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51 terms

EARS 003: Lectures 4, 5, and 6

Stuff worth memorizing from lectures 4, 5, and 6.
STUDY
PLAY
Stars
All elements in the universe except for the first five (H, He, Li, Be, B) were created by nuclear fusion within _____.
13.7 (on quiz 1)
The universe began with the Big Bang, which occurred _____ billion years ago. (xx.x) (on quiz 1)
lower (on quiz 1)
We know that the universe is expanding due to the Doppler effect, which causes light sent from objects moving away from us to have _______ frequency. (on quiz 1)
gravity
After the Big Bang, gases came together to form nebulae due to _______.
angular momentum
The nebula from which the Solar System was formed began to spin faster as it condensed due to conservation of __________. (2 words)
4.56
The solar system is approximately ___ billion years old. (x.xx)
accretion disk (on quiz 1)
After the sun was formed, matter from the ____________ around the sun came together to form planets. (2 words) (on quiz 1)
radiometric dating
What type of dating, involving decay from parent isotopes to daughter isotopes, has allowed scientists to figure out Earth's age? (2 words)
electromagnetic and strong forces
What two forces battle to keep a nucleus stable or unstable? (alphabetical order) ("_______ and _______ forces")
half-life
The time it takes half of a large sample of a radioactive substance to decay.
4.5
Uranium-lead dating makes use of a half-life of ___ billion years. (x.x)
1.3
Potassium-argon dating makes use of a half-life of ___ billion years. (x.x)
lava
Earth in the Hadean era was inhospitable to life because the planet was covered in _____.
planetoid (on quiz 1)
The moon is thought to have formed when a ______ collided with Earth. (on quiz 1)
f
True (t) or false (f): the Earth's atmosphere 4 billion years ago contained a lot of oxygen.
4.2
Evidence suggests that the first oceans formed _____ billion years ago. (x.x)
volume
density = mass per unit _______
density
Each layer of Earth has a higher _______ than the layer outside of it. In other words, the planet is STRATIFIED by _______.
surface
Seismic waves that travel along the Earth's surface are known as ________ waves.
body
Seismic waves that travel though the Earth's interior are known as ________ waves.
primary (on quiz 1)
P-waves, or _______ waves, are BODY waves that CAN travel through both solids and liquids. (also known as "pressure waves") (on quiz 1)
secondary (on quiz 1)
S-waves, or _______ waves, are BODY waves that CANNOT travel through both solids and liquids. (also known as "shear waves") (on quiz 1)
3.5
The oldest fossils are approximately ___ billion years old. (x.x).
ozone
Lots of harmful solar radiation reached the early Earth's surface because there was no ______ layer.
mantle
The majority of the Earth's mass is contained in the ______.
iron and nickel
The two major elements that form Earth's core are _____ and _____. (alphabetical order) ("_____ and _____")
liquid outer
The S-wave "shadow zone" reveals the Earth's (solid/liquid) (inner/outer) core. (i.e., "liquid inner")
solid inner
The P-wave "shadow zone" reveals the Earth's (solid/liquid) (inner/outer) core. (i.e., "liquid inner")
f
True (t) or false (f): S-waves move faster than P-waves.
elasticity (on quiz 1)
The velocity of seismic waves depends on density and ________. (on quiz 1)
perpendicular
In S-waves, the direction of particle motion is __________ to the direction of wave propagation.
parallel
In P-waves, the direction of particle motion is __________ to the direction of wave propagation.
refracted
When seismic waves pass from one material to another having different density, the wave energy is bent, or _______.
Fermat's Law (on quiz 1)
Between two given locations, A and B, the seismic wave travels along a path that takes the shortest time from A to B. This is called: (on quiz 1)
density
A seismic wave does not take a direct path through the Earth due to changes in _______ inside the planet.
lithosphere
Layer of planet containing the crust and uppermost mantle. Rigid and brittle.
asthenosphere
Layer of planet containing the upper mantle. Ductile rather than rigid. Material is like a slushie rather than solid or liquid.
temperature
Even though pressure increases with depth, deep rocks will still start to melt or deform due to the increase in __________.
oceanic
Denser type of lithosphere, 40-60km thick.
continental
Less dense type of lithosphere, 75-200km thick.
Alfred Wegener
German meteorologist who first proposed continental drift in 1915.
outgassing
The volcanic venting of volatile substances.
Pangaea
Super-continent that existed 225 million years ago.
sea-floor spreading
Idea, proposed by Harry Hess, that continental drift is driven by convection beneath the crust, driving oceans to expand.
magnetometer
Device that measures the magnetic field at a given location; used to expose symmetric patterns of magnetic reversals around mid-ocean ridges.
Curie
A rock gets permanently magnetized once it cools past the _____ point, around 580 degrees Celsius.
200
All ocean crust is less than ___ million years old (round to nearest hundred million).
water
Earth has plate tectonics and other planets don't because Earth has ______ in liquid form, which acts as a lubricant!
subduction
We know that the Pacific is shrinking because it is surrounded by _________ zones.
f
True (t) or false (f): plates can only contain one type of crust, continental or oceanic.
t
True (t) or false (f): oceanic crust is constantly formed, while continental crust is not.