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Flashcards in geology 4 Deck (23):
1

what is the inner core made of

solid nickel and iron

2

what is the outer core made of

liquid, iron

3

what is the mantle made of

iron-rich rock
semi-solid
top of mantle called the asthenosphere

4

what is the evidence that there was once a super continent

fit of continents
mountain chains and rock types
volcanoes and earthquake locations
glacial evidence

5

what are the two plate types

oceanic plates-made of basalt, dense
continental plates-made of granite, less dense

6

how do plates move

convection currents in the mantle
move very slowly
are constantly in motion

7

what are the 4 types of plate motions

converge-compression of plates
diverge-tension(pull apart)
transform-slide past eachother
subduction-ocean plate is pushed under crust

8

what is a hot spot

volcanoes that occur in the middle of a plate
no plate boundaries
plate moves-hot spots don’t

9

what is an earthquake

ground motion caused by a geological event
energy is transferred through the earths crust

10

what are the three types of earthquake waves and their characteristics

p-waves- primary waves,compression waves, move very fast
s-waves-secondary, shear waves, move slower than p-waves, do not travel through liquids
l-waves-slowest waves, most damaging, rolling motion, side to side motion

11

what is the epicenter and focus

epicenter-place on earths surface directly above the focus
focus-where the actual break occurs

12

what are the energy and ground displacement

energy released increases 32x(5 magnitude is 32x more energy than a 4)
ground displacement increases 10x (5 moves the ground 10x more than a 4)

13

what are the three ways to measure earthquake magnitude

richter scale-older system, not accurate for earthquakes far away from seismograph station
moment magnitude scale-more accurate at long distances
mercalli scale-measured by observation

14

what are primary effects of earthquakes

ground shaking
ground rupture
liquefaction

15

what are secondary effects of earthquakes

structure collapse
fires
flooding
starvation and disease

16

what is relative and absolute time

relative-compares rocks or fossils to one another based on logical rules
absolute-actual age of rock or fossil in years ago

17

what is instability and 3 examples of elements becoming stable

radioactive elements are unstable
uranium-238->lead-206
carbon-14->nitrogen-14
potassium-40-> argon-40

18

three forms of radioactive decay and what each changes

alpha decay-atomic number -2 and mass-4
beta decay-atomic number +1
electron capture- atomic number -1

19

what is a half life

amount of time it takes for half of the radioactive element or parent element to decay into stable daughter products

20

what are the 6 geologic principles

uniformitarianism-present is the key to the past
superposition-the oldest rocks are at the bottom, youngest at top
cross-cutting relationships-object being cut is older than the object doing the cutting
original horizontality-rocks are deposited flat
inclusions-older than surrounding rock
uncomformities-erosion, folding and erosion, different rock types

21

what is sea level rise

fine upward, fine/coarse

22

what is sea level fall

coarsen upward, coarse/fine

23

what is correlation

matches rocks across distances
use age/fossil data
uses stacks of rocks