"Dinosaur-Killer" Asteroid Crater Imaged for First Time "Dinosaur-Killer" Asteroid Crater Imaged for First Time National Geographic News March 7, 2003 A high-resolution map from NASA's Shuttle Radar Topography Mission (SRTM), released yesterday, has provided the most telling visible evidence to date of a 112-mile (180-kilometer) wide, 3,000-foot (900-meter) deep impact crater, the result of a collision with a giant comet or asteroid on one of Earth's all-time worst days. The existence of the impact crater, Chicxulub, was first proposed in 1980. In the 1990s, satellite data and ground studies allowed it to gain prominence among most scientists as the long sought-after "smoking gun" responsible for the demise of the dinosaurs and more than 70 percent of Earth's living species 65 million years ago. Digg StumbleUpon Reddit The relatively obscure feature is all but hidden in the flat limestone plateau of Mexico's Yucatán Peninsula.

But using 3-D measurements of the Earth made with instruments on board an orbiting Space Shuttle, the remnants of the crater can now be seen clearly. "There are spectacular features that pop out in these maps as never before, and more subtle features, like Chicxulub, become apparent for the first time," said Michael Kobrick, SRTM project scientist at NASA's Jet Propulsion Laboratory (JPL), Pasadena, California. "In fact, much of the surface expression of Chicxulub is so subtle; if you walked across it you probably wouldn't notice it. That's where the view from space becomes invaluable, " Kobrick said. The Chicxulub data show a subtle, yet unmistakable, topographic indication of the impact crater's outer boundary: a semicircular trough 10 to 15 feet (3 to 5 meters) deep and 3 miles (5 kilometers) wide. Scientists believe the impact, centered off Yucatán's coast in the Caribbean, disturbed the subsurface rocks, making them unstable. The rocks were subsequently buried by limestone sediments, which erode easily. The crater rim's instability caused the limestone to fracture along the rim, forming the trough.

Exactly how the Chicxulub impact caused Earth's mass extinctions is not known (see links below). Scientists imagine three possible scenarios: Some think the impact threw massive quantities of dust into the atmosphere which blocked the sun and arrested plant growth. Others believe sulfur released by the impact lead to global sulfuric acid clouds that blocked the sun and also fell as acid rain. Another possibility is that red-hot debris from the falling asteroid or comet triggered global wildfires. In February, NASA finished processing the SRTM mission's North America data set and delivered it to the National Imagery and Mapping Agency (NIMA). More than eight terabytes of data recorded aboard the Space Shuttle Endeavour were refined into 200 billion research-quality measurements of Earth's landforms. NIMA will perform additional data finishing and send it to the U.S. Geological Survey's Earth Resources Observation Systems Data Center, Sioux Falls, South Dakota, for final archiving and distribution. Read More About Chicxulub: Researchers to drill below the Chicxulub crater in Mexico to find out if asteroid killed off dinosaurs | Daily Mail Online Share this article Share Previous researcher has questioned the theory that a global firestorm accompanied the asteroid that killed off the dinosaurs.

A team of researchers has found that heat near the impact site would not have been sufficient to ignite plants. It suggests our understanding of the mass extinction event that wiped out the dinosaurs may not be as complete as thought. The team of researchers from the University of Exeter, University of Edinburgh and Imperial College London recreated the immense energy that would have been released from the asteroid impact 66 million years ago. Further away from the impact site in Mexico (shown), in places like New Zealand, the heat could have lasted up to seven minutes and caused some localised fires. But the theory that a global firestorm accompanied the asteroid impact is not correct, according to the scientists They found that the intense but short-lived heat near the impact site could not have ignited live plants, challenging the idea that the impact led to global firestorms. These firestorms have previously been considered a major contender in the puzzle to find out what caused the mass extinction of life on Earth 66 million years ago. The impact site is believed to be the 125 mile (200km) wide Chicxulub crater buried underneath the Yucatán Peninsula in Mexico.

Researchers believe that when a big rock smashes into Earth at high enough velocities, the collision causes the crust temporarily to act like a liquid, first forming a so-called transient crater (like the indentation that forms on a lake surface after a rock is thrown in), and the center rebounds, or splashes, upward and then outward. WERE THE DINOSAURS KILLED BY COLOSSAL BAD LUCK? For years scientists have debated whether an asteroid, climate change or a combination of catastrophes were responsible for the demise of dinosaurs. But last year, a study claimed that the majority of the prehistoric creatures were wiped out by a perfect storm of 'colossal bad luck'. Dinosaurs might have survived the asteroid strike that led to their extinction if it had come slightly earlier or later in history, scientists said. But when the six-mile-wide (10km) asteroid hit what is now Mexico approximately 66 million years ago, dinosaurs were experiencing environmental upheaval, which left them vulnerable. The study by an international team of palaeontologists led by the University of Edinburgh looked at an updated catalogue of dinosaur fossils, mostly from North America.

They found that widespread volcanic activity, changing sea levels and varying temperatures had weakened the dinosaurs' food chain when disaster struck. If the asteroid impact had come a few million years earlier, when the range of species was bigger and food chains more robust, they may have survived, according to the study. A heat pulse in the surrounding the area lasted for less than a minute followed the impact. While this was too short to ignite live plant material nearby, the effects of the impact further away could have been sufficient to set some material alight. The researchers said as far away as New Zealand, the heat would have been less intense but longer lasting, heating the ground for seven minutes - enough to ignite live plant matter. But nearer the site such a scenario was unlikely, pouring water on the global firestorm theory. The experiments carried out in the laboratory showed that dry plant matter could ignite, but live plants including green pine branches, typically do not. 'By combining computer simulations of the impact with methods from engineering we have been able to recreate the enormous heat of the impact in the laboratory,' said Dr Claire Belcher from the Earth System Science group in Geography at the University of Exeter.

'This has shown us that the heat was more likely to severely affect ecosystems a long distance away, such that forests in New Zealand would have had more chance of suffering major wildfires than forests in North America that were close to the impact. 'This flips our understanding of the effects of the impact on its head and means that paleontologists may need to look for new clues from fossils found a long way from the impact to better understand the mass extinction event.' The experiments carried out in the laboratory showed that dry plant matter could ignite, but live plants typically do not. Pictured is the fire propagation apparatus recreating the impact induced thermal pulse at the Cretaceous-Palaeogene (K-Pg) boundary. Halogen lamps are delivering the thermal radiation in the image Plants and animals are generally resistant to localised fire events - animals can hide or hibernate and plants can re-colonise from other areas, implying that wildfires are unlikely to be directly capable of leading to the extinctions. If, however, some animal communities - particularly large animals - were unable to shelter from the heat, they may have suffered serious losses. It is unclear whether these would have been sufficient to lead to the extinction of species.

'This is a truly exciting piece of inter-disciplinary research,' said Dr Rory Hadden from the University of Edinburgh. 'By working together engineers and geoscientists have tackled a complex, long-standing problem in a novel way. 'This has allowed a step forward in the debate surrounding the end Cretaceous impact and will help Geoscientists interpret the fossil record and evaluate potential future impacts. 'In addition, the methods we developed in the laboratory for this research have driven new developments in our current understanding of how materials behave in fires particularly at the wildland-urban-interface, meaning that we have been able to answer questions relating to both ancient mass extinctions at the same time as developing understanding of the impact of wildfires in urban areas today.' Read more: Has Earth Gobbled up Giant Craters? Has Earth Gobbled up Giant Craters? World | Indo-Asian News Service | Updated: May 28, 2014 14:10 IST EMAIL PRINT COMMENTS New York: Do you know that in past 3.5 billion years, over 80 asteroids - larger than the rocks that wiped out dinosaurs 66 million years ago - have bombarded earth?

But if you look around, only four of craters produced by their impacts could persist until today. Geologists have found three such craters like the Chicxulub crater - a prehistoric impact crater buried underneath the Yucatan Peninsula in Mexico. So where have all the craters disappeared? "Tectonic processes, weathering and burial quickly obscure or destroy craters. If earth were not so dynamic, its surface would be heavily cratered like the Moon or Mercury," said geologists BC Johnson and TJ Bowling from department of earth, atmospheric and planetary sciences at Purdue University. Their findings indicate that craters on earth cannot be used to understand earth's bombardment history. According to them, layers of molten rock blasted out early in the impact process may act as better records of impacts - even after the active earth has destroyed the source craters. "Searches for these impact ejecta layers will be more fruitful for determining how many times earth was hit by big asteroids than searches for large craters," Johnson suggested. Till date, geologists have proof of giant craters in South Africa, and Yucatan Peninsula. The study was published online for the journal Geology.

Chicxulub crater - Video Learning - WizScience.com - YouTube Chicxulub crater - Video Learning - WizScience.com Want to watch this again later? Sign in to add this video to a playlist. Need to report the video? Sign in to report inappropriate content. The interactive transcript could not be loaded. Loading... Rating is available when the video has been rented. This feature is not available right now. Please try again later. Published on Jul 29, 2015 The "Chicxulub crater" is an impact crater buried underneath the Yucatán Peninsula in Mexico. Its center is located near the town of Chicxulub, after which the crater is named. The age of the Chicxulub asteroid impact and the Cretaceous–Paleogene boundary coincide precisely. The crater is more than 180 km in diameter and 20 km in depth, making the feature one of the largest confirmed impact structures on Earth; the impacting bolide that formed the crater was at least 10 km in diameter.

The crater was discovered by Antonio Camargo and Glen Penfield, geophysicists who had been looking for petroleum in the Yucatán during the late 1970s. Penfield was initially unable to obtain evidence that the geological feature was a crater, and gave up his search. Through contact with Alan Hildebrand, Penfield obtained samples that suggested it was an impact feature. Evidence for the impact origin of the crater includes shocked quartz, a gravity anomaly, and tektites in surrounding areas. The age of the rocks marked by the impact shows that this impact structure dates from roughly 66 million years ago, the end of the Cretaceous period, and the start of the Paleogene period. It coincides with the K-Pg boundary, the geological boundary between the Cretaceous and Paleogene. The impact associated with the crater is thus implicated in the Cretaceous–Paleogene extinction event, including the worldwide extinction of non-avian dinosaurs. This conclusion has been the source of controversy. In March 2010, 41 experts from many countries reviewed the available evidence: 20 years' worth of data spanning a variety of fields.

They concluded that the impact at Chicxulub triggered the mass extinctions at the K–Pg boundary. Wiz Science™ is "the" learning channel for children and all ages. SUBSCRIBE TODAY Disclaimer: This video is for your information only. The author or publisher does not guarantee the accuracy of the content presented in this video. USE AT YOUR OWN RISK. Background Music: "The Place Inside" by Silent Partner (royalty-free) from YouTube Audio Library. This video uses material/images from , which is released under Creative Commons Attribution-Share-Alike License 3.0 . This video is licensed under Creative Commons Attribution-Share-Alike License 3.0 . To reuse/adapt the content in your own work, you must comply with the license terms. Category Chicxulub crater - Wikipedia, the free encyclopedia Chicxulub crater Jump to: navigation , search For the town the crater is named after, see Chicxulub, Yucatán .

Radar topography reveals the 180 kilometer (112 mi) ring of the crater; clustered around the crater's trough are numerous sinkholes , suggesting a prehistoric oceanic basin in the depression left by the impact (Image courtesy NASA/JPL-Caltech). The Chicxulub Crater ( IPA : [tʃikʃuˈlub] ) is an ancient impact crater buried underneath the Yucatán Peninsula in Mexico . [1] Its center is located near the town of Chicxulub , after which the crater is named—as well as the rough translation of the Mayan name, "the tail of the devil." [2] The crater is more than 180 kilometers (110 mi) in diameter, making the feature one of the largest confirmed impact structures in the world; the impacting bolide that formed the crater was at least 10 km (6 mi) in diameter. The crater was discovered by Glen Penfield , a geophysicist who had been working in the Yucatán while looking for oil during the late 1970s. Evidence for the impact origin of the crater includes shocked quartz , a gravity anomaly , and tektites in surrounding areas.

The age of the rocks and isotope analysis show that this impact structure dates from the end of the Cretaceous Period , roughly 65 million years ago . The impact associated with the crater is implicated in causing the extinction of the dinosaurs as suggested by the K–T boundary , although some critics argue that the impact was not the sole reason [3] and others debate whether there was a single impact or whether the Chicxulub impactor was one of several that may have struck the Earth at around the same time. Recent evidence suggests that the impactor may have been a piece of a much larger asteroid that broke up in a collision in distant space more than 160 million years ago. [4] Contents 7 External links Discovery In 1978, geophysicist Glen Penfield was working for the Mexican state-owned oil company Petróleos Mexicanos , or Pemex, as part of an airborne magnetic survey of the Gulf of Mexico north of the Yucatán peninsula. [5] Penfield's job was to use geophysical data to scout possible locations for oil drilling.

[6] Within the data, Penfield found a huge underground arc with 'extraordinary symmetry' in a ring 70 kilometers (40 mi) across. [2] He then obtained a gravity map of the Yucatán made in the 1960s. A decade earlier, the same map suggested an impact feature to contractor Robert Baltosser, but he was forbidden to publicize his conclusion by Pemex corporate policy of the time. [7] Penfield found another arc on the peninsula itself whose ends pointed northward. Comparing the two maps, he found the separate arcs formed a circle, 180 kilometers (111 mi) wide, centered near the Yucatán village Chicxulub ; he felt certain the shape had been created by a cataclysmic event in geologic history. Pemex disallowed release of specific data but let Penfield and company official Antonio Camargo present their results at the 1981 Society of Exploration Geophysicists conference. [8] That year's conference was underattended and their report attracted scant attention.

(Ironically, many experts in impact craters and the K-T boundary were attending a separate conference on Earth impacts.) Although Penfield had plenty of geophysical data sets, he had no rock cores or other physical evidence of an impact. [6] He knew Pemex had drilled exploratory wells in the region in 1951; one bored into what was described as a thick layer of andesite about 1.3 kilometers (4,200 ft) down. This layer could have resulted from the intense heat and pressure of an Earth impact, but at the time of the borings it was dismissed as a lava dome -- a feature uncharacteristic of the region's geology. Penfield tried to secure site samples but was told such samples had been lost or destroyed. [6] When attempts at returning to the drill sites and looking for rocks proved fruitless, Penfield abandoned his search, published his findings and returned to his Pemex work. Penfield with the sample of shocked quartz found at Well #2, Chicxulub.

At the same time, scientist Luis Walter Alvarez put forth his hypothesis that a large extraterrestrial body had struck Earth; and in 1981, oblivious to Penfield's discovery, University of Arizona grad student Alan R Hildebrand and faculty adviser William V Boynton published a draft Earth-impact theory and were seeking a candidate crater. [9] Their evidence included greenish-brown clay with surplus iridium containing shocked quartz grains and small weathered glass beads that looked to be tektites . [10] Thick, jumbled deposits of coarse rock fragments were also present, thought to have been scoured from one place and deposited elsewhere by a kilometers-high tsunami likely resulting from an Earth impact. [11] Such deposits occur in many locations but seem concentrated in the Caribbean basin at the K–T boundary. [11] So when Haitian professor Florentine Morás discovered what he thought to be evidence of an ancient volcano on Haiti , Hildebrand suggested it could be a telltale feature of a nearby impact. [12] Tests on samples retrieved from the K–T boundary revealed more tektite glass, formed only in the heat of asteroid impacts and high-yield nuclear detonations .

[12] In 1990, Houston Chronicle reporter Carlos Byars told Hildebrand of Penfield's earlier discovery of a possible impact crater. [13] Hildebrand contacted Penfield in April 1990 and the pair soon secured two drill samples from the Pemex wells, stored in New Orleans . [14] Hildebrand's team tested the samples, which clearly showed shock-metamorphic materials. A team of California researchers including Kevin Pope , Adriana Ocampo, and Charles Duller, surveying regional satellite images in 1996, found a sinkhole ( Cenote ) ring centered on Chicxulub that matched the one Penfield saw earlier; the sinkholes were thought to be caused by subsidence of the impact crater wall. [15] More recent evidence suggests the actual crater is 300 kilometers (190 mi) wide, and the 180 kilometer ring an inner wall of it. [16] Impact specifics An animation showing the impact, and subsequent crater formation (University of Arizona, Space Imagery Center).

The impactor's estimated size was about 10 km (6 mi) in diameter and may have released an estimated 400 zetta joules (4×1023 joules ) of energy, equivalent to 100 teratons of TNT (1014 tons), [17] [18] on impact. By contrast, the most powerful man-made explosive device ever detonated, the Tsar Bomba or Emperor Bomb, had a yield of only 50 megatons , [19] making the Chicxulub impact 2 million times more powerful. [20] Even the largest known explosive volcanic eruption, which released approximately 10 zettajoules and created the La Garita Caldera , [21] was substantially less powerful than the Chicxulub impact. Effects The impact would have caused some of the largest megatsunamis in Earth's history, reaching thousands of feet high. A cloud of super-heated dust, ash and steam would have spread from the crater, as the impactor burrowed underground in less than a second.

[22] Excavated material along with pieces of the impactor, ejected out of the atmosphere by the blast, would have been heated to incandescence upon re-entry, broiling the Earth's surface and possibly igniting global wildfires; meanwhile, enormous shock waves spawned global earthquakes and volcanic eruptions . [23] The emission of dust and particles could have covered the entire surface of the Earth for several years, possibly a decade, creating a harsh environment for living things to survive in. The shock production of carbon dioxide caused by the destruction of carbonate rocks would have led to a dramatic greenhouse effect . [24] Another consequence of the impact is that sunlight would have been blocked from reaching the surface of the earth by the dust particles in the atmosphere, cooling the surface dramatically. Photosynthesis by plants would also have been interrupted, affecting the entire food chain . [25] [26] In February 2008, a team of researchers led by Sean Gulick at the University of Texas at Austin’s Jackson School of Geosciences used seismic images of the crater to determine that the impactor landed in deeper water than was previously assumed. They argued that this would have resulted in increased sulfate aerosols in the atmosphere.

According to the press release, that “could have made the impact deadlier in two ways: by altering climate (sulfate aerosols in the upper atmosphere can have a cooling effect) and by generating acid rain (water vapor can help to flush the lower atmosphere of sulfate aerosols, causing acid rain).” [27] Geology and morphology In their 1991 paper, Hildebrand, Penfield, and company described the geology and composition of the impact feature. [28] The rocks above the impact feature are layers of marl and limestone reaching to almost 1,000 meters (3,300 ft) in depth. These rocks date back as far as the Paleocene . [29] Below these layers lie more than 500 m (1,600 ft) of andesite glass and breccia . These andesitic igneous rocks were found only within the supposed impact feature; similarly, quantities of feldspar and augite , normally only found in impact-melt rocks, are present, [30] as is shocked quartz .

[29] The K–T boundary inside the feature is depressed between 600 and 1,100 m (2,000–3,600 ft) compared to the normal depth of about 500 m (1,600 ft) depth 5 km (3 mi) away from the impact feature. [31] Along the edge of the crater are clusters of cenotes or sinkholes, which suggest that there was a water basin inside the feature during the Tertiary period , after the impact. [31] Such a basin's groundwater dissolved the limestone and created the caves and cenotes beneath the surface. [32] The paper also noted that the crater seemed to be a good candidate source for the tektites reported at Haiti . [33] Origin On September 5, 2007 a report published in Nature proposed an origin for the asteroid that created Chicxulub Crater. [25] The authors, William F.

Bottke , David Vokrouhlický, and David Nesvorný, argued that a collision in the asteroid belt 160 million years ago resulted in the creation of the Baptistina family of asteroids, the largest surviving member of which is 298 Baptistina . They proposed that the "Chicxulub asteroid" was also a member of this group. The connection between Chicxulub and Baptistina is supported by the large amount of carbonaceous material present in microscopic fragments of the impactor, suggesting the impactor was a member of a rare class of asteroids called carbonaceous chondrites , like Baptistina. [4] According to Bottke, the Chicxulub impactor was a fragment of a much larger parent body about 170 km (105 mi) across, with the other impacting body being around 60 km (40 mi) in diameter. [34] [4] Chicxulub and mass extinction Main article: Cretaceous–Tertiary extinction event The piece of clay, held by Walter Alvarez, which sparked research into the impact theory. The second green band from bottom (third band up) is extremely rich in iridium .

The Chicxulub Crater lends support to the theory postulated by the late physicist Luis Alvarez and his son, geologist Walter Alvarez , that the extinction of numerous animal and plant groups, including dinosaurs , may have resulted from a bolide impact. The Alvarezes, at the time both faculty members at the University of California, Berkeley , postulated that the extinction event roughly contemporaneous with the postulated date of formation for the Chicxulub crater, could have been caused by just such a large impact. [35] This theory is now widely, though not universally, accepted by the scientific community . Some critics, including paleontologist Robert Bakker , argue that such an impact would have killed frogs as well as dinosaurs, yet the frogs survived the extinction event. [36] Gerta Keller of Princeton University argues that recent core samples from Chicxulub prove the impact occurred about 300,000 years before the mass extinction, and thus could not have been the causal factor. [37] The main evidence of such an impact, besides the crater itself, is contained in a thin layer of clay present in the K–T boundary across the world.

In the late 1970s, the Alvarezes and colleagues reported [38] that it contained an abnormally high concentration of iridium . In this layer, iridium levels reached 6 parts per billion by weight or more compared to 0.4 [39] for the Earth's crust as a whole; in comparison, meteorites can contain around 470 parts per billion [40] of this element. It was hypothesised that the iridium was spread into the atmosphere when the impactor was vaporized and settled across the Earth's surface amongst other material thrown up by the impact, producing the layer of iridium-enriched clay. [41] Multiple impact theory In recent years, several other craters of around the same age as Chicxulub have been discovered, all between latitudes 20°N and 70°N. Examples include the Silverpit crater in the North Sea [42] and the Boltysh crater in Ukraine . [43] Both are much smaller than Chicxulub, but likely to have been caused by objects many tens of metres across striking the Earth.

[44] This has led to the hypothesis that the Chicxulub impact may have been only one of several impacts that happened nearly at the same time. [45] Another possible crater thought to have been formed at the same time is the Shiva crater , though the structure's status as a crater is contested. [46] The collision of Comet Shoemaker-Levy 9 with Jupiter in 1994 demonstrated that gravitational interactions can fragment a comet, giving rise to many impacts over a period of a few days if the comet should collide with a planet. Comets frequently undergo gravitational interactions with the gas giants , and similar disruptions and collisions are very likely to have occurred in the past. [47] This scenario may have occurred on Earth 65 million years ago. [45] In late 2006, Ken MacLeod, a geology professor from the University of Missouri–Columbia , completed an analysis of sediment below the ocean's surface, bolstering the single-impact theory.

MacLeod conducted his analysis approximately 4,500 kilometers (2,800 mi) from the Chicxulub Crater to control for possible changes in soil composition at the impact site, while still close enough to be affected by the impact. The analysis revealed there was only one layer of impact debris in the sediment, which indicated there was only one impact. [48] Multiple-impact proponents such as Gerta Keller regard the results as "rather hyper-inflated" and do not agree with the conclusion of MacLeod's analysis. [49] See also Has earth gobbled up giant craters? Has earth gobbled up giant craters? Indo Asian News Service Tweet Share New York, May 28 (IANS) Do you know that in past 3.5 billion years, over 80 asteroids - larger than the rocks that wiped out dinosaurs 66 million years ago - have bombarded earth? But if you look around, only four of craters produced by their impacts could persist until today. Geologists have found three such craters like the Chicxulub crater - a prehistoric impact crater buried underneath the Yucatan Peninsula in Mexico. So where have all the craters disappeared?

"Tectonic processes, weathering and burial quickly obscure or destroy craters. If earth were not so dynamic, its surface would be heavily cratered like the Moon or Mercury," said geologists BC Johnson and TJ Bowling from department of earth, atmospheric and planetary sciences at Purdue University. Their findings indicate that craters on earth cannot be used to understand earth's bombardment history. According to them, layers of molten rock blasted out early in the impact process may act as better records of impacts - even after the active earth has destroyed the source craters. "Searches for these impact ejecta layers will be more fruitful for determining how many times earth was hit by big asteroids than searches for large craters," Johnson suggested. Till date, geologists have proof of giant craters in South Africa, and Yucatan Peninsula. The study was published online for the journal Geology. Reblog Jump to: navigation , search For the town the crater is named after, see Chicxulub, Yucatán .

Radar topography reveals the 180 kilometer (112 mi) ring of the crater; clustered around the crater's trough are numerous sinkholes , suggesting a prehistoric oceanic basin in the depression left by the impact (Image courtesy NASA/JPL-Caltech) Chicxulub Crater ( IPA : [tʃikʃuˈlub]) is an ancient impact crater buried underneath the Yucatán Peninsula , with its center located near the town of Chicxulub , Yucatán , Mexico . The crater is over 180 kilometers (112 mi) in diameter, making the feature one of the largest confirmed impact structures in the world; the asteroid or comet whose impact formed the crater was at least 10 km (6 mi) in diameter. The crater was named for the eponymous town, as well as for the literal Maya translation of the name: "tail of the devil ." [1] The crater was discovered by Glen Penfield, a geophysicist who had been working in the Yucatán while looking for oil during the late 1970s .

The presence of tektites , shocked quartz and gravity anomalies , as well as the age of the rocks and isotope analysis , show that this impact structure dates from the late Cretaceous Period , roughly 65 million years ago . The impact associated with the crater is implicated in causing the extinction of the dinosaurs as suggested by the K–T boundary , although some critics disagree that the impact was the sole reason [2] and also debate whether there was a single impact or whether the Chicxulub impactor was one of several that may have struck the Earth at around the same time. Recent evidence suggests that the impactor was a piece of a much larger asteroid which broke up in a collision more than 160 million years ago. [3] Contents [ edit ] Discovery In 1978 , Glen Penfield, a geophysicist, had been working for Petroleos Mexicanos (PEMEX, the Mexican state-owned oil company) as a staff member for an airborne magnetic survey of the Yucatán Peninsula, trying to find oil. [4] With aerial surveys, he attempted to use magnetic data to find underground oil deposits.

When Penfield examined the survey data, he found a huge underground "arc", with "extraordinary symmetry" in an enormous ring, 70 km (43.5 mi) across. [1] Penfield then obtained a gravity map of the Yucatán that had been made in the 1960s . He found another arc, but this one was on the Yucatán itself, and its ends pointed north. He matched up the two maps and found that the two arcs joined up in a circle, 180 km (111 mi) wide, with its center near the village of Puerto Chicxulub . Penfield was certain that the arrangement was created by a single event in geologic history. Although PEMEX would not allow him to release specific data, the company did allow him and PEMEX official Antonio Camargo to present their results at a geological conference in 1981 . [5] The conference was under-attended that year, ironically because most geologists were attending a workshop on Earth impacts, and their report attracted very little attention. While Penfield had plenty of geophysical data sets, he had no physical evidence of an impact in the form of rock cores.

[4] Penfield knew that PEMEX had drilled exploratory wells in the region in 1951 . One of the wells had bored into a thick layer of andesite about 1.3 kilometers (4,200 ft) down. Such a structure could have resulted from the intense heat and pressures of an Earth impact, but at the time of the borings it had been written off as a " volcanic dome ", even though such a feature was out of place in the geology of the region. Penfield attempted to secure samples from these sites, but was told that all the samples had been lost or destroyed. [4] Attempts at returning to the drill sites and looking for rocks proved fruitless. Penfield abandoned his search, wrote up his findings, and returned to working for PEMEX at the same time scientist Luis Alvarez proposed his hypothesis that a giant extraterrestrial body had struck the earth. Penfield with the sample of shocked quartz found at Well #2, Chicxulub. Meanwhile, Alan R. Hildebrand, a graduate student at the University of Arizona , was searching for a crater, unaware of Penfield's discovery. In 1981 Hildebrand and his faculty advisor, William V.

Boynton, published their preliminary theory about an earth impact. [6] Their evidence included a greenish brown coloured clay with an excess of iridium and containing shocked quartz grains and small beads of weathered glass that appeared to be tektites . [7] There was also the presence of thick, jumbled deposits of coarse rock fragments, thought to have been scoured up from one location and deposited elsewhere by a kilometers-high tsunami that most likely resulted from an Earth impact. [8] Such deposits occur in many locations but seem to be concentrated in the Caribbean Basin at the K–T boundary . [8] At the same time, Florentine Moras, a Haitan professor, discovered what he believed was evidence of an ancient volcano on Haiti ; Hildebrand suggested it might be another distinctive feature of an impact nearby. [9] Tests on samples retrieved from the K–T boundary revealed more tektite glass, associated only with asteroid impacts and the site of high yield nuclear detonations .

[9] Later in 1990, Carlos Byars, a reporter for the Houston Chronicle , contacted Hildebrand and told him that Penfield had discovered what might be the impact crater years earlier, buried under the northern Yucatán Peninsula . [10] After Hildebrand got in touch with Penfield in April 1990, the two men were able to locate two separate samples from the wells drilled by PEMEX, which were stored in New Orleans , Louisiana . [11] Sending the samples back to Hildebrand, Hildebrand and his team performed tests, which clearly showed shock-metamorphic materials in the samples. In 1996 , a team of California researchers, including Kevin O. Pope , Adriana Ocampo, and Charles Duller, conducted a survey of satellite images of the region. They found that there was a ring of sinkholes centered on Puerto Chicxulub that matched the ring Penfield had found in his data. The sinkholes were likely caused by subsidence of the crater's wall. [12] Further studies have reinforced this consensus.

Recent evidence suggests that the actual crater is 300 kilometers (186 mi) wide, and the 180 kilometer ring is just an inner wall. [13] [ edit ] Impact specifics An animation showing the impact, and subsequent crater formation. (University of Arizona, Space Imagery Center) The impactor's estimated size was about 10 km (6 mi) in diameter, releasing an estimated 500 zetta joules (5.0×1023 joules ) of energy, equivalent to 100 teratons of TNT (1014 tons), [14] on impact. By contrast, the most powerful man-made explosive device ever detonated, the Tsar Bomba or Emperor Bomb, had a yield of only 50 megatons , [15] making the Chicxulub impact 2 x 106 times more powerful. [16] The impact caused some of the largest megatsunamis in Earth's history, hitting the Caribbean island of Cuba especially hard. A cloud of dust, ash and steam would have spread from the crater, as the impactor burrowed underground in less than a second.

[17] Pieces of the impactor, ejected out of the atmosphere by the blast, would have been heated to incandescence upon reentry, broiling Earth's surface and igniting global wildfires; meanwhile, shock waves spawned global earthquakes and volcanic eruptions . [18] The emission of dust and particles could have covered the entire surface of the earth for several years, possibly a decade, creating a harsh environment for living things to survive in. The shock production of carbon dioxide caused by the destruction of carbonate rocks would have led to a dramatic greenhouse effect , [19] and sunlight would have been filtered out by dust particles in the atmosphere. The photosynthesis of plants would be interrupted, subsequently affecting the entire food chain . [20] [21] [ edit ] Geology and morphology In their 1991 paper, Hildebrand, Penfield, and company described the geology and composition of the impact feature. [22] The rocks above the impact feature are layers of marl and limestone reaching to almost 1000 meters (3280 ft) in depth. These rocks date back as far as the Paleocene .

[23] Below these layers lie more than 500 m (1640 ft) of andesite glass and breccia . These andesitic igneous rocks were found only within the supposed impact feature; similarly, quantities of feldspar and augite , normally only found in impact-melt rocks, are present, [24] as is shocked quartz . [23] In addition, the K–T boundary inside the feature is depressed between 600 and 1100 m compared to the normal depth of about 500 m (1640 ft) depth 5 km (3.1 mi) away from the impact feature. [25] Along the edge of the crater are clusters of cenotes or sinkholes, which suggest that there was a water basin inside the feature during the Tertiary period , after the impact- [25] such a basin's groundwater dissolved the limestone and created the caves and cenotes beneath the surface. [26] The paper also noted that the crater seemed to be a good candidate source for the tektites reported at Haiti.

[27] [ edit ] Origin On September 5 , 2007 a report was issued in Nature that proposed a possible origin of the asteroid that created Chicxulub Crater. [20] The authors, William F. Bottke , David Vokrouhlický, and David Nesvorný argue that a collision occurred in the asteroid belt 160 million years ago that resulted in the creation of the Baptistina family of asteroids, the largest surviving member of which is 298 Baptistina , and that the "Chicxulub asteroid" was also a member of this group. The connection between Chicxulub and Baptistina is supported by the large amount of carbonaecous material present in microscopic fragments of the impactor, suggesting the impactor was a member of a rare class of asteroids called carbonaceous chondrites , like Baptistina. [3] According to Bottke, the Chicxulub impactor was a fragment of a much larger parent body about 170 km (105 mi) across, with the other impacting body being around 60 km (37 mi) in diameter.

[28] [3] It has been speculated that the impactor that produced the 85 km diameter lunar crater Tycho 108 million years ago was another member of the same group. [ edit ] Chicxulub and dinosaur extinction Main article: Cretaceous–Tertiary extinction event Alvarez holding the piece of clay which sparked research into the impact theory. The second green band from the bottom is extremely high in iridium . The size and damage that would have been wrought by the Chicxulub impact is in good agreement with the theory postulated by the late physicist Luis Alvarez and his son, geologist Walter Alvarez , for the extinction of the dinosaurs . The Alvarezes, at the time both faculty members at the University of California, Berkeley , postulated that the extinction of the dinosaurs, roughly contemporaneous with the K–T boundary , could have been caused by just such a large impact. [29] This theory is now widely, though not universally, accepted by the scientific community . Some critics, including paleontologist Robert Bakker , argue that such an impact would have killed frogs as well as dinosaurs, yet the frogs survived the extinction event.

[30] Gerta Keller of Princeton University argues that recent core samples from Chicxulub prove the impact occurred about 300,000 years before the extinction of the dinosaurs, and thus could not have been the cause of their demise. [31] The main evidence present of such an impact, besides the crater itself, is a widespread, thin layer of clay present in the K–T boundary across the world. In the late 1970s , the Alvarezes and colleagues reported [32] that it contained an abnormally high concentration of iridium . In this layer, iridium levels reached 6 parts per billion by weight or more compared to 0.4 [33] for the Earth's crust as a whole; in comparison, meteorites can contain around 470 parts per billion [34] of this element. It was hypothesised that the iridium was spread into the atmosphere when the impactor was vapourized and settled across the Earth's surface amongst other material thrown up by the impact, producing the relatively iridium-rich layer of clay.

[35] [ edit ] Multiple impact theory See also: Roche limit In recent years, several other craters of around the same age as Chicxulub have been discovered, all between latitudes 20°N and 70°N. Examples include the Silverpit crater in the North Sea , and the Boltysh crater in Ukraine . Both are much smaller than Chicxulub, but likely to have been caused by objects many tens of metres across striking the Earth. [36] This has led to the hypothesis that the Chicxulub impact may have been only one of several impacts that happened nearly at the same time. Another possible crater thought to have been formed at the same time is the Shiva crater , though the structure's status as a crater is contested. [37] The collision of Comet Shoemaker-Levy 9 with Jupiter in 1994 proved that gravitational interactions can fragment a comet, giving rise to many impacts over a period of a few days if the comet should collide with a planet. Comets frequently undergo gravitational interactions with the gas giants, and similar disruptions and collisions are very likely to have occurred in the past.

[38] This scenario may have occurred on Earth 65 million years ago. [39] In late 2006 , Ken MacLeod, a geology professor from the University of Missouri–Columbia , completed an analysis of sediment below the ocean's surface bolstering the single-impact theory. MacLeod conducted his analysis approximately 4,500 kilometers (2,800 mi) from the Chicxulub Crater to control for possible changes in soil composition at the impact site while still close enough to be affected by the impact. The analysis revealed there was only one layer of impact debris in the sediment, indicating only one impact. [40] Reuters quoted multiple-impact proponent Gerta Keller as saying, "Unfortunately, these claims are rather hyper-inflated and do not withstand close examination." [41] Did you know.... that a meteor that was credited for the dinosaur extinction hit only a few miles from Progreso Yucatan.. Chicxulub crater From Wikipedia, the free encyclopedia For the town and municipality, see Chicxulub, Yucatán....

Imaging from NASA's Shuttle Radar Topography Mission STS-99 reveals part of the 180 km (110 mi) diameter ring of the crater; clustered around the crater's trough are numerous sinkholes, suggesting a prehistoric oceanic basin in the depression left by the impact.[1] The Chicxulub crater (/ˈtʃiːkʃəluːb/; Mayan pronunciation: [tʃʼikʃuluɓ]) is a prehistoric impact crater buried underneath the Yucatán Peninsula in Mexico.[2] Its center is located near the town of Chicxulub, after which the crater is named.[3] The age of the Chicxulub asteroid impact and the Cretaceous–Paleogene boundary (K–Pg boundary) coincide precisely.[4] The crater is more than 180 kilometres (110 mi) in diameter and 20 km (12 mi) in depth, making the feature one of the largest confirmed impact structures on Earth; the impacting bolide that formed the crater was at least 10 km (6 mi) in diameter.

The crater was discovered by Antonio Camargo and Glen Penfield, geophysicists who had been looking for petroleum in the Yucatán during the late 1970s. Penfield was initially unable to obtain evidence that the geological feature was a crater, and gave up his search. Through contact with Alan Hildebrand, Penfield obtained samples that suggested it was an impact feature. Evidence for the impact origin of the crater includes shocked quartz, a gravity anomaly, and tektites in surrounding areas. The age of the rocks marked by the impact shows that this impact structure dates from roughly 66 million years ago, the end of the Cretaceous period, and the start of the Paleogene period. It coincides with the K-Pg boundary, the geological boundary between the Cretaceous and Paleogene. The impact associated with the crater is thus implicated in the Cretaceous–Paleogene extinction event, including the worldwide extinction of non-avian dinosaurs. This conclusion has been the source of controversy. In March 2010, 41 experts from many countries reviewed the available evidence: 20 years' worth of data spanning a variety of fields.

They concluded that the impact at Chicxulub triggered the mass extinctions at the K–Pg boundary, Chicxulub Crater · August 23, 2014 · Police here in Progreso Yucatan, Mexico... We're posting this because a lot of the times the presence of our police force here in Progreso can be alarming to visitors. We here at Progreso Yucatan Today wanted to explain... when visiting Progreso or the Yucatan you will see many police officers with automatic weapons and road blocks and such.. 1st of all.. there are two different types of policing in the world.. (One) being Apprehension and the (Second) being Preventive... the...re are a lot of good policeman in the USA and other countries but unfortunately in the USA they will wait in a lot of cases until your home is broken into and then attempt to apprehend the suspect if they can solve the crime. Here in Progreso Yucatan they use Preventive Policing.. they do this by a show of force... there is very little Violent Crime here if any... there is a little petty theft if you leave your stuff unattended... So!... it looks like there style of policing works...

(129)Chicxulub crater,Yucatán Peninsula,Mexico(HD)2 - YouTube (129)Chicxulub crater,Yucatán Peninsula,Mexico(HD)2 Want to watch this again later? Sign in to add this video to a playlist. Need to report the video? Sign in to report inappropriate content. Rating is available when the video has been rented. This feature is not available right now. Please try again later. Uploaded on Aug 7, 2011 Here is one of the site of destiny on the Earth =) I feel something of invisible energy here too . Chicxulub crater may have some other secrets ;-) ※The Chicxulub crater is an ancient impact crater buried underneath just here :-o Category

Question: The Chicxulub crater is a prehistoric impact crater buried underneath the Yucatan Peninsula in what country?
Answer: Mexico