Natural Hazards Exam ll

what are the three rock types?

igneous, sedimentary, metamorphic

what is the definition of igneous rocks?

when magma or lava cools and hardens

how are igneous rocks classified?

intrusive and extrusive

what are the names of the different types of igneous rocks?

memorize table in notes lecture 10

what is the difference between intrusive and extrusive igneous rocks?

intrusive is "made" under the surface, extrusive is "made" above the surface

what is the difference between lava and magma?

magma is below the surface, lava is molten rock that has erupted to the earth's surface

what are the different type of igneous rock structures?

location and composition

what is the difference between a sill and a dike?

sills form when magma intrudes between two layers of rock, dikes form when magma squeezes into a cross-cutting fracture and solidifies

what are the three mechanism for generating melt inside the earth?

decompression melting, flux melting, heat transfer melting

what is the melt generation mechanism for subduction zones?

flux melting

what is the melt generation mechanism for mid ocean ridges?

decompression melting

what is the melt generation mechanism for hot spots?

heat transfer melting

what are the two types of eruptive styles?

effusive and explosive

what are the three factors that affect lava viscosity?

temperature, silica content, and gas content

name the three types of lava?

basaltic, rhyolitic, andesitic

what are the three types of volcanos?

shield, composite, cinder cone

what is the relationship between volcano type and eruptive style?

effusive: lava flow, for shield volcanos, explosive: composite volcanos

what factors can be used to forecast volcano eruptions?

increase heat flow, volcanic deformation, earthquakes, increase in ash and gas emission

what is a lahar and a pyroclastic flow?

lahar: post eruption mud flow

pyroclastic flow: fast-moving current of hot gas, ash, and volcanic rock

what type of rocks are associated with pyroclastic flows?

tuff, ignimbrite, volcanic breccia, and pumice

what is a caldera and how do they form?

a very large crater, collapse of the volcanos summit

what is the difference between a caldera and a crater?

crater: forms from an explosion
caldera: forms from collapse

what is the order of minerals that solidify from a melt?

olivine, pyroxene, amphibole, biotite mica

what is fractional crystallization?

process by which minerals crystallize out of a cooling magma at different temperatures, and the crystals are separated from the remaining liquid

where do sedimentary rocks form: at the surface or interior of the earth?

surface

what are the three types of sedimentary rocks?

clastic, biochemical (organic), chemical

what are at least five types of clastic sedimentary rocks?

breccia, conglomerate, arkose, sandstone, graywacke

what are at least three types of chemical sedimentary rocks?

evaporates, dolomite, chert

what are at least two types of biochemical sedimentary rocks?

coal and limestone

what are the depositional environments for the different types of sedimentary rocks?

marine, fluvial, terrestrial

what is the difference between a breccia and conglomerate?

breccia: angular grain
conglomerate: rounded grain

what are at least three types of sedimentary rock structures?

layering, cross bedding, graded bedding, surficial features

what is cross bedding and how can it be used to infer flow?

contains angled layers, can provide information on the direction of flow, rate of flow, and the amount of sediment available

what causes tsunamis?

earthquakes

what is the definition of stress and strain?

strain: the change in shape

stress = force/area

what is the difference between brittle and ductile deformation?

brittle: deformation is discontinuous fractures

ductile: deformation is continuous, flow

what are the differences between fractures, joints, and faults?

fractures: planar breaks in the crust

joints: little or no movement between the sides of the crack

faults: significant movement between the two rocks

what is the earthquake cycle and how can it be used to forecast earthquakes?

a process of stress building up along a front due to plate movement, reaching a breaking point, and the releasing that stress through a sudden rupture, estimating time between large earthquakes

what are the causes of earthquakes?

when the earth's crust breaks along a fault

what are the three types of dip slip faults?

normal, reverse, thrust

what are the two types of strike slip faults?

right and left lateral

how do seismic waves move through the earth?

traveling in both curving paths and along the ground

how does the magnitude scale for earthquakes work?

measures the amplitudes of the seismic waves

what are the two types of body waves and two types of surface waves?

body waves: s-waves, p-waves

surface waves: love waves, rayleigh waves

what is the fastest and slowest waves between p, s, and surface waves?

fastest: p-wave

slowest: surface waves

name four hazards posed by earthquakes?

liquefaction, landslide, tsunamis, fire

what is the definition of liquefaction?

when loose, wet soil loses its strength and starts to behave like a liquid

what are the most damaging seismic waves?

surface waves

what is a geyser and how do they form?

geyser is a natural hot spring that intermittently erupts with bursts of steam and hot water, where magma heats groundwater beneath the earth's surface

where do deep earthquakes occur on the earth?

subduction zones

what is the definition of metamorphism?

solid minerals react with each other under high pressures and temperature, and new materials are formed

know at least four types of foliated metamorphic rocks?

slate, phyllite, schist, gneiss

know at least two types of nonfoliated metamorphic rock?

marble, quartzite

list three agents of metamorphism?

mineral composition, temperature, and pressure

know what a protolith is and be able to identify the protolith for marble?

the rock that exists before metamorphism starts, limestone

know what prograde and retrograde metamorphism is?

prograde: change in rocks texture due to increasing pressure and texture

retrograde: alteration of metamorphic rocks at lower temperatures and pressures after they have been subjected to higher conditions

where do major volcanic eruptions threaten people?

Indonesia, the Philippines, and japan

what are the two types of weathering?

chemical and physical

be able to give examples of mechanical/physical and chemical weathering?

mechanical/physical: erosion, salt wedging

chemical: dissolution, hydrolysis

what is the definition of regional metamorphism?

what happens to continental crust along convergent tectonic margins