Evaluate How Plate Tectonics Theory Helps Our Understanding of the Distribution of Seismic and Volcanic Events.

Plate Tectonics is a scientific theory which study how the Earth’s plates are driven and shaped by geological forces to keep them in constant movement. The theory explains the present-day tectonic behavior of the Earth, particularly the global distribution of mountain building, earthquake activity, and volcanism in a series of linear belt. (Pitman, W.C., 2007)

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 three theories all have many similarities, but only a few stand out specifically. They all involve tectonic plates and use the mantle in the theories. Seafloor spreading occurs because magma erupts and the old floor is always being subducted. Continental drift and plate tectonics

Using geological evidence, scientists have determined that there was, in fact, once a supercontinent. This supercontinent, Pangea, was made up of the seven continents and was a large landmass surrounded by water. The theory of a supercontinent originated from Alfred Wegener’s theory of continental drift. This theory suggests that continents are slowly drifting around earth. Wegener wasn’t the only one who proposed this theory. The idea has been around since the 16th century, the first time being by Abraham Ortelius. Wegener used geologic, fossil, and glacial evidence from opposite sides of the Atlantic Ocean to support his theory. During the 1960s, discoveries of sea-floor spreading and magnetic reversal proved that Wegener's theory was real.

Earthquake Hazards occur when there are adverse effects on human activities. This can include surface faulting, ground shaking and liquefaction. In this essay I will be discussing the factors that affect earthquakes, whether human such as population density, urbanisation and earthquake mitigation or physical such as liquefaction, magnitude, landslides and proximity to the focus.

Earthquakes are an example of seismic activity created by plate boundaries. They can be caused by the subduction of oceanic crust which is densest at 2.9 g/cm3 under continental crust which weighs 2.7g/m3 at destructive plate boundaries. Earthquakes can also occur along conservative plate boundaries such as that shared by the Pacific and North American plates which move at 5-9 cm/year and 2-3 cm/year respectively causing the 1994 Los Angeles earthquake along the San Andreas fault alongside which lies the San Gregorio and Hayward faults. Earthquakes have different impacts dependent on the location of their foci, the point at which they originate from underground, the presence of land in the surrounding areas, but also the human factors such

A piece of evidence we have for plate tectonics is when the continents separated from one another. We have evidence this happened because there have been fossils found in two different areas of the world and we know that they couldn't have physically gotten there endless at one time the continents were together. Another piece of evidence is mountain ranges because in order for a mountain range to exist there has to be two plates colliding causing the ground push up to form the mountains.

Based on the information in the textbook and the instructor note, plate tectonics is the Earth’s surface divided into several plates that move slowly and change in size. I found the video Plate Tectonics: “Birth of a Theory” in session 13 very useful. It helps me understand the material easily by using the animation to illustrate the process of plate tectonics. It is amazing about the fact that the continents can be made to fit together like pieces of a picture puzzle. About 225 million years ago, the Earth seemed to contain only one piece of continent. However, as time goes by, the plate boundaries have happened. The plates that move away from one another are called divergent plate boundaries. The plates that move toward each other are called

Plate tectonics happens when the convection currents in the mantle move and the earth breaks and the result is earthquakes. “Before plate tectonics, people had to come up with explanations of the geologic features in their regions….” (www.livescience.com) This shows how important plate tectonics is to scientist and to helps explain to people. JApan plus many other places have been destroyed by plate tectonics happening. “1995 Earthquake

First and foremost, plate tectonic theory deals with the idea that lithospheric plates or tectonic plates move around the crust. Tectonic plates are slabs of the Earth’s lithosphere which is a combination of the crust and uppermost mantle. The lithosphere is characterized by its rigid and cooler nature. On the other hand, the asthenosphere is hotter and more viscous and lies beneath the lithosphere. Together, the lithosphere and the asthenosphere makes up the outer layers of the Earth. These two layers are really important because the rigid pieces of the lithosphere ride on the viscosity of the asthenosphere (2). As previously mentioned, the Nepal earthquake was caused collision of these plates and it has numerous underlying factors that started

This Mid Atlantic Ridge was discovered in the 1950s and is very important to the globe because the discovery of the ridge led to the theory of seafloor spreading. Seafloor spreading is where new ocean lithosphere gets created through eruptions and also how the basin of the ocean becomes wider. Its discovery also allowed many people to accept Wegener’s theory of the continental drift. The Ridge separates the North American Plate form the Eurasian Plate in the Northern part of the ocean. In the South Atlantic, the ridge separates the South American and African Plates. These plates continue spreading, causing the Atlantic to

Wegener believed that the continents conformed into a full unit at one point, similar to that of a puzzle. This idea of a single, large continent came to be known as Pangea, which in translation, means ‘all-earth.’ Wegner also brought forth the idea that throughout the Jurassic period, Pangea split into two smaller supercontinents, called Laurasia and Gondwanaland. On the other hand, Wegener did not acquire an explanation for how the continents were capable of moving around the planet. Researchers today, however, are able to explain that. For example, Nicholas van der Elst, a seismologist at Columbia University's Lamont-Doherty Earth Observatory in Palisades, New York, explains that the driving force behind plate tectonics is convection in

The plate tectonic theory was conceived through the initial concept of continental drift. Plate tectonic theory suggests that the Earth’s lithosphere is divided into a number of different ‘plates’. The lithosphere is the outer part of the Earth which consists of the crust and upper mantle. The lithosphere is made up of 10 major plates as

The theory of plate tectonics also explains the formation of destructive plate boundaries which account for creating 80% of the world’s active volcanoes. The melting crust at Subduction Zones (oceanic-oceanic or continental-oceanic) are due to differences in density between oceanic and continental lithospheres, where the less dense plate is pushed beneath the more dense plate, and becomes part of the asthenosphere forming magma that is andesitic in its nature. This creates the most violent volcanic activity. Island Arc volcanoes such as Pinatubo and Fold Mountain Volcanoes such as Nevado Del Ruiz (Andes) are very destructive.

For our fourth and fifth units of the year, we investigated the interior of Earth and how it affects the surface, focusing on lithospheric plates and their movements. We also delved into one of the most infamous of natural disasters, earthquakes, which have impacted our area many times over the years. And, as always, I concluded the unit with an essay summarizing everything I have learned, from the layers of our planet to seismic waves and seismographs. What are lithospheric plates? How do they move? What causes earthquakes, and what do you do when one occurs? Be prepared to find out!