached. But many studies still indicate that this is the same crater that caused a global environmental disaster 65 million years ago. A leader in this area of research is Jaime Urrutia Fukugauchi, a researcher at the Institute of Geophysics of the National University of Mexico (UNAM). His office has a small warehouse where flat corrugated plastic boxes are stored on shelves. These boxes contain hundreds of meters of cylindrical core samples recovered from wells in the Yucatan. The samples were collected in the 1990s and early 2000s during drilling projects under the International Continental Scientific Drilling Program. These samples helped establish that the Chicxulub crater indeed fits Alvarez's theory.
Today, Chicxulub's research goals extend far beyond the cause of the extinction of the dinosaurs. For example, in March of this year, scientists met in the Yucatan city of Merida, located near the center of the crater, to fine-tune the strategy for a new offshore drilling program that will begin in 2016. On the agenda is obtaining rock samples from a region known as the Ring Peak - a nearly circular chain of hills that typically form around the center of a powerful impact.
There are ring peaks on other rocky bodies in the solar system. Pictured is the Dürer basin on Mercury. There are craters with ring structures on the Moon and Mars. Chicxulub is the only known crater on Earth with preserved ring peaks. The other two largest craters - in Canada and South Africa - are significantly destroyed due to their older age. Upcoming studies of the Chicxulub crater will help scientists understand how these rings form and how the final structure of the crater depends on exposure parameters and planetary conditions (such as gravity, density and rock properties). As a result, this may allow geoscientists to infer
underground characteristics of other planetary bodies - especially the Moon - simply by studying their craters.
There are two competing models for ring formation. In both, the rock temporarily behaves like a liquid. In one model, the impact at the center causes a splash of rock to shoot upward, just as a drop of water does. The central rise then breaks down, spreading outward like ripples in a pond and solidifying to form a ring. In the second model, a ring is created when a newly formed crater collapses and material moves inward.
Samples from Chicxulub ring structures will help scientists determine which model is best.
The project will also help scientists understand how materials behave at incredibly high rates of deformation - when rocks break, as well as how the transition from solid to liquid occurs - this is the behavior of solid rocks when deformation occurs over a very short time.
The deformation of mountains takes millions of years. But craters form in the blink of an eye. With such an interaction, when hit by an asteroid, the rise of rocks to a height comparable to the Himalayas would occur in about 2 minutes.
Although Chicxulub has been extensively studied for 20 years, scientists still speculate about what actually caused the environmental changes that led to the mass extinction.
When the asteroid hit Earth, it released energy equivalent to 510 million bombs dropped on Hiroshima. That is, approximately one for every square kilometer of the planet’s surface.
The Alvarezes' work suggested that a biological catastrophe occurred because the Earth
was enveloped in a huge cloud of debris and dust, and the planet remained dark and cold for many years after the impact. Later, other scientists proposed additional effects, such as the release of greenhouse gases and acid rain. Another theory suggests that within a minute of the asteroid's impact, rocks ejected from the suborbital flight re-entered the atmosphere and, burning as they fell, caused temperatures to rise to several hundred degrees over a very short period, possibly starting fires.
Recent calculations and experiments show that there were probably no fires at all.
A 2008 study found that immediately after the impact, the ring peaks were immersed in melt from nearby rocks. This heat source existed for millions of years, and may have created the conditions for exotic life forms. The results of future drilling may shed light on how life forms in the very distant past coped with extinction. After all, three billion years ago, during the Precambrian, asteroid impacts were much stronger and more frequent than today or during the time of the dinosaurs, but some species still managed to recover from these events.
There is another intriguing consequence of impact theory. During the impact, the ejected material could acquire such speed that it escaped the earth's gravity and ran far into space.
Some of these materials could end up landing on our closest cosmic neighbors. So in the future, perhaps pieces of Yucatan will be found on the Moon or Mars...