chap 3b vocxab

Question 1

abyssal fan

Answer 1

underwater geological structures associated with large-scale sediment deposition and formed by turbidity currents.

Question 2

abyssal hills

Answer 2

a hill on the ocean floor formed by volcanic activity

Question 3

abyssal plain

Answer 3

a flat expanse at the bottom of an ocean basin

Question 4

antartic circle

Answer 4

the latitude of 66.5 degrees south of the equator, which marks the southernmost limit of sunlight at the june solstice

Question 5

arctic circle

Answer 5

the latitude of 66.5 degrees north of the equator, which marks the northernmost limit of sunlight at the december solstice

Question 6

bathygraphic features

Answer 6

the physical features of the ocean bottom

Question 7

biogenous sediments

Answer 7

sediments formed from the remains of living organisms

Question 8

calcareous ooze

Answer 8

sediment composed of 30% or more of the remains of organisms that produce shells made of calcium carbonate

Question 9

chronometer

Answer 9

a clock that keeps accurate time and can be used to determine longitude

Question 10

continental margin

Answer 10

the region of ocean that lies beneath the neritic zone. it is composed of the continental shelf and the continental slope

Question 11

continental rise

Answer 11

a gentle slope at the base of a steep continental slope

Question 12

continental shelves

Answer 12

the edge of a continental landmass

Question 13

continental slope

Answer 13

the transition between the continental shelf and the deep floor of the ocean

Question 14

cosmogenous sediments

Answer 14

sediments formed from dust and debris from outer space

Question 15

equator

Answer 15

a circle drawn around the center of the earth that is perpendicular to its axis of rotation

Question 16

global positioning system

Answer 16

a system of satelites that can be used to find an exact position anywhere on earth

Question 17

greenwich prime meridian

Answer 17

the primary line of longitude that passes through the royal naval observatory in greenwich, england, and is designated 0 degrees longitude.

Question 18

hydrogeneous sediments

Answer 18

sediments formed by the precipitation of dissolved minerals from seawater

Question 19

international date line

Answer 19

the line that lies at approximately 180 degrees from the prime meridian that marks the beginning of each calendar date

Question 20

latitude

Answer 20

the angular distance north and south of the equator measured in degrees. also known as a parallel

Question 21

longitude

Answer 21

the angular distance east and west of the prime (or greenwich) meridian measured in degrees. also known as meridian.

Question 22

nautical mile

Answer 22

a unit of distance equal to 1 minute of latitude, 1.85km, and 1.15 land miles

Question 23

seamount

Answer 23

a steep sides formation that rises sharply from the ocean bottom

Question 24

sextant

Answer 24

a device used to measure the angle of a star with respect to the horizon

Question 25

shelf break

Answer 25

an abrupt change in the underwater landscape that occurs where the continental shelf ends and the continental slope begins

Question 26

silicious ooze

Answer 26

sediment composed of 30% or more of the remains of organisms that produce shells made of silica

Question 27

submarine canyons

Answer 27

underwater canyon similar to canyons on land that are found on some continental slopes

Question 28

terrigenous sediments

Answer 28

sediments that originate on land and are washed into the sea

Question 29

trench

Answer 29

long, narrow depressions on the seafloor that form at the boundaries of tectonic plates

Question 30

tropic of cancer

Answer 30

the latitude 23.5 degrees north of the equator. it marks the northernmost extent of the tropics

Question 31

tropic of capricorn

Answer 31

the latitude 23.5 degrees south of the equator. it marks the southernmost extent of the tropics

Question 32

turbidity currents

Answer 32

a swift underwater avalanche of sediment and water