GEOG EXAM 3
orogenesis refers to
a general term for a mountain-building episode that thickens continental crust
a hypsographic curve is
a generalized curve showing earth's surface by area and elevation in relation to sea level
a general term for a mass of perennial (i.e. longterm) ice, resting on land or floating in the sea attached to a landmass is
a glacier
glacial polish results from
abrasion
at which of the following locations does subduction occur?
along collision zones between continental and oceanic plates
alpine glaciers include all of the following except
an ice cap
earth's magnetic poles
are migrating approximately 55 to 60 km (34 to 37 mi) per year.
________ are sharp ridges that form when glaciers erode parallel valleys.
arêtes
earth's crust is roughly made up of
at least 14 plates capable of movement
which of the following is an example of an age-relationship based on relative dating?
australopithecines evolved before homo erectus.
the san andreas system in california is an example of a
both a strike-slip and transform fault
a glacier's mass balance is determined by
both accumulation and ablation
sedimentary rock formed from dissolved minerals that precipitate out of water solution and build up to form rock are
chemical/non-clastic
a glacier in a bowl-shaped recess is known as a(n)
cirque glacier
sedimentary rock formed from the combined processes of weathering, erosion, transportation, deposition, lithication, and compaction of rock fragments of other rocks are
clastic
metamorphism that occurs when rocks are exposed to the pressure and extreme temperature associated with intruding magma is known as
contact metamorphism
circular surface depressions usually found at or near the summit of a volcano are known as
craters
which of the following gives the correct sequence of layers in Earth, from the surface to the center?
crust, mantle, outer core, inner core
the zone where accumulation balances ablation is known as the
equilibrium line
a long, narrow, sinuous ridge of stratified sand and gravel located in a till plain is known as a(n)
esker
exogenic
external Processes such as weathering by wind or water
when rock strata are strained beyond their ability to remain an intact unit, displacement occurs in a process known as
faulting
partially compacted snow that is an intermediate between snow and ice is called a(n)
firn
the subsurface area where the motion of seismic waves is initiated along the fault plane is called the
focus, or hypocenter
glacial ice is
formed from continual accumulation of snow that recrystallizes under its own weight into an ice mass over a period of many years
terranes refer to
fragmented crustal material from one plate and accreted to another plate
which of the following is incorrect about glacial movement?
glaciers are mostly stationary, only moving several centimeters over tens of years
which of the following is correct regarding Alfred Wegener's theory of continental drift?
he believed that 225 million years ago all the continents were joined together to form pangaea
africa is dominated by which topographic region?
hills and low tablelands
a topographic region that is characterized by local relief of more than 100 m (325 ft.), but less than 600 m (2000 ft.), is considered a
hills or low tablelands
________ are sites of upwelling of magma from the mantle independent of plate boundaries
hot spots
the measurement of land elevation relative to sea level is known as
hypsometry
vatnajökull is the largest and most voluminous Icelandic glacier. It is roughly circular in shape, overlays several volcanoes, and covers an area of approximately 8,100 km^2(3,100 mi^2) with an average thickness of 400 m (1,300 ft). this is an example of a(n)
ice cap
an extensive, continuous mass of ice covering a continental scale is known as a(n)
ice sheet (greenland & antartica)
the process of calving produces
icebergs
what type of rock forms from the solidification of molten material?
igneous
knowledge of Earth's interior is mostly derived from
indirect evidence involving the analysis of seismic waves
increased seismicity in colorado, new mexico, and oklahoma has been linked to
injection wells associated with hydraulic fracturing
endogenic
internal processes such as volcanic and tectonic activity
an effusive eruption ________, whereas an explosive eruption ________.
is an outpouring of low-viscosity magma onto the ground; is a violent explosion of magma, gas, and pyroclastics
why is glacial ice analogous to a metamorphic rock?
it forms as a result of recrystallization caused by pressure
molten rock that pours forth on earth's surface is called
lava
effusive eruptions are not related to which of the following?
magma with a 50-75 percent silica content, high in aluminum
molten rock beneath the earth's surface is known as ________, whereas molten rock on the earth's surface is called ________.
magma; lava
boundaries between intervals of the geological time scale are determined by
major events in the earth's history, such as major extinctions.
earth's interior is layered because
materials became sorted based on density as the Earth solidified
if two glaciers with lengthy ridges of till along each side of the glacier merge, a ________ moraine may form.
medial
a rock transformed from any other rock through extreme heat and or pressure is referred to as
metamorphic
along ________ new ocean floor is formed by upwelling flows of magma, whereas along ________ old oceanic crust is destroyed.
mid-ocean ridges; subduction zones
the boundary between the crust and the rest of the lithospheric upper mantle is a discontinuity known as the
moho
tension
normal fault
tensional stress along a fault can result in a dropped hanging-wall block relative to the footwall side, producing a
normal fault
a topographic region that is characterized by local relief of less than 100 m (325 ft.) is considered a
plain
the aesthenosphere can best be described as
plastic
________ is the theory that describes the motion of the earth's lithosphere.
plate tectonics
vertical elevation differences in a local landscape are referred to as
relief
an assemblage of minerals bound together is called a
rock
the continuous alteration of earth materials from one rock type to another is known as the
rock cycle
what type of rock is derived from the bits and pieces of former rocks?
sedimentary
the three basic rock types are
sedimentary, metamorphic, igneous
an instrument used to record vibrations in the crust is the
seismometer
if you wanted to avoid earthquakes, which of the following areas would be the safest to live?
shield
a gently sloping mountain landform built from effusive eruption is known as a
shield volcano
folded layers of rock can form a wavelike pattern of troughs and crests. the layers near the trough (i.e. downward fold or "smile") form
syncline
eroded debris dropped at the glacier's farthest extent is called ________ moraine.
terminal
which of the following is not used to rate an earthquake on the moment magnitude scale?
the amount of death and destruction that occurred
a continental craton is best described as
the inactive remains of ancient tectonic activity
which of the following statements about Earth's core is not correct?
the inner core is believed to be liquid and the outer core solid.
which of the following is correct in regards to the geologic time scale
the largest defined unit is an eon or, according to some, a supereon.
the bulk of Earth's history has occurred during
the precambrian eon
uniformitarianism
the principle that the same physical processes currently active in the environment we're operating throughout earth's history
an example of the principle of uniformitarianism
the processes by which streams carve valleys at present are the same as those that carved valleys 500 millions years ago.
an earthquake is best described as
the sharp release of energy in the Earth's crust that creates seismic waves
which of the following is correct regarding continental drift?
the term "continental drift" is now called plate tectonics
fault types are defined by
the tilt and orientation of the fault plane
the general term for the undulations and other variations in the shape of the Earth's surface is called
topography
areas where plates slide past one another, usually are right angles to a seafloor spreading are
transform boundaries
when geologists conclude that the grand canyon sequence of rocks was formed through hundreds of millions of years of deposition, mountain building, and erosion, they are basing this conclusion on the principle of ________ which states that ________.
uniformitarianism; the geologic processes that operated in the past are the same as those that operate today, and they occurred in accordance with the same laws of nature that are operating today
glacial surges may be associated with
water pressure, soft bed, or lubrication.
which of the following shows the general sequency of an orogeny?
weathering and/or erosion—uplift—thickening of crust through accretion or magma intrusion
the precambrian eon encompasses what percentage of earth's total history
88.3%