Earth's Interior Flashcards
earth’s relatively thin rocky outer skin
Crust
How many percentage of Earth’s volume
a. Mantle
b. Core
a. 82%
b. 16%
a solid, rocky shell that extends to a depth of about 2900km.
Mantle
Composition of iron-nickel alloy with minor amounts of oxygen, silicon and sulfur
Core
the strong rigid outer layer consisting of the crust and a portion of the upper mantle
Lithosphere
has a temperature/pressure regime that results in a small amount of melting.
Asthenosphere
it is the movement of metallic core within this zone that generates Earth’s magnetic field
Outer Core
Natural geologic hazard caused by sudden and rapid movement o a large volume of rock
Earthquake
the result of rupture and slippage along fractures in Earth’s crust
Faults
Origin of an earthquake occurs at depths between 5 and 700 km
Focus
Point at the surface directly above the focus.
Epicenter
Form of elastic energy that causes vibrations in the material that transmits them.
Seismic Waves
produced by the rapid release of elastic energy stored in rock that has been deformed by differential stress. Once the strength of rock is exceeded, it suddenly ruptures, causing vibrations
Earthquakes
are smaller earthquakes that occur in the same general area during the days to years following a larger event or mainshock
Aftershocks
are earthquakes that precede larger earthquakes in the same location
Foreshock
Study of earthquake waves
Seismology
Instrument that record earthquake waves.
Seismograph
Records obtained from seismographs
Seismogram
motion is restricted to near Earth’s surface
Surface Wave
waves that travel through Earth’s interior.
Body Waves
push-pull waves, they push and pull rocks in the direction the wave is travelling.
P Wave
or
Primary Wave
“shake” the particles at right angles to their direction of travel.
S-wave
or
Secondary Wave
travel about 1.7 times faster than S waves in any solid matter
P-wave
is 10 percent slower than S waves
Surface Wave
is based on the amplitude of the largest seismic waves recorded on a seismogram.
Richter Scale
a measure of the degree of earthquake shaking at a given locale based on observed effects
Intensity
relies on data gleaned from seismic records to estimate the amount of energy released at an earthquake’s source
Magnitude
determines the strain energy released along the entire fault surface
Moment magnitude
where unconsolidated materials are saturated with water, earthquake vibrations can turn stable soil into mobile fluid
Liquefaction
large undersea earthquakes occasionally set in motion massive waves.
Tsunami
segment of an active fault zone that has not experience a major earthquake over a span when most other segments have. Such segments are probable site for future major earthquakes.
Seismic Gap
A hypothesis suggesting that the continents moved over the Earth’s surface.
Continental Drift
Evidences of Continental Drift (6)
- Jigsaw fit
- Distribution of life forms
- Structural Evidence
- Glaciers
- Paleomagnetic evidence
- Similarity in Sedimentary record
a. Fossil remains in the fresh water
b. What landmass/landmasses they is/are found?
a. Mesosaurus
b. South America & Africa
a. Fossil remains of a Triassic land reptile approx 3 m long
b. What landmass/landmasses they is/are found?
a. Cynognathus
b. South America & Africa
a. Fossils of the fern found on all southern continents, show that they were all joined
b. What landmass/landmasses they is/are found?
a. Glossopteris
b. South America, Africa, Antarctica, Australia, India
a. Fossil of the Triassic land reptile
b. What landmass/landmasses they is/are found?
a. Lystrosaurus
b. Africa, Antarctica, India,
the study of the Earth’s past magnetism as recorded at the time of their formation.
Paleomagnetism
A compass needle will always point to the Earth’s magnetic North and South poles. If rotated vertically, it will form an angle with the horizontal plane
Magnetic Inclination
A tectonic boundary where two plates are moving away from each other and new crust is forming from magma that rises to the Earth’s surface between the two plates
Divergent Plate Boundary
A region of active deformation where two or more tectonic plates or fragments of the lithosphere near the end of their life cycle.
Converging Plate Boundary
where one plate slides horizontally past another plate along a fault or a group of parallel faults
Transform Plate boundary
is the measurement of ocean depths, sound energy is used to measure water depths
Bathymetry
the historic three and-a-half-year voyage
HMS Voyager
the first device that used sound to measure water depth.
Echo Sounders
The features comprising _______ include the continental shelf, the continental slope, and the continental rise. It is consist of continental crust capped with weathered materials eroded from adjacent landmasses.
Passive Continental Margin
is a gently sloping, submerged surface extending from the shoreline toward the deep-ocean basin
Continental Shelf
a relatively steep structure that marks the boundary between continental crust and oceanic crust. It averages about 5 degrees and in places exceeds 25 degrees
Continental Slope
a more gradual incline that may extend seaward for hundreds of kilometers. Consists of a thick accumulation of sediment that has moved down the continental slope and onto deep-ocean floor.
Continental Rise
Deposited sediments in the flat ocean floor
Deep Sea Fan
Occur where oceanic lithosphere subducts into the mantle beneath the edge of a continent
Active Continental Margin
Chaotic accumulation of deformed sediment and scraps of oceanic crust
Accretionary Wedge
Between the continental margin and the oceanic ridge lies the ___________-
Deep Ocean basin
are extremely deep linear depressions in the ocean floor
Trench
measured a portion of one trench in the Mariana trench at 11,022 meters (36,163 feet) below sea level, making it the deepest known part of world ocean
Challenge Deep
submarine flat areas
Abyssal Plain
Tall underwater volcanic peaks
Seamount
Submerged, flat-topped seamounts
Guyout
or
Tablemounts
Large flood basalt provinces
Oceanic Plateau
Along well-developed divergent plate boundaries, the seafloor is elevated, forming a broad linear swell called the ____-
Oceanic Ridge
or
Mid-Oceanic Ridge
Along the axis of some segments of the oceanic ridge system are deep, down faulted structures called ____
Rift Valleys
occurs along the crests of oceanic ridges where hot mantle rock rises to replace the material that has shifted horizontally.
Seafloor Spreading
Ophiolite Sequence
Layer 1.
Layer 2
Layer 3
Layer 4
Layer 1: Deep Sea Sediment Layer 2: Basaltic Pillow Lavas Layer 3: Sheeted Dike Complex Layer 4: -Gabbro -Layered Gabbro
numerous interconnected dikes having a nearly vertical orientation
Sheeted Dike
general term that refers to all changes in the original shape, size (volume), or orientation of a rock body
Deformation
forces that deform rocks
Stress
fractures in the crust along which appreciable displacement has taken place
Fault
fractures along which no appreciable displacement has occurred.
Joint
bent layer or series of layers that were originally horizontal and subsequently deformed
Fold
processes that collectively result in the formation of mountains
Orogenesis
formed y convergence of two oceanic plate
Volcanic Island Arc
subduction of oceanic lithosphere beneath a continental bloc
Andean-type Margin
any crustal fragment that has a geologic history distinct from that of the adjoining ones
terrane
- Mountain formed by displacement of rock along a fault
- Form in response to broad uplifting, which causes elongation and faulting
Fault Block Mountains
concept of a floating crust in gravitational balance
isostasy
process of establishing a new level of gravitational equilibrium
Isostatic Adjustment
gradual subsidence of mountains caused by lateral spreading of weak material located deep within these structures
Gravitational Collapse
