“Volcanic and Seismic Events Are Major Pieces of Evidence Towards Proving That Plate Tectonics Theory Is Valid’ Discuss the Extent to Which You Agree with This Statement

The Earth is constantly moving and this causes both earthquakes and volcanic eruptions to take place. As the plates drift and collide into each other, pressure builds beneath the surface of the earth. If it occurs near a fault, then an earthquake results. If the pressure is near a volcano, then the volcano will erupt. Sometimes the surface near a volcano will experience many small earthquakes before an eruption. The amount of pressure that is built up from the plates moving causes damage to the Earth’s surface. This can be seen at the Mid-Atlantic Ridge. The seafloor is spreading apart in the Atlantic Ocean which is pushing the plates apart. The surface that is experiencing volcanoes from this is Iceland.

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.

Magma can also push up under the middle of a lithosphere plate, though this is much less common than magma production around plate boundaries. This interplate volcanic activity is caused by unusually hot mantle material forming in the lower mantle and pushing up into the upper mantle. The mantle material, which forms a plume shape that is from 500 to 1000 km wide, wells up to create a hot spot under a particular point on the earth. Because of the unusual heat of this mantle material, it melts, forming magma just under the earth's crust. The hot spot itself is stationary; but as a continental plate moves over the spot, the magma will create a string of volcanoes, which die out once they move past the hot spot. The Hawaii volcanoes were created

The continental drift is where all continents were all as one. This giant continent was named "Pangea". The Earth and Ocean are always shifting. These movements are known as "Plate Tectonics". The scientists who discovered these movements and came up with the idea were known as Alfred Wegener and Frank Taylor.

First, I'm going to talk about earthquakes. "Earthquakes and volcanoes are closely related." Their home is the ring of fire. In 1980 a small earthquake happened in Mt. St. Helens. That small earthquake caused the northern mountain to slide down a hill. If tectonic plates bump into each other an earthquake can happen. Nearly all the world's earthquakes happen in the ring of fire.

The Ring of Fire is an area in the Pacific Ocean where earthquakes happen the most. Roughly 90% of all earthquakes happen in this area, and 75% of the world’s active volcanos are within The Ring of Fire as well. The Ring of Fire isn’t exactly a ring. It’s more of a crooked horseshoe but “The Crooked Horseshoe of Fire” doesn’t have the same charm to it. The Ring of Fire is a result of the tectonic plate boundaries. Tectonic plates are huge slabs of the earth’s crust which fit together like pieces of a puzzle. Because the pieces move around, them rubbing together and scraping about causes the earthquakes, and when the plates pull apart magma with potential slowly push up towards the surface. This makes a volcano. The process

The second theory was Alfred Wegener’s theory. He thought that the continents were moving. He based his argument on the observation that the coast lines matched up like puzzle pieces. He also observed that similar fossils were found oceans apart. He tried to explain this by something called continental drift. So, Alfred Wegener’s theory was that during some point in history, the plates moved from one giant supercontinent to where they are now.

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 suggests that the surface of the earth is broken into massive plates and these plates slowly drift towards and away from each other. When the edges of these plates meet, they produce intense activity, marked by earthquakes and other geological events. The plate tectonics theory is a combination of two other theories: continental drift and sea-floor spreading.

Here, two plates meet and the denser oceanic lithosphere of the Nazca plate is forced down under the more buoyant continental lithosphere of the South American plate, descending at an angle into the mantle in a process called subduction. This is marked on the ocean surface by the presence of the Peru-Chilie trench. The friction between the plates prevents the subducting oceanic plate from sliding smoothly. As it descends it drags against the overlying plate causing both fracture and deform. This results in frequent shallow focus earthquakes The subduction of the Nazca plate under southern Chile produced the largest earthquake ever recorded, with a magnitude of 9.5 in 1960. Volcanoes are also created here as one plate subducts and partially melts; the magma rises up through fissures and can reach the surface. The type of lava here is andesitic, very high in silica and not very hot resulting in a composite volcano being formed out of layers of ash and lava. The cascade mountain range is an example of where a destructive plate boundary has caused the Juan de Fuca plate to subduct under the North American plate. This resulted in 15 composite volcanoes being formed, one of them, Mount St. Helens.

Volcanic and Seismic events are major pieces of evidence towards proving that plate tectonics theory is valid.

A plate tectonic is defined as a solid rock mass that builds up the Earth’s surface. The plate tectonic theory is a theory that geologists use to help explain the surface processes and events. The word plate means large pieces of the earth that are always in motion, lithosphere plates. Tectonics means how the continents formed and move over time. This is the theory that most geologists accept as to what happened to our continents. It states that Earth is made up of two layers, the lithosphere, outer, and the inner asthenosphere.

Alfred Wegner was a German meteorologist and geophysicist and in 1912 he developed the idea that Earth’s continents were once a large supercontinent, which he named Pangaea, that had fractured and slowly drifted apart from each other (Trujillo, Pg 36). Wergner had observed from maps that the coastlines of the continents of Africa and South America matched. He also observed that many fossils, plant life, and minerals matched up on the different contents. This is what led Wergner to the concept of continual drift (“Birth of a Theory”). Wergner’s theory was not widely accepted by others during this time. It was Wergner’s theory on how the continents moved through the ocean basins and the fact that he did not have a strong theory on how thick continental plates

Davies (2009) states hot spots can be described as irregularly spaced areas within the mantle that do not correspond with any plate tectonic processes. It was thought 50 years ago high temperatures were found at hot spots, so rocks within the region were liquefied to create molten magma, resulting in the term ‘hot spot volcanos’. The accepted theory for the formation of hotspots was put forward by Geophysicist John Tuzo-Wilson in 1963, who specified the Earth has areas of fixated magma plumes deep within the mantle that have been created from intense radioactivity in the Earth’s interior (Foulger, 2003). As demonstrated in figure one the Earth’s crust passes over the mantle, the magma plume forces the boiling magma up through the Earth’s crust where the ‘hot spot’ remains until the tectonic plate passes over it and the boiling lava creates a series of new volcanoes, like the Hawaiian Islands (Davies, 2009). Although this concept is easy to accept due to it leaving room for further research and hotspots appearing to have a deep source, alternative hypotheses’ have since been argued to challenge the theory, as the accepted hypothesis was created long before scientific evidence was available. For example, there were discoveries such as hotspots not actually being high in temperature or being fixated relative to one another (Stein et al, 2003). An example of contradictory evidence is the Canary Islands; the island of Fuerteventura aged 23 MA lies closer to the ridge than the

Plate tectonics should sound familiar and also sound like something that is a definitive piece of earth, however, it is just a theory. It is thought that the earth is broken into sections and is slowly moving. There are many pieces of evidence stating why the theory of plate tectonics are valid. Continental drift is the most valid evidence to the plate tectonics theory.