Plate Tectonics and Earth's Internal Processes

Plate Tectonics Theory

Theory that explains the different processes that cause the formation of different geologic features and phenomena.

Alfred Wegener

Hypothesized and suggested that the landmasses of Earth were once merged into a supercontinent known as Pangaea.

Tectonicus or tektonikos

The term tectonic is from the Latin word ____ or the Greek word _________.

To build

Tectonic means _.

Tectonic

Has been coined to give rise to the idea of the formation or sculpting of Earth’s lithosphere.

Lithosphere

It is the outermost layer of Earth composed of the upper part of the mantle and the crust.

Crust

Made of various types of rocks and sediments floating on top of the malleable upper mantle that extends from the surface to about 50 km deep.

Continental Crust

Type of crust which is thicker and less dense.

Oceanic Crust

Type of crust which is denser and relatively thinner.

Plates

The plate tectonics theory suggests that the lithosphere is divided into fragments known as _.

Primary and Secondary Waves

Travel within the interior of Earth, and are responsible for the detection on the epicenter of an earthquake.

Long surface waves and Rayleigh waves

Waves such as _____________ are surface.

Triangulation method

If three recorded measurements were done at different stations, the _

Charles Wyville Thomson

He and the rest of the members of the expedition discovered the Mid-Atlantic ocean ridge.

Mid-Atlantic Ocean Ridge

A long oceanic ridge in the Atlantic Ocean, which is formed by plates that are pulling apart.

Plate Margins

The distribution of volcanoes is mostly found along _.

Destructive or constructive boundary

Plate margins can be in an either ___________________.

Subduction

When a plate goes und

Volcano Arc

The melted r

Harry H. Hess

Became the major proponent of seafloor spreading.

Alfred Wegener

Is known as the father of the plate tectonics theory, which is the modern version of the continentral drift theory that he first proposed.

Convection current in the mantle

Encompasses the driving mechanism of plate movement.

Asthenosphere

It is primarily composed of rocks that are partly molten due to high temperature and pressure under the lithosphere.

Cells

Each convection current is divided into _ that move in the opposite direction.

Plate margins / plate boundaries

____ are of three types, namely, convergent, divergent, and transform.

Divergent Plate Boundaries

Plate boundaries where the plates move apart from each other, resulting in the production of a new seafloor.

Convergent Plate Boundaries

Plate boundarie where the plates move toward each other.

Oceanic-continental convergence

Type of collision between an oceanic crust and a continental crust.

Subduction

The process at which the oceanic crust sinks down the continental crust and goes back to the mantle.

Continental Volcanic Arcs

Chains of volcanoes parallel to the subduction zone.

Trench

deep, narrow depression on the ocean seafloor caused by the collision and/or subduction of plates.

Oceanic-oceanic convergence

Type of collision between two oceanic crustal plates.

Volcanic island arc

At the top of the other oceanic crust forms the _.

Continental-continental convergence

Two continental crust plates move toward one another.

Transform plate boundary

The plates slide past horizontally to each other without destroying the lithospheric plate.

Rift Valley

Another feature that results from plate movement.J

J. Tuzo Wilson

Introduced the idea that continents and oceans are formed in a continuous motion.

Wilson Cycle

Explains the cyclic process of the opening and the closing of ocean basins due to plate movement.

Andrew Lawson

Discovered the San Andreas fault after he found the northern zone of the fault.

San Andreas fault

Transform fault brought about by the tectonic boundary between the Pacific and the North American Plates, moving in a horizontal strike-slip motion.

Earthquake

The shaking of the ground caused by the tremendous release of energy due to pressure in Earth’s crust.

Fault

The slipping of a block of Earth’s crust with another block, which is the feature of a _, also causes a sudden shake in the surface of the Earth.

Hypocenter or focus

The origin at which the earthquake occurs.

Epicenter

The point directly above the focus.

Body waves

are in the form of primary or secondary waves.

Primary waves or compressional waves

travel through the interior of Earth and through solid and fluid materials.

Secondary waves or transverse waves

travel through solid materials only within the interior of Earth.

Surface waves

waves that occur on the surface of the lithosphere.

Love waves

sweep the surface in a side-to-side movement, similar to how a snake moves on the ground.

Rayleigh Waves

shake the ground in an up-and-down movement, similar to the wave that you see in the ocean.S

Seismograph

Instrument that detects and measures seismic waves.

Seismometer

Internal part of a seismograph.

Magnitude

Quantitative measure of the amount of energy released by an earthquake.R

Richter Scale

Most common scale for the magnitude of an earthquake.

Intensity

strength of the ground shaking during an earthquake.

Rossi-Forel Intensity Scale

First scale used in identifying earthquake intensity was _.

Modified Mercalli Intensity Scale

The Rossi-Forel Intensity scale became the basis for the development of the now widely used scale known as _.

Philippine Volcanology and Seismology

Developed an intensity scale used in the country to determine the extent of the effect of such earthquakes.

Volcanism

The process wherein magma escapes from Earth’s interior to form cool and hard rocks is called _.

Volcano

Is a landform with an opening at its tip.

Crater

Allows molten magma to flow outside the surface.

Lava

Pertains to magma that has finally reached the surface.

Extrusive volcanism

When lava flows on the surface, it is called _.

Igneous Rock

As time goes by, lava cools and hardens, and then it becomes a rock. This type of rock is known as _.

Intrusive volcanism

Entrapped lava flow that does not reach the surface is called _.

Viscosity

Magma’s ability to flow.H

Hotspots

Volcanoes that arise from the excretion of magma to the mantle.

Orogeny

Process of mountain building.Mou

Mountain

refers to a large surface feature that rises above its relative.Mo

Mountain Range

A series of mountain chain.

Orogenesis

Process of mountain formation due to the deformation of Earth’s crust.

Fault

It is the fracture between two blocks of rock.

Mohorovicic’s law

Function used to calculate the increasing velocity of seismic waves with increasing depth.

Crust

Outermost layer of the earth.

Mantle

Layer beneath the crust.

Mantle

Is made up of solid rock and lies between the core and the crust.

Convection

caused by heat currents that allow materials to flow and move freely.

Convection cells

Responsible for the movement of the crust.

Core

Inner part of the earth.L

Lithosphere

Composed of the crust and the upper mantle.

Asthenosphere

Region of partially molten mantle materials that can flow.

Mesosphere

region of increased pressure where the flow ceases.Me

Mesosphere

Lowest part of the mantle, next to the outer core.

Outer core

External part of the core.

Mohorovicic Discontinuity

Can be found in the boundary between the mantle and the crust.

Gutenberg Discontinuity

Boundaries in the core-mantle.

Lehmann Discontinuity

Inner core-outer core boundaries.

Pangaea

Earth was once a large mass called _ about 200 million years ago.

Gondwanaland and Laurasia

Then, Pangaea broke into smaller supercontinents known as ______________.

Fossils

Preserved remains of organisms

Coal

Formed from organic compounds such as dead plants and animals.

Tillites

Deposits of rock debris left by glaciers.

Seafloor Spreading Theory

This theory suggests that hot, less dense materials moving out from the crus rise towards the surface through the mid-ocean ridge.

Magnetite

Naturally occurring iron-rich mineral that is influenced by a magnetic field.

Mantle Convection

Happens when heat is transferred from the core to the crust.

Convection

Transfer of heat through a fluid motion.

Slab Pull

This phenomenon happens when the dense cold slab of the oceanic lithosphere sinks due to the pull of gravity in the mantle, eventually pulling the rest of the plate with it.

Ridge Push

Driving mechanism that pushes the lithosphere from the elevated position along the ridge due to its own gravity.

Mantle Convection

Driving mechanism of plate movement