Term
| What is some proof of Pangea? |
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Definition
1. continents fit together
2. identical fossils found on different continents
3. mountain belts match
4. age of the rocks match
5. ice flow directions |
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Term
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Definition
| rocks can preserve a “fossil” record of the earth’s magnetic field. |
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Term
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Definition
| attraction for iron->aligns/ produce invisible lines of force extended between poles of an object. |
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Term
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Definition
| - location of 2 magnetic poles (switches every 10,000-1,000,000 yrs) |
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Term
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Definition
| direction to the magnetic pole. |
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Term
| What are some Paths of Apparent Polar Wandering? |
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Definition
-when the declination of ancient rocks are measured, they don’t point to the modern pole position.
-different ages= different declinations
-same age on different continents= different declinations. |
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Term
| Is there more than one pole? |
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Definition
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Term
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Definition
| where new oceanic lithosphere is created. |
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Term
| How do you determine Spreading Rate ? |
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Definition
rate=distance/time
Average of 3cm per year. |
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Term
| What is the Origin and evolution of divergent boundaries |
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Definition
1. begin as rift zones on continents pull apart the crust.
2. continent pulled apart, basaltic magma extrudes in to the rift valley. (oceanic crust is forming)
3. valley floor sinks and fills with sea water.
4. divergence continues and results in large ocean basin. |
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Term
| What are Convergent margins? |
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Definition
places where 2 lithospheric plates move towards each other.
-convergent margins are characterized and categorized by type of crust riding along on the lithosphere. |
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Term
| What are some Physical aspects of faults? |
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Definition
a. earthquakes->shallow and abundant
b. stress-shear
c. NO volcanism
EX: san Andres fault. |
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Term
| What are some characteristics of Hot spots? |
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Definition
-heat anomaly in asthenosphere
-magma makes its way to earth’s surface from deep depths
-stationary
-they create a linear chain of volcanoes
-oldest volcanoes are farthest away from hot spot-dormant
EX: Hawaii, Yellowstone |
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Term
| What is the theory of Sea Floor Spreading |
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Definition
1. moves laterally from ocean ridges
2. magma rises to the sea floor at ridges
3. magma hardens and forms near the sea floor
4. ridges crack in half and move apart. |
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Term
| What is some evidence of sea floor spreading? |
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Definition
1. age of the sea floor (youngest by ridges)
2. sea floor sediment thickens away from ridges
3. valleys (tensional features) run down the center of the ridges
4. paleomagnetism- polarity stripes on the sea floor
-as basalt cools at ridges, it presumes the earth’s magnetic field. |
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Term
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Definition
Crust
-between 6-25mi thick
-continental crust=granite
- oceanic crust (lemi)=basalt
* most covered w/sediment
60% shale 20%limestone 20% sandstone
Mantle
-80% of earth
-olivine (mg, fe, si, o)
Core
- outer- liquid (fe ni)
- inner- solid
*circulation of outer=the earth’s magnetic field |
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Term
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Definition
| force per unit area-stalletos |
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Term
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Definition
| measure of change in shape to a stressed material-deformation |
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Term
| What are some controls of plate tectonic settings? |
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Definition
-rate of strain
-temperature
*hot=ductile/ cold=brittle
*slow=ductile/ fast=brittle |
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Term
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Definition
| Waves that travel through rock |
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Term
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Definition
| distance from crest to crest |
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Term
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Definition
| height of ½ of a wave (high wave=high wave) |
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Term
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Definition
This thing that a woman has.
JK!
time it takes for 1 wavelength to pass |
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Term
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Definition
| cycles per second (hertz) |
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Term
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Definition
a. alternating pulses of compression and expansion
b. produce changes in volume and density
c. travel through solids, liquids, and gasses
d. has fastest velocity (6km/s)
e. motion= parallel to direction |
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Term
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Definition
a. shear wave (side to side)
b. deform material by changing shape not volume
c. can’t pass through gas and liquid
d. last velocity to arrive (3km/s)
e. motion of wave is perpendicular to direction |
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Term
| What are some effects of an earthquake? |
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Definition
1. ground motion- destruction of buildings
2. faults-breaks grounds surface
3. fire-gas lines break
4. landslides and avalanches
5. liquefaction- transformation of granular material from solid to liquid
6. tsunami- series of sea waves generated by an undersea disturbance
7. harbor wave
8. flooding-dams and levies break
9. differential ground settlement |
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Term
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Definition
| -water saturated soil or sediment lose strength and fail during ground shaking. |
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Term
| What is ground oscillation? |
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Definition
slope is too gentle to permit lateral movement
-blocks of soil may decouple and begin to shake
-fissures open and close
Sand boils up out of the ground |
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Term
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Definition
| caused by earthquakes, landslides, volcanic eruptions, explosions, and meteorite impact. |
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Term
| When was the big tsunami in Asia? |
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Definition
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Term
| How many people were killed in the Asian tsunami? |
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Definition
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Term
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Definition
-location where- quake hasn’t occurred in a long time
-helps in prediction of where occur
-areas where built up stress hasn’t released |
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Term
| How many deaths were in the Great Alaskan earthquake? |
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Definition
| 131 (122 by tsunami) (16 in cali) |
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Term
| What was the primary cause of fatalitites in the San Fransico earthquake of 1906? And how many? |
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Definition
Fire.
73,000 deaths-225,000homeless-25,000destroyed buildings |
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Term
| How many deaths were in the 1989 loma prieta? |
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Definition
| 67 deaths-4000injured-12,000 homeless- 22 fires |
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