...The Theory of Plate Tectonics Melissa Schroeder Columbia College For millions of years, tectonic plates have been determinate of changes in the physical face of the earth, and they continue to do so today. These massive plates move underneath the surfaces of the oceans and the continents, producing earthquakes, volcanoes and uplifts. This paper will discuss the composition, movement and history of tectonic plates, the theory of plate tectonics and its history, and tectonic plates affect the surface of the earth today and will continue to do so in the future. The earth is divided into three main layers: the core, the mantle and the crust. The core is further divided into the solid inner core and the liquid outer core. This layer is mostly iron and nickel and is extremely hot. The mantle is divided into the lower and upper mantle and is composed mostly of iron, magnesium, silicon, and oxygen. The outermost layer, which contains all life on earth, is the crust. This layer is rich in oxygen and silicon as well as aluminum, iron, magnesium, calcium, potassium, and sodium. It is in between the crust and the mantle that we find tectonic plates. The outermost layers of the earth are divided into two categories based on their physical properties. The asthenosphere is the lower of these categories, composed of clastic or flowing mantle. The upper layer is known as the lithosphere and contains both the top, rigid layer of the mantle and the crust. The lithosphere is what makes up...
Words: 1540 - Pages: 7
...Plate Tectonics Paper Name: Tonia Erskine Date: 01/09/2015 Instructor: Allen Fronabarger According to the U.S. Geological Survey (USGS) one of the leading agency that monitor real time earthquake in the state of Los Angeles, states it is a very high risk for frequent damaging earthquakes. These earthquakes are results from many fault systems that moving through Los Angeles that leads to earthquakes of many different types and sizes. South California has more than 10,000 earthquakes every year; many of them are very small and sometime never even cause any damage or even felt. However, Los Angeles do have large earthquake that create after shocks the causes many damages and sometimes these aftershock can create sequence of additional earthquake that can occur for months. On March 10, 1933 at 5:54 p.m. magnitude 6.4 earthquakes hit the Newport-Inglewood Fault, causing serious damage in Long Beach and other communities. The earthquake resulted in 120 deaths and more than $50 million in property damage. Most of the damaged buildings were of unreinforced masonry. The most recent earthquake in South California caused severe structural damage to buildings but did not caused any deaths, however, on February 9, 1971 caused the city about $500 million in damages and 65 deaths. On October 1, 1987 at 7:42 a.m. an earthquake of the magnitude 5.9. struck the city causing eight deaths...
Words: 796 - Pages: 4
...Plate Tectonics Theory Gaining Credence The theory of Plate Tectonics is a surprisingly recent discovery. The first driving force was in 1915 when Alfred Wegener published his book The Origin of Continents and Oceans. Wegener proposed the idea that the earth’s continent had once been a single super-continent, which he named Pangaea. Wegener explained how many things on earth were interconnected and Pangaea could be the solution for many scientific queries at the time. Many colleagues in the geologic field were skeptical of Wegener’s proposal because he couldn’t explain why the plates moved. It wasn’t until the 1960’s when enough data was collected on projects such as Bathymetry and the Phenomenon of Polar Wander, that a majority of scientists accepted Plate Tectonics. The theory of Plate Tectonics is best described in layers. On top we have the least dense particles such as nitrogen and oxygen gas that make up our atmosphere. As we look deeper into the earth, data shows that denser elements and molecules are pulled into the center and less dense objects ejected due to mass. The core of our earth is made mostly of nickel and iron. The plates that move on the earth’s surface are dominantly solid objects that consist of our earth’s crust and the upper mantle. This is called the lithosphere. The upper part of the lithosphere, the crust, can be separated into two types, continental and oceanic. Continental crust is much thicker than the oceanic crust. This means the lithosphere...
Words: 741 - Pages: 3
...Associate Level Material Plate Tectonics Worksheet Answer the lab questions for this week and summarize the lab experience using this form. Carefully read Ch. 8 of Geoscience Laboratory. Complete this week’s lab by filling in your responses to the questions from Geoscience Laboratory. Although you are only required to respond to the questions in this worksheet, you are encouraged to answer others from the text on your own. Questions and charts are from Geoscience Laboratory, 5th ed. (p. 133-150), by T. Freeman, 2009, New York, NY: John Wiley & Sons. Reprinted with permission. Lab Questions: 8.4 Which has the greater proportion of Iron, Magnetite, or Hematite? Magnetite 8.7 When the reverse switch of a drill is thrown the drill rotates in the opposite direction. How does that affect the drill’s circuitry? It causes a negative current causing the drill to turn in the opposite direction 8.9 Name the 2 other spheres. Hydrosphere- all the water on or near the earth Atmosphere- the air surrounding the earth 8.11 As Columbus’s fleet sailed westward the discrepancy between magnetic north and celestial north changed. Did it increase of decrease? The discrepancy increased because as they sailed the magnetic field decreased. 8.12 Explain the difference in the orientations of the inclined compass needles in figure 8.18. Toward which cardinal direction is the observer facing? East 8.16 During which of these 5 geologic...
Words: 866 - Pages: 4
...Plate Tectonics SCI/245 January 13, 2010 Aimee Pellet Plate Tectonics One of the first scientists to theorize plate tectonics was Alfred Wegener. Alfred Wegener was a German scientist that lived from 1880-1930. He proposed that the continents shifted as time has gone by. “Wegener found that large-scale geological features on separated continents often matched very closely when the continents were brought together. For example, the Appalachian mountains of eastern North America matched with the Scottish Highlands, and the distinctive rock strata of the Karroo system of South Africa were identical to those of the Santa Catarina system in Brazil”(University of California Museum of Paleontology, 2004-2010). His theory was not accepted at first, it took decades for other scientists to see what he had originally tried to explain when publishing his theory in 1915. The reason his theory was not taken seriously is because there was no explanation for how the continents would move. Because the continents do not fit from shore line to shore line we have to look below the sea level and see where they fit best. The shore line do not stop at the water’s edge they slope into the water, this is called the continental shelf. Down about 100 meters there is a shelf break called the continental slope this is where the true edges of the continents can be found. “In Wegener’s time, the technique of radiometric dating was just being developed, so it was not easy to determine the...
Words: 579 - Pages: 3
...Evaluate how plate tectonics theory helps our understanding of the distribution of seismic and volcanic events. Plate tectonics is a relatively new theory that was developed by Alfred Wegner in 1912 who came up with the idea of Pangea which tells us about the structure of the earth. The earths structure consists of a crust which varies in thickness from 5 to 10 km beneath the oceans to 70 km under continents. The lithosphere is the next part which consists of the crust and the upper mantle and is where plate tectonics are formed. The mantle is the widest section of the earth because it is 2900km thick. Also the rocks in the upper part of the mantle are solid and sit on top of the asthenosphere. The core is made up of two parts the inner core which is semi-liquid and consists mostly of iron and the outer core which is solid and made up of iron-nickel alloy. Volcanoes occur mainly at destructive plate margins. Destructive margins occur when a continental plate converges with an oceanic plate but oceanic-oceanic convergences do also occur. When a oceanic plate collides with the continental plate because the oceanic plate is denser the lighter continental plate the oceanic plate will subduct underneath. The bending of the oceanic plate is where the two plates have collided and is where you will find an ocean trench for example the marianas trench located the Pacific Ocean, just east of the 14 Mariana Islands near Japan. As the two plates collide the continental land mass is...
Words: 1043 - Pages: 5
...Plate Tectonics Nicole Anderson GLG/220 Dr. A. Kem Fronabarger November 7, 2011 What is an Earthquake and where do they come from? Many people are unaware of what an actual earthquake is and how they come to be. There are several myths that have been created to help people understand how earthquakes have been produced. In Japan, legend has it the earth is shaken by the movement of a giant catfish hidden in the ground. The Chinese believe that the earth is resting on a giant ox, and in India, one myth suggest that the earth was held in place by four elephants, which were standing on top of a giant turtle, which in turn was standing on top of a giant cobra; whenever one animal moved, the earth is shaking (Zerve, 2000). In the 1960’s we finally found the true cause of earthquakes. The theory of plate tectonics was created. This theory suggests that the earth’s crust consists of “plates” that move relative to one another, and seismic activity is associated mostly with this motion (Zerva, 2000). Most of the earthquake sources are located along the boundaries of these plates. Earthquakes can be very hazardous, so it is important to understand how an earthquake happens and the earthquake preparedness techniques. In order to understand the earthquakes and the tectonic plates, we must first understand the earth and its layers. The earth is made up of three layers: the crust, the mantle and the core (Zerva, 2000). The lithosphere is the crust and upper most solid mantle...
Words: 912 - Pages: 4
...From the tallest mountains, all the way to the deepest ocean trenches, plate tectonics explains all the features & movements of earther’s surfaces in both the past & present. Plate tectonics, the theory that earth’s external shell is separated into numerous plates which glide over the rocky internal layer of the core called the mantle. The plates act like a rigid & hard shell compared to earth’s mantle. The lithosphere is what the strong outer layer is referred to as. Developed between the 1950s all the way through to the 1970s, plate tectonics is the up-to-date version of the theory first proposed in 1912 by the scientist Alfred Wegener, called continental drift. Alfred Wegener couldn’t explain how the continents move around the plant but...
Words: 1769 - Pages: 8
...The Plate Tectonic theory The Plate Tectonic theory states that the continents have moved over hundreds of millions of years due to gigantic slabs of Earth underneath them known as tectonic plates. According to this theory, these plates are the reason why there are mountains, volcanoes, trenches, mid-ocean ridges, and other landforms. There are 4 plate boundaries that create mountains, volcanoes, trenches, and mid-ocean ridges.They are called; Subduction zone, convergent boundary, divergent boundary, and transform boundary.the reason why the tectonic plates move is due to convection currents created in the mantle.as the hot relative temperature from the heat source or the core causes hot materials to rise then colder materials fall to keep a balance of warm and hot temperatures, this cycle in the mantle causes convection currents which slowly move the tectonic plates little by little each year. One of the 4 plate boundaries is a subduction zone.A subduction zone is a convergent boundary that happens...
Words: 637 - Pages: 3
...PLATE TECTONICS THEORY The theory of plate tectonics is widely accepted by scientists and it derived from the Continental Drift theory devised by Alfred Wegener. * In the 17th century is occurred to people that Africa and South America look as though they once fitted together. There were suggestions that the continents have moved apart. * In 1912, Alfred Wegener proposed the theory of continental drift. He suggested all continents were once joined as one supercontinent called ‘Pangaea’ which drifted apart. * He based the theory on geological evidence and fossils, but could not back it up with a mechanism explaining how the continents separated in the first place. * In the 1950’s palaeomagnetism provided evidence supporting continental drift. * In the 1960’s the process of seafloor spreading was discovered which provided a mechanism for continental drift. * The continental drift theory was further developed after these findings and became the foundations of plate tectonics theory. Evidence for the theory: Geology: - Areas of South America and Africa have rocks of the same age and composition. If you fit the continents together the distribution of the rocks match up. You can also match up the age, rock type and distribution of some mountain ranges. E.g. mountains in Scotland, Norway, Sweden and Finland are similar to those on the east coast of North America. These rocks and mountains must have formed under the same conditions and in the same...
Words: 607 - Pages: 3
...Geography plate tectonics and associated hazard notes Plate tectonics and associated hazards Geomorphology – the study of landforms of the earth’s surface Plate tectonics – a theory explaining the structure of the earth’s crust and many associated phenomena as resulting from the interaction of the rigid lithosphere. Geomorphological hazard – an event causing harm to people or property, caused by Geomorphological processes e.g. plate tectonic movement. Francis Bacon 1620 As far back as 1620, Francis Bacon spotted that the west coast of Africa and the east coast of South America looked as if they would fit together, like pieces of a jigsaw puzzle. Between then and 1912 other people identified further similarities between other continental coastlines. Robert Mallet 1870s Robert Mallet was a nineteenth century scientist who managed to measure the speed at which earthquakes spread. Alfred Wegner 1911 While at Marburg, in the autumn of 1911, Wegener was browsing in the university library when he came across a scientific paper that listed fossils of identical plants and animals found on opposite sides of the Atlantic. Intrigued by this information, Wegener began to look for, and find, more cases of similar organisms separated by great oceans. Orthodox science at the time explained such cases by postulating that land bridges, now sunken, had once connected far-flung continents. But Wegener noticed the close fit between the coastlines of Africa and South America. Might the similarities...
Words: 6295 - Pages: 26
...University of Phoenix Material Effects of the Motions of Tectonic Plates Worksheet From Visualizing Earth Science, by Merali, Z., and Skinner, B. J, 2009, Hoboken, NJ: Wiley. Copyright 2009 by Wiley. Adapted with permission. Part 1 This diagram was similar to one Alfred Wegener drew to show the distribution of continents 300 million years ago. His theory of continental drift was met with skepticism in the scientific community. [pic] 1. Describe three forms of evidence Wegener used to support his ideas of continental drift. Wegner suggested that the continental shelves of the continents seemed to fit together similar to a puzzle. According Bugielski (1999), "continents in the southern hemisphere exhibit an identical pattern of rock and fossils known as the Gondwana sequence. The most logical explanation was that the continents themselves were once parts of a much larger super-continent (Early development of plate tectonics). Another point that Wegener used as evidence was by looking at the glacial till deposits. When the contintents were together, the glacial movement was, "more streamlined motion of the glacier from southern Africa and Northern Australia outward" (Bugielski, 1999). The last important piece of evidence that was used was by examinung sedimentary rock that was able to show a change in climates proving the theory of the continental drift or that the poles had moved. (Bugielski, 1999). Bugielski, M. (1999). The Richard Stockton...
Words: 859 - Pages: 4
...Evolution and Theory of Plate Tectonics The most important and vital development of plate tectonic theory and evolution appeared to be among the most crucial scientific achievements in the 20th century. The theory concept offers a relevant structure towards the knowledge of all natural Earth attributes. It additionally provides one particular framework with regard to the knowledge of both planet's origin and outlook. Notably, the evolution of life on the planet remains significantly impacted by plate tectonic processes. This may involve the historic, societal, and cultural advancement of humanity. In other words, plate tectonic theory is an encompassing conjecture regarding different scientific theories that demonstrate the naturally occurring Earth characteristics have actually formed the historical past from the solid Earth, the oceans, the atmosphere, and all life organisms. Many scientific theories are so well established that no new evidence is likely to alter them substantially. For example, no new evidence will demonstrate that the Earth does not orbit around the sun (heliocentric theory), or that living things are not made of cells (cell theory), that matter is not composed of atoms, or that the surface of the Earth is not divided into solid plates that have moved over geological timescales (the theory of plate tectonics). Like these other foundational scientific theories, the theory of evolution is supported by so many observations and confirming experiments...
Words: 1128 - Pages: 5
...processes that it goes through over times which relates to the theory of plate tectonics, as well as boundaries, hotspots, and forces. We begin with the PLate Tectonic Theory which developed along with many other theories to describe the world’s processes and common natural occurrences. In the theory, it describes how the Earth’s lithosphere is divided up into many different plates that push and pull which affects the creating of many of the Earth’s features like mountains, ocean ridges, earthquakes, etc. The plates have different boundaries with one such being the divergent boundary which helps recycle and create a new lithosphere as we discovered in lab. It does this by splitting apart due to...
Words: 468 - Pages: 2
...January 2011 Plate Tectonics and Associated Hazards (25 marks) a) The Philippines are located on the Philippine plate which is largely involved in the tectonic activity of the Pacific Ring of fire where you can find volcanoes and earthquakes which are two primary tectonic hazards, this is due to its location and the fact that numerous trenches are a strong piece of evidence to the presence of the sub-duction of tectonic plates. This makes me think that there is a strong degree to which this area of the Philippines is subject to tectonic hazards. Another piece of evidence supporting a strong chance of tectonic activity is the sheer volume of active faults on the islands compared to the actual land area of the countries, these are were the land has sustained damage over the years of plate movement and the rocks beneath are trapped against each other and creating tension that can be released to create an earthquake of a strong magnitude. Also visible from the image is the location of 5 volcanoes nad if these were to become active most of the countries in the Philippines would be in serious danger from tectonic hazards both primary and secondary like volcanic bombs or lahars. b) Hot spots are points where convection plumes are focusing on a single point beneath the crust as hot magma rises from the super-heated mesosphere into the asthenosphere where it cools and then proceeds to sink back down again. As this magma rises it carries radioactive elements with it and these...
Words: 1056 - Pages: 5
