The Earth/Atmosphere Interface
Why are subduction volcanoes so dangerous?
Subduction volcanoes are so dangerous because they build up pressure due to trapped subsurface gases that can be released in sudden explosive eruptions.
Which of the following is an example of an age-relationship based on relative dating?
The Coconino Sandstone of the Grand Canyon is younger than the Hermit Shale.
What is the center of the Earth is called?
The center of the Earth is called the inner core.
What geological process causes the continents to drift apart?
The continents drift apart because hot rock, heated by the earth's core, rises to the crustal layer. Once it nears the surface, the heated rock spreads in opposite directions, dragging the earth's crust apart.
The earth's continents are moving apart how many centimeters every year?
The earth's continents are moving apart at a rate of approximately 2 centimeters a year.
The earth's surface is broken up into how many major plates?
The earth's surface is broken up into seven major plates.
What is the outer core?
The outer core is a ball of molten metal, approximately 2,000 miles below the surface.
What was this super continent called?
The single super continent was called Pangaea.
What volcano on the island of Sumatra is described as the world's most ominous volcano?
Toba
Why are volcanoes not found at transform boundaries?
Transform boundaries do not cause changes to the pressure, temperature, or composition of the mantle.
Why are volcanic rocks often exposed at Earth's surface as hills, ridges, and mountains surrounded by areas of lower elevation?
Volcanic rocks are often more resistant to erosion than surrounding rock.
As the discharge of a stream increases, which of the following also happens?
Width, depth, and/or velocity increase.
What produces plunging folds?
a combination of folding and tilting
What is a syncline?
a fold shaped like a right-side-up U
What is an anticline?
a fold shaped like an upside-down U
What does the term "plunging fold" mean?
a fold that is tilted down into the Earth
Base level refers to
a level below which a stream cannot erode its valley.
What was Pangea?
a supercontinent that formed 300 million years ago
Which of the following human activities can contribute to mass movement?
any human disturbance of a slope, including road cuts, surface mining, and development
Where are tectonic plates located?
at Earth's surface
Where are most modern divergent plate boundaries found?
at mid-ocean ridges
Maximum velocity in a straight channel is found
at the center and near the surface, corresponding with the deepest parts of the stream channel.
What is foliation?
banding in metamorphic rocks that results from the reorientation of minerals
When rainwater attacks formations of limestone, the minerals dissolve and wash away with the mildly acid rainwater. This is an example of
carbonation.
As a stream's velocity decreases, which of the following sizes of sediments will be deposited last?
clay
Stream drainage patterns are determined by which of the following?
climate, regional steepness and relief, landscape characteristics, and variations in rock resistance.
Which type of force causes folding?
compressional force
Which type of plate boundary is most closely associated with uplifting continental regions and mountain building?
convergent boundaries
A mass of falling and tumbling rock, debris, and soil traveling at a high velocity owing to the presence of ice or water is a
debris avalanche.
What are the three types of plate boundaries?
divergent, convergent, transform
Watersheds are defined by
drainage divides.
Processes that are related expressly to streams and rivers are termed
fluvial.
The drop in stream elevation per unit distance is known as
gradient.
An active volcano is defined as one that
has erupted at least once within recorded history.
In which climates would rocks experience the highest amounts of chemical decomposition and decay?
hot and wet
Which phenomenon can explain the presence of volcanoes in the middle of the Pacific Ocean?
hot spots
Knowledge of Earth's interior is mostly derived from
indirect evidence involving the analysis of seismic waves.
What lies underneath volcanic features at Earth's surface?
magma chambers and volcanic conduits
Along ________, new ocean floor is formed by upwelling flows of magma, whereas along ________, old oceanic crust is destroyed.
mid-ocean ridges; subduction zones
What is mass movement?
movement of material under the influence of gravity alone
In a given section of channel, the greatest flow velocities are usually
near the surface, near the center.
What forms at divergent plate boundaries?
new oceanic lithosphere
Which type of faulting is associated with the development of new ocean floor?
normal faulting
Exfoliation occurs because
overlying rock is removed, thereby allowing the underlying rock mass to expand and fracture.
A(n) ________ is a meander that becomes isolated from the rest of the river.
oxbow lake
The three most abundant elements in Earth's crust are
oxygen, silicon, and aluminum.
Which process causes the surface geography of Earth to change over time?
plate tectonics
When was the Precambrian eon?
prior to 600 million years ago
Factors influencing the weathering process include
rock composition and structure, climate, organic processes, and subsurface water.
The continuous alteration of Earth materials from one rock type to another is known as the
rock cycle.
The three basic rock types are
sedimentary, metamorphic, and igneous.
An instrument used to record vibrations in the crust is the
seismograph.
The dominant element in oceanic crust are
silica and magnesium.
The scientific study of caves is known as
speleology.
The general term for channelized water flow, regardless of size, is
stream.
Transform boundaries are classified under what type of fault?
strike-slip
The world's deep ocean trenches coincide with
subduction zones.
When did the Appalachian Mountains of North America begin to form?
450 million years ago
In general, where do both earthquakes and volcanic eruptions occur?
Divergent and convergent
________ streams begin in moist regions and flow downstream into arid landscapes with high evapotranspiration.
Exotic
What metal comprises the Earth's core?
Iron
Do fracture zones near transform boundaries play a role in plate motion?
No; fracture zones play no role in plate motion.
How do plates move at divergent plate boundaries?
Plates move apart.
How do plates move at transform plate boundaries?
Plates move side by side.
How do plates move at convergent plate boundaries?
Plates move together.
How are metamorphic rocks formed?
Preexisting rock is altered through heat and pressure.
What causes most casualties resulting from volcanic eruptions?
Pyroclastic flows
If you live in an area that was flooded by the 100-year flood last year, you can conclude that
there is a 1% chance you could be flooded by the 100-year flood again this year.
What is a river's primary job?
to transport silt, sand, and rocks (sediment) out of the mountains and down to the sea
The principle that the same physical processes currently active in the environment were operating throughout Earth's history is known as
uniformitarianism.
Which of the following is an endogenic process?
volcanism
Which of the following is an exogenic process?
weathering
When do new oceans form?
when a continent is broken apart by a divergent boundary
A stream is more likely to deposit its load of sediment when which of the following occurs?
when its speed decreases
Where do most divergent boundaries originate?
within continents