GEL 001 Midterm 1

Question 1

Solar nebula hypothesis

Answer 1

Plants form from discs of gas and dust that surrounded the sun as it formed.
Planets are byproduct of star formation from nebula.

Question 2

Nebula

Answer 2

Clouds of gas and dust in space that Mark birthplace of stars

Question 3

Solar system

Answer 3

Begin with slow, spinning cloud of gas, nebular cloud begins in collapse and toward center, because of gravity
As it collapse It heats up and compresses the center (proto-sun) revolving gas and dust become trapped and stable orbits (rings)
When’s sons internal fusion? Reactor turns on a become real son, and rings matter, clumps as temps drop, planetestimals become planets.

Question 4

Planetestimals

Answer 4

Constant collisions caused Boulder
Astreoid size particles coalesce because of Gravity

Question 5

Accretion

Answer 5

Collision growth of planets by constant bombardment

Question 6

4.6 b.y age of Earth

Answer 6

Formation of sun, 8 planets, over 130 mins, and assorted space debris —> Determined by dating of radioactive elements within meteorites found on earth

Question 7

Meteorites

Answer 7

Chunks of rock metal that fall to earth from space

Question 8

Differentiation

Answer 8

Planets, evolved by progressive differentiation (separation) of materials, according to
density,
under the influence of internal heating,
heavy moved to core

Question 9

Core

Answer 9

Dense interior, in planets

Question 10

Mantle

Answer 10

Surrounds core, less dense

Question 11

Crust

Answer 11

Thin, least dense

Question 12

Hydrosphere

Answer 12

Surface water on earth, along with ground water

Question 13

Atmosphere

Answer 13

Develops from for volcanic gas

Question 14

Heat of formation

Answer 14

Frictional heating through constant collision, (kinetic energy of informing matter converts to heat energy)

Question 15

radioactive heat

Answer 15

Accumulation of U, Th, K, that spontaneously Decay to form heat

Question 16

Magma ocean

Answer 16

Young earth was hot enough for the uppermost several tens of kilometers to covered by magma ocean

Question 17

Hadean Era

Answer 17

Magma rock existing in cooling off,
unlivable period,
First 600–700 million years of earth history

Question 18

Volcanic outgassing

Answer 18

Volcanoes emenate copious quantities of water, paper, CO2, SO2, NO2, and other gases

Question 19

Rules of comets

Answer 19

“Dirty snowball”
Contributed huge amounts of water to interior of planet,
outgasesand contributed to early atmosphere and hydrosphere

Question 20

Main elements in the Earth

Answer 20

Fe, O, Si, and Mg

Question 21

Silica & Silicates

Answer 21

Si and O Create silica (SiO2) Which is the main component of silicates. Silicates doninates the rocky mantle and crust

Question 22

Geothermal gradient

Answer 22

Rate of change in temperature with depth
Temperature increases towards the center of the Earth

Question 23

Iron inner core

Answer 23

(s), Very hot and dense, made of metallic Fe With small amounts of Ni and S

Question 24

Iron outer core

Answer 24

(l), Very hot in tents, made out of metallic Fe with small amounts of Ni and S

Question 25

Composition and characteristics of core

Answer 25

Solid inner core- pure crystalline Fe, But “frozen” At center of planet, because intense pressure
Liquid outer core- (l), Molten Fe With traces of other metals, generates Earths magnetic field, (l), Because pressure and temperature increases (the Temp melts it)

Question 26

Composition and characteristics of mantle

Answer 26

(s), Dense, ‘Silicate rock and metal oxides that are a thick(l), Behaves, like plastic, greatest volume of earth

Question 27

Composition and characteristics of crust

Answer 27

(s), thin, silicate rock that is brutal

Question 28

seismology

Answer 28

study of earthquake waves that can be analyze to discern the interior dimensions and compositions of the earth

Question 29

body waves

Answer 29

pass through interior of Earth (P and S waves)

Question 30

P waves (primary)

Answer 30

travels fastest, compresses and pull rock, can travel through (s) and (l)

Question 31

S waves (secondary)

Answer 31

slower, shears rock sideways or up/ down, only (s)

Question 32

wave paths & rays

Answer 32

seismic energy moves as series as waves and rays show direction of wave movement

Question 33

reflection and refraction

Answer 33

Seismic waves may reflect or refract (bend)

Question 34

seismic velocities

Answer 34

depends on densite and elastic properties

Question 35

crust/mantle boundary (Moho)

Answer 35

P-wave velocities that increase rapidly because of abrupt increase in densite of mantle rock realtive to crustal rock

Question 36

core/mantle boundary

Answer 36

P-wave decreases at the abrupt change from mantle to liquid outer core

Question 37

inner core/outer core boundary

Answer 37

P-velocity changes at outer-to-inner core

Question 38

shadow zone

Answer 38

Where no s-waves penetrate the liquid outer core of Earth

Question 39

seismic tomography

Answer 39

computer-aided technique that details variations in seismic velocity of materials within Earth

Question 40

Wegener

Answer 40

German meterologist/geologist; 1915 book suggested all continents combined into Pangea but then drifted into configurations of today

Question 41

Pangea

Answer 41

Super-continent that contained ALL continents that was proposed by
Wegner

Question 42

continental drift

Answer 42

criticized idea b/c no one could find a way where continents could move

Question 43

exploration of oceans

Answer 43

happened in WWIl and Cold War; helped understand continent configurations

Question 44

echo sounding

Answer 44

recording of a sound wave bounced off the ocean floor