Geo final

tectonic plates move at rates that are approximately

1 to 15 cm/year

temperatures generally encountered during volcanic eruptions are approximately

1,000 C

How many seismograph stations are needed to locate the epicenter of an earthquake?

3

In a hot spot volcanic island chain, such as the Hawaiian Islands, which of the following is not true?

All volcanoes in the chain can be simultaneously active

Which of the following statements is true concerning rock produced at mid-ocean ridges?

Basalt is produced at shallow depths and gabbro at deeper depths

___ is an example of continental rift and the ___ is/ are the result of collision

East Africa; Himalayan Mountains

Which measures an earthquake's intensity based on the observed effects on people and structures?

Modified Mercalli scale

What earthquake did not occur at a plate boundary

New Madrid Missouri, 1812

Volcanic activity is commonly found where

One plate is subducted underneath another

Body waves consist of the

P and S waves

Which of the types of seismic waves arrive at a seismograph first

P waves

List of wave arrival from first to last

P waves, S, Surface

Which of the following waves is the slowest

Surface waves

Where does an island volcanic arc occur in the present day

The Aleutian Islands of Alaska

What theory describes the build up and release of stress during an earthquake

The elastic rebound theory

The shape of the longitudal profile of all streams is

a concave upward curve

In the scope of plate tectonics, an active margin is defined as

a continental coastline that coincides with a plate boundary

An explosive volcanic eruption most likely is associated with

a large amount of water in the magma

The youngest sea floor is typically found

along mid-ocean ridges

How do rock particles move during the passage of a P wave through the rock?

back and forth parallel to the direction of wave travel

How do rock particles move during the passage of an S wave through the rock?

back and forth parallel to the direction of wave travel

What is the dominant rock type on most of the Hawaiian Islands?

basalt

The athenosphere lies ____the lithosphere

beneath

how do geologists classify mass movements

by the speed of the mass movement by the nature of the material by the nature of the movement

stalactites and stalagmites in caves are composed of

calcite

Crater Lake, Oregon, is a lake within a

caldera

A volcano built almost exclusively from ejected fragments (pyroclastic material) is a

cinder cone

what process is associated with the formation of a caldera

collapse of the roof rock into an evacuated magma chamber

When two plates composed of continetal lithosphere are pulled together at a convergent boundary, the result is

collision and mountain formation

Residents at the base of which one the following would face the greatest danger of a nuee ardente

composite cone

The largest volcanoes found in Oregon are

composite cones

A large volcano built from a combination lava flows and pyroclastic flows is a

composite volcano

the lowering of the water table in the vicinity of a well due to pumping is called an

cone of depression

Large, thick, nonvolcanic mountain belts, like the Himalayas, have features associated with

continent-continent collisions

___ involves transfer of heat by the physical movement of the material

convection

Subduction zones are found at which basic plate bouondary type?

convergent

The volcanoes of the Cascades Mountains in the northwest United States are related to melting of rock associated with a

convergent boundary

deep earthquakes, up to 600 km deep, are associated with

convergent plate boundaries

Where is the focus with respect to the epicenter

directly below the epicenter

Under the theory of plate tectonics, the plates themselves are

discrete pieces of lithosphere at the surface of the solid Earth that move with respect to one another

Iceland is one of the few places in the world that is both above sea level and situated atop a ___ plate boundary.

divergent

the lithosphere of the earth is generally thinnest at _____ plate boundaries

divergent

The distribution of __ across the globe provides a primary indicator of boundaries between all tectonic plates

earthquakes

At transform plate boundaries

earthquakes are common but volcanoes are absent

Summed over the entire surface of Earth, the rate of spreading at divergent boundaries is __ lithospheric consumption at subduction zones.

equal to

True or false: the athenosphere is stronger than the lithosphere

false

true or false: The time and loaction of most major earthquakes can be predicted several days in advance

false

The point where movement occured which triggered the earthquake is the

focus

in general igneous rocks

form at high and low pressures, form at relatively high temps, form by crystallization of solid from a liquid

lowest porosity: sandstone, shale, gravel, or granite

granite

What is the dominant force that causes mass movement

gravity

Compared to typical oceanic lithosphere, the thickness of continental lithosophere is

greater

Hot spots are caused by

hot plumes of mantle material that rise up though cooler, dense surrounding rock

The theory of plate tectonics

incorporates and explains both sea-floor spreading and continental drift

As a rock breaks into smaller pieces, the ratio of surface area to volume

increases

With increasing travel time the difference in arrival times between the P and S waves

increases

Atoms that have gained or lost electrons are no longer electrically neutral and are called:

ions

the four most common elements on earth are oxygen, silicon, magnesium, and

iron

Unlike the lithosphere, the asthenosphere

is able to flow over long periods of time

At a subduction zone, the downgoing (subducting) plate

is always composed of oceanic lithosphere

continental lithosphere

is thicker than oceanic lithosphere

Marble is a metamorphic rock that forms from

limestone

the name of the layer that separates the crust from the core is

mantle

Which boundary marks a change from 100% solid to 100% liquid

mantle... outer core

At a subduction zone, the overriding plate

may be composed of either oceanic or continetal lithosphere

chemical and biochemical rocks are classified primarily on the basis of

mineral composition

lava is

molten silicate at Earth's surface

Batholiths are generally assoiciated with:

mountains

Earthquakes typically occur

near plate boundaries

A volcanic island arc forms when

oceanic lithosphere subducts beneath another oceanic lithospheric plate

What mineral is least satble at the Earth's surface

olivine

soil is composed of

organic matter, fragments of bedrock, clay minerals

The primary difference between lithospheric and asthenospheric mantle that gives rise to numerous different patterns of physical behavior is

physical state: the lithosphere is rigid: the athenosphere is capable of flow

Hot-spot tracks result from moving

plates

What farming practive helps to prevent erosion of topsoil

plowing a field parallel to contour lines

The precentage of a rock's total volume that is taken up by pore space is called the

porosity

What type of volcanic rock contains a large amount of cavities that form when gases escape from the molten rock?

pumice

Bombs, ash, and cinders are all examples of

pyroclastic debris

what type of drainage pattern would you expect to find on a volcano

radial

Batholiths are

regionally extensive discordant intrusive igneous rocks

Mt. Kilimanjaro is an active volacno in Tanzania in eastern Africa that has formed as a result of

rifting

Which best describes the state of earthquake prediction

scientists can characterize the seismic risk of an area, but can not yet accurately predict most earthquakes

What volcano type is the largest

shield volcano

Which of the volcano types is typically formed from low viscosity magma

shield volcano

On either side of a mid-ocean ridge, the lithosphere begins to

sink because it cools and contracts

The amount of ground displacement in an earthquake is called the

slip

In general the most destrucive earthquake waves are the

surface waves

a sill is a

tabular intrusion that lies parallel to surrounding layers of sedimentary rock

Stratificatin refers to

the development of layering within sedimentary rocks

The S wave shadow zone is caused by

the outer core

What is the differnce between the saturated and unsaturated zones of groundwater?

the pore spaces in the saturated zone are completely full of water, the pore spaces in the unsaturated zone are not completely full of water

The San Andreas Fault zone in California is an example of a ___ plate boundary

transform

Segments of the mid-ocean ridge system are offset. Between the offset segments we observe

transform faults

True or false: snow is a mineral

true

true or false: sill a concordant intrusive rock

true

a glassy texture indicates

very rapid cooling

Important volatiles in magmas include

water and carbon dioxide

general process by which rocks are broken down at the Earth's surface

weathering

A hill consisting of loose, dry sand that slopes at the angle of repose and has no vegetation

will be more stable if vegetation takes root on the hill, may flow if it become saturated with water, is stable unless over steepened by excavation

Hot spots can occur

within either continental or oceanic plates