Environmental Geology Exam 2

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

a measuring instrument for detecting and measuring the intensity and direction and duration of movements of the ground (as an earthquake)

a depression produced where groundwater removed soluble rock. (gradually sinks, or fast if cavern collapses)

(plate tectonics) a hypothetical continent including all the landmass of the earth prior to the Triassic period when it split into Laurasia and Gondwanaland

Crust, Mantle, Outer Core, Inner Core

as the lithosphere plate moves, the _____ stay still and "burn" their way through the lithosphere as it moves above them. It then forms inactive volcanoes along a linear _____ trail.

approximately 30

brick

A region of the earth's surface where limestone is exposed and abundant and caverns, natural bridges, and sinkholes are common

an inclined fault in which the hanging wall appears to have slipped downward relative to the footwall

the branch of geology studying the folding and faulting of the earth's crust

Withdrawal of groundwater between 1925-75 caused the ground surface to subside up to 28 feet in places

earthquake that caused fire to break out and took several days to put the fire out

large plates of rock that make up the foundation of the earth's crust and the shape of the continents

An area along a seismically active fault where no earthquake activity has occurred over a long period of time

M 7.2 earthquake with shallow focus and with a strike-slip mechanism. surface rupture resulted in about 1.5 meters of horizontal displacement. 5100 deaths, fires started

continental transform fault through California. Horizontal Strike-slip motion forming tectonic boundary between Pacific Plate and Northern American Plate

fault rupture of the ground generates vibrations or waves in the rock that we feel as ground shaking. nearly vertical and during an earthquake one slides past the other. ex. San Andreas Fault

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

A dipping plane, or seismic zones, of earthquake defines subduction zones. Most of these zones dip from oceanic trenches beneath adjacent island arcs.

the sudden collapse of something into a hollow beneath it

The solid, plastic layer of the mantle beneath the lithosphere; made of mantle rock that flows very slowly, which allows tectonic plates to move on top of it

an area where a column of hot material rises from deep within a planet's mantle and heats the lithosphere above it, often causing volcanic activity at the surface, ex: Hawaiian Islands

Outer shell of the earth, composed of the crust and the rigid, outermost part of the mantle outside the asthenosphere; material found in earth's plates.

an old, dense ocean plate (basalt) sinks into the mantle beneath another over-riding plate and produces big earthquakes and volcanoes

compositional boundaries between continental and ocean crust, but they are NOT active tectonic plate boundaries.

the point on the Earth's surface directly above the focus of an earthquake

a directional force on rocks that is caused by plate tectonic motion; force with a given direction

A vibration that travels through earth carrying the energy (strain) released during an earthquake

The transformation of a stable soil into a fluid that is often unable to support buildings or other structures

Boundary created when two plates pull apart from each other, resulting in an opening between the plates where magma rises and cools (creates new crust)

Deep depression found at the edge of the ocean floor. Represents area of tectonic plate subduction. Usually near volcanic mountains

ground shaking by the sudden release of energy stored in subsurface rocks, vibrations caused by breakage movement of subsurface rock

a crack in the earth's crust resulting from the displacement of one side with respect to the other; planar surface-where rocks rupture

energy stored in rocks that are subjected to stress. (bow and arrow example, strain builds up and releases quickly)

An earthquake that occurs after a larger earthquake in the same area.

A boundary in which two plates move together, causing one of the slabs of lithosphere to be consumed into the mantle as it descends beneath on an overriding plate.

a plate boundary where two plates move past each other in opposite directions

regions where new divergent boundaries form in a continental lithospheric plate

The point beneath Earth's surface where rock breaks under stress and causes an earthquake; point of rupture below the ground - area of biggest impact

surface rupture with vertical component - linear steep slope 3ft high

maximum amount of strength that a structure or material can withstand before breaking

seasmic sea wave that typically occur in the Pacific basin. ocean water vertically displaced during earthquakes

The quake with the epicenter in Santa Cruz that set San Fransisco on fire; caused 5 Billion dollars of damage and killed 62 people

continent splitting apart; a new ocean basin produced by rifting

mid ocean ridge present above sea level. island is WIDENING at the rate of 4mm per year

earthquake triggered tsunami killing 230,000 people

The crust is the thin layer of solid rock that surrounds the Earth. It is thinnest under the ocean (mostly dense rock called basalt) and thickest under mountains (on the continents, mostly granite). made up of silicon, oxygen, and aluminum

The thickness of Earth's layers, located between the outer core and the Earth's crust, composed mostly of compounds rich in iron, silicon, and magnesium

The solid, inner most layer of the Earth, composed of iron and nickel under extremely high pressure and temperature

is the liquid layer of the earth's core that lies beneath the mantle and surrounds the inner core.

travel the fastest-back and forth motion-moves through solids,liquids,and gases; arrives first

slower than p waves, side to side motion. only travels through SOLIDS and arrives 2nd.

waves moving up and down around the earth's surface.

slowest waves that move side to side or a circular motion around earth's surface and goes through nothing

fault movement and ruptures

liquifaction of ground, landslides, fires, disease, tsunamis

loading earth's crust, disposing of waste deep in the ground, underground nuclear explosions

this feature was produced by a continent/continent (c/c) convergent plate boundary

Island chains that are the result of hot spot activity

Tsunami waves are 3 feet high out further from shore, but near to shore they bunch together and pile up vertically making a 66ft high wave

a few centimeters per year; about the same rate that finger nails grow.

produced at ridges and recycled at trenches

remains at surface and never subducted

measures energy released

measures amount of shaking

measures damage caused

house codes, better building types

plate movements, ancient faults, magma movements, liquid injected into the ground, reservoir filling

cavern collapse, ground water withdrawal, petroleum production, sediment loading

The ocean crust is more dense- it is made of mafic rock- the continents are made of felsic rock.

Limestone

We use the difference in the arrival time of P waves (fast) and S waves (slower). The farther you are from the earthquake, the bigger the difference in their arrival time.

energy builds up for a long time while nothing happens, then all energy is released suddenly when rocks break. The longer you go without an earthquake, the more energy builds up, and the larger the magnitude when it finally does happen.

Areas on a fault that haven't had an earthquake in a long time are most likely to experience a large magnitude event, So these are the areas that need to be most prepared (like Seattle).