The Theory Of Plate Tectonics

It is unclear why this is happening and research is currently taking place. There have been many hypotheses formed, one suggests that the plate boundary might be shifting towards the east and away from the San Andreas fault. (LiveScience) If you refer to Ch.7 page 228 in the textbook Earth Science, figure 7.25 illustrates where Earths landmasses may be 50 million years from now if present plate movements persist during this time

The plate tectonics theory was made by a German named Alfred Wegener. He stated that a single continent existed about 300 million years ago named Pangaea and that it split into two continents of Laurasia in the north and Gondwanaland in the south. Today’s continents were formed by further splitting of the two masses.

II: Plate tectonics shows the features and movement of the Earth. The theory of plate tectonics says that the outer shell of the earth is broken down into pieces often called plates (Korenaga). These plates hover over the mantle creating movement (Marshak). With plate tectonics you can determine the earth’s features without actually seeing it.

The theory of plate tectonics was first developed by Alfred Wegener. He concluded that the continents seem to have a similar shape and could potentially fit together. This suggested that they were at one time joined together as part of 2 super continents called Gondwanaland and Laurasia was in the north. This theory was said to be proven by the discovery of fossilised remains of a mesosaurus that were found on the coasts of Brazil and Gabon. Sea floor spreading is another theory that supports the idea of plate tectonics; this theory discovered that rock is being formed under the ocean as a new sea floor. Sea floor spreading was shown in the Atlantic, where it is believed the Eurasian and North American plates are moving apart on a

2. The theory of “Pangaea” exists suggesting that the continents were once nestled together into one mega-continent. The continents then spread out as drifting islands.

In junior high school, I have learned the Continental Drift Theory, and my geography teacher told me there was a new theory based on the Continental Theory, i.e. Plate Tectonics. I accessed to the Internet to find the information about Plate Tectonics.

The theory of plate tectonics states that Earth’s outer shell is divided into plates. The crust and upper mantle is broken into plates that move around on the mantle, changing in size throughout time. The lithosphere makes up the crust and upper mantle and the asthenosphere a plastic like layer beneath the lithosphere. There are three types of plate boundaries. Divergent boundaries where two plates move away from each other. The ocean widens and new crust forms at the mid-oceanic ridge. Convergent boundaries has three types of converging, moving two plates towards each other. First we have an ocean floor plate that collides with a less dense continental plate. Next an ocean floor plate collides with another ocean floor plate. Finally a continental plate collides with another continental plate. Transform boundaries were two plates slide past one another. The resulting effects of plate tectonics is landforms such as rift valleys,

To support the theory of continental drift is through topography, surveying the floors of oceans, charts of rock magnetism, and statistics on rock ages (Trefil & Hazen, 2010). At one time scientist believed that the deep ocean floors were flat; accumulating the sediment that progressively wore away from the prehistoric landmasses (Trefil & Hazen, 2010). However, they discovered steep-walled valleys and elevated highlands. This was evidences that just as the continents are transformed and are active, so to is the seafloor (Trefil & Hazen, 2010). The Mid- Atlantic Ridge, positioned in the central part of the Atlantic Ocean, is recorded to be the longest mountain range on this planet. Volcanoes, lava flow, and earthquakes are a source of

The theory of Pangaea suggests that the continents were once stuck together into one huge continent. Eventually they started drifting into separated landmasses, which gave birth to the modern continents.

In ionic bonding one atom transfers electrons to another, creating ions with differing electrical charge.

Plate tectonics is the scientific theory that attempts to explain the movements of the Earth's lithosphere that have formed the landscape features we see across the globe today” (Briney). Geology defines “plate” as a large slab of solid rock, and “tectonics” is part of the Greek root word for “to build.” Together the words define how the Earth’s surface is built up of moving plates. The theory of plate tectonics dictates that individual plates, broken down into large and small sections of rock, form Earth’s lithosphere. These fragmented bodies of rock move along each other atop the Earth’s liquid lower mantle to create the plate boundaries that have shaped Earth’s landscape. Plate tectonics originated from meteorologist Alfred Wegener’s theory, developed in the early 20th century. In 1912, he realized that the east coast of South America and the west coast of Africa appeared to piece together like a jigsaw puzzle. He further examined the globe and deduced that all of Earth’s continents could somehow be assembled together and proposed the idea that the continents had once been linked in a single supercontinent called Pangaea. To explain today’s position of the continents, Wegener theorized that they began to drift apart approximately 300 million years ago. This theory

Continental drift was a theory offered by Alfred Wegener in 1912 that hypothesized that all the continents at one time fit together as one land mass. Wegener, explained that the ends of each continent could fit together like a puzzle and that over time the continents drifted apart. "The model explained why the same types of fossils occur in sedimentary rock on both sides of the vast Atlantic Ocean" (Star, 2008, pg. 250), in other words allopatric speciation. Wegener's theory did not have a supporting geological mechanism. Many years later and advances in technology brought about the plate tectonics theory. Essentially it says:

A German meteorologist and explorer Alfred Wegener put forth the theory of continental drift in the early 1900’s. Wegener pointed out that the earth’s continents looked as if they were all connected at one point in time. He also pointed out that some of earth’s features, including the long S-shaped mountain structure formed on the Atlantic seafloor, could fit snugly against the corresponding western seafloor of Europe and Africa (Sieh and LeVay 1998). Wegener proposed that all of the earth’s continents once formed one single landmass, which he named Pangaea or “all-land”. He concluded that Pangaea had broken up and separated due to the unidentifiable forces estimated 300 million years ago (Sieh and LeVay 1998). Geologists did not fully understand at the time that Earth’s continents could drift (Hazen 2012). After all, the continents do not float in the oceans. They are made from a solid material connecting to the mantle, a sphere of solid rock

The tectonic plate model project was a fun, yet informative project that showed students how to effectively move things from one place to another and also how Pangaea moved to how it is today. By using two big foam boards, big blue sheet, artificial grass sheet, magnets, tape, copy paper, and pencils, we were able to create an accurate representation of how Pangaea moved from over 4 billion years to now. How we created this project was by using magnets. Magnets are very versatile and we attached them accordingly onto the continents and poster board to create a moving project of Pangaea. By gluing magnets onto each continent and the blue sheet, we were able to create moving continents that show Pangaea’s movement.

In the middle of the eighteenth century, James Hutton proposed a theory, uniformitarianism; “the present is the key to the past”. It held that processes such as geologic forces- gradual and catastrophic-occurring in the present were the same that operated in the past. (Matt Rosenberg, 2004) This theory coincides with the theory of Continental Drift that was first proposed by Abraham Ortelius in December 1596, who suggested that North, South America, Africa and Eurasia were once connected but had been torn apart by earthquakes and floods. He also discovered that the coasts of the eastern part of South America and the