oceanography chapter 3

Of the following statements about Earth's hypsographic curve, which is/are true? Choose all that apply. A) The hypsographic curve shows the percentage of Earth's surface area that is covered by ocean waters. B) The hypsographic curve shows that a majority of the exposed land is below 1 kilometer in elevation. C) The hypsographic curve shows that the average depth of the ocean is about four times the average height of the continents. D) The hypsographic curve shows that a majority of the ocean floor is more than 4 kilometers deep. E) The hypsographic curve shows that the volume of water in the oceans is greater than the volume of water in lakes and glaciers.

A B C D

Of the following statements about turbidity currents, which is/are true? Choose all that apply. A) Turbidity currents are episodic events (they don't occur all the time, but only every so often, like a flash flood). B) Turbidity currents move sediment down the continental shelf and the continental slope to be deposited on the continental rise. C) The material carried by turbidity currents is what builds deep-sea fans. D) Turbidity currents are highly erosive and carve submarine canyons. E) Turbidity currents are composed of low-density water that sinks and follows the shape of the seafloor.

A B C D

Of the following techniques, which one(s) can be used to map the sea floor? Choose all that apply. A) recording many depths using a long cable B) direct visitation of the sea floor C) measuring seawater clarity D) using satellites to measure the sea surface E) sending sound through water (sonar)

A B D E

What processes influence the shape and features of continental shelves? Choose all that apply. A) major climate changes, such as ice ages B) trench formation at convergent boundaries C) the creation of pillow lavas along the mid-ocean ridge D) large fluctuations in sea level over geologic time E) tectonic activity produced by offshore faults

A B D E

The majority of ocean trenches are associated with ___________. Choose all that apply. A) the Pacific Ring of Fire B) the mid-ocean ridge C) volcanic arcs and active continental margins D) subduction zones and associated faults E) narrow or no continental shelves F) very deep ocean water depths

A C D E F

Graded bedding provides evidence that __________. A) turbidity currents carry large particles farther than smaller, lighter particles B) large, heavy particles settle out first as current velocity decreases C) submarine canyons were cut by streams during ice ages when the continental shelves were above sea level D) glaciers deposited sediments on continental shelves E) turbidity currents are triggered by earthquakes

B

Measurement of ocean floor bathymetry from satellites relies on ___________. Select only one answer. A) calculations of how much water versus rock there is at any ocean location B) sea surface elevation, which varies depending on the shape of the underlying seafloor C) density differences of ocean waters D) water temperature, which is higher in areas of shallow ocean waters and can easily be detected by satellites E) the amount of time it takes for a radar pulse to travel from the satellite to the seafloor

B

Most large ocean floor features owe their origins to _________. A) biological activity B) plate tectonic processes C) extreme pressure at depth D) erosion and weathering E) ocean current activity

B

Nearly all oceanic islands are __________. (Choose the best answer.) A) parts of volcanic island arcs B) volcanic in origin C) parts of continents D) separated from continents formed at hot spots as lithospheric plates pass over mantle plumes E) formed at high-standing areas of mid-ocean ridges

B

The measurement of ocean depth and the charting of seafloor topography is called __________. A) tomography B) bathymetry C) navigation D) cartography E) hydrology

B

Which of the following feature(s) is/are associated with the mid-ocean ridge? Choose all that apply. Hint 1. The mid-ocean ridge is a divergent plate boundary where new sea floor is generated. See Section 3.4 in the text. A) a trench B) basalt volcanism and pillow lavas C) volcanoes D) thick layers of sediment E) hydrothermal vents F) a central rift valley

B C E F

In comparison with other ocean basins, major sedimentary features such as continental rises and abyssal plains are relatively rare in the Pacific. The primary reason for their scarcity in the Pacific is that __________. A) turbidity currents are rare in the Pacific, so little sediment is carried down the continental slopes B) rivers do not carry much sediment into the Pacific C) sediment is trapped within the trenches of the convergent plate boundaries D) ringing the Pacific the numerous volcanoes of the Pacific rim and islands prevent normal sedimentation E) the Pacific Ocean is too large for those features to form

C

The greatest proportion of Earth's surface lies in this elevation/depth interval. 0 - 1,000 m above sea level 3,000 - 4,000 m below sea level 4,000 - 5,000 m below sea level 1,000 - 2,000 m above sea level 5,000 - 6,000 m below sea level

C

Trenches are typically associated with ________. fracture zones A) passive continental margins B) convergent continental margins C) transform continental margins D) abyssal hills

C

Of the following items, which is/are associated with a passive continental margin? Choose all that apply. A) volcanic eruptions and pillow lavas B) an abundance of earthquake activity C) a wide continental shelf D) a continental rise E) a deep-ocean trench

C D

Of the following statements about mapping the ocean floor, which is/are true? Choose all that apply. A) Nearly 80% of the ocean floor has been accurately mapped using sonar from ships. B) Satellites can be used to determine the structure and composition of the seafloor. C) Measurements of sea surface elevation by satellites are used to produce maps of the seafloor. D) Multibeam surveys from ships produce very detailed maps of the seafloor. E) Only about 20% of the seafloor has been accurately mapped in detail.

C D E

A ship's fathometer (an echo sounder) transmits a sound pulse and records the return of an echo 7.4 seconds later. If the speed of sound in water is 1,500 m/second, what is the water depth in meters? A) 7,400 meters B) 11,100 meters C) 4,550 meters D) 5,550 meters E) 3,000 meters

D

An oceanographic vessel is mapping a section of the ocean floor stretching for tens of miles in all directions. The seafloor is extremely flat, with a slope of less than one degree, and the water depth is about 4,500 meters. The area being mapped is most likely a(n) __________. A) continental rise B) continental shelf C) continental slope D) continental borderland E) abyssal plain

E

Sediments deposited by the process of suspension settling produce the majority of sediment found on ___________. Select only one answer. A) the continental shelf B) the continental slope and rise C) submarine fans D) shallow islands in tropical seas E) abyssal plains

E

Where a mid-ocean ridge is offset, the linear feature connecting and between the crests of the ridge segments is called a __________. A) central rift valley B) seismic fissure C) hydrothermal vent D) fracture zone E) transform fault

E