Geology 101 Test Review
The oldest rocks on the ocean floors are about __________ years in age.
200 million
Earth is about __________ years old.
4.5 billion
In 2015 the human population of the world was about __________.
7.3 billion
Which of the following buildings would likely be the safest to be located in during an earthquake?
A two-story modern wood frame house
The most famous and outspoken of the early proponents of continental drift was ______________.
Alfred Wegener
Based on data for the period from 1970 to 2013, __________ experienced the greatest loss of life from natural disasters.
Asia
The _________ waves' motion is similar to S waves, except it is from side-to-side in a horizontal plane roughly parallel to Earth's surface.
Love
Seismic waves that travel only near Earth's surface are of two main types: _________ waves.
Love and Rayleigh
When a number of earthquakes along in the same general area over the course of a few months or years, the event is referred to as a(n) __________ .
earthquake cluster
The rapid increase in human population during the past several centuries is an example of __________ growth.
exponential
The Moon is thought to have formed __________.
from material that coalesced after an impact between Earth and a Mars-sized object
P waves can travel through ________________.
gases, liquids, and solids
An isotope's half-life is equal to the time it takes __________.
half of the parent atoms to decay into daughter atoms
in the last two or three centuries birthrates __________.
have changed little, while death rates have plunged
A rock subjected to higher temperatures would be expected to behave __________.
in a more ductile manner
As the global human population increases, the death toll from natural disasters is expected to __________.
increase
Most of the 40 deadliest disasters between 1970 and 2013 occurred in a belt running from China and Bangladesh through India and Iran to Turkey. This area was particularly vulnerable because __________.
it has a high population density
In San Francisco's Marina district in 1989, some fill underwent permanent deformation and settling, and some formed slurries as underground water and loose sediment flowed like a fluid in a process known as __________.
liquefaction
Earthquake-induced ground motions cause buildings to sway at certain periods. In general, the taller the structure, the _______ the period.
longer
Flexible buildings (made of wood or steel) have a ________ resonant period than a stiffer building (one of brick or concrete).
longer
In the _______, evidence abounded, mechanisms seemed plausible, and the plate-tectonic theory was developed and widely accepted.
mid-1960s
The principle of uniformitarianism, developed by James Hutton, implies that __________.
natural laws are uniform through time and space
When oceanic lithosphere collides with another plate, the ________ in the process of subduction.
older, colder plate turns downward beneath the younger, warmer plate
Steno's law of __________ states that sediment layers are continuous, ending only by butting up against a topographic high, such as a hill or a cliff, by pinching out due to lack of sediment, or by gradational change from one sediment type to another.
original continuity
The law of __________ explains that sediments (such as sand, gravel, and mud) are originally deposited or settled out of water in horizontal layers.
original horizontality
Most earthquakes are explainable using __________.
plate-tectonics theory
The hot-spot-melting-through-lithosphere process forms lines of extinct volcanoes on the ocean floor, from youngest to oldest, __________.
pointing in the direction of plate movement
As radioactive atoms decay, heat energy is _________.
released
With compressional forces, the hanging wall moves upward relative to the footwall; this type of fault is referred to as a __________ fault.
reverse
Earthquakes are most commonly caused by ______________.
sudden earth movements along faults
In the law of __________, Steno stated that in an undeformed sequence of sedimentary rock layers, each sedimentary rock layer is younger than the bed beneath it, but older than the bed above it.
superposition
he early differentiation of Earth into a mantle and a core was created by ________________.
the buildup of heat and the melting of iron, which was pulled by gravity to the center of Earth
The solar radiation we receive on Earth is the result of __________.
the nuclear fusion of hydrogen into helium
The frequency of a wave is __________________.
the number of waves passing a given point per unit time
If sea floor spreading occurs at a constant rate, the widths of magnetized seafloor strips have__________ ratios as the lengths of time between successive reversals of Earth's magnetic field.
the same
Human-caused and natural events can be distinguished using seismic waves because __________.
they produce different S and P wave patterns
A triple junction is the point where __________.
three tectonic plates touch
Our solar system formed __________.
through collisions of matter within a rotating cloud of gas, ice, dust, and other solid debris
A rock with only 25% of the parent isotope left has been decaying for time equal to __________ half-lives.
two
Liquefaction occurs when seismic waves cause __________.
water to be injected into sediment causing the grains to lose cohesion and behave like a fluid
The greatest earthquakes in the world occur _____________.
where plates collide with each other
The point on Earth's surface directly above the point where the fault first ruptures is called the ____________.
P
ll of the continents were once combined into a single supercontinent called ________________.
Pangaea
__________ occurs when a building's period matches period of passing seismic waves.
Resonance
__________ are the down-dropped areas in the middle of spreading-center domes that are being pulled apart.
Rift Valleys
waves travel only through solids; on reaching liquid or gas, the wave energy is reflected back into rock or is converted to another form.
S
Which statement accurately describes the planets of our solar system?
The four inner planets are smaller and rocky and the four outer planets are giant icy bodies composed mostly of hydrogen and helium.
Which of the following is NOT a basic tenet of plate tectonics?
The slab pulled into the asthenosphere begins the process of melting and moves into the liquid core.
Using the S-P timing method, epicenters can be located using seismograms from a minimum of ______ recording stations.
Three
A building's period of swaying is determined, in part, by the material used to build it.
True
Disasters occur where Earth unleashes its concentrated energy.
True
Each year, Earth is shaken by millions of earthquakes.
True
Earthquake intensity scales such as the Modified Mercalli scale assess the effects on people and buildings.
True
For magnitudes above about 6, the bigger earthquake magnitude means that more people in a larger area and for a longer time will experience the intense shaking.
True
Gravitational pull on a dense, down-going plate at a subduction zone (slab pull) is one of the forces that keeps the lithospheric plates moving.
True
Hot spots have active volcanoes above them on Earth's surface and moving plates carry the volcanoes away from their hot-spot source.
True
In general, there is an inverse correlation between the frequency and the magnitude of a disaster process.
True
Most of the subduction-zone earthquakes of today occur around the rim of the Pacific Ocean or the northeastern Indian Ocean.
True
Of the 40 worst disasters between 1970 and 2013, the most frequent mega-killers were hurricanes and earthquakes.
True
P and S waves do not follow simple paths as they pass through Earth; they speed up, slow down, and change direction, and S waves even disappear when they reach Earth's core.
True
Parallel bands of magnetized rock that show alternating polarities stripe the floor of the Atlantic Ocean; the pattern is symmetrical and parallel with the spreading center.
True
Passing through the mantle below the asthenosphere, the seismic wave velocities vary but generally increase until about 2,900-km depth where P waves slow markedly and S waves disappear at the core-mantle boundary zone.
True
Resonance can increase the duration buildings shake during an earthquake.
True
The biggest shaking event is called "the earthquake," the smaller ones before it are known as foreshocks, and the smaller ones after it are called aftershocks.
True
The compressional movements at subduction zones and continent-continent collisions generate the largest tectonic earthquakes and they affect the widest areas.
True
The decrease in the worldwide fertility rate is likely linked to urbanization and increased opportunities for women.
True
The gigantic pieces of lithospheric plates diverging, sliding past, or colliding with each other are directly responsible for most of the earthquakes, volcanic eruptions, and mountains on Earth.
True
The human population growth presently varies greatly from one region to another.
True
The largest moment magnitudes measured to date are from earthquakes that occurred in subduction zones.
True
The likelihood over 20 years of a hurricane that kills 1,000 people is greater than that of an earthquake that kills 1,000 people.
True
The moment magnitude is more accurate than the classical Richter scale because it is tied directly to physical parameters such as fault-rupture area, fault slip, and energy release, and because other earthquake scales use indirect measures such as how much a seismograph needle moves.
True
The processes that reverse the polarity of the magnetic field are likely related to changes in the flow of the iron-rich liquid in the outer core
True
The relation between distance and damage from an earthquake seems obvious: the closer to the hypocenter/epicenter, the greater the damage, but this is not always the case.
True
The types of rock or sediment on which a structure's foundation sits are of paramount importance with respect to whether the structure will be damaged by shaking from an earthquake.
True
Typically fewer than 20 major and great earthquakes (magnitudes of 7 and higher) each year account for more than 90 percent of the energy released by earthquakes.
True
When data from the Earth's magnetic field locked inside seafloor rocks became widely understood, most skeptics around the world were convinced that seafloor spreading occurs and that the concept of plate tectonics is valid.
True
Where the frequencies of seismic waves match the natural vibration frequencies of local geology and buildings, destruction may be great.
True
With their up-and-down and side-to-side motions, S waves shake the ground surface and can do severe damage to buildings.
True
eginning in the eighteenth century, discoveries in science, medicine, and public health caused death rates to drop dramatically.
True
ftershocks are smaller than the main shock in an earthquake sequence.
True
Which of the following disasters has the highest probability of causing a "1,000-fatality event" each year?
a hurricane
Which of the following disasters has the highest probability of causing a "10-fatality event" each year?
a tornado
A rock smashed into many pieces by a scientist using a hammer is undergoing ______ deformation.
brittle
he time of day an earthquake strikes is NOT a critical factor affecting loss of life from the event.
False
Transform faults have mostly vertical displacement rather than horizontal displacement.
False
Which of the following concepts best explains why a mass of low-density material in the mantle rises?
Buoyancy
After lava cools below the __________ point atoms in iron-bearing minerals become magnetized in the direction of Earth's magnetic field at that time and place.
Curie
A normal fault occurs when the hanging wall moves ________ relative to the footwall.
Down
The point on Earth's surface directly above the point where the fault first ruptures is called the ____________.
Epicenter
Disasters occur where Earth unleashes its concentrated energy.
False
Earth's interior is homogeneous.
False
Earth's magnetic pole and rotational pole coincide.
False
Large earthquakes do not generate body waves energetic enough to be recorded on seismographs all around the world.
False
Normal faulting occurs when the hanging wall moves upward relative to the footwall.
False
Spreading ridges produce the largest number of great earthquakes.
False
The ages of former volcanoes decrease with their distance from their parent hot spot.
False
The duration of the shaking is NOT a significant factor in damages suffered and lives lost.
False
The primary cause of deaths in earthquakes in modern times is people being swallowed alive by the ground, rather than by building collapse.
False
Earth's inner core is a 2,450-km diameter _________ mass with temperatures up to 4,300°C (7,770°F).
Solid
When most of the movement along a fault is horizontal, the fault is referred to as a __________ fault.
Strike- Slip
Which of the following wave types travels slowest through rock?
Surface Waves
The greatest insurance dollar losses related to natural disasters between 1970 and 2013 occurred in __________.
The United States
The best time for an earthquake to occur to minimize loss of life is __________.
during the night when most people are home and asleep
