Exam 3
Knowledge of the Earth's interior is derived from
Indirect evidence involving the analysis of seismic waves
Wegener used ________ to name a supercontinent approximately 225 million years ago.
Pangaea
A landslide differs form a debris avalanche in that
a landslide moves more slowly than a debris avalanche
Landslides occur when
all of the above
which of the following can lead to hill slope failure?
all of the above
At which of the following locations does the subduction occur?
along collision zones between continental and oceanic plate
Which of the following is true of spheroidal weathering?
it attacks the corners and edges of rocks
The steepness of a slope made of loose material is called the
angle of repose
All processes that cause reduction and rearrangement of landforms are included in the term of
denudation
Approximately what percentage of Earth's surface is exposed above sea level?
29%
The oceanic crust thickness is about __km, and the average continental crust thickness is ___km
5 and 30
List four of Earth's coninental shields
Canadian, Brazilian, African, and Indian
In 1912, German geophysicist and meteorologist, Alfred Wegener first proposed the ______________ hypothesis about the Earth's land mass migration.
Continental drift
List four volcanic activity zones:_______________________, _______________________, _________________________, _______
Continental rift valley, oceanic continental plate convergent, oceanic- oceanic plate convergent, and hot spot
Which of the following gives the correct sequence of layers in the Earth,from the surface to the center?
Crust, asthenosphere, lower mantle, core
When rock strata are strained beyond their ability to remain intact unit, displacement occurs, in a process known as
Faulting
List three forms of physical weathering _________, _______ and, __________.
Frost action, salt crystal growth, and pressure-release jointing.
___________ threshold is the point at which there is enough energy to overcome resistance against movements.
Geomorphic
The decay rate is expressed as the ______ the time required for one of the half of the unstable atoms in a sample to decay into "daughter" isotopes.
Half Life
The youngest epoch in the geologic time scale is ______
Holocene
In which climates would rock be weathered to the greatest depth?
Hot and Wet
Volcanic activity located away from plate boundaries is associated with
Hot spots
The geologic cycle is composed of three subsystems:
Hydrologic cycle, rock cycle, tectonic cycle
Three basic rock types are _______ (fire-formed, molten), ________(from settling out), and __________ (transformed from any other rock through extreme heat or pressure).
Igneous, sedimentary, metamorphic
The principle of buoyancy and balance, when applied to Earth's crust, helps us to explain fluctuations in Earth's outer crust, a property known as
Isostatic adjustment
An example of chemical weathering is
Karst topography
Which layer of planet forms 80% of the Earth's total volume, and has an average density of 4.5 g/cm3.
Mantle
Which of the following gives the correct sequence of layers in the mantle, from bottom to top?
Mantle, upper mantle, asthenosphere
The combination effects of _________(powered by internal enegry) and ____________(powered by the sun through motion of air, water, and ice) create Earth's continental crust.
Mechanical activity (and) weather and erosion
Which of the following is true of joints
Only B and C are true
Uplift of the landscape creates ______ energy which is converted to _______ energy when materials begin to move downslope.
Potential, Kinetic
Which of the following is incorrectly matched?
Radioactive decay heat-exogenic energy source
List two types of scale to rate earthquakes _____________ and ______________
Richter scale and moment magnetic scale
Several large, linear lakes are formed in East Africa, this is evidence of what process?
Rifiting
Divergent plate boundaries are characteristics of
Sea-floor spreading centers
Which of the following is incorrectly matched?
Shearing--- stretching
If you were paranoid of earthquakes, which of the following are would be the safest to live?
Shield
The Earth's dominant materials are _______ and _______
Silicone and Iron
When geologist or archaeologists dig downward into a unit of rock or sediment, they are digging "back in time". This fact is based on the principle of _______
Superposition
A hypsographic curve is a graph that shows the earth's surface by area and elevation in relation to sea level
TRUE
A residual "synclinal ridge" may form within a trough of a fold
TRUE
A slope is stable if its strength exceeds the weathering and erosion process
TRUE
Depth of earthquake focus increases with increasing distance from ocean trench
TRUE
Earth was once in a molten state, during which materials became sorted based on density
TRUE
Ocean floor subducts under continents because the ocean floor is denser than continental material
TRUE
Orogeny means mountain generating
TRUE
The Hawaiian Islands were formed as a result of a rising plume of magma from the mantle
TRUE
The Moho mirrors the surface topography, i.e., high places on the surface of the Earth overlies areas in which the Moho descends to grater depths, and vice versa
TRUE
The age of the sea floor increases with increasing distance from a mid-ocean ridge
TRUE
The angle of repose depends on the size and texture of the grains
TRUE
The fluid outer core generates 90% of Earth's magnetic Field
TRUE
The magnetic stripes found around mid-Atlantic ridge were due to the magnetic reversal.
TRUE
The mean sea level is at 0m.
TRUE
The pressure-release jointing is a physical weathering process that does not involve water.
TRUE
The salt crystal growth is primarily found in arid environments
TRUE
Uniformitarianism assumes that the same physical processes we see today are a key to understand the processes that have been operating throughout the geologic time
TRUE
Which of the following is not an example of an age-relationship based on absolute dating?
The Coconino formation in the Grand Canyon is older than the Kaibab formation.
Which of the following statements about Earth's core is not true?
The inner core is believed to be liquid and the outer core solid
Which of the following is true of the earthquake in the Liaoning Province of NE China on February 4, 1975?
The quake was successfully forecasted and 3 million people were evacuated.
List two forms of landslides ________ and _________.
Translational and Rotational
Which of the following are located along the mid-ocean ridge?
Volcanoes
The most active tectonic regions of North and South America are on the
Western coast
People often say that California is going to "fall into the ocean". This idea is totally wrong because the San Andreas fault would have to be a _____ fault associated with ____ forces for this to happen.
`Normal; Tension
The dynamic equilibrium model refers to
a balancing act between tectonic uplift and rates of denudation by weathering and erosion in a given landscape
Movement at the geomorphic threshold signals
a conversion of potential energy to kinetic energy
After a threshold is crossed, the landscape
adjusts to a new equilibrium condition
Rocks are subjected to stress due to ____
all of the above
The form that a landscape exhibits results from a balance between
all of the above
The rate at which rocks weathering depends on
all of the above
Which of the following lists the correct sequence of divisions in the geologic time scale, from largest to smallest?
eon, era, period, epoch
The motion of seismic waves is initiated in a subsurface area along the fault plane called the
focus, or hypocenter
On which part of a slope would rocks tend to fall at the highest speed?
free face
Compared to oceanic crust, continental crust is
generally more complex on content and structure
The science that specifically studies the origin, evolution, form, and spatial distribution of landforms is
geomorphology
Chemical weathering is greatest under conditions of
higher mean annual rainfall and temperature
The transportation and deposition of materials by media powered by solar energy is the
hydrologic cycle
Earth's magnetic field
is variable, and it has phased to zero some nine times during the past 4 million years
List three types of orogenesis: ______________, ______________, and _______________
oceanic plates- continental plate, oceanic plates-oceanic plate, continental plate- continental plate
In reality, a landscape behaves as a (an) _______ system
open
Exfoliation occurs because
overlaying rock is removed, thereby allowing the underlying rock mass to expand and fracture
Two most abundant chemical elements in Earth's crust are _____ and _______
oxygen and silicone
When rock is broken and disintegrated without dissolving, the process in operation is
physical weatherin
The asthenosphere can be described as
plastic-like
In most areas, the upper surface of bedrock is partially weathered to broken-up rock called
regolith
Vertical elevation differences in a local landscape are referred to as
relief
Human-induced mass movements produce a category of processes known as
scarification
An instrument used to record vibrations in the curst is the
seismograph
A continental _________ is a region with a craton is exposed at the surface
shield
A slow persistent mass movement of surface soil is called
soil creep
Heat energy and new materials are brought to the surface from the interior by the
tectonic cycle
Normal faults are associated with
tension forces
List three types of stress ______, ___________ and ________
tension, shear, and compression
The most detailed order of relief applies to ______ order relief features
third
Other than the rock itself, the most important chemical substance needed for the majority of weathering processes is
water
The disintegration and dissolving of surface and subsurface rock is called
weathering
Which of the following is an exogenic process?
weathering
List three types of plate boundaries______,_______, and _____
Divergent, convergent, tranform
Which of the following is an endogenic process?
Volcanism
There are two types of time, which are ______ and ______
Absolute and Relative
Which of the following is true of the asthenosphere?
All of the above
Which of the following plays a role in the shaping of Earth's surface?
All of the above
The San Andreas system in California is an example of a
All of these are correct
Folded layers of rock can form a wavelike pattern of troughs and crests. The layers near the crest form
An anticline
Which of the following is an example of a first order of relief?
An ocean basin
The area at the surface directly above the subsurface location where seismic waves are initiated is termed the
Epicenter
Convergent plates boundaries are characteristics of
collision zones between plates
List four evidences Wegener used to prove his hypothesis _____,_________,______, and ________
costal lines, fossils, rock types, and ancient climates.
A __________ or heartland region, is an old and stable part of the continental crust
craton