module 2

Question 1

core

Answer 1

• radius: 3500 km
  -inner core is solid
  -outer core is liquid
  -made of nickle and iron

Question 2

mantle

Answer 2

• radium:3900km
• solid but can flow
• made of oxygen, silicon, iron, and magnesium

Question 3

oceanic crust

Answer 3

• thin (5-12km)
• basaltic (igenous rock)
• density: 3.0g/cm^3

Question 4

continential crust

Answer 4

-thicker: up to 75km
- granitic (granit rock)
- density 2.7g/cm^3

Question 5

how do we know about earth’s layers

Answer 5

-drilling
-earth materials (volcanoes, molten magma forms lava, composotion can provide info about earths composition)
-sesmic activity
- note: we cannot ctually know structue of earth because we cannot drill to the core because increased temperature and increased pressure

Question 6

lithosphere

Answer 6

crust and uppermost mantle are rigid

Question 7

Moho discontinuity

Answer 7

boundary between crust and mantle

Question 8

asthenosphere

Answer 8

soft underlying mantle that flows

Question 9

what material can provide information about the mantle

Answer 9

diamonds. they are formed at depths of the approx 150 km below earths crust (in the mantle). all diamonds have approx the same age (3.3 billion years). this gives info about the mantle. high pressure form of crystallin carbon

Question 10

what is the deepest hole

Answer 10

12km (in russia)

Question 11

what is diferentiation

Answer 11

seperation of materials within a planet such that dense materials sink to the core and lighter materials float upward. in earth’s case, the denser materials are iron and nickle, adn the lighter materials are sicilcate materials. In order for differentiation to occur, the entire planet must be melted. Metal is denser so metals sink, becoming the core. Silicate melt rise up to become crust and mantle. Earth unmixed itself

Question 12

sesmic reflection

Answer 12

return of some energy of sesmic waves after reflection from a rock boundary

Question 13

sesmiogram

Answer 13

record reflected sesmic waves, which measures the amout of time waves take to travel down to the boundary, reflect off it, and return to the surface. this can determine depth of boundary

Question 14

sesmic refraction

Answer 14

bending of sesmic waves as they pass material to one another. sesmic waves bend towards lower velocity material

Question 15

lithoprobe

Answer 15

multidisiplinary project investigating structure and composition of canadian shield. they dropped large hammers and created sesmic waves. anaylsis of sesmic waves helped determine material composition of shield. mapped lithosphere structure. from 1984-2005