EARTH AND SPACE SCIENCE FINAL

the following count initiate the formation of stream terraces within a floodplain

-a decrease in global sea level -a long-term increase in precipitation -a local tectonic movement that lowers the streams base level

primary agents in contact metamorphism

-changes are driven by a rise in temperature (heat) -occurs near a body of magma

domes

-circular or slightly elongated -upwarped displacement of rocks -oldest rocks in core

basin

-circular or slightly elongated -down warped displacement of rocks -youngest rocks in core

non-foliated texture

-contain equidimensional crystals -resembles a course-grained igneous rock

how are tsunamis formed?

-formed by earthquakes -volcanic landslides -impacts of meteorites -anything that displaces water vertically

normal fault

-hanging wall block moves down -associated with fault block mountains -prevalent at spreading centers -caused by tensional forces

reverse fault

-hanging wall block moves up -caused by strong compressional stresses -dips greater than 45 degrees

thrust fault

-hanging wall block moves up -caused by strong compressional stresses -dips less than 45 degrees

the following are necessary for the formation of metamorphic rocks

-heat -chemically active fluids -pressure

what determines the amount of destruction in an earthquake?

-intensity of the earthquake -duration of the vibrations -nature of the material upon which the structure rests -the design of the structure

depositional features of rivers

-levees -deltas -meanders

foliated texture

-minerals are in a parallel alignment -minerals are perpendicular to the compressional force

how do p and s waves differ?

-p waves are the fastest and have the lowest vibration -s waves are the second fast and have the second lowest vibration

epicenter

-point on the surface directly above the focus -located using the difference in the arrival times between P and S wave recordings, which are related to distance

the most important factors controlling the character of metamorphic rocks include

-pressure -temperature -composition of the parent rock -water

what is liquefaction?

-saturated material turns fluid -underground objects may float to surface

geologists use the term stream to refer to

-small local creeks -tributaries to rivers -major rivers

to locate the epicenter of an earthquake, a seismologist must determine

-the distance from the epicenter to at least three different seismological stations -the difference in travel times between P waves and S waves -the velocity of both P waves and S waves

erosional features of rivers

-waterfalls -oxbow lakes

this is the minimum number of recording stations needed to determine the epicenter location

3

on the Richter scale a 6.4 is how much larger than a 5.4 earthquake

30 times

largest river in the world in terms of discharge

Amazon River

how does rock salt form?

By the evaporation of salty water ***it is an evaporite

the Mississippi river is the river in...

North America with the highest discharge

strike slip faults

Occur when opposing forces cause rock to break and move horizontally. -right lateral and left lateral

earthquake waves that alternately cause rocks to compress and dilate are

P waves

if an earthquake occurs the first waves to arrive at a seismograph are the

P waves

what is a graben?

a block of rock that has moved down

this term is used to describe all materials deposited by streams

alluvium

an anticline is a fold shaped like a _______ with the oldest rock in the center of the fold

arch

stream valleys have a distinctive V-shape because

as a valley is cut, overland flow and mass movement remove loosened material from its slopes

a stream crossing a delta splits into a network of distributaries because

as the delta grows, the decreased stream gradient causes greater sedimentation and clogging of the delta channels

where would contact metamorphism be most likely

at shallow depths close to an igneous pluton

what is a horst?

blocks of rock with a normal fault on either side

the total amount of sediment transported by a stream is known as its

capacity

how are sedimentary rocks formed?

compaction and cementation

a thrust fault is the result of

compressional stress and the hanging wall moves up relative to the footwall

______ stress results in rocks being shortened or flattened

compressive

what type of stress would you expect at convergent plate boundaries

compressive

________ metamorphism occurs adjacent to a pluton when a body of magma intrudes a relatively cool country rock

contact

this may cause a change in orientation, location, and shape of a rock body

deformation

types of changes that physical metamorphic rocks undergo

deformation of objects, rotation, shearing, folding, fracturing

three types of sediment

detrital, biochemical, chemical

a fault with mostly all vertical movement of the blocks is called

dip slip

in metamorphic rocks, foliation is caused by

directed pressure

primary agents in regional metamorphism

directed pressures and high temperatures during mountain building -produces the volume of metamorphic rock

at the head of a delta the main channel splits into smaller channels known as

distributaries

where are major earthquakes least likely?

divergent boundaries

the high areas that separate drainage basins are known as

divides

syncline

downfolded rock layers

the area a given stream drains is called its

drainage basin

_______ are fractures in bedrock along which sliding movement has taken place

faults

blind faults are

faults with little or no surface expression

in geology the term stress refers to

forces that might cause deformation of a rock unit

where do coal beds form?

freshwater swamps

the rock that results from the metamorphism of relatively pure limestone is

gneiss

parts of a stream and how gradient changes downstream

gradient decreases from the head to the mouth

the side of the fault above the inclined fault surface is the

hanging wall

a stream increases its length by a process known as

headward erosion

in a straight section of a stream channel, the fastest water is

in the middle just below the surface

how does urbanization affect runoff and infiltration in a small, previously forested, drainage basin

infiltration decreases, runoff increases

deposition is concentrated in what part of a stream meander

inner bank

gneiss can be distinguished from other metamorphic rocks by

its dark and light mineral bands

What does the Richter scale measure?

magnitude of an earthquake

waterfalls tend to

migrate upstream and become smaller as erosion wears away their edge

a rectangular stream pattern characterizes a topography of

numerous joints or fractures, many with right angles

where in the bend of a river is the most erosion

outside ** water on the outside of bends flows faster than on the inside of bends

in the process of transpiration...

plants give off water

types of changes that chemical metamorphic rocks undergo

pressure solution, recrystallization, remobilization

which of the following best describes the conditions of regional metamorphism

pressures are high, rock is deeply buried, temperatures are raised by the geothermal gradient

this drainage pattern develops on areas with limestone bedrock underneath

rectangular

rocks in which plastic deformation occurs

remain in deformed shape when the stress is released

during metamorphism, the material that is deforming...

remains a solid

for most of the 20th century earthquake magnitude was reported on the ___________ scale, a scale that has never exceeded a magnitude 8.6

richter

the Mississippi has the highest what in the world

sediment rate

which of the following types of rocks can become metamorphic rocks

sedimentary, igneous, or metamorphic rocks

when rocks break or a fault moves, energy is released in the form of

seismic waves

the paper record of an earthquake is a

seismogram

what instrument is used to record an earthquake?

seismograph

natural levees result when

streams flood their banks and deposit sediment directly on top of the banks

what type of fault would you expect to find at a transform plate boundary?

strike slip

the Mississippi River will soon take a shorter route to the Gulf of Mexico by way of

the Atchafalaya River

stream gradient is defined as

the decrease in elevation divided by the distance the water traveled

a streams base level is

the lowest level to which a stream can erode its channel

focus

the place within Earth where earthquake waves originate

hanging wall

the rock above the fault surface

footwall

the rock below the fault surface

left lateral fault

things across the fault moved to the left

right lateral fault

things across the fault moved to the right

capacity is the...

total sediment load of a river

true or false frost action is the most important mechanical weathering process

true

a ________ is a huge ocean wave usually caused by a displacement of the sea floor and commonly associated with massive earthquakes

tsunami

anticline

upfolded, or arched, rock layers

What are seismic waves?

vibrations from an earthquake

discharge

volume of water flowing in the stream

how does gypsum rock form?

when water evaporates in mineral-rich marine soil environments ***it is an evaporite

which of the following conditions is most favorable for delta formation

where a large sediment load is delivered to quiet coastal waters

the first criteria used to classify metamorphic rocks is

whether it is foliated or nonfoliated