Plate Tectonics Vocabulary Words

Mary George King

Core 1

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Inner Core

• A ball of hot, solid metals

• The inner core is very, very hot.

• There is enormous pressure on the center of the Earth.

• The core is Earth’s densest region.

• It is made up of two regions, the inner core and the outer core.

Outer Core

• It is a layer of liquid metals that surrounds the inner core.

• The temperature is lower than the inner core.

• The pressure is lower.• Since it is has lower pressure the metal

remains liquid.• The outer core isn’t as hot as the inner

core.

Mantle

• The layer of the earth between the crust and the core.

• The mantle is the third level of the Earth.

• The mantle is the thickest layer of the Earth.

• The mantle is similar to an igneous rock.

• The mantle is below the inner core and the outer core.

Crust• The outer layer of the Earth.

• All life on Earth is right there.

• It is the coldest layer of the Earth.

• The crust makes up less than 1% of the Earth’s mass.

• We are on the Crust right now.

Lithosphere

• The crust and upper mantle of the earth.• The Earth consists of many layers ranging from

the mantle to the atmosphere, and all of it works together perfectly.

• In other words, the lithosphere is made up of solid rock, which is the Earth's outer surface, and magma, the hot liquid center of the Earth..

• There are some interesting facts about the lithosphere, including how much it is responsible for Earth's changes; in fact, the Earth wouldn't change at all if it weren't for it.

• The lithosphere is made up of more than one plate

Asthenosphere

• A zone of the earth's mantle that lies beneath the lithosphere and consists of several hundred kilometers of deformable rock.

• About 85 kilometers thick. • A layer of the Earth that lies at a depth of 60--150

mi (100--250 km) beneath Earth's surface. • It was first named in 1914 by the British geologist

J. Barrell• This layer is about 85 kilometers thick!

Tectonic Plates

• the two sub-layers of the earth's crust (lithosphere) that move, float, and sometimes fracture and whose interaction causes continental drift, earthquakes, volcanoes, mountains, and oceanic trenches

• Convergent plates move towards one another• Divergent plates separate from each other• Alfred Wegener founded Pangaea, a super

continent that was supposedly all of the seven continents put together

• Tectonic Plates are under the Crust.

Continental Drift• the theory that the earth's continents move gradually over the

surface of the planet on a substratum of magma. The present-day configuration of the continents is thought to be the result of the fragmentation of a single landmass, Pangaea, that existed 200 million years ago

• According to the theory of continental drift, the world was made up of a single continent through most of geologic time.

• That continent eventually separated and drifted apart, forming into the seven continents we have today.

• The first comprehensive theory of continental drift was suggested by the German meteorologist Alfred Wegener in 1912.

• Continental Drift is a theory.

Pangaea• A hypothetical supercontinent that included all the landmasses of the earth

before the Triassic Period. Pangaea broke apart during the Triassic and Jurassic Periods, separating into Laurasia and Gondwanaland.

• Pangaea Early in the twentieth century the German scientist Alfred Wegener postulated that, commencing in the Mesozoic and continuing up to the present, a huge supercontinent, ‘Pangaea’ (meaning ‘all land’), had rifted and the fragmented components had moved apart as a result; this soon came to be generally known as continental drift.

• His interpretation was that South America and Africa began to separate in the Cretaceous, as did North America and Europe, but North America and Europe had retained contact in the north as late as the Quaternary.

• The Indian Ocean had begun to open up in the Jurassic but the principal movements took place in the Cretaceous and Tertiary.

• Pangaea was a and is a supercontinent.

Convection Current

• Mass movement of subcrustal or mantle material as the result of temperature variations

• A convection current requires a heat source and a fluid that can circulate to transfer heat.

• In the atmosphere, the heat source is the sun and the fluid is air.

• Inside the Earth, the heat source is the core and the fluid is magma

• Convection Currents are under the Earth.

Divergent Boundary• A tectonic boundary where two plates are moving away from

each other and new crust is forming from magma that rises to the Earth's surface between the two plates. The middle of the Red Sea and the mid-ocean ridge (running the length of the Atlantic Ocean) are divergent plate boundaries.

• Divergent plate boundaries are locations where plates are moving away from one another.

• This occurs above rising convection currents. The rising current pushes up on the bottom of the lithosphere, lifting it and flowing laterally beneath it.

• This lateral flow causes the plate material above to be dragged along in the direction of flow.

• Divergent Boundary deals with two plates.

Convergent Boundary• A tectonic boundary where two plates are moving toward each

other. If the two plates are of equal density, they usually push up against each other, forming a mountain chain. If they are of unequal density, one plate usually sinks beneath the other in a subduction zone. The western coast of South America and the Himalayan Mountains are convergent plate boundaries.

• Convergent plate boundaries form where lithospheric plates collide along their boundaries with each other.

• Such collisions cause extensive deformation at the Earth's crust, leading to the formation of volcanoes, the lifting of mountain ranges and the creation of deep oceanic trenches.

• Convergent plate boundaries are also characterized by extensive earthquake activities, which occur along the sections of the Nazca-Pacific convergent boundary in Chile and Peru, for example.

• Convergent boundaries also deal with two plates like Divergent boundaries.

Transform Boundary• where 2 plates slide past each other,

happens at continental vs. oceanic plates• Places where plates slide past each other are called

transform boundaries. • Since the plates on either side of a transform boundary are

merely sliding past each other and not tearing or crunching each other, transform boundaries lack the spectacular features found at convergent and divergent boundaries.

• Instead, transform boundaries are marked in some places by linear valleys along the boundary where rock has been ground up by the sliding.

• Transform plates are when two plates slide across each other.

Magnetic Reversal

• A change in the Earth's magnetic field.• The Earth has a magnetic field, as can be

seen by using a magnetic compass. It is mainly generated in the very hot molten core of the planet and has probably existed throughout most of the Earth's lifetime. The magnetic field is largely that of a dipole, by which we mean that it has one North pole and one South pole.

• Magnetic Reversal is a change in the Earths magnetic fields.

Hot Spot• a place in the upper mantle of the earth at which hot magma

from the lower mantle upwells to melt through the crust usually in the interior of a tectonic plate to form a volcanic feature; also: a place in the crust overlying a hot spot

• Hot spot, Region of the Earth’s upper mantle that upwells to melt through the crust to form a volcanic feature.

• Most volcanoes that cannot be ascribed either to a subduction zone or to seafloor spreading at midocean ridges are attributed to hot spots.

• The 5% of known world volcanoes not closely related to such plate margins (see plate tectonics) are regarded as hot-spot volcanoes.

• Hot spots are in the upper mantle!!

Subduction• The sideways and downward movement of the edge of a plate

of the earth's crust into the mantle beneath another plate.• Geology is the science that comprises the study of the solid

Earth and the processes by which it is shaped and changed.• Geology provides primary evidence for plate tectonics, the

history of life and evolution, and past climates..., subduction is the process that takes place at convergent boundariesConvergent boundary

• In plate tectonics, a convergent boundary, also known as a destructive plate boundary , is an actively deforming region where two tectonic plates or fragments of lithosphere move toward one another and collide...

• Subduction is the sideways movement on the edge of a plate.

Conclusion