GGS 102: Chapter 11 Review

At the peak of the Pleistocene glaciation, sea level was ________ than today.

130 m (430 ft) lower

The Mid-Atlantic Ridge runs through what country?

Iceland

The most important factor that causes ocean tides on Earth is the __________.

Moon

How do the oceans contribute to maintaining a climate that is habitable for humans?

Oceans absorb large quantities of carbon dioxide from the atmosphere.

What would you do to both grow a large beach and protect a harbor mouth?

Place two jetties on either side of the harbor mouth, and build a breakwater upcurrent from the harbor mouth.

What impact will increased carbon dioxide absorption by the oceans have on coral reefs?

Reefs will degrade over time, ultimately resulting in large-scale mortality.

Why have the beaches on Dauphin Island become smaller over the last few decades?

Sand dredged from the mouth of Mobile Bay has reduced the supply of sand to Dauphin Island. Submit

A thin peninsula called a spit extends beyond the bluffs of the outer beach on Cape Cod. What has caused this spit to form?

Sand from the bluffs is carried and deposited by longshore currents. Submit

Which of the following statements is true about seawater?

Seawater is a solution.

What is the Abyssal Plain?

The Abyssal Plain is the vast, deep, generally flat surface that covers most of the ocean floor.

Why is the continental shelf one of the most valuable places on Earth?

The continental shelf is one of the most valuable places on Earth because of oil.

What is the relationship between wave base and wavelength?

The depth of the wave base is one-half the wavelength of the waves.

Why does wave height increase as waves enter shallow water?

The energy of the wave must be contained within a smaller water column in shallow water.

What is the name of the largest canyon on the planet?

The largest canyon on the planet is called the Zhemchug Canyon.

How will increases in atmospheric carbon dioxide levels affect oceans?

The oceans will become more acidic.

How does the tide cycle affect erosion along a sea coast?

The tide cycle causes erosion to occur at different elevations along a sea coast.

Why do ocean waves bend around headlands?

The waves are moving more slowly just in front of the headland, causing the waves to bend. Submit

Why are scientists doing research in an underwater lab in the Great Barrier Reef?

To replicate future carbon dioxide levels and measure the changes in coral reef productivity, mortality and health

As a whole, the pH of surface waters of the ocean is slightly __________.

alkaline

Which of the following affect the chemical composition of seawater?

atmosphere, minerals, bottom sediments, and living organisms

Seawater with less than 35 ppt but more than 30 ppt is termed _______.

brackish

How do jetties protect harbor entrances?

by inhibiting the deposition of sand in the harbor mouth

The depth at which calcite dissolves rapidly in the ocean is called the __________.

calcite compensation depth or CCD

Carbon dioxide (CO2) combines with water (H2O) to form __________.

carbonic acid (H2CO3)

What two main driving forces produce a barrier island's perceived migration?

changes in sediment supply and sea-level fluctuation

Calcite-secreting organisms such as __________ and __________ live in the ocean's sunlit surface waters and form the basis of most marine food webs.

coccolithophores; foraminifers

Over the past decade, the salinity of high-latitude oceans has ________ due to________.

declined; freshwater inputs from melting ice

Within the mixing zone and thermocline, average temperature and salinity primarily __________.

decrease with depth.

What is the name of the gigantic boulders left behind as the glaciers receded?

erratics

On the side of Earth closest to the Moon, gravitational forces __________ the centripetal forces.

exceed

The Moon's influence on Earth's tides is __________ the influence of the Sun.

greater than

The pH scale is a measure of the __________ ion concentration of a solution.

hydrogen

The height of a tsunami grows as it approaches a coastline primarily because ______________.

its wavelength shortens.

Which of the following structures are types of coastal stabilization structures?

jetties breakwaters

A general term for the coastal area and shallow offshore environment is ____________.

littoral zone.

What term describes the local currents that flow parallel to a shore and transport sediment?

longshore currents

On average, ocean water is ______.

moderately basic (a pH slightly higher than 8)

The weakest gravitational force caused by the Moon is called the __________, which is found at the point on Earth farthest from the Moon.

nadir

In which direction does the longshore current move?

parallel to shore

To survive, beaches need a constant supply of what?

sand

If the sediment that makes up the beaches of Cape Cod were to lithify, what kind of rock would it become?

sandstone

Alabama's Gulf Coast sand originally came from where?

the Appalachian Mountains

What is refraction?

the bending of waves due to a change in wave velocity

What is the wave base?

the lower limit of wave-induced motion in the water Submit

If the side of Earth that faces the Moon experiences a tidal bulge (high tide), then the opposite side of Earth will experience a __________.

tidal bulge or high tide

The low and high tides experienced on Earth are the result of __________.

tidal bulges

Why are coastal stabilization structures built along coastlines?

to protect coastal property from wave erosion to stop beach sand erosion

Resultant forces result in __________ tidal bulge(s) on Earth.

two

It is Thursday and an angler is planning a fishing trip in two days on Saturday. The angler knows from experience that the fishing is best at a particular location at the beginning of high tide. He does not have a tide table, but the angler noted that the high tide on Thursday was at 12:15 PM. At what time on Saturday should he plan to arrive to start fishing, assuming that this location has a diurnal tide type?

1:55 PM

A lunar day is __________ in duration.

24 hours and 50 minutes

The worldwide average salinity of seawater is ___________.

3.5%

How does a sea stack form?

A stack forms when a sea arch collapses, leaving a vertical column of rock offshore.

How is an arch formed along a sea coast?

An arch forms when a sea cave breaks through a headland or where two sea caves coalesce as they erode back due to wave action.v

What is the primary cause of the nearly 20 percent increase in atmospheric carbon dioxide levels since the 1960s?

Burning of fossil fuels

Which of the following statements regarding active and/or passive margins is NOT true?

Cape Cod represents an active margin, as evidenced by its large sand dunes.

How does water move as waves pass?

Water moves in a circle in the same direction as wave movement.

How is a cave created in a cliff face along a sea coast?

Wave action erodes areas of weakness in rock in a sea cliff.

How does wave amplitude change with depth in water?

Wave amplitude decreases as depth increases. Submit

How does wave refraction at headlands affect deposition and erosion?

Wave refraction at the headland increases erosion at the headland and causes deposition in adjacent bays. Submit

Select the statements that are true about wind erosion.

Wind is most effective as an erosional agent in dry places. Sediment deposited by wind in deserts can mostly be found in the form of sand dunes and loess deposits. An important erosion-related role of wind in a desert is abrasion of rock surfaces.