Term
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Definition
| Geology is the scientific study of Earth and other terrestrial bodies, including its compostion history and the process that act upon it. Geoligists use the scientific method in its studies. |
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Term
| What is the scientific method? |
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Definition
| The scientific method is the process where scientists make observations and measrements that hypothesize what their data and their observations mean in a form of a question that is answerable, and then experiment and or model their data to help answer their hypothesis. |
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Term
| What are the key differences between a hypothesis and a theory in science? |
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Definition
| Hypothesis asks a question that is answerable; a theory is a well tested vie that is widely accepted by the scientific community that helps explain certain observable facts. Plate tectonic theory for example. |
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Term
| What are key differences b/w a a theory and a law in science? |
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Definition
| A law or principle explains events in nature with uniformity under ideal condition. These are specific principles that can be explained easily with a mathematical equation. (unlike theories, which are too extensive) |
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Term
| Explain the internal processes of the planet. How do these differ from the surficial processes of our planet? |
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Definition
| Internal processes stems from the Earth's internal heat. theis internal heat comes from the primodial heat fromed during the creation of the planet and radioactive elements. Plate Tectonics is an example of a process that is run purely on this internal heat engine. Surficial processes are governed by atmospheric processes on the planet, which is driven purely by solar energy. |
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Term
| Layers defined by their composition? |
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Definition
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Term
| Layers defined by their physical properties? |
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Definition
LITHOSPHERE
ASTHENOSPHERE
MESOSPHERE
OUTER CORE
INNER CORE
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Term
| Layers defined by their physical properties and are also part of the mantle? |
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Definition
LITHOSPHERE
ASTHENOSPHERE
MESOSPHERE
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Term
Names of Layers defined by their phisical properties that are :
A. Brittle
B. Ductile |
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Definition
Britle: Lithosphere
Ductile: Asthenosphere, Mesosphere |
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Term
| What is the difference between the lithospehere and asthenosphere? |
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Definition
| The lithosphere is the topmost layer defined by their physical properties and is brittle. The asthenosphere sits just below the lithosphere and is a ductile solid. |
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Term
| What is the difference between the crust and the lithosphere? |
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Definition
The crust is defined by its composition
( felsic & mafic) and the lithosphere is defined by its physical property of being brittle. the lithosphere includes BOTH the crust and the uppermost part of the brittle mantle together. (Note: this is why it would be incorrect to say that the crust and lithosphere are the same layer. |
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Term
| What seems to be happening to the magnetic field of the earth? |
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Definition
| Scientists discovered that there is a storm breweing deep within the Earth . The storm is weakening our vital magnetic shield. The magnetic shield is rapidly fading. |
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Term
| Where is the magnetic field of the earth created? |
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Definition
| The MF is created deep in the earths core, it streams out near the south pole loops around the planet and then runs back into the core near the north magnetic pole. |
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Term
| What does the MF shield us from? |
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Definition
| It protects us against radiation from space and space whether. |
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Term
| Ho did mars lose its thick atmosphere? why is this conerning for our panet? |
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Definition
| Mars entered a catostrophic decilne . Gradually the oceans and atmosphere of mars mysteriously dissapeared. It was exposed to wind radiation from the sun , therefore suggests that w/o protection from the magnetic field the earth too is in danger & become a dead planet. |
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Term
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Definition
| is an iron based mineral at the microscopic level magnetite contains lots of distinct magnetic region. In all these microscopic magnets all point in different directions. |
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Term
| What did gary glatzmaier of u.c. santa cruz discover when he simulated our earths core of thousands of years using computer technology? |
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Definition
| He realized that it was in reverse polarity, the field reversed spontaniously . Whenever it has reversed its polarity /direction it happened when the magnetic intensity was very weak. WHen di pole part was very weak the field reversed. |
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Term
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Definition
| Alfred Wegener set forth his continetal drift hypothesis . One of his major tenets was that pangea began breaking apart about 200 million years ago. The rifted continental fragments then drifted to their present positions. To support his hypothesis wegner used the fit of south america ... |
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Term
| Continetal drift ...objections to hypothesis |
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Definition
| its inability to provide an acceptable mechanism for the movement of continents. |
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Term
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Definition
| Replaced Continental drift theory...According to plate tectonics, Earths rigid outer layer (Lithosphere) overlies a weaker region called the asthenosphere. Further, the lithosphere is broken into several large & numerous smaller segements, called plates, that are in motion & cont. changing is shape & size. Plates move as relatively coherent units & are deformed mainly along their boundaries. |
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Term
| Divergent Plate Boundaries (constructive margins) |
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Definition
| Where two plates move apart, resulting in upwhelling of hot material from the mantle to create seafloor.Most divergent boundaries occur along the axis of the ocean ridge system & are associated with seafloor spreading. New divergent boundries may form within a continent , where they may fragment a landmass & develop a new ocean basin |
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Term
| Convergent Plate Boundaries (destructive margins) |
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Definition
| where two plates move together, resulting in oceanic lithosphere descending beaneath an overriding plate, eventually to be reabsorbed into the mantle possibly in the collision of two continentaa blocks to create a mountain system . |
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Term
| Transform Plate Boundary ( conservative margins) |
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Definition
where two plates grind past eachother without the production or destruction of lithosphere.
Account for 20% |
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Term
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Definition
| Convergent boundaries are also called subduction zones, because they are sites where lithosphere is descending( being subducted) into mantle. Subduction occurs b/c density of the descending tectonic plate is greater than the density of the underlying asthenosphere. |
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Term
| Oceanic-continental convergence |
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Definition
When continental plate and oceanic plate converge . The oceanic plate is more dense due to its composition and subducts underneath the continental plate. The buoyant continental block remains "floating" while the denser oceanic slab sinks into mantle.
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Term
| Oceanic-Oceanic Convergence |
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Definition
Two oceanic plates converge one descends beneath the other, initiating volvanic activity by the same mechanism that operates subduction zones.
In process a deep oceanic trench is formed. |
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Term
| Continental-Continental Convergence |
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Definition
Two continent meets head-on neither is subducted bc continental rocks are relatively light resist downward motion.
RESULT: is formation of new mountain range composed of deformed sedimentary and metamorphic rocks that often contain silvers of oceanic crust. |
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Term
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Definition
| an underwater mountain range, formed by plate tectonics |
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Term
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Definition
| He suggested that a supercontinent he called Pangaea had existed in the past, broke up starting 200 million years ago, and that the pieces ``drifted'' to their present positions. |
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Term
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Definition
| Thought the idea that the seafloor itself moves (and carries the continents with it) as it expands from a central axis |
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Term
mid ocean ridges
found in divergent boundary |
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Definition
big mountain range 6,000 -12000 feet above sea floor
iceland ex. mid atlantic ridge
fissure at the top of ridge allows magma to escape to the surface.
shallow earthquakes only
- earthquakes focus is no deeper than 100km
- 100km is the thickness of the lithosphere
oceanic crust is created here |
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Term
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Definition
occurs where opposing tectonic forces act to pul the lithosphere apart .
modern exampke east african rift. |
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Term
| Cause of the December 26, 2004 Quake |
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Definition
| Mega Thrust Quake (9.1m), occurred along a subduction zone near Sumatra |
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Term
| Indian Ocean Tsunami Warning System (Prior to 2004) |
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Definition
| No, installed 18 months later |
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Term
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Definition
| 1989 Earthquake, m7.1, caused by San Andreas Fault |
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Term
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Definition
| Due to San Andreas Fault System, Fire further damaged San Francisco |
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Term
| Four main ocean Basins (EC) |
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Definition
| Atlantic, Pacific, Indian, Arctic |
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Term
| Evidence Supporting Plate Tectonics |
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Definition
ocean drilling
hotspots
paleomsgnetism |
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Term
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Definition
Deep sea drilling project of 1983...researchers used fossils to remains to date seafloor at eachsite.
succesor: ocean drilling program JODIES RESOLUTION allowed for studies of earthquake generating zonesat convergent plate margins & for direct examination of oceanic plateus & seamounts. |
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Term
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Definition
| an area of volcanism high heat flo and crustal uplifting that is a fe hundred kilometers across. |
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Term
| When does the clock start for a basalts age? (birthday) |
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Definition
| At the time the lava solidified into basalt |
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Term
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Definition
| our magnetic shield around the planet. something that protects us from solar winds. |
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Term
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Definition
| analyzes motion (speed&direction) of an indivdual plate |
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Term
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Definition
| analyzes motion b/w two or more plates relative to eachother(requires atleast two plates to calculate) |
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Term
| Ocean ocean convergence (Example) |
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Definition
| a long narrow linear or gently curving trench, earthquake to depths of several hundred km. and volcanos paralleling the trenches as islands |
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Term
| Divergent Boundary (example) |
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Definition
| A long linear rise in seafloor, & quakes & volcanic activity found along side ridge |
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Term
| Transform Boundary (example) |
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Definition
| A land or seafloor region with many quakes with depths that are shallow, not particularly impressive topography & no volcanos |
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Term
| Ocean continent convergent boundary (example) |
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Definition
| A long narrow linear or gently curving trench earthquakes to depths of several km. & volcanos paralleling the trenches on continents. |
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Term
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Definition
| A sudden release of energy within the brittle lithosphere, that typically occurs along faults. |
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Term
| What are earthquake waves? |
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Definition
| This is the transport mechanism of the released stored energy during an earthquake. |
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Term
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Definition
| Exact location along a fault where rupture and slip occur (or begin) |
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Term
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Definition
| Point on the surface that lies directly above the focus or hypocenter |
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Term
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Definition
| body & surface waves being generated from the earthquakes focus. |
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Term
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Definition
Rayleigh Waves- Surface waves that cause the ground to ripple up and down vertically (also known as ground roll)-Strong Enough to knock over clouds
Love Waves- Surface waves that cause the ground to ripple back and forth, in a snake-like movement. (Most difficult to civil engineers) |
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Term
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Definition
p waves: compressional wave- comes through as wave energy travels through the earth it takes the rock , compresses it 7 expands it. 1st to arrive at siesmograph
S wave: as energy travels forward, makes rock move up & down & its part of earthquake people tend to feel. middle
surface waves: slowest.
ALL WAVES generated at same time from focus of erathquake |
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Term
| Which causes more damage during an earthquake Surface or Body waves? |
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Definition
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Term
Earthquake Magnitude
2 popular scales: |
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Definition
estimates amount of energy released at the focus of an earthquake. Right when earth starts to rupture & energy is released that is what is considered magnitude.
- Local Magnitude Scale:ritcher scale- distance & amplitude... problem data unreliable at mag. 6.4
- Moment Magnitude Scale-dr. thomas hanks, seismic movement calculated directly from fault by using: fault rigidity
- fault rupture area, fault slipamount
- not reliable for small magnitude events.
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Term
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Definition
A measure of the degree of shaking at a given locale based on the amount of damage.
Scale used: modified mercalli intensity scale. |
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Term
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Definition
| in areas where unconsolidated materials are saturated with water, earthquake vibrations can turn stable soil into mobile fluid. |
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Term
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Definition
Foreshock- earthquake that precedes a major earthquake, identidied as such when larger event happens at same location.
Aftershock- adjustments along the fault that follow a major earthquake.
Foreshocks & afterschocks each create their own individual body & surface waves. |
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Term
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Definition
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Term
earthquake prediction
Short range
Long range |
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Definition
Short Range: Predictions is within days, months, or a year. science cannot do this reliably. Not one prediction methodd has been repeatable
Long Range: Prediction over a period of 30 years or more
Based on premise that earthquakes are repetitive & cyclical. |
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Term
midwest earthquakes
why so dangerous? |
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Definition
northeast aarkansas : 1811 7.7 mag. 7.0 after schock
New Madrid Missouri: jan. 1812 7.5 mag.
Feb. 7th 1812 7.7 mag.
DEVASTATING: why?
whole area luviant no bedrock
houses in this area highly populated building codes.
events ccold happen again.. |
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Term
| What happened in Sumatra? |
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Definition
Indian Plate, stuck under Burma plate
-M 9.1
-Measurable throughout the world |
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Term
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Definition
-Strike-Slip**
Jan 12, 2010
-Caribbean and North American plate
-M 7.0
->200,000 deaths
-Cholera |
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Term
| What happened in Honshu, Japan? |
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Definition
March 11, 2011
-Pacific plate under North American
-M 9.0
-Nuclear plants damaged
-Tsunami |
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Term
| which type of plate boundary can generate dangerous tsunami by motion generated along a fault during an earthquake? why? |
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Definition
Convergent Boundary- subduction zone
During the earthquake, the ocean floor is either pushed up or down dropped, which also pushes up or down drops the ocean water column at that location. This generated the tsunami. |
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Term
| general causes of tsunamis |
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Definition
| underwater earthquake, underwater landslide, underwater volcanic eruption & asteriod impact into water. |
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Term
| How fast do tsunami travel across ocean? |
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Definition
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Term
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Definition
| produced by wind goes across ocean surface |
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Term
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Definition
naturally occuring
a homogeneous
it is inorganic
it possesses an orderly internal structure
it has a specific chemical composition |
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Term
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Definition
2 types
continental
oceanic |
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Term
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Definition
roughly 7 km (5 miles) thick & and composed of dark basalt .
younger and denser. 180 million yrs old. or less |
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Term
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Definition
35 km. (22 miles) thick but may exceed in some mountainous regions such as rocckies and himalayas. Many rocky types. avarage density of 2.7 g/cm^3 some discovered to be 4 billion yrs old.
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Term
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Definition
| more than 82% of earths volume is contained in the mantle, a solid, rocky shell that extends to a depth of nearly 2900 km. |
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Term
| What is the dominnt rock type in the uppermost mantle? |
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Definition
| peridotite which is richer in the metals magnesium and iron than minerals found in either continental or oceanic crust |
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Term
| extends from the crust mantle boundary down to a depth of about 660 km. It can be divided into to different parts . The top portion of upper mantle is part of the stiff lithosphere, & beneath the weaker asthenosphere. |
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Definition
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Term
Contains of the entire crust and uppermost mantle & forms Earth's relatively cool, rigid outer shell.
avrg. 100 km in thickness, it is more than 250 km thick below the oldest portions of the continents. |
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Definition
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Term
a comparitively weaker layer . The top portion has temperature.pressure regime that results in a small amount of melting.
Uppermost is weak b/c it is near its melting point,just as hot wax is weaker than cold wax. |
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Definition
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Term
| 660 km to the top of the core, at depth 2900 km. Bc of an increase in pressure (caused by the weight of the rock) the mantle gradually strengthens with depth . despite their strengthh however , the rocks within the lower mantle are very hot & capable of very gradual flow. |
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Definition
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Term
| thought to be an iron nickel alloy ith minor amounts of oxygen , silicon, & sulfur-elements that readily form compounds with iron. At the extreme pressure found at the core , this iron rich material has an average density of nearly 11g/cm ^3 & approaches 14 times the density of water at earths center. |
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Definition
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Term
| liquid layer 2270 km thick . It is the movement of metalic iron within this zone that generates earths magnetic field . |
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Definition
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Term
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Definition
| sphere having a radius of 1226 km . Despite its higher temp. the iron in the inner core is solid due to immense pressures that exist in the center of the planet. |
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Term
| Is the layer of the Earth's atmosphere that is directly above the stratosphereand directly below the thermosphere. In the mesosphere temperature decreases with increasing height. |
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Definition
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Term
| one or more valence electrons are shared between two atoms. |
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Definition
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Term
| the most common rock forming minerals |
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Definition
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Term
| how many iron cations were you able to dra in for the single tetrahedron ? what does this represent? |
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Definition
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