WEEK 1 & 2: The Shape of the Oceans

What features of ocean basins are chains of basaltic rock that stretch more than 1.5 times Earth's circumference around the world at spreading centers? a. abyssal plains. b. abyssal hills. c. seamounts. d. oceanic ridges. e. island arcs.

D

What zone is classified by its location in the open water? a. benthic zone. b. pelagic zone. c. bathyl zone. d. abyssal zone. e. littoral zone.

B

The name of the vast single ocean that was present about 200 million years ago is: a. Sinus Borealis. b. Pangaea. c. Tethys. d. Panthalassa. e. Gondwana.

D

The process by which a lithospheric plate descends is called: a. continental drift. b. induction. c. seafloor spreading. d. subduction. e. faulting.

D

An abundance of foraminifera shells would be described as what type of sediment? a. calcareous ooze. b. turbidic sediment. c. siliceous ooze. d. evaporitic sediment. e. diatomaceous earth.

A

Density is... a. the mass of a substance per unit volume. b. a measure of weight. c. the mass of a substance multiplied by its molecular weight. d. a measure of volume. e. the volume of a substance relative to that of water at the same temperature.

A

How is the surface water above a deep trench in the ocean floor distorted as a result of the trench? a. downward distortion. b. upward distortion. c. sideways distortion. d. vortex distortion. e. no distortion.

A

Which of the following is not true of mid-ocean ridges? a. Earthquakes and volcanoes are associated with ridges. b. The sediment cover is thickest on and near ridges. c. The rock on the sea floor is youngest on ridges. d. Sea floor spreading is associated with ridges. e. New seafloor is created at ridges.

B

The outer edge of the continental margin is the.... a. shelf break. b. continental slope. c. continental rise. d. edge of the abyssal plain. e. continental edge.

A

What feature distinguishes a guyot from a seamount? a. flat top. b. forms at spreading centers. c. moves with the seafloor. d. steep sides. e. rises above sea level.

A

What type of marine sediment is derived from rocks on land? a. terrigenous. b. biogenous. c. hydrogenous. d. cosmogenous. e. calcareous.

A

Which particle size is transported the farthest by waves and currents? a. silt. b. sand. c. pebble. d. cobble. e. boulder.

A

Which statement is true of sediments in the ocean? a. Biogenous sediments comprise a larger area than terrigenous sediments. b. Terrigenous sediments comprise a larger area than biogenous sediments. c. Hydrogenous sediments cover more volume than biogenous sediments. d. Cosmogenous sediments cover more volume than biogenous sediments. e. Terrigenous and biogenous sediments are equal in area and volume.

A

Most marine sediments are composed of what size of particles? a. boulders. b. sand, silt, and clay (aka mud). c. cobbles. d. pebbles. e. cobbles or granules.

B

Oceans comprise most of the Earth's surface in the... a. Northern hemisphere. b. Southern hemisphere. c. Eastern hemisphere. d. Western hemisphere. e. The ocean is evenly distributed.

B

The steepest part of the continental margin is the a. shelf break. b. continental slope. c. continental rise. d. edge of the abyssal plain. e. continental edge.

B

What do satellites measure that provides data for seafloor topographical mapping? a. "pings" reflected from seabed. b. sea surface height. c. sound pulses from ships. d. seawater density. e. wave energy.

B

What is an example of authigenic sediment? a. Quartz sand. b. Gypsum evaporite deposits. c. Volcanic dust. d. Diatomaceous ooze. e. Cosmogenous spheres.

B

What is the main source of terrigenous sediments to the ocean? a. volcanic eruptions. b. rivers / estuaries. c. dust and ash. d. cosmic dust. e. marine snow.

B

What kind of sediments are likely to be abundant beneath upwelling areas? a. terrigenous. b. hydrogenous. c. biogenous. d. cosmogenous. e. authigenic.

C

Which is classified as cosmogenous sediment? a. evaporites. b. ooliths. c. microtektites (fairy dust). d. manganese nodules. e. siliceous ooze.

C

What is the particle size distribution from largest to smallest? a. cobble → boulder → granule → pebble. b. coarse silt → granule → fine silt → clay. c. coarse sand →granule →medium sand → fine sand. d. boulder → granule → coarse sand → coarse silt. e. cobble → granule → pebble → coarse sand.

D

What region of a continental margin blends into the deep-ocean basin? a. Continental slope. b. Continental shelf. c. Continental basin. d. Continental rise. e. Continental plain.

D

_______ lie between the continental margins and the oceanic ridges. a. spreading centers. b. shelves. c. slopes. d. abyssal plains. e. rises.

D

Evidence of plate tectonics is provided by: a. magnetic anomalies. b. seafloor spreading. c. the existence of mid-ocean ridges. d. similar fossils on the rims of ocean basins. e. all of the above

E

How much of the Earth's surface is covered by oceans? a. 35%. b. 50%. c. 55%. d. 60%. e. 71%.

E

Most geologists believe that submarine canyons have been formed by ____. a. stream erosion. b. subduction. c. volcanoes. d. sea level changes. e. turbidity currents.

E

The largest and deepest sea is the... a. Atlantic Ocean. b. Arctic Ocean. c. Indian Ocean. d. Antarctic Ocean. e. Pacific Ocean.

E

The shallow and gently-sloping part of the continental margin closest to land is the... a. shelf break. b. continental slope. c. continental rise. d. edge of the abyssal plain. e. continental shelf.

E

Trenches are formed in areas where... a. a plate is lifted by another. b. a plate moves sideways. c. a plate splits and spreads. d. intense seafloor spreading occurs. e. a plate sinks beneath another plate.

E

What instrument used during the early part of the twentieth century improved the accuracy of ocean depth measurements compared to the rope and weight? a. remotely operated underwater vehicle. b. acoustic doppler current profiler. c. satellites. d. autonomous underwater vehicles. e. echo sounders.

E

What is a s of the Earth's oceans? a. The height of Mt. Everest is greater than the depth of the deepest ocean trench. b. Alluvial fans make up a large portion of ocean basins. c. An ocean basin is shaped like a giant bathtub. d. Abyssal plains are located within continental margins. e. The average ocean depth is greater than the average elevation of continents.

E

What is the most abundant marine sediment in total volume? a. cosmogenous. b. authigenic. c. biogenous. d. hydrogenous. e. terrigenous.

E

Which areas of the ocean are most likely to have the thinnest accumulation of sediment? a. abyssal plains. b. continental shelfs. c. continental slopes. d. deep-sea trenches. e. oceanic ridges.

E

Which particle size has the fastest settling velocity? a. clay. b. very fine sand. c. fine sand. d. coarse sand. e. granules.

E