Earth Science Final
What is an isochron ?
a line on a seafloor map that connects points of equal range
What is a pyroclastic flow?
a mixture of volcanic gas, ash and other tephra
What is the name for an igneous intrusion that is smaller than a batholith but similar in shape?
a stock
An earthquake on the ocean floor can produce ______________________________
a tsunami
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 texture do most plutons have?
coarse
Where do most volcanoes form?
at plate boundaries
Where does an earthquake originate?
at the focus
Where is andesitic magma found?
at the margins of the continents
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 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
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 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
look at figure for subduction zone
section C
What is the study of earthquakes called?
seismology
what is the study of earthquakes called
seismology
How is a volcanic crater connected to a magma chamber?
by a vent
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
When magma reaches the surface it is called___________________
lava
What causes the seafloor to spread?
rising molten magma
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
How many times larger is a magnitude 3 than a magnitude 1 earthquake on the Richter Scale?
100 times
A ___________________ is a device that can detect changes in the strength of the Earth's magnetic field.
Magnetometer
Which type of wave arrives first at a seismic facility?
P
Places where two tectonic plates are moving away from each other are called _____________________________.
divergent boundaries
What is the Earth's core composed of?
iron and nickel
Why does magma move up and through the Earth's crust?
it is less dense than the surrounding rock
During the time of Pangaea, what had the greatest impact on Earth's climate?
it was a time of a giant global ocean
Which mineral may preserve magnetic patterns on the ocean floor, in support of tectonic plates?
magnetite
What two topographic features of the ocean floor were discovered only with the use of sonar?
mid ocean ridges and deep sea trenches
Which scale measures the damage done by an earthquake to determine an earthquake's intensity?
modified mercalli scale
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
The supercontinent from Wegener's theory of continental drift is called ___________________________.
pangea
___________________ is the force per unit area acting on a material.
stress
What type of fault is the San Andreas Fault
strike slip
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
Much of the Earth's internal heat comes from _______________________
the decay of radioactive materials
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
When does magma form?
when temperatures are hot enough to melt rock
Rocks close to the mid-ocean ridge are _____________________ rocks far from the mid-ocean ridge
younger than
the subduction of an oceanic plate beneath a continental plate produces a
a chain of volcanic mountains
What happens as a lithospheric plate moves over a HOT SPOT?
a chain of volcanoes form
____________________ is the internal resistance to flow of a liquid.
viscosity
What are large, angular fragments thrown from a volcano called?
volcanic blocks