Integrated Geoscience Accel Chapter 4 Unit Review
Batholith
a mass of rock formed from the cooling of magma inside of the crust
Pipe
connects the chamber to the surface
aa
cooler slower flowing, jagged
Continental crust is made mostly of________ and oceanic crust is made mostly of ___________
granite, basalt
Explosive
high silica and high dissolved gases (felsic, granitic)
Caldera
hole that occurs when the magma chamber collapses
What is the probability of earthquake occurrence based on
reoccurrence rates of earthquakes in an area and the rate of strain buildup
Dome mountain
rising magma where the crust is blocks the escape of the magma, Black Hills
Which type of information was NOT collected by Wegener to support his continental drift hypothesis
seafloor magnetic data
Harry Hess' theory of _______ explained how ocean crust is generated and destroyed
seafloor spreading
crater
the bowl shaped depression at the top of the volcano
elastic deformation
the straight line on a stress-strain graph
Plate technonics
12 major plates Plate motion causes compression, tension or shear Causes continental drift
What causes the seafloor to spread
Rising molten magma
Transform examples
San Andreas Fault
Seafloor Spreading explained
Seafloor spreading is NOT equal Younger crust near the ridges Earthquakes and volcanoes come from young seafloor Magnetic fields can be determined Hottest near the ridges
S-waves
Secondary waves Transverse waves Travels through solids
Oceanic-Oceanic Convergence
Similar to Oceanic-Continental Volcano is created under the ocean and creates a volcanic island
Asthenosphere
Subsection Below the Lithosphere Plastic
Lithosphere
Subsection Crust Top of mantle Makes up the plates
L-waves
Surface waves Slowest Most damaging
Richter Scale
1 to 10 scale 1 = 1x 2 = 10x 3 = 100x
Tsunami
A large ocean wave that is generated by vertical motions of the seafloor during an earthquake
Convergent O/O examples
Aleutian islands Caribbean Mariana Trench
If an Earthquake registered high on the Richter scale and low on the Mercalli scale, then it occurred most likely in which type of location?
An area with few residents
Convergent O/C examples
Andes
Oceanic-Oceanic Divergent
As convection cells push upward, magma breaks through the crust and creates new crust
Where does an earthquake originate
At the focus
Plastic
Causes permanent deformation
Core
Center Iron and nickel Very dense Outer core: Liquid Inner core: Solid
Why did Wegener think that the Antarctic continent had been closer to the equator in the geologic past
Coal beds were found to exist near the equator
Hot spot
NOT A BOUNDARY Age doesn't change No earthquakes Creates island complexes Crust neither created nor destroyed
Continental drift geographic evidence
Evidence of similar fossils found on multiple continents Mountain ranges match across oceans Evidence of glacial deposits on multiple continents
Earth's Internal Structure
Heterogeneous Liquid and solid
Convergent C/C examples
Himalayas Rockies
What is the crustal part of the lithosphere primarily composed of
Igneous rock
Seismogram
Instruments that measures the type of earthquake waves and magnitude
Which waves are called body waves
P waves and S waves
Earthquake waves
P, S, and L waves Mechanical
Most of the world's major earthquakes occur in areas bordering the
Pacific Ocean
Where are most earthquakes associated with
Plate boundaries
______ waves push and pull rocks in the same direction along which the waves are traveling
Primary
Which type of fault results in horizontal shortening
Reverse
The record produced by a seismometer is called a _______
Seismogram
What is the study of earthquakes called
Seismology
What type of instrument can measure the vibrations of an earthquake
Seismometer
What is the rating from the Richter scale based on
Size of the largest wave
What type of fault is the San Andreas
Strike Slip
What is a rating for an earthquake from the modified Mercalli scale based on?
The amount of damage
Tectonic
The deformation of the crust as a consequence of plate interaction
What are shallow, intermediate, and deep earthquake classifications based on
The depth of the focus
How are convection currents set in motion
The heat from radioactive decay
Why do mountains have roots
The roots provide buoyancy to support the large mass of the mountains
Why does knowledge of Earth's interior come from seismic waves?
They change speed and direction when they encounter different materials
Rift valley
When a divergent plate boundary forms on continents
Laccolith
a domelike sill
Magma chamber
a pocket of pooling magma
Composite
alternating pyroclastic flow and lava flows
Pyroclastic flow order
ash, Cinder, Tephra, Bombs, Blocks
Shield volcano
basaltic, broad gentle slopes, thin layers of lava
Pluton
batholith of stock, rock formed from the cooling of magma under the crust
Side vents
can burst through the surface branching off of the pipe
Ductile Deformation
causes permanent strain
What is isostasy
equilibrium that has been established between continental and oceanic crust
Cinder cone
explosive, small, steep slopes, lots of pyroclastic material
Pahoehoe
faster, billowy, hotter
Fractures in rock where sections of rock might suddenly move to create an earthquake are called
faults
he thickness of the ocean sediments that are close to a mid-ocean ridge is ________ the thickness of ocean sediments that are far away from the mid-ocean ridges
less than
Quiet
low silica and low dissolved gases (mafic, basaltic)
Stock
mass of rock formed when a smaller body of magma forms inside of the crust
Which scale measures the damage done by an earthquake due to its intensity
modified Mercalli scale
sill
occurs when lava moves parallel to the layers formed on a volcano
Dike
occurs when lava moves perpendicular to the layers formed on the volcano
Pyroclastic flow
occurs when particulate matter erupts
The roots of a mountain are______
often many times deeper than the mountain is high
During oceanic-oceanic convergence, where do island arc volcanoes form?
on the plate that is subducted
Subduction
one plate is forced beneath another at a convergent plate boundary Forms trenches Melted crust forms volcanism
Vent
opening
Which type of stress pulls a material apart
tension
An Earthquake on the ocean floor can produce a(n)
tsunami
Lava flow
what comes out
Branch pipe
when a pipe branches off of the main pipe but does not burst through the surface
What is isostatic rebound?
when the crust rises as it loses overlying material and mass
Volcano
where the magma exits the surface and becomes magma
What is the polarity of a magnetic field that has the same polarity as the present magnetic field
A normal polarity
What type of force is exerted on a tectonic plate near the part of the convection current where the mantle is cooling
A sinking force
Which cannot form as a result of oceanic-oceanic convergence?
Rift zones
What is the name of Alfred Wegener's hypothesis about moving landmasses
Continental Drift
What is thought to be the driving mechanism of plate movement
Convection of heat in the mantle
The lesser Antilles and Appalachian Mountains are similar in that they were both formed by
Convergence
Amplitude
Degree of ground movement - caused by magnitude of waves
Compared to the continental crust, the oceanic crust is
Denser and thinner
What causes differences in elevation on Earth?
Density and thickness of the crust
Locating the epicenter
Difference between P and S waves = distance Triangulation Intersection = Earthquake
Earth's Interior
Direct: Composition of rocks Indirect: Travel path and time of earthquake waves
The Mid-Atlantic Ridge mountains are an example of mountains forming
Divergent boundaries
Strike slip/Transform fault
Due to shear force Side to side movement
Which type of mountains form as the result of uplift far from plate boundaries?
Faulted mountains
Sir William Gilbert
First noted paleomagnetism
Stress
Force rocks experience The force per unit area acting upon a material
Heat
Formation of Earth Friction from moving plates Radioactive elements in mantle Little heat is lost
What evidence did Wegener use to estimate the time of Pangea's breakup
Fossil data
Evidence Alfred Wegener looked at
Geographic fit Fossil evidence Mountain evidence Glacial evidence
Seismograph
Graph produced by an earthquake
Reverse fault
Hanging wall is above the footwall Creates an acute angle
Normal Fault
Hanging wall is below the footwall Creates an obtuse angle
Hot Spot examples
Hawaii Yellowstone
What was one reason that Wegener's hypothesis of continental drift was rejected
He could not explain what was moving the continents
SP Interval
Lag time between P and S waves
Which of the following can not form as the result of oceanic-oceanic convergence?
Rift zones
Crust
Rigid outermost layer Very thin Varying rock compositions Silicate materials
Elastic
Material is able to snap back
Strain
Material's response to stress
Magnitude
Measures the amplitude of a wave
Divergent examples
Mid Atlantic Ridge Mid Ocean Rise
What two topographic features of the ocean floor were discovered only with the use of sonar
Mid-ocean ridges and deep-sea trenches
Tectonic activity examples
Mountain building Volcanism Trenches Earthquakes
Shadow zones
No P and S waves P waves are bent when passing through core S waves cannot pass through core
Mercalli Scale
Observational damage Less reliable
Which of the following is not associated with orogeny at convergent boundaries?
Ocean ridges
Continental-Continental Convergence
Pile on top of each other Creates mountains Rocks are bent and broken New crust near mountains No volcanism
Failure
Plastic is exceeded Earthquake is created
Divergent boundary
Plates move away from each other
Principles of Plate Tectonics
Plates move horizontally Plates interact along their edges Lots of tectonic activity
Transform boundary
Plates move past each other Does not age No creation or destruction
Convergent boundary
Plates move towards each other
Wegener proposed that the continents were
Plowing through oceanic crust
Epicenter
Point on Earth's surface above the focus
P-waves
Primary waves Longitudinal waves Travel through Earth
John Tuzo Wilson
Proposed the theory of plate tectonics Combined Hess and Wegener's ideas Plate movement due to convection in the mantle
Tension
Pulling materials apart Reverse fault
Compression
Pushes material together Normal fault
Henry Hess
Put evidence together to prove seafloor spreading
Paleomagnetism
The study of Earth's magnetic record
Pangea
The supercontinent from Wegener's theory of continental drift
Alfred Wegener
Theory of continental drift Did not prove it
Shear
Twisting materials Strike slip/Transform fault
Oceanic-Continental Convergence
Two convection cells point downward, more dense plate subducts Crust melts and builds pressure to create a volcano on the continental side
The Adirondack Mountains are an example of mountains that form due to:
Uplift
What type of mountains are generally made up of undeformed rocks?
Uplifted mountains
Which is not a mountain associated with plate boundaries?
Uplifted mountains and Hot spots
Mantle
Upper layer is semi-plastic Lower layer is rigid Hotter and more pressure Ultramafic minerals Magnesium and iron silicates (Green and black)
Moment-Magnitude
Used today More reliable than Richter scale
Convection Cells
When two cells are pushing up, a mid ocean ridge occurs Causes spreading and creates new crust Magma breaks through the surface and separates the crust, creating new crust When two cells are pushing down, trenches occur Causes subduction
Focus
Where the earthquake comes from
Continental drift supporting evidence
World seismicity Volcanism Age of seafloor Paleomagnetism Heat flow
Rocks close to the mid-ocean ridges are _______ rocks far from mid-ocean ridges
Younger than
Isochron
a line on the seafloor map that connects points of equal age
Why would a certain thickness of continental crust displace less of the mantle than the same thickness of oceanic crust?
continental crust is less dense
Why does the continental crust rise higher above the surface of Earth than the oceanic crust?
continental crust is thicker and is less dense