Features of the Ocean Floor

Question 1

bathymetry def

Answer 1

measurement of ocean depths and charting of the shape of the ocean floor

Question 2

abyssal plains

Answer 2

deep flat features that are occasionally interuppted by seamounts, that have thick accumulations of sediment that bury rugged floor

Question 3

what are 3 things that abyssal plains consist of

Answer 3

1) fine sediments from currents
2) precipitated mineral matter
3) shells and skeletons

Question 4

what ocean has the most abyssal plains and why

Answer 4

atlantic bc it has so few trenches

Question 5

Seamounts

Answer 5

submarine volcaanoes that can become oceanic islands but most don’t have enough eruptive history

Question 6

where ocean has the most seamounts

Answer 6

pacific

Question 7

where can seamounts form over

Answer 7

hot spots

Question 8

volcanic island

Answer 8

volcano that grows large enough before it’s carried from its magma source by plate motion

Question 9

examples of volcanic islands

Answer 9

easter island, tahiti

Question 10

guyots

Answer 10

submereged, flat topped seamounts

Question 11

how do guyots form

Answer 11

inactive volcanic islands are lowered to sea level by weathering and erosion and are moved away from ridge or hot spot where they formed and sink

Question 12

oceanic plateaus

Answer 12

composed of thick accumulations of pillow basalts and other mafic rocks

Question 13

how do oceanic plateaus form

Answer 13

bulbous heat of a ring mantle plume melts and produces outpourung of basaltic lavaaa

Question 14

mid ocean ridges

Answer 14

ridges that run throught the middle of an ocean basin

Question 15

rise

spreading rate
distance from center of ocean

Answer 15

ridges far from the center of fthe ocean (flatter and faster spreaading rate)

Question 16

slab pull

Answer 16

subduuction of cold dense slabs of coeanic lithosphere which are more dense than thee underluying warm asthenosphere due to gravity

Question 17

ridge push

Answer 17

gravity driven force that results from the elevated position of ridge, causing slabs of lithosphere dto slide ddown ridge

Question 18

what contributes more to plate motion? ridge push or slab pull

Answer 18

slab pull

Question 19

What are features of convection

Answer 19

flow-upwelling of hot rock and mantle plummes (up flow) and cool lithopheric plates sink (drive downward moving flow)

transports heat away from interior to surface to space

Question 20

whole-mantle convection aka

Answer 20

plume model

Question 21

whole mantle convection

Answer 21

cold oceanic lithosphere sinks and stirs eentire mantle and ultimate burial ground for lithosphere is core. Balancedd by mantle plumes of hot mantle rock to ssurface.

Question 22

whole mantle convection plumes

Answer 22

mantle plume is narrow and tube like from coree-mantle noundary
large mega plumes

Question 23

layer cake model

Answer 23

two zones of convection: thin dynamic layer in upper mantle and thick, large sluggishh one in lower mantle and drives heat up

Question 24

leyer cake model oceanic lithosphere

Answer 24

drives downward convective flow but doesn’t reach depths of no more than 1000 km

Question 25

SOURCE OF Magma for volcanism away from plate boundaries cak model

Answer 25

melting of lithosphereic frangments