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Naman Pujari

The Supporting Evidence Of Continental Drift Theory - 19 views

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    Must-See Site For Evidence For Continental Drift
Annabelle Cheng

Wegener and Continental Drift Theory - 15 views

  • Alfred Wegener was the scientist who championed the Continental Drift Theory through the first few decades of the twentieth century. Simply put, his hypothesis proposed that the continents had once been joined, and over time had drifted apart. The jigsaw fit that the continents make with each other can be seen by looking at any world map.
  • Since his ideas challenged scientists in geology, geophysics, zoogeography and paleontology, it demonstrates the reactions of different communities of scientists. The reactions by the leading authorities in the different disciplines was so strong and so negative that serious discussion of the concept stopped.
  • Why did Alfred Wegener's work produce such a reaction? He was much more diplomatic in presenting his theory than Galileo. Although he believed himself to be right and that some of his arguments were compelling, he knew he would need more support to convince others. His immediate goal was to have the concept openly discussed. Wegener did not even present Continental Drift as a proven theory. These modest goals did not spare him. The fact that his work crossed disciplines exposed him to the territoriality of scientific disciplines. The authorities in the various disciplines attacked him as an interloper that did not fully grasp their own subject. More importantly however, was that even the possibility of Continental Drift was a huge threat to the established authorities in each of the disciplines.
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  • One of Alfred Wegener's critics, the geologist R. Thomas Chamberlain, could not have summarized this threat any better : "If we are to believe in Wegener's hypothesis we must forget everything which has been learned in the past 70 years and start all over again." He was right.
  • In spite of the criticisms from several different disciplines Wegener was able to keep Continental Drift part of the discussion until his death. He knew that any argument based simply on the jigsaw fit of the continents could easily be explained away as a coincidence. To strengthen his case he drew from the fields of geology, geography, biology and paleontology. Wegener questioned why coal deposits, commonly associated with tropical climates, would be found near the North Pole and why the plains of Africa would show evidence of glaciation. Wegener also presented examples where fossils of exactly the same prehistoric species were distributed where you would expect them to be if there had been Continental Drift (e.g. one species occurred in western Africa and South America, and another in Antartica, India and central Africa) [_1_] . The graphic below shows the striking distribution of fossils on the different continents.
  • The main problem with Wegener's hypothesis of Continental Drift was the lack of a mechanism. He did not have an explanation for how the continents moved. Some argue that this failing justified the early reactions to his work and to its dismissal. But Charles Darwin was missing a mechanism for the inheritance of beneficial traits when he published the Origin of Species in 1859.
  • Wegener also shares much in common with Galileo. Wegener probably had at least as strong a case for Continental Drift in 1929 as Galileo had for the Copernican model in 1633
Annabelle Cheng

BBC - GCSE Bitesize: Wegener's theory - 11 views

  • Alfred Wegener proposed the theory of continental drift at the beginning of the 20th century. His idea was that the Earth's continents were once joined together, but gradually moved apart over millions of years. It offered an explanation of the existence of similar fossils and rocks on continents that are far apart from each other. But it took a long time for the idea to become accepted by other scientists.Before Weg
  • Wegener suggested that mountains were formed when the edge of a drifting continent collided with another, causing it to crumple and fold. For example, the Himalayas were formed when India came into contact with Asia.
  • se the Earth was cooling down, and in doing so contracted. This was believed to form wrinkles, or mountains, in the Earth's crust. If the idea was correct, however, mountains would be spread evenly over the Earth's surface. We know this is not the case.
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  • Wegener’s evidence for continental drift was that: the same types of fossilised animals and plants are found in South America and Africathe shape of the east coast of South America fits the west coast of Africa, like pieces in a jigsaw puzzlematching rock formations and mountain chains are found in South America and Africa
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    • Annabelle Cheng
       
      clear slideshow that explains wegener's theory
buycashapp12

Buy Verified CashApp Accounts - USA - 0 views

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    There are a few reasons why you might want to have multiple CashApp accounts. Maybe you have different groups of friends that you want to keep separate, or maybe you need one for business and one for personal use. Whatever the reason, it's actually pretty easy to set up more than one account. First, you'll need to create a new account using a different email address or phone number. Once you've done that, open up the Cash App and tap on the icon in the top-left corner. This will bring up a menu where you can select "Add another Cash Card." From here, just follow the prompts to add your new card. Now that you have two accounts set up, there's one more thing to do if you want to keep them completely separate. By default, Cash App will link your bank account to all of your accounts.
maddie willen

Discovery Channel :: Tsunami - 1 views

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    2004 Indian Ocean earth quake 
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        2004 Indian Ocean Earthquake Pictures: USGS | SUBSCRIBE TO OUR NEWSLETTERS Discovery Channel | TLC | Animal Planet | Discovery Health | Science Channel | Planet Green Discovery Kids | Military Channel | Discovery News | Investigation Discovery | HD Theater | Turbo | FitTV HowStuffWorks | TreeHugger | Petfinder | PetVideo | Discovery Education Visit the Discovery Store: Toys & Games | Telescopes | DVD Sets | Planet Earth DVD | Gift Ideas By visiting this site, you agree to the terms and conditions of our Visitor Agreement. Please read. Privacy Policy. ATTENTION! We recently updated our privacy policy. The changes are effective as of September 10, 2008. To see the new policy, click here. Questions? See the policy for the contact information. Copyright © 2011 Discovery Communications, LLC. The leading global real-world media and entertainment company.   Advertisement Sponsored Links Sustainable Development Health-Social Justice-Human Rights MA MS degrees Brandeis University heller.brandeis.edu   Feedback Diigo Web Highlighter (v1.6.4)  Highlight     Boo
Annabelle Cheng

Alfred Wegener - 9 views

  • Reaction to Wegener's theory was almost uniformly hostile, and often exceptionally harsh and scathing; Dr. Rollin T
  • Part of the problem was that Wegener had no convincing mechanism for how the continents might move. Wegener thought that the continents were moving through the earth's crust, like icebreakers plowing through ice sheets, and that centrifugal and tidal forces were responsible for moving the continents.
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    Part of the problem no one believed his theory
Rima Touya

What evidence did Alfred Wegener use to support his theory of continental drift - 18 views

  • Alfred Wegener's fully developed theory of continental drift attempted to point out evidences that the continents were once joined into a single continent he called Pangea. Wegener's theory hypothesized that the continents were able to push through the rock of the seafloor to their present positions. As evidence, he noted, as had others before him, of the geographic correlation in coastline perimeters of South America and Africa. This was the feature that led Wegener to investigate for other evidences. His investigations revealed that mountain ranges in South America and Africa, and strata and composition of coal fields in Europe and North America matched or lined up. Additionally, matching reptilian fossils were found on either side of the ocean, indicating that the continents were once joined together. Although he was unable to find a mechanism for his proposed continental drift theory, he also observed that the more shallow an ocean, the younger its geologic age. It wasn't until the 1950's and 1960's, with the discovery of the Mid-Atlantic Ridge, and other sea floor mapping discoveries that Wegener's hypothesis started to become more accepted. The newer science of plate tectonics owes much to Wegener's scientific groundwork.
Natasha Premmanisakul

How Volcanoes Work | LiveScience - 0 views

  • How Volcanoes Work Below: History of Volcanoes While earthquakes and hurricanes often seem the most devastating types of natural disasters, volcanoes can have more wide-ranging effects than either. Gallery As the Philippine's Mount Pinatubo showed in 1991, a volcano can create a cloud of sulfuric acid that encircles the entire planet. Personnel Management 2011 www.singaporehcsummit.comLeading HR Experts Share Insight On Personnel Management & Development.French Polishing Edinburg www.gabrielpolishing.co.ukWe are the cheapest French Polisher in Edinburgh,we also do MDF + GlassNMR Rock Core Analyser www.magritek.com/rcaFast NMR Rock Core analyser for oilfield reservoir core samplesAds by Google Volcanoes form w
Isabel Hahn

Google Image Result for - 1 views

shared by Isabel Hahn on 09 Oct 11 - No Cached
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    image 1998 tsunami dam
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