Plate Tectonics and Crust Oceanic Lithosphere

This lab uses earthquake data to construct profiles of two convergent boundaries: the Tonga Trench and the Peru-Chile Trench. Where two tectonic plates converge, if one or both of the plates is an oceanic lithosphere, a subduction zone will form. When crust is formed at a mid-ocean ridge, it is hot and buoyant meaning it has a low density. As it spreads away from the ridge and cools and contracts, or becomes denser, it is able to sink into the hotter underlying mantle. When two oceanic plates collide, the younger of the two plates, because it is less dense will ride over the edge of the older plate. The density of the

The theory of plate tectonics states that Earth’s outer shell is divided into plates. The crust and upper mantle is broken into plates that move around on the mantle, changing in size throughout time. The lithosphere makes up the crust and upper mantle and the asthenosphere a plastic like layer beneath the lithosphere. There are three types of plate boundaries. Divergent boundaries where two plates move away from each other. The ocean widens and new crust forms at the mid-oceanic ridge. Convergent boundaries has three types of converging, moving two plates towards each other. First we have an ocean floor plate that collides with a less dense continental plate. Next an ocean floor plate collides with another ocean floor plate. Finally a continental plate collides with another continental plate. Transform boundaries were two plates slide past one another. The resulting effects of plate tectonics is landforms such as rift valleys,

Plate tectonics is the theory that has been studied for over thirty years that states that the outside layer of Earth are actually large plates, approximately forty kilometers thick, that slide across the magma beneath the exterior of the planet. The theory of plate tectonics explains the enormous amount of volcanic and seismic activity surrounding certain areas of the world, stating that the sliding of these plates either away from each other, sliding past each other, or sliding into each other and causing one of the plates to slide beneath the other. When the plates slide away from each other, new ocean floor is formed. When the plates slide past each other, minor earthquakes will occur. When the plates slide toward each other and

The youngest oceanic crust is located along the mid-ocean ridges where new crust is formed when the old crust is pushed away from mid – ocean ridges as a result of the seafloor spreading.

The Earth’s outer crust is made up many tectonic plates that move over the surface of the planet. When the plates come collide, volcanoes will form sometime (National Ocean Service). Volcanoes can also form in the middle of a plate, where magma rises upward until it erupts on the sea floor, at what is called a “hot spot” (National Ocean Service). A hot spot is a plume of magma or molten rock that rises from within the Earth then reaches the surface forming underwater volcanoes which may grow tall enough to

The thicker sections fo the plates are the continents; the thinner parts make up the ocean beds. When two plates meet, the result is geologic upheaval on a vast scale. Such an encounter occurred about 20 million years ago in the region between North and South America. The Cocos Plate, a piece of the Pacific crust some 300 miles wide, moved eastward until it met the crustal plate underlying the Caribbean. The eastern edge of the Cocos Plate was driven beneath the western edge of the Caribbean Plate. As the Cocos Plate was forced downward, the friction, as well as the hear deep within the earth, liquefied its rock into magma, which found release by thrusting up in a chain of volcanoes. The volcanic islands that resulted formed a line of stepping-stones between the northern and southern

The seven major tectonic plates comprise mostly on continental plates and the Pacific plate. The seven major plates from greatest to least are called: the Pacific Plate stretching 103,300,000 km2, North American Plate being 75,900,000 km2, Eurasian Plate being 67,800,000 km2, African Plate stretching 61,300,000 km2, Antarctic Plate being 60,900,000 km2, Australian Plate being 47,000,000 km2, and the South American Plate being 43,600,000 km2. With different tectonic plates, there are different ways they can move: divergent, convergent, and transform. Divergent plate movement is when both plates moving away from each other, creating a canyon that has magma pushing out from the bottom, forming new ground. Convergent is usually an oceanic plate and a continental plate are moving into one another, causing the oceanic plate to subducts into the mantle. This causes move active volcanos and earthquakes. Even though all of the plates are in the lithosphere, it's only the where Earth is flexible enough to move rather than flow. The lithosphere flexes when loads of weight are placed on it or

The different tectonic plates rest on the mantle, a very hot layer of earth that is directly beneath the crust. There are seven major tectonic plates, their names are The Pacific Plate, The North American Plate, The Eurasian Plate, The African Plate, The Antarctic Plate, The Australian Plate, and The South American Plate. In addition to these major plates there are also many smaller tectonic plates that make up parts of the Earth's crust. When the boundaries between plates shift, this causes earthquakes. There are three types of movements that cause earthquakes. Divergent is when the plates move away from each other, Subduction is when one plate moves underneath another, and Transform is when the plates grind against each other. The lithosphere is another name for earth's crust and mantle, it is made up of all the tectonic

Obduction - Where the Continental Plate runs under the Oceanic Plate causing oceanic ridges to form.

Natural or human-made structures that cross a transform boundary are offset—split into pieces and carried in opposite directions. Rocks that line the boundary are pulverized as the plates grind along, creating a linear fault valley or undersea canyon. As the plates alternately jam and jump against each other, earthquakes rattle through a wide boundary zone. The lithosphere is the solid, outer part of the Earth. The lithosphere includes the brittle upper portion of the mantle and the crust, the outermost layers of Earth’s structure. The lithosphere is divided into 15 major tectonic plates: the North American, Caribbean, South American, Scotia, Antarctic, Eurasian, Arabian, African, Indian, Philippine, Australian, Pacific, Juan de Fuca, Cocos, and

Another type of plate tectonics (when the plates crash into each other), is called convergent. This causes the earths crust to be pushed into the earths interior where it is remelted at the same rate the new crust is being made. Convergent boundaries have two kinds of surface features associated with them. With oceanic convergence a deep ocean trench is formed along a line of the two colliding plates. The narrow and deep trench is formed under

This is a divergent boundary that has continental plates are made out of granite. The plates move apart and make a giant dip in the crust of the Earth. As the plates move apart they form a Rift Valley in the crust and keeps getting bigger, but this takes time.

When two plates diverge, initially, a rift valley may occur. Magma rises from the mantle filling in the gaps between the two plates, which can cause submarine volcanoes to occur, (volcanoes under water). These volcanoes may rise above sea level thus forming islands. Two examples of this are the island of

The earth is made up of land masses under the crust called tectonic plates. These tectonic plates sit on the upper mantle and lower crust also known as the lithosphere. Tectonic plates are always moving because of the magma churning underneath them in convection currents. Because the tectonic plates are always moving it can cause plates to run into each other which means that one must give way to the other and slide under this can create mountain ranges as the pressure has to do somewhere, this is called a subduction zone this usually occurs with one oceanic plate being pushed under a continental plate. Plates can also slide beside each other and get stuck so pressure builds up and then they will quickly slide past which can cause very major earthquakes to cities along the plate margins, this is the main cause of earthquakes this is called sliding plates.

Earth is in fact an intricate planet that has multiple layers of differing compositions. To be exact the earth has four main layers. The uppermost layer is the one humans come in most contact with, the crust. The crust consists of “thin silicate rock material”(Structure of the). Although the crust is not entirely the same. Actually there are two distinct types of crust, oceanic and continental. “The continental crust is made up of mostly rocks similar to granite while the oceanic crust is much denser and made up of a material similar to basalt”(Structure of the, Rose). The second layer is called the mantle. “The mantle is much denser than the crust and contains similar to the crust mostly solid silicate crust”(Structure of the). “As we travel further down the earth we wind up in the outer core. The outer core is a core of molten nickel and iron. Finally there’s the inner core. The inner is a solid metal core made up of nickel and iron”(Structure of the). All these layers functioning together cast out a magnetic