Research into the theory of plate tectonics first began around 1920. This research was spearheaded by Alfred Wegner, a German meteorologist and geophysicist. His work presented the theory that today’s continents once were joined as one to form a huge supercontinent commonly referred to as Pangaea today. Wegner’s theory stated that the super continent broke up and the pieces (today’s continents) drifted over time into their current positions, he called this “Continental Drift”. Wegener's theory also provided an alternate explanation for the formation of mountains (orogenesis).
Alfred could not explain how the huge masses of land could have moved so far. The major means for the lithospheric plates to float on the asthenosphere comes from the process of convection in the mantle of the Earth. Heat from the outer core rises in the mantle and “melts” the upper part, which is called the asthenosphere. The plates of the lithosphere move in three main ways. There are divergent boundaries where the plates are moving away from each other and new land is formed as magma is released from inside the mantle.
Plate tectonics was first suggested as a theory by the geologist Alfred Wegener in 1915 when he proposed the concept of continental drift. Back in the geological past, what is now South America, Africa, Australasia and Antarctica fitted together into a supercontinent known as Gondwanaland; with North America, Europe and Asia fitting into another supercontinent known as Laurasia. (OCR AS/A2 Geology, Mugglestone et al, 2008). These were once believed to be joined to form one major central global landmass known as Pangaea (Introducing Geology, Graham Park). But now due to the global distribution of these major plates it has been proposed by Wegener and his successors that convection currents in the mantle are the cause of the movement of plates.
How to predict an volcanic eruption Ground Deformation Ground deformation is the change in shape that happens before during or after a volcanic eruption. This happens because the sides of the volcano change shape because the magma in many ways to measure the change of shape of the volcano, like leveling, triangulation and more recently using continuous Global Positioning System (CGPS). It is also possible to use lakes as large tilt meters. Tilt meters measure the tiny degrees of tilt or slope on land. This is one of the oldest methods of knowing when ground deformation was caused because of rising lava.
The force of one plate being dragged under another causes intense friction and the pressure increases. Eventually, there is so much pressure that the plates suddenly jolt, causing an earthquake. Where an oceanic plate meets a continental plate, sediments are thrust upwards. Due to the friction caused by the plates scraping against each other, the temperature in the mantle increases. Magma rises forming a long chain of volcanic fold mountains for example the Andes.
Plate Tectonic Theory What is Plate Tectonics? Plate tectonics is the main force that shapes our planet’s surface over a long period of time the study of how the Earth's crust is shaped by geological forces. It relies on the understanding that the crust is divided into large pieces, or plates, that sit on the molten interior of the planet. Currents within the interior cause the plates to move, which causes many different geological events, including earthquakes and the forming of mountains and volcanoes. Understanding how plates move and interact is the main purpose of plate tectonics.
Intrusive igneous rocks, also known as plutonic rocks, are formed inside earth's crust. Molten rock rises and fills openings or melts overlaying rocks. This eventually hardens creating an intrusive igneous rock. An extrusive igneous rock, or volcanic rock, is created by magma rising the earth's surface. Magma is known as lava when it reaches the surface.
Plate tectonics (also known as the conveyor belt principle) is a scientific theory that describes the large-scale motions of the Earth’s lithosphere, building on concepts from the theory of continental drift (movement of the Earth’s continents relative to each other). The lithosphere is broken up into 7 main tectonic plates which move from 0-100mm annually. It is thought that the continents once formed a single land mass called Pangea that drifted apart, this is the start of the main idea of plate tectonics. In 1596, Abraham Ortelius first made the speculation that continents might have ‘drifted’ but the concept was developed further by Alfred Wegener in 1912. Presently, Earth Scientists agree on the observation and assumption that the plates have moved with respect to one another, but they still debate as to how and when.
The Era is made up of six Geologic periods, the Cambrian, Ordovician, Silurian, Devonian, Carboniferous, and the Permian. Much of the plants and animals that exististed and evolved was due to the climate and location of the continents. At the beginning of the Paleozoic period, the continents were far apart, but by the end they were close together and on the way in forming the supercontinent called Pangaea. The land was moving by Plate Tectonics. Four hundred and thirty million years ago there was glaciation; this caused an ice sheet to cover what is now North Africa.
The reason for the movement is convection currents originating in the core caused by radioactive decay. Knowing the theory of plate tectonics is a useful tool in understanding the distribution of earthquakes and volcanoes as they correlate very closely. If we map out the location of major earth quakes, location of active volcanoes and a map of general plat tectonic, the 3 would overlap. This gives us a general idea of locations and correlations. Each boundary between 2 plates have the capability of being a different type of boundary.