WHAT KILLED THE DINOSAURS?
VS
CAN OZERDEM 11F
Contents Page
Page 1: ............................................................Title Page
Page 2: .....................................................Contents page
Page 3: ..................................................................Introduction
Page 4: ................................................Scientific Theory
Page 5: ...............................What killed the Dinosaurs?
Page 6: ................................What killed the Dinosaurs; was it the asteroid collision or the volcanic eruption?
Page 8: ..................................Evidence against my idea
Page 9:...........................................................Conclusion
Page 10: ....................................................Bibliography
INTRODUCTION
I have been assigned to study a scientific question in detail. The question I have chosen to study is "What killed the dinosaurs?" the reason I have chosen this question is because over 100s of years this question is trying to be solved but every time it is attempted new evidence and theory is found.
Although there are two main theories' (The asteroid collision and the volcanic eruption) scientists have found other evidence to make their own theory's today I am going to talk about these theories and which one I think is accurate.
Definition of a reliable source: Reliable sources are authors or publications regarded as trustworthy or authoritative
Thursday, 4 March 2010
An international panel of experts has strongly endorsed evidence that a space impact was behind the mass extinction event that killed off the dinosaurs.
He added: "The explosion of hot rock and gas would have looked like a huge ball of fire on the horizon, grilling any living creature in the immediate vicinity that couldn't find shelter."
They also added that the crater weren't a direct cause of the mass extinction they claimed that the crater theory caused other problems such as lack of food and resources.
There are also other evidences supporting other theories I will also talk about them but personally I think the mass extinction was linked to the crater theory.
Scientific Background
There is a lot of theory's hiding behind the question "What killed the dinosaurs?" Some of the theories are the crater theory, the ice age theory and the volcanic eruption theory.
) 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 asteroid collision theory, which was brought to wide attention in 1980 by Walter Alvarez and colleagues, links the extinction event at the end of the Cretaceous period to a bolide impact approximately 65.5 million years ago.
2) Before 2000, arguments that the Deccan Traps flood basalts caused the extinction were usually linked to the view that the extinction was gradual, as the flood basalt events were thought to have started around 68 million years ago and lasted for over 2 million years. However, there is evidence that two-thirds of the Deccan Traps were created in only 1 million years about 65.5 million years ago, and so these eruptions would have caused a fairly rapid extinction, possibly over a period of thousands of years, but still longer than would be expected from a single impact ...
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2) Before 2000, arguments that the Deccan Traps flood basalts caused the extinction were usually linked to the view that the extinction was gradual, as the flood basalt events were thought to have started around 68 million years ago and lasted for over 2 million years. However, there is evidence that two-thirds of the Deccan Traps were created in only 1 million years about 65.5 million years ago, and so these eruptions would have caused a fairly rapid extinction, possibly over a period of thousands of years, but still longer than would be expected from a single impact event.
3) The ice age theory was that during the ice age the dinosaurs failed to adapt to the changing environments and the numbers of the dinosaurs decreased.
The most reliable and supported one is the crater theory.
What killed the dinosaurs?
There are a lot of theories that explains the extinction of dinosaurs. There is two main theories' lying behind this extinction of dinosaurs. Probably the most popular theory right now is the Asteroid Theory. According to this theory a large asteroid or comet collided with Earth about 65 million years ago. Scientists think that such a large collision would throw so much dust into the air that sunlight would not be able to shine and plants and animals would die. The dramatic changes in climate that resulted from this huge collision were too much for the dinosaurs. They were not able to survive.
Another theory that could explain how the dinosaurs became extinct is volcanic activity. A huge increase in volcanic activity at around 65 million years ago could have pumped so much ash into the air that it blocked out the sun killing the dinosaurs.
Some scientists believe that there was a severe ice age. Throughout Earth's history there have been many ice ages. The last one ended about 10,000 years ago. A very severe ice age could have changed temperatures and frozen a lot of Earth's water. The dinosaurs would not be able live under such conditions and that is how the dinosaurs became extinct.
Last theory was believed to be about a disease that killed off the dinosaurs. A very deadly and contagious disease may have circulated among the dinosaurs forcing them to become extinct.
There are still many more theories including ethnic and other ones too.
What killed the Dinosaurs; was it the asteroid collision or the volcanic eruption?
The Chicxulub Crater at the tip of the Yucatán Peninsula; the impactor that formed this crater may have caused the dinosaur extinction.
According to the Crater theory it is said that after the crater struck Yucatan, dinosaurs that were alive couldn't find a mate to reproduce and food to live around the Yucatan Peninsula. Paleontologists Zielinski and Budahn claimed that the dinosaurs that were alive failed to adapt to changing conditions. It is also said that the Cretaceous period ended approx. 65 million years ago. And the asteroid collision theory, which was brought to wide attention in 1980 by Walter Alvarez and colleagues, links the extinction event at the end of the Cretaceous period to a bolide impact approximately 65.5 million years ago. Although the speed of extinction cannot be deduced from the fossil record alone, various models suggest that the extinction was extremely rapid. The consensus among scientists who support this theory is that the impact caused extinctions both directly (by heat from the meteorite impact) and also indirectly (via a worldwide cooling brought about when matter ejected from the impact crater reflected thermal radiation from the sun).
Recently a panel of 41 international experts reviewed 20 years' worth of research to determine the cause of the Cretaceous-Tertiary (K-T) mass extinction, around 65 million years ago.
When the 10km-15km space rock struck the Yucatan, the explosive energy released was equivalent to 100 trillion tonnes of TNT - over a billion times more explosive than the bombs dropped on Hiroshima and Nagasaki.
"You can actually trace debris right up to the rim of the crater from across the world," Co-author Dr David Kring, from the Lunar and Planetary Institute in Houston, told BBC News. This shows that the impact was so big that the whole world was affected by it which can be another evidence for the mass extinction. The scientist claimed that the asteroid triggered many more things that were earthquakes, volcanic eruptions and continental landslides which generated tsunamis. These are some of the quotes that the scientists said:
He added: "The explosion of hot rock and gas would have looked like a huge ball of fire on the horizon, grilling any living creature in the immediate vicinity that couldn't find shelter."
Dr Joanna Morgan, another co-author from Imperial, commented: "The final nail in the coffin for the dinosaurs happened when blasted material was ejected at high velocity into the atmosphere. This shrouded the planet in darkness and caused a global winter, killing off many species that couldn't adapt to this hellish environment."
Scientists have previously argued about whether the extinction was caused by a space impact or by volcanic activity in the Deccan Traps in India, where there were a series of super-volcanic eruptions that lasted approximately 1.5 million years.
These eruptions spewed more than 1,000,000 cu km of basaltic lava across the Deccan Traps - enough to fill the Black Sea twice. These were thought to have caused a cooling of the atmosphere and acid rain on a global scale. Despite evidence for relatively active volcanism in the Deccan Traps at the time, marine and land ecosystems showed only minor changes within the 500,000 years before the time of the K-T mass extinction.
Furthermore, computer models and observational data suggest the release of gases such as sulphur into the atmosphere after each volcanic eruption in the Deccan Traps would have had a short-lived effect on the planet.
The panel also discounted previous studies that suggested the Chicxulub impact occurred 300,000 years prior to the mass extinction event.
There is also new evidence made up of a thermal camera capturing all the possible places the crater affected. 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 Silver pit crater in England's 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. 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.
Evidence against my idea
Evidence was found in India following:
A series of monumental volcanic eruptions in India may have killed the dinosaurs 65 million years ago, not a meteor impact in the Gulf of Mexico. The eruptions, which created the gigantic Deccan Traps lava beds of India, are now the prime suspect in the most famous and persistent paleontological murder mystery, say scientists who have conducted a slew of new investigations honing down eruption timing.
The main phase of the Deccan eruptions spewed 80 percent of the lava which spread out for hundreds of miles. It is calculated to have released ten times more climate altering gases into the atmosphere than the nearly concurrent Chicxulub meteor impact, according to volcanologist Vincent Courtillot from the Physique du Globe de Paris. Keller's crucial link between the eruption and the mass extinction comes in the form of microscopic marine fossils that are known to have evolved immediately after the mysterious mass extinction event.
Previous work had first narrowed the Deccan eruption timing to within 800,000 years of the extinction event using paleomagnetic signatures of Earth's changing magnetic field frozen in minerals that crystallized from the cooling lava. Then radiometric dating of argon and potassium isotopes in minerals narrowed the age to within 300,000 years of the 65-million-year-old Cretaceous-Tertiary (a.k.a. Cretaceous-Paleogene) boundary, sometimes called the K-T boundary.
Conclusion
So I have come to a conclusion that the answer for the question "what killed the dinosaurs" is a link between crater theory and mass extinction.
There are a lot of ideas/theories and beliefs hiding behind this mystery. Think the most reliable theory is the crater theory according to the theory a massive asteroid struck earth that linked to the mass extinction of the dinosaurs. Also if you look at the report that submitted by BBC and by Dr David Kring, you can see how this evidence was not actually a myth or belief. According to Dr David Kring he and his colleagues, they found major evidence around the Yucatan and pieces of the crater around the world. They have also found other craters around the world including United Kingdom. But the crater wasn't a direct cause of the mass extinction the asteroid just triggered many more events such as movements of the tectonic plates and lack of resources around the crater. But on the other hand the volcanic eruption theory too has evidence. According to what Dr Kring has said the volcanic eruption might be one of the events that were made by the asteroid that struck earth.
Major evidence was found in Canada. A fossil found in Canada was said to be found 100,000 years after the volcanic eruption. So even after the volcanic eruption dinosaurs were existing. Some scientists also believe the volcanic eruption happened after the mass extinction.
BIBLIOGRAPHY
http://en.wikipedia.org/wiki/Dinosaur
http://www.associatedcontent.com/article/433940/new_evidence_volcanoes_killed_the_dinosaurs.html
http://news.bbc.co.uk/1/hi/8550504.stm
http://www.allaboutcreation.org/dinosaur-extinction.htm
http://www.sciencedaily.com/releases/2007/10/071029134743.htm
http://themanyfacesofspaces.com/MFS-StrangeButTrue-Places4.html