Geology
At a delta _______?
-Stream gradient decreases -A single channel breaks into multiple, radiation distributary channels
If a 50 year flood occurs on the Mississippi River in 201, what is the probability that a flood of the same magnitude will occur in 2011?
2%
The oldest oceanic crust is approximately _______ years old
200 million years
What percentage of seawater, on average, consists of dissolved salt ions?
3.5%
For dry sediments, the angle of repose is typically between _____ and _____ degrees
30;37
The average depth of the abyssal plains below sea level is about _________?
4.5 KM
Approximately what percentage of the Earths surface is covered with water?
70%
The discharge of a river traveling though a humid region will typically _____ downstream; the discharge of a river traveling through an arid region will typically _____ downstream
?Increase;Decrease
Which type of coastline usually has a broader continental shelf?
A passive continental margin
Which has greater competence?
A small mountain stream
___________ make up a majority of the ocean floor worldwide?
Abyssal plain
Which of the following factors decreases the risk of mass movement?
Adding vegetation to the side of a hill
To the geologist, ____________
All landslides are mass movements, but not all mass movements are landslides.
As the velocity of flow decreases, ________
All of the Above
Coastal California is particularly susceptible to mass wasting because of _________?
All of the above
Conditions such as ________ may exacerbate a developing slump?
All of the above
Mass movement along coastal cliffs in southern California is so common because _______?
All of the above
__________ are surface features indicative of a developing slump
All of the above
____________ may help prevent stabilize slopes to prevent mass wasting?
All of the above
Major oceanic surface currents travel ________?
At an angle to prevailing winds as a result of the Coriolis effect
Which river is a threat to capture the flow of the Mississippi River through stream piracy?
Atchafalaya River
________ occur(s) when debris or snow mixes with air to form a chaotic cloud.
Avalanches
The lowest elevation to which a stream can downcut is the ___
Base level
The form and topography (depth profile) of the ocean floor is termed ________?
Bathymetry
____________ in sedimentary rock may become a failure surface
Bedding planes
Moisture among sediment grains ________
Can promote stability if present in small amounts, but promotes mass wasting if sediment is saturated
Braided streams _________
Consist of a series of intertwined channels that are overloaded with sediment
Which portion of the sea floor is most steeply sloped?
Continental Rises
The shallowest portions of ocean found along the margins of continents are the ___________
Continental shelves
Which of the following types of mass movement takes place most gradually?
Creep
The outer edge of a meander, where material is being eroded, is a(n)
Cut bank
The principle difference between a debris flow and a debris slide is the _________
Debris flow contains abundant water, whereas the debris slide is dry
The density of seawater increases with ______ and _______
Decreasing temperature; increasing salinity
In uniform sediments with a relatively constant slope at the surface, a __________ drainage network is expected?
Dendritic
Compared to continental crust, oceanic crust is _________
Denser
On a bathymetric map, contour lines connect points of equal _____
Depth of the sea floor below sea level
Slope stability is determined by which two forces?
Downslope and resistance
Unstable slopes start to move when the ______ force exceeds the _______ force that holds the material in place
Downslope; resistance
If currents are largely directed toward shore, the area is likely to experience _____
Downwelling
___________ may form parallel to slope surfaces in granite and become a failure surface
Exfoliation joints
All flooding events occur so rapidly that there is no time to alert people in harm's way
FALSE
All flowing water on the continents' surfaces is confined to stream channels
FALSE
All the water in rivers and streams arrives directly from rainfall runoff?
FALSE
Coastal processes are of interest to geologist, but affect relatively few people because less than 10% of the world's population lives within 10 km of the sea coast
FALSE
For the Earth as a whole, ocean water temperatures vary more than surface-air temperatures.
FALSE
High tide occur simultaneously at all coastlines around the world, except for minor effects on bays
FALSE
If a stream cuts though flat-lying sediments to reach an anticline produced in an ancient orogenic even, the course of the stream will likely be unaffecteed
FALSE
Mass wasting always involves sudden movement of material downslope
FALSE
One of the most problematic aspects of landslides is that large-scale, cataclysmic examples are the norm, whereas small-scale landslides are much more rare.
FALSE
Scientist have determined that Mars has actively flowing water-filled stream channels
FALSE
Slumps typically arrive intact at the bottom of a slope?
FALSE
The deltas of all major rivers consist of multiple radiating lobes of sediment in a "bird's foot" configuration, similar to the Mississippi River delta
FALSE
The major oceans, such as the Atlantic, have been present since the Precambrian
FALSE
The sediment load of a stream consists of only those grains that are fine enough to stay in suspension
FALSE
Well-rounded sand has a larger angle of repose than irregularly shaped gravel
FALSE
A guyot is a(n)
Flat-topped seamount
Which of the following increases the risk of mass movement?
Flooding the sediment with water to the point of saturation
The flat-lying area surrounding a river channel is termed the _______
Floodplain
__________ in metamorphic rock may become a failure surface
Foliation planes
Composition
Geologist distinguish among different types of mass wasting based on factors such as the _____ of the moving material and the rate of movement.
The slope of a stream surface measured between two points along its course is the ____________.
Gradient
The principle difference between a debris flow and a mudflow is the _________
Grain size of the moving mass
The principle difference between a debris slide and a debris avalanche is the ________
Grain size of the moving mass
The immediate cause of incidents of mass movement is ________
Gravitation
Meandering streams ___________
Have a channel that is highly sinuous (curvy)
Ephemeral streams _________
Have flowing water either episodically or during a portion of the year
Pirate streams ________?
Have increased their drainage areas
The deepest segments of the ocean floor are found _______
In trenches associated with subduction zones
The dissolved cations sodium, potassium and calcium are ______?
Introduced to the ocean by the inflow of rivers
The stream gradient of most rivers ________
Is greater near the source than near the mouth
The principle difference between a lahar and a mudflow is the __________
Lahar contains pyroclastic debris from a volcanic eruption
________ are likely to occur along volcanic slopes
Lahars
Moving away from its headwaters, the flow of a stream usually becomes more _______
Laminar
Ground shaking can transform wet sediment into liquid-like slurries in a process known as ___________
Liquidifaction
The base level of a tributary would become ______ if a dam and reservoir were constructed where is flowed into a trunk stream
Lower
Which trench includes the worlds deepest sea floor (more than 11 km below sea level)?
Marianas trench
V-shaped stream valleys result from the downcutting of stream erosion and ____________
Mass wasting on the valley sides
Which of the following types of mass movement is least coherent (most like a liquid)?
Mudflow
Within a meander, where is sediment most likely to be deposited?
On the inner banks of the meander
A meander that is cut off to become completely isolated from the main channel, by which retains water, is a(n) _________
Oxbow Lake
With time, a river may erode terrain to produce a low-lying plain termed a(n) _______
Peneplain
The inner edge of a meander, where sediment is deposited, is a(n) _______?
Point bar
In the region immediately surrounding an isolated volcano, a ______ drainage network is expected
Radial
In a region with prominent orthogonal sets of joints, a _______ drainage network is expected
Rectangular
__________ can occur where undercutting waves remove support beneath sea cliff overhands
Rock falls
Strictly speaking, which of the following types of mass movement is a landslide?
Rock slide
Which of the following types of mass movement is likely to move most rapidly?
Rock slide
Gyres __________
Rotate clockwise in the Northern hemisphere and counterclockwise in the Southern hemisphere
At a waterfall, where two sedimentary lithologies are juxtaposed, which lithology is more likely to form the cliff over which the water falls?
Sandstone
A _________ may form at the head of a slope
Scarp
Ultimately, the base level of a stream valley can be no lower than _________
Sea level
Which type of bedrock provides the greatest risk of landslide?
Shale
The principle difference between a slump and a debris slide is the __________
Shape of the path taken by the moving mass
At the equatorial ocean basins, sea surface temperatures may reach 30 degrees or greater; at the sea floor 4KM to 5KM below, the temperature is _______
Slightly warmer
Which of the following types of mass movement always travel down a curved surface?
Slump
________ occur(s) when a semi coherent mass of material moves downslope on a failure surface
Slumps
________ occur(s) where thawed sediments move downslope over permafrost
Solifluction
__________ occur(s) when regolith moves slowly downslope due to freezing and thawing?
Solifluction
All else being equal, water will flow faster in a stream that has a _______
Steep stream gradient
All else being equal, water will flow faster in a stream with _______
Straight channel
________ may trigger tsunamis
Submarine mass movements
Between subaerial and submarine mass movements, we have a much better historical record of ________.
Submarine movements
A 100 year flood is more catastrophic than a 50 year flood.
TRUE
All regions are susceptible to mass movements?
TRUE
Although the Nile River is longer, the Amazon River has the greatest discharge of any stream on Earth
TRUE
Fires and deforestation may lead to slope failure
TRUE
Geological evidence suggest that many millions of years ago, the Amazon flowed toward the west rather than the east
TRUE
In cold, dry, mountainous climate, rock glaciers consisting of rocks held together by a smaller volume of ice can slide down slopes
TRUE
Tectonic activity destabilizes the ground?
TRUE
Submarine mass movements have been found along hot-spot volcanoes and active plate boundaries. These massive slumps have been attributed to _________.
Tectonic activity
The deepest part of the channel, where the stream flows fastest is the ______________
Thalweg
Which has greater capacity?
The Mississippi River
The distinction between a valley and a canyon is _________
The sides of a canyon are more steep than those of a valley
Compared to continental lithosphere, oceanic lithosphere is ________?
Thinner
In a region characterized by a parallel series of ridges and valleys, a ___________ drainage network is expected
Trellis
The primary stream fed by tributaries within a drainage basin is termed a _______
Trunk stream
A rock slide in a reservoir triggered catastrophic flooding of the landscape below which dam?
Vaiont (Italy)
The shape of a delta is primarily determined by _______
Whether river currents, wave-driven currents, or tidal currents are locally predominant
Most of the igneous rocks within oceanic abyssal plains are _____
covered by clay and the skeletal remains of microplankton
The two most abundant rocks with oceanic crust are ____ and _____
granite;gabbro
Which type of mass movement includes a large proportion of ash derived from a volcanic eruption?
lahar
Saline ocean water is _______ than fresh water, and provides ______ to objects floating in it
more dense;more buoyancy
