Abstract
This paper explains that plate tectonics is one of the most important discoveries in science and geology because it explains why the continents share many similarities, which could not be explained if they had always existed apart and it explains why, even today, the surface of the earth is constantly shifting, rearranging and moving. The author points out that an important discovery, which ultimately led scientists to believe the theory of plate tectonics was correct, was the discovery of seafloor spreading. The paper relates that plate tectonics and the continual shifting it produces can create many changes in the surface of the earth from weather to earthquakes and volcanic eruptions.

From the Paper
"Several theories of geologic process and scientific discovery helped lead to the discovery of plate tectonics in the 1920s, and the theory was generally accepted by the 1950s. The plate tectonic theory evolved from earlier theories, beginning with continental drift. The first time continental drift was mentioned was in 1908, by an American named Frank Bursey Taylor. However, the theory really did not gain acceptance until 1912 when German meteorologist and geophysicist Alfred Wegener detailed the theory and gave it more basis in fact. The continental drift theory believes that between 275 and 175 million years ago, all the continents were joined together in one land mass. Later, this massive continent broke apart into two gigantic landmasses in the north and south, those continents further divided about 100 million years ago into more currently recognizable shapes, and they began to drift apart during this time, too."

Tags:seafloor, continents, earthquakes, drift, recycling

Abstract
This paper first explains that the plate tectonic theory, which suggests that the Earth is made up of a dozen rigid plates, moving independently of each other, is used to explain the movement of the plates on the Earth's lithosphere. Next, the author relates the history of the development of this theory starting from the work of Alfred Wegener, a German geophysicist and meteorologist, in 1912. The paper examines that the studying ocean floor and earthquake and volcanic activity are commonly used as evidence to support the plate tectonic theory.

From the Paper
"By scanning the ocean floors with magnetometers, they hypothesized that the oceanic crust constantly reformed at the crest of the mid-ocean ridges. The further you move away from that ridge crest, the sediment would become increasingly older. As they had been able to see evidence of seafloor spreading, it was accepted that the tectonic plates had moved. They also endeavored to determine and document the earthquake and volcano activity across the globe, to see how it related to the oceanic trenches and underwater mountain ranges."

Tags:asthenosphere, continental drift theory, paleomagnetic polar changes, magnetic field, subduction zones

Abstract
This paper describes the continental drift and plate tectonic theories and traces their history, discusses the key players who were involved in developing the theories and examines the current state of scientific knowledge about Earth's geology and paleontology.

From the Paper
"The idea that the earth's continents have drifted has a long history. As long ago as 1596 the Dutch map maker Abraham Ortelius in his work Thesaurus Geographicus Ortelius suggested that the Americas were "torn away from Europe and Africa . . . by earthquakes and floods." He had been the first (and certainly not the last) to notice the apparent "jig-saw" fit of the bulge of eastern South America into the bight of Africa. (Kious and Tilling, 1999) In around 1850 A.D., a French scientist Antonio Snider-Pellegrini, while researching the similarity of the fossil plants and coal deposits in North American and European and concluded that the phenomenon could only be explained if the two continents had once been connected. In 1908 Frank B. Taylor of the United States invoked the notion of continental collision to explain the formation of some of the world's mountain ranges."

Tags:continents, land, masses, constantly, moving, collided, broken, apart, drifted, framented, oceans

Abstract
The writer of this paper details the exploration of the ocean floor which began in the 1940s and aided scientists in developing the theory of plate tectonics. This paper explores how the work of researchers like Albert Wegener and James Hutton and the study of plate tectonics helped predict with some degree of accuracy where and when an earthquake will strike as well as predict which of the world's active volcanoes will erupt, saving countless lives.
Topics covered in this report include:
The Theory of Continental Drift
This Dynamic Earth-Developing the Theory
Plate Tectonics
Works Cited

From the Paper
"Abraham Ortelius, a Dutch mapmaker, first suggested the possibility that the earth's landmasses were not fixed in 1520. He suggested that the Americas were once attached to Africa and Europe. They were then ripped apart by earthquakes and floods, creating three continents. It wasn't until the early part of this century, when a German meteorologist named Alfred L. Wegener became intrigued by this concept and the ideas set forth by other scientists that land bridges had been connected the continents at one time, but had then sunk into the ocean."

Tags:science, james, hutton, earthquake, volcano, geology, abraham, ortelius, alfred, wegener, ocean, earth

Abstract
This paper help explains how Plate Tectonics has caused changes in continental landmasses through geological occurrences. It presents the main controversy in the Plate tectonic theory - whether the movement of the plates has displaced landmass across the continents or not and whether it is the sole reason for the change of the landmass or it is through atmospheric influence.

From the Paper
"Thousands of years ago the earth's surface has been hypothesized as one big landmass. The Earth's surface has been constant motion. "Fragmented into giant sheets of solid rock that glide atop a layer of hotter, more pliable material, the globe's appearance is forever changing." [Cowen, 1999] . These plates are semi rigid, floated on flow of mantle. The plates measured around 50 miles, thickness of 25 miles on land and 4 miles thick under the oceans. Their movement was categorized by an average of a few inches a year. Even today, geologists and tectonicists hypothesize the earth to continue this movement in similar slow manner, even if we do not notice it. The plates' movement is called the Plate Tectonic Theory, a theory presented in 1912 but upheld in 1960 . "

Tags:volcano, earthquake, earth, california, mountain, collision, layer, global, meltdown, ocean, rock

Abstract
This paper discusses how science has developed many theories of how the earth works to explain natural disasters and why they are a continuous part of human life. According to this paper, one such theory concerns the continental drift and plate tectonics that was explored to explain why certain natural formations upon the earth and in the seas are consistently changing.

From the Paper
"Redfern attempts, through his writing, to explain a concept of science that has been beneficial to humankind by exploring natural change sin the earth. Redfern contends that the concept behind the continental drift is that the earth is formed in large plates, which are massive sections beneath the surface. Redfern states that Continental crust is very different from the crust that floors the oceans. Ocean crust is predominantly magnesium silicate, whereas the continents contain higher proportions of aluminum silicates. They also contain less iron than the denser material of the mantle or of the ocean floor. "

Tags:natural, science, tectonic

From the Paper
"During the past century, considerable advances have been made in the field of geology. The discovery of plate tectonics has provided researchers with a unifying theory that explains many fundamental earth processes. Of the various hypotheses that led to plate tectonic theory, the most important was proposed by Alfred Wegener. Wegener's ideas on continental drift were supported by much evidence. However, perhaps because of its overwhelming implications, the theory was met with considerable resistance. Only in recent decades has scientific investigation collected sufficient evidence to definitively establish the validity of the continental drift hypothesis.

The theory of plate tectonics describes a lithosphere consisting of approximately the Earth's outer 100 kilometers.... "

Abstract
This paper looks at the life and work of Karl Gauss. It examines his theory on Plate Tectonics, the theory of Motion of Heavenly Bodies and several other theories that were developed during his lifetime. The writer first briefly gives a bio of Gauss and then attempts to explain the theories in laymen's terms.

From the Paper
"There are many well known mathematicians from history whose work is well known and position widely recognized. However, there are also many lesser known mathematicians that have also made equally valuable contributions. Karl Friedrich Gauss is one of these, and as such is a worthwhile individual to study. Gauss developed many ideas and theories which are still in use today. He is best known for his theory of plate tectonics and his work entitled "Theoria Motus Corporum Coelestium" ; Theory of the Motion of Heavenly Bodies in 1809. With Wilhelm E. Weber; a physicist he also developed a theory concerning geomagnetism. Much of his work is still used today, including work in the fields of physics, astronomy, and his statistical theories are even used in software algorithms. In this we see man who has made large contributions to the world of mathematics and related disciplines (Schaaf, 1964)."

Tags:mathematics, motion, plate, tectonics, compass, geometry, logic, calculation, Theoria, Motus, Corporum, Coelestium, Euclidean

Abstract
This paper looks at the numerous theories that have been presented over time regarding the reason for dinosaur extinction. The author discusses explanations such as a sudden catastrophic event, like a meteor hitting the earth or a volcanic eruption, and also slow, environmental causes like global warming or shifting plate tectonics.

From the Paper
"First, around the time of the mass extinction of the dinosaurs there was a global climate change. During this time, the environment changed from the warm and mild one present in the Mesozoic era to the cooler one of the Cenozoic. Second, evidence exists to support a massive terrestrial disturbance at the end of the Cretaceous period that included soot in the air, acid rain, the emission of poisonous gases, and a cooling similar to that of a nuclear winter. This terrestrial disturbance caused periods of darkness on the earth as well as a global greenhouse effect. Third, the dinosaurs were only one species that became extinct during this time. According to scientific evidence, approximately 60 percent of all species below the line of the K-T boundary did not exist above that line."

Tags:earth, sudden, impact, environment, volcano, meteor, era, period, mesozoic, cretaceous, k-t, boundary, evidence, science, decline, global, cause

Abstract
This paper purports to investigate our greater understanding of the unified theory of plate tectonics and seafloor spreading. The structure of the earth and the traditional theory of continental drift is examined, followed by a look at the more unified theory of plate tectonics. The global ramifications of this theory is investigated by examining the damaging tectonic activity caused by seafloor spreading, specifically earthquakes as well as the hazards these earthquakes in turn generate, namely tsunamis. Case studies are provided to illustrate the damaging nature of these natural forces. Finally the paper examines whether these hazards can be predicted or prepared for given our greater understanding of their causes.

From the Paper
"The Earth is a layered planet consisting of the crust, mantel and core as illustrated in Figure 1 below. Due to the intense heat during the formation of the planet, Earth was mostly molten. The more dense materials sank to the centre forming the core while the lighter materials floated to the surface and gradually formed a rigid layer called the lithosphere (Byatt 2001:18). The upper part of this lithosphere is called the crust, a layer about 80km to 40km thick (Strahler & Strahler 1989:254). The lithosphere also includes the upper part of the mantle called the asthenosphere, which is highly heated to a state that is semi plastic. The rigid, brittle lithosphere, which is broken into large fragments called lithospheric plates, has the capability of moving over the soft, plastic asthenosphere."

Tags:drift, earthquakes, floor, hazards, lithosphere, plate, sea, spreading, tectonic, tectonics, tsunamis