SMCHS Earth Science Sem 1 Final
Places where two tectonic plates are moving away from each other are called _____________________________.
Divergent Boundaries
Fractures in rock where sections of rock might suddenly move to create and earthquake are called _________________
Faults
What evidence did Wegener use to estimate the time of the continent Pangaea's break up into smaller continents?
Fossil data
Why does magma move up and through the Earth's crust?
It is less dense than the surrounding rock
When magma reaches the surface it is called___________________
Lava
What is the study of earthquakes called?
Seismology
A wide, dome shaped volcano built from thin, freely flowing lava is called a(n) __________ _________
Shield Volcano
Hawaii, which sits over a HOT SPOT located near the center of the Pacific Plate, is which type of volcano?
Shield Volcano
What is the rating from the Richter Scale based on?
Size of the largest wave
___________________ is the force per unit area acting on a material.
Stress
What type of fault is the San Andreas Fault
Strike Slip
What is an isochron ?
a line on a seafloor map that connects points of equal age
What is a pyroclastic flow?
a mixture of volcanic gas, ash, and other tephra
Where is andesitic magma found?
at the margins of the continents
A _________ is the unaltered remains of a once-living organism.
fossil with original preservation
What is the Earth's core composed of?
iron and nickel
During the time of Pangaea, what had the greatest impact on Earth's climate?
it was a time of a giant global ocean
What two topographic features of the ocean floor were discovered only with the use of sonar?
mid-ocean ridges and deep-sea trenches
Where do most volcanoes form?
plate boundaries
What causes the seafloor to spread?
rising molten magma
Much of the Earth's internal heat comes from ________________________
the decay of radioactive materials
How many times larger is a magnitude 3 than a magnitude 1 earthquake on the Richter Scale?
100 times
How old is a mammoth's tusk if there is only 25 percent Carbon -14 remaining in the sample?
11,400 years
the figure, after four half-lives (22,820 years), how much C-14 would be left?
6.25%
What is the name for an igneous intrusion that is smaller than a batholith but similar in shape?
A Stock
How is a volcanic crater connected to a magma chamber?
A Vent
What characterizes an index fossil?
All of the above
What is the longest division of time in the geologic time scale?
An Eon
What is the shortest division of time in the geologic time scale?
An Epoch
Where does an earthquake originate?
At the Focus
Where are the youngest rocks on the ocean floor located?
At the Mid-ocean ridges
What type of magma has the lowest silica content and is the least explosive?
Basaltic
A _________________ is a large intrusive rock body that covers at least 100 square kilometers.
Batholith
What happens as a lithospheric plate moves over a HOT SPOT?
a chain of volcanoes form
What is the name for a large crater formed when a magma chamber collapses?
Caldera
What is the name of a large volcanic crater over 1 km in diameter?
Caldera
What isotope is used for finding the age of materials that are organic in origin?
Carbon-14
The subduction of an oceanic plate beneath a continental plate produces a(n) ____________________________
Chain of volcanic mountains
What texture do most plutons have?
Coarse
What type of volcano forms from alternating layers of tephra and non explosive lava?
Composite Volcano
What is the name of Alfred Wegener's hypothesis about moving land masses?
Continental Drift
The subduction zone in the figure is?
D
Which mineral may preserve magnetic patterns on the ocean floor, in support of tectonic plates?
Magnetite
A ___________________ is a device that can detect changes in the strength of the Earth's magnetic field.
Magnetometer
Which scale measures the damage done by an earthquake to determine an earthquake's intensity?
Modified Mercalli Scale
Which type of wave arrives first at a seismic facility?
P
Most of the world's major earthquakes occur in the areas bordering the _________________________
Pacific Ocean
What is the study of the Earth's ancient magnetic record?
Paleomagnetism
What era of geologic time ended with the largest extinction event in Earth history?
Paleozoic
The supercontinent from Wegener's theory of continental drift is called ___________________________.
Pangaea
Petrified wood is an example of __________.
Permineralization
What are most earthquakes associated with?
Plate Boundaries
The tremendous amount of heat within the Earth powers ___________________
Plate Tectonics
_______________ push and pull rocks in the same direction along which the waves are traveling.
Primary Waves
Which feature shown in the figure is the oldest?
Q
What method is used to determine the exact age of a rock or fossil?
Radiometric Dating
Which type of fault results in horizontal shortening?
Reverse
When a divergent plate boundary forms on a continent, (land), a ___________________forms.
Rift valley
Harry Hess's theory of _________________________ explained how ocean crust is generated and destroyed.
Seafloor spreading
Which factor could give scientists a clue about changes in Earth's atmosphere over time?
Sedimentary Rock Layers
What geologic principle states that in an undisturbed rock sequence, the oldest rocks are on the bottom and the youngest are on the top?
Superposition
Which waves are called body waves?
Surface waves only
Which type of stress pulls a material apart?
Tension
Rock fragments thrown into the air during a volcanic eruption are called _______________
Tephra
What are shallow, intermediate, and deep earthquake classifications based on?
The depth of the focus
Why does knowledge of Earth's interior come from seismic waves?
They change speed and direction when they encounter different materials
A place where two plates slide laterally past each other is called a _______________________________
Transform Boundary
(LAB reference) What type of material is used in the dating technique of Dendrochronology?
Tree Growth Rings
An earthquake on the ocean floor can produce ______________________________
Tsunami
The Principle of __________ states that the processes that have been occurring today have been occurring since Earth formed.
Uniformitarianism
____________________ is the internal resistance to flow of a liquid.
Viscosity
What are large, angular fragments thrown from a volcano called?
Volcanic Blocks
When does magma form?
When temperatures are hot enough to melt rock (1000 degrees)
Rocks close to the mid-ocean ridge are _____________________ rocks far from the mid-ocean ridge.
Younger than
