Natural Disasters Vocab: Tectonic Plate Movement

continental drift

The hypothesis that states that the continents once formed a single landmass, broke up, and drifted to their present locations

Convection

The transfer of thermal energy by the circulation or movement of a liquid or gas [think the mantle and convection currents :D]

Asthenosphere

the upper layer of the earth's mantle where convection occurs, is the reason for plate tectonics

Pangea

A supercontinent containing all of Earth's land that existed about 225 million years ago that is thought to have broken apart and drifted into our current continents

Epicenter

Point on Earth's SURFACE directly above an earthquake's focus

Pacific Ring of Fire

region around the boundary of the pacific plate where most of the volcanoes and earthquakes on Earth occur regularly

seafloor spreading

the process by which new oceanic crust forms along a mid-ocean ridge and older oceanic crust moves away from the ridge

mid-ocean ridge

An undersea mountain chain where new ocean floor is produced; a divergent plate boundary.

transform boundary

plates slide past each other

San Andreas Fault

A major geological fault in California. Sliding Boundary, also a site of a lot of earthquakes

Alfred Wegener

Proposed the continental drift theory in the 1900s

Subduction

denser plate going under less dense plate [happens at ocean/ocean and ocean/continental convergent boundaries], causes volcanoes, earthquakes, and tsunamis

convergent boundary

the boundary between tectonic plates that are colliding

ocean-ocean convergence

when two oceanic slabs converge & one goes under the other; forms islands and earthquakes

ocean-continent convergence

a plate boundary where oceanic crust meets continental crust, causes mountain volcanoes and earthquakes

divergent boundary

A plate boundary where two plates move away from each other.

trench

extremely deep areas in the ocean that are created by a subducting plate

focus

Point UNDER Earth's surface directly below an earthquake's epicenter

Mantle Hot Spots

the earths acne. Places in the middle of a plate where heat rises

Richter scale

A scale that rates an earthquake's magnitude based on the size of its seismic waves [energy]

Mercalli scale

A scale that rates earthquakes according to their intensity and how much damage they cause at a particular place

aftershock

a smaller earthquake following the main shock of a large earthquake.

P wave

A type of seismic wave that compresses and expands the ground. It happens first [primary wave], and can go through all types of matter

S waves

secondary waves, moves side to side, only goes through solid matter

megathrust earthquakes

strongest of earthquakes, happens at deep trenches...cause tsunamis, one plate jumps up over another

sheild volcano

a broad, domed volcano with gently sloping sides, characteristic of the eruption of fluid, basaltic lava. [think hawaii!]

Stratovolcano

a volcano built up of alternate layers of lava and ash, explosive!! [think mt.st. helens]

pryoclastic flow

a destructive cloud of volcanic material that moves quickly down the side of a volcano after an explosive eruption, its very hot and is the biggest reason why people die

Lahar

A volcanic mudflow containing ash, rock, and water from melting snow or rainfall that races down river valleys during an eruption.

Natural Service Functions

the good that comes out of a natural disaster [ex. a new island being formed b/c of a volcanic eruption]

plate tectonics

The theory that pieces of Earth's lithosphere are in constant motion, driven by convection currents in the mantle.

Tsunami

A giant wave usually caused by an earthquake beneath the ocean floor.

What are the features and natural disasters from Transform Boundaries?

Features: Sliding motions
Nat. Dis.: Earthquakes

What are the features of a divergent boundary?

volcanoes and mid ocean ridges

What natural disasters are caused by divergent boundaries?

Earthquakes, tsunamis, volcanic eruptions

What are the features of an ocean continental boundary?

Land volcanoes, earthquakes, trenches

What are the features of an ocean ocean boundary?

Island volcanoes, earthquakes, and trenches

What are features of continental continental boundaries?

Mountains [that keep on growing!]

What natural disasters are common in the southeastern part of the US?

Hurricanes, tornadoes, and floods

What natural disasters are common in the southwestern part of the US?

Dry weather, heat waves

What natural disasters are common in the northwestern part of the US?

Wildfires, mass movements, earthquakes and tsunamis