earth science CH 3,5
A stream begins at an elevation of 200 meters and flows a distance of 400 kilometers to the ocean. What is the average gradient?
0.5 m/km
A typical rate of seafloor spreading in the Atlantic Ocean is ________.
2 centimeters per year
Mount St. Helens and the other Cascade volcanoes are ________.
A Young, active stratovolcanoes built on a continental margin above a sinking slab of oceanic lithosphere
A transform plate boundary is characterized by ________.
A deep, vertical fault which two plates slide past one another in opposite directions
In the early part of the 20th century, ________ argued forcefully for continental drift.
Alfred Wegener
The world's largest river in terms of discharge is the
Amazon
________ is an abandoned, cutoff, meander loop.
An oxbow
Today, ________ is in about the same geographic position as during late Paleozoic time.
Antartica
All of the following are evidence supporting the theory of plate tectonics except for ________.
Changes in the Moon's orbit due to shifting plates
The volcanoes and deep valleys of east Africa are related to a ________.
Continental rift along which parts of the African continent are beginning to slowly separate.
The temperature below which magnetic material can retain a permanent magnetization is called the ________.
Curie Point
Which one of the following is an important fundamental assumption underlying the plate tectonic theory?
Earth's surface area has been essentially constant over time
Which of the following energy sources is thought to drive the lateral motions of Earth's lithospheric plates?
Export of heat from deep on the mantle to the top of the asthenosphere
Earth's radius and surface area are slowly increasing to accommodate the new oceanic crust being formed at mid-ocean ridges.
False
Hawaii is the oldest island of the Hawaiian Island chain.
False
The modern-day Red Sea is explained by plate tectonics theory because it is ________.
a rift zone that may eventually open into a major ocean if Arabia and Africa continue to separate
The continental drift hypothesis was rejected primarily because Alfred Wegener could not ________.
all of these
Permeable rock strata or sediment that transmit groundwater freely are called ________.
aquifers
Examine the words and/or phrases for the question below and determine the relationship the majority of words/phrases. Choose the option which does not fit the pattern.
aquitard
A natural levee is ________.
both a depositional feature and essentially parallel to its stream channel
Which of the following is NOT part of the water cycle?
calcium carbonate dissolving in soil water and groundwater
Examine the words and/or phrases for the question below and determine the relationship among the majority of words/phrases. Choose the option which does not fit the pattern.
capacity
________ describes the total sediment load transported by a stream.
capacity
During various times in the geologic past, the polarity of Earth's magnetic field has been reversed.
changes in the Moon's orbit due to shifting plates
When water is pumped from a well, a depression is often produced in the water table. Such a depression is a(n) ________.
cone of depression
The Aleutian Islands occur at a ________.
convergent boundary on a volcanic arc above a northward-subducting Pacific plate
the most common drainage pattern is
dendritic
Which one of the following factors does NOT influence stream velocity?
discharge
At the head of a delta, the major channel splits into smaller channels that follow different paths to the sea. These smaller channels are known as ________.
distributaries
Pull-apart rift zones are generally associated with a ________ plate boundary.
divergent
New oceanic crust and lithosphere are formed at ________.
divergent boundaries by submarine eruptions and intrusions of basaltic magma
As its name implies, the water table is always very level (flat).
false
As the South Atlantic basin widens by seafloor spreading, Africa and South America are moving closer together.
false
Floods are the least destructive of all geologic hazards.
false
For a well to be characterized as being artesian, water must flow freely at the surface.
false
Iceland is a good example of an island arc, formed from an oceanic-oceanic plate collision.
false
Karst topography is most commonly associated with areas underlain by massive sandstone strata.
false
Lowering of the water table around a pumping well results in a cone of infiltration.
false
Most hot springs in the United States are located in the southeast, especially Georgia.
false
Point bars are depositional features located along the outer portions of meander bends.
false
The capacity of a stream measures the maximum size of particles it is capable of transporting.
false
The formation of stalactites and stalagmites occurs in the zone of saturation.
false
The rate of seafloor spreading is, on the average, about one meter per year.
false
A very long-lived magma source located deep in the mantle is called a ________.
hot spot
________ was never proposed as evidence supporting the existence of Pangaea.
islands of precambrian rocks along the mid - Atlantic ridge
Caves most commonly form in ________.
limestone
Which of the following features characterize meandering streams and valleys?
natural levees; broad floodplains
Linear, magnetic patterns associated with mid-ocean ridges are configured as ________.
normal and reversed magnetized strips roughly parallel to the ridge
The ________ is an example of an active, continent-continent collision.
northward movement of India into Eurasia
Where would you drill to recover samples of the oldest basalts of the oceanic crust, which are Jurassic in age?
oceanic side of the Aleutian trench.
At a bend in a river, the main erosion is ________.
on the outside of the bend
The ________ is (are) a logical evolutionary analog of the African Rift Valleys ten million years from now.
red sea
The single most important erosional agent is ________.
running water
Which of the following must result in a lower base level for rivers and streams?
sea level falls; land rises
Deep ocean trenches are surficial evidence for ________.
sinking of oceanic lithosphere into the mantle at a subduction zone
________ would have the largest capacity to naturally remove sewage pollutants.
slightly clayey sand
which following is associated with areas of karst topography
soluble rock caverns sinkholes
A ________ is the icicle-like speleothem that grows down from the roof of a cavern.
stalactite
If you were to examine the profile of a typical river, you would probably find that the gradient is ________.
steepest near the head
Cooler, older, oceanic lithosphere sinks into the mantle at ________.
subduction zones along divergent plate boundaries
________ generally constitutes the highest percentage of the annual sediment load moved by a stream.
suspended load
The term karst topography was first used in ________.
the Republic of Slovenia, a province of the former Yugoslavia
Which of the following is the correct definition of stream gradient?
the drop in elevation of a stream divided by the distance the water travels
Early results of the Deep Sea Drilling Project clearly justified the conclusion that ________.
the ocean basins are relatively young; most ocean basin rocks and sediments cretaceous or younger in age.
Which of the following paleoclimatic evidence supports the idea of the late Paleozoic supercontinent in the Southern Hemisphere?
tillites (rocks formed by glaciers) in South Africa and South America
The release of water vapor to the atmosphere by plants is called ________.
transpiration
A ___________ stream pattern develops on lands underlain by title or folded, alternating hard soft, and sedimentary strata.
trellis
A________ drainage pattern is common in the Appalachian Valley and Ridge Province.
trellis
A V-shaped valley and no floodplain indicate a youthful, downcutting stream.
true
Alluvium refers to stream deposits, mainly sand and gravel.
true
An extensive, late Paleozoic glaciation affected southern India, southern Africa and southeastern South America.
true
Creating artificial cutoffs increases stream velocity.
true
Gradients usually decrease downstream in a major river system
true
In general, rocks of the continental crust are less dense than rocks of the oceanic crust.
true
More water is evaporated from the ocean than is returned to the ocean by precipitation.
true
Most caves and caverns originate by solution of limestone.
true
One environmental problem associated with groundwater is land subsidence caused by withdrawal.
true
One river can be the base level for another.
true
Porosity is a measure of the volume of open space in rocks and unconsolidated geological materials such as alluvium and soils.
true
Seafloor spreading rates can be estimated if the geologic ages of the magnetic field reversals are independently known.
true
Sinkholes are actively forming in portions of the southeastern United States.
true
Stream discharge is defined as the quantity of water flowing past a specific channel location per unit time.
true
The Mississippi River is North America's largest river in terms of discharge.
true
The lowest base level for most streams is sea level.
true
The oldest rocks of the oceanic crust are found in deep ocean trenches far away from active, mid-ocean ridges.
true
The oldest rocks on the seafloor are much younger than the oldest rocks on the continents.
true
The source of heat for most hot springs is hot igneous material beneath the surface.
true
The velocity of a river usually increases downstream.
true
The volcanoes of Hawaii are localized above a deep mantle hot spot; they are not part of the East Pacific oceanic ridge. level:1
true
Wegener's continental drift hypothesis was weakened because a viable mechanism for moving the continents was lacking.
true
Downcutting (also known as rejuvenation) of a stream may be due to ________.
uplift of land
The suspended load of a stream
usually consists of fine particles
As stream discharge increases ________.
velocity, width, and depth increase
An artesian well is one in which ________.
water rises above the top of the aquifer without any pumping
Hot springs are most numerous in which region of the United States?
west
Which one of the following concerning artesian well is not true These are true The well penetrates an aquifer underlain by an impermeable bed. The aquifer is generally inclined, and it is saturated to an elevation above the point where the well penetrates the aquifer. When the well penetrates the aquifer, the water rises only to the bottom of the aquitard above the aquifer. The well penetrates an aquifer overlain by an aquitard.
when the well penetrates the aquifer, the water rises to the bottom of the aquitard above the aquifer.
________ most effectively outline the edges of the lithospheric plates.
Lines of earthquake epicenteres
was an ancient reptile that lived in South America and Africa during the late Paleozoic.
Mesosaurus
Deep-oceanic trenches are most abundant around the rim of the ________ ocean basin.
Pacific
The former late Paleozoic super continent is known as ________.
Pangaea
________ is the volume of voids or open space in a rock or unconsolidated material.
Porosity
A ________ stream pattern is developed only on growing mountains like volcanoes or where the land surface is tectonically doming upward.
Radial
___ are characteristics of downcutting streams and a youthful stage of valley evolution.
Rapids and lots of whitewater
Which one of the following statements is correct?
Sea level drops when water is stored in expanding ice sheets and continental glaciers.
Which one of the following most accurately describes the volcanoes of the Hawaiian Islands?
Shield volcanoes fed by a long-lived hot spot below the Pacific lithospheric plate
________ make up the suspended loads of most rivers and streams.
Silt and clay-sized, detrital grains
Which of the following statements apply to the asthenosphere, but not the lithosphere?
Zone in the upper mantle that deforms by the plastic plate
The water table is ________.
a boundary between saturated rock below and unsaturated rock above
A natural, meandering, river channel is modified into a more or less straight and smooth, canal-like channel. Which of the following statements is correct?
The natural channel had a lower gradient and higher friction than the straight channel.
During the geologic past, the magnetic field poles have generally been very close to Earth's rotational poles.
True
The Himalayan Mountains are the tectonic product of a collision between India and Eurasia that began in Eocene time and still continues.
True
________ first related the symmetrical magnetic patterns in seafloor basalts to seafloor spreading at a mid-ocean ridge.
Vine and Matthews
Which of the following best describes how geysers erupt?
With a slight reduction in pressure, water in a saturated, natural conduit suddenly boils, sending a plume of steam and hot water into the air above the vent.
