ESC Final Exam Flashcards
A tsunami
may be just a broad, gentle swelling out at sea but grows as it approaches shore.
Aftershocks are usually
much weaker than the mainshock.
Andrija Mohorovicic discovered the crust-mantle boundary, which is now named after him, because he realized that
P-waves were refracted at the boundar
Earthquake prediction is not highly reliable, but geologists do know
more earthquakes happen along plate boundaries than happen at intraplate locations.
Earthquakes in California are
due to stick-slip behavior along the San Andrea fault.
Examining sedimentary bedding in a particular geologic area reveals disrupted layers that formed 260, 820, 1,200, 2,100, and 2,300 years ago. Assuming that all the earthquakes that have occurred in this area are represented by these disrupted layers, what is the recurrence interval of earthquakes in this area?
510 years
Interpret the travel-time curve shown. Approximately how many minutes elapsed between the arrival of the first P-wave and the arrival of the first S-wave at Station 3?
7
Liquefaction
can affect sand layers below the ground surface and cause them to erupt as sand volcanoes or sand boils.
Long-term earthquake predictions
are based on the study of historic recurrence intervals.
One difference between P- and S-waves is that
only P-waves can travel through a liquid.
The 2010 Haiti earthquake was so destructive because
of poor construction standards that caused many buildings to collapse.
The Modified Mercalli Intensity scale measures
earthquake damage.
The P-wave shadow zone marks the
core-mantle boundary.
The Richter scale
measures the size of earthquake by the amount of ground motion.
The S-wave shadow zone indicates
the outer core is liquid.
The areas shown in gray occur because
P-waves are refracted at the core-mantle boundary.
The earthquake foci pattern east of Australia and just north of New Zealand indicates which tectonic setting?
Convergent plate boundary
The locations of major earthquakes
are usually along plate boundaries.
To find the location of an earthquake’s epicenter, you need to calculate the distance from the epicenter to ____ different seismometer stations.
3
When a fault slips and the rock units on either side return to their original shape by generating vibrations, it is called
elastic rebound.
Which of the following is a good technique for building safer structures in an earthquake zone?
Use wood-frame construction.
Which peripheral hazard of earthquakes caused the damage shown in the photo?
Landslide
Which type of wave is a compressional body wave?
P-wave
A radioactive isotope of the element potassium decays to produce argon. If the ratio of the number of argon to potassium atoms is found to be 7:1, how many half-lives have occurred since the sample of radioactive potassium started to decay?
3
An area of slightly dipping sedimentary rock layers has large inclusions and is intruded by an igneous dike. Using the basic principles for determining relative ages you can infer that the
sedimentary rock “baked” by the igneous intrusion is older than the intrusion.
An organism is most likely to be fossilized if it
dies in an oxygen-poor environment.
Footprints, feeding traces, burrows, and dung are considered to be
trace fossils.
Geologists estimate that the Earth is 4.54 billion years old, based on
isotopic dating of meteorites from the first differentiated bodies of the Solar System.
If a sandstone contains pieces of basalt, then the sandstone is younger than the basalt according to the principle of
inclusions.
If you equate all Earth history to one calendar year, our species (Homo sapiens) would appear on
11 P.M. on New Year’s Eve.
In 1815, William Smith correlated strata from many locations and plotted them on paper to show the spatial distribution of rock units on Earth’s surface. This document was the first modern
geologic map.
In the cross-section, identify the oldest feature in the sequence.
Bed 1
In the cross-section, identify youngest event in the sequence.
Erosion of the land surface
Petrified wood is an example of a
permineralized fossil.
The age of beds exposed in one location is related to the age of beds exposed in another location based on similarities in rock type between the two locations. What is this process called?
Lithologic correlation
The boundary surface between any two stratigraphic formations is called a
contact.
The concept that times of relative stability in the number and identity of species alternate with times of rapid change is called
punctuated equilibrium.
The determination that one feature is older or younger than another feature, without calculating their actual ages, is known as
relative dating.
The evolution of life is tied to the geologic column, with the first life appearing in the _________, the ________ referred to as the Age of Mammals, and the _________ referred to as the Age of Dinosaurs.
Archean Eon, Cenozoic Era, Mesozoic Era
The image shows a stratigraphic section of the Grand Canyon. Between which two groups is there an angular unconformity?
Unkar Group and Tapeats Sandstone
The observations of _____________ led to the principle of uniformitarianism.
James Hutton
Uniformitarianism means
geologic processes that operate today operated in the past at about the same speed.
What type of unconformity is illustrated by the sequence?
Angular unconformity
What type of unconformity is illustrated by the sequence?
Nonconformity
Which of the following accurately ranks the subdivisions of geologic time in order from largest to smallest?
Eon, era, period, epoch
Which of the following correctly lists the time divisions shown from oldest to youngest?
Proterozoic Eon, Paleozoic Era, Mesozoic Era, Cenozoic Era
Which of the following is NOT true about William Smith’s observations?
He noted that a fossil species could disappear then reappear in much younger strata.
Which principle states that in an undisturbed sedimentary sequence, the oldest layer lies at the bottom and the youngest layer at the top?
Principle of superposition
A seal rock
is a necessary component of an oil trap.
A seismic-reflection profile
shows the shapes and depths of underground sedimentary layers.
A typical reservoir rock, into which oil has migrated and collected, is
highly porous and permeable.
A typical source rock for oil, which starts out as mud in which dead organic matter settles, is
shale.
As organic material is compacted to form coal, which stages does it pass through, from first to last?
Peat, lignite, bituminous coal, anthracite
Galena (PbS) is an important ore mineral of
lead.
Glass is made from
silica.
Hydrofracturing is used to extract hydrocarbons from
shale.
In a nuclear power plant
control rods regulate the rate of the reaction by absorbing excess neutrons.
In the rock layers that are drawn in the diagram, oil would most likely be found in layer
C
Macroscopic organic material (leaves, stems, trunks) of swampy areas is exposed to heat and pressure in an oxygen-poor environment over a geologically long period of time. The result is
coal.
Metallic and nonmetallic mineral resources are considered nonrenewable because
natural processes make minerals much more slowly than we can mine them.
Nuclear fusion is the reaction that
produces the energy that causes the Sun to shine.
Oil is most likely to form when
tiny algae and plankton decompose under conditions of heat, pressure, and low oxygen.
On the diagram,
oil well B would yield the most oil because it is on an anticline crest in permeable reservoir rock.
The Deepwater Horizon disaster refers to
a catastrophic oil rig blowout that occurred in the Gulf of Mexico in 2010.
The first modern oil well was drilled
by Edwin Drake in 1859 in Titusville, Pennsylvania.
The oil window
is the relatively narrow range of temperatures between 90-160°C in which oil can form.
The type of energy that requires the building of dams is called
hydroelectric.
The type of energy that uses Earth’s internal heat is called
geothermal.
The world’s largest conventional oil reserves are found
in the Persian Gulf area.
This image shows an intact slab of rock destined to become a kitchen countertop. What is this type of mineral resource called?
Dimension stone
What is the grade of an ore?
The concentration of useful metal in an ore
What type of mineral ore deposit is shown in this image?
Magmatic deposit
Which is an example of an unconventional fossil fuel reserve?
Tar sand
A channel is
an elongated depression or trough of running water.
A well in which the water rises on its own to a level above its aquifer is called
an artesian well.
About ____ of Earth’s freshwater is groundwater.
30%
An ephemeral stream
in dry climates may sometimes become a dry wash.
Deltas
may form where a stream empties into the slower waters of a lake or the ocean.
Features that are created when water dissolves surface and subsurface limestone, like sinkholes, troughs, caverns, natural bridges, and towers, are collectively called
karst landscapes.
Geologists have interpreted the lakes in the figure of central Florida as
sinkholes.
Groundwater
typically moves slowly within the ground through porous rock layers like sandstone.
Groundwater contaminants
like methane, arsenic, and salt may occur naturally in groundwater.
In the hydrologic cycle,
sheet wash is a thin film of water that moves down slopes.
Lake Baikal and Lake Tanganyika formed as a result of
rifting.
Porosity increases
when rocks develop joints or fractures.
Stream-eroded landscapes that are early in their evolutionary progression have
narrow, deep valleys.
Streams that flow down steep mountains onto much flatter land will spread out and lose velocity, and drop material in triangular-shaped structures called
alluvial fans.
The discharge of a stream is
likely to decrease downstream in arid regions and increase downstream in temperate regions.
The image shows water flowing around rocks and boulders, resulting in inconsistent direction and velocity of water flow. What feature of fluid motion describes this type of flow?
Turbulent flow
The interaction of groundwater with limestone bedrock can create a geologic hazard called a
sinkhole.
The largest river in the world, on the basis of discharge, is the
Amazon River.
The rate of groundwater flow
depends on the permeability of the material it flows through and on the slope of the water table.
The total load that a stream can carry is called its
capacity.
The two images show a change in course of a river system. What process is represented in this sequence of images?
Stream piracy
This figure shows the progressive development of a meander in a river system. What feature is created in the fourth panel?
Oxbow lake
What drainage network is produced when bedrock is relatively uniform and unfractured?
Dendritic
Which drainage network follows pre-existing fracture patterns in the bedrock?
Rectangular
Which would always result in a flash flood?
Dam collapse
A glacially-carved, deep valley filled with water is called a(n)
fjord.
A glacier can have only one of which of the following types of moraines?
Terminal
According to Milankovitch, which of the following is a contributing causative factor to the short-term glacial and interglacial cycles within an ice age?
Variations in the shape of Earth’s orbit
Based on its location, what kind of desert is the Sahara?
Subtropical desert
Continental ice sheets today are found only in
Antarctica and Greenland.
Desertification in the southern Great Plains of the United States in the 1930s occurred because
of drought and poor management of agricultural land.
During the last ice age (in the Pleistocene), glaciers held so much water that
sea level dropped as much as 100 m.
Ice
becomes coarser over time in a glacier.
In deserts, a lag deposit forms when wind
blows away finer sediment, leaving a layer of pebbles and cobbles behind.
Permafrost
that thaws and refreezes produces a pentagonal or hexagonal ground pattern.
Scientists can determine the direction of movement of continental ice sheets or glaciers by looking at glacial
striations.
The dark shiny brown coating of iron oxide, manganese oxide, and clay found on exposed desert rocks is called
desert varnish.
The illustration on the left shows the glacial processes that created the feature in the photograph on the right. What glacial feature does the photograph on the right show?
Esker
The image shows common landscape formations found in a desert. Which letter properly identifies a playa?
D
The image shows some of the landforms left behind after glacial retreat. Which letter identifies a drumlin?
A
This image shows an idealized illustration of how air interacting with a mountain range can create a desert. What type of desert does the illustration show?
Rain shadow desert
This image shows the gradual accumulation and building of soil in desert environments. What is produced by the process shown in the image sequence?
Desert pavement
Tillites
consist of large clasts in a matrix of sandstone and mudstone.
When an ephemeral stream flows onto the flat land at the mouth of a desert canyon,
an alluvial fan is deposited.
When there is an abundant sand supply and strong steady winds, _________ dunes form.
longitudinal
Which is a possible long-term cause of major ice ages?
Plate tectonics
Which is the correct sequence of structures formed by desert landform erosion over time, from first to last?
Mesa, butte, chimney
Which of the following climate conditions would most likely allow glaciers to form?
Heavy snowfall in winter coupled with relatively cool summers
Which of the following is part of a continental ice sheet?
Ice shelf
Wind-blown glacial deposits are called
loess.
