GEO CH 15

_____ make up the majority of the ocean floor worldwide.

abyssal plains

Major oceanic surface currents travel:

at an angle to prevailing winds as a result of the Coriolis effect

The form and topography of the ocean floor is termed:

bathymetry

Most of the igneous rock within ocean abyssal plains are:

covered by clay and skeletal remains of microplankton

As waves approach shore in shallow water, their speed...

decreases

Sand groins:

increase erosion rates in the region downcurrent from the groin

Approximately what percentage of Earth's surface is covered with water?

70%

Compared to continental lithosphere, oceanic lithosphere is:

thinner

What percentage of seawater, on average, consists of dissolved salt ions?

3.5%

Estuaries most commonly have salinity that is _____

brackish (between freshwater and marine salinity)

How is sediment transported along the shore?

by longshore currents

The shallowest portion of the ocean is found along the margins in continents in regions termed:

continental shelves

Which portions of the sea floor are most steeply tilted?

continental slopes

The density of seawater increases with:

decreasing temperature and increasing salinity

What is upwelling?

deep water being pushed upward

As compared to fresh water, saline ocean water is _____ and therefore provides _______ support to floating objects.

denser; more buoyant

A bathymetric map of the ocean would utilize contours to connect points of equal ______

depth of the sea floor below sea level

Rip currents flow:

directly away from the shoreline

If currents are largely directed towards shore, the area is likely to experience:

downwelling

When the sea level rises, the ocean may invade a river valley, producing a nearshore body of water mixed and variable salinity termed:

estuary

As compared to continental interiors, surface temperatures in coastal regions:

experience a less extreme range throughout the year

Every shoreline experiences a tidal reach (difference in elevation between high and low tide) of about 3 m. T/F

false

When high tide occurs at any shoreline, that means it is also high tide at all other coasts throughout the world. T/F

false

Flooded valleys that were excavated by glaciers are termed _____

fjords

Wave refraction causes longshore currents to travel:

from headlands towards embayments

Tidal reach will be greatest locally during a:

full or new moon

Because of the wave refraction, erosion along an irregular coastline is:

greatest in headlands (points of land projected out toward the sea)

The deepest segments of the ocean floor are found:

in trenches associated with subduction zones

Which trench includes the world's deepest sea floor (more than 11 km below sea level)?

mariana trench

The most prominent force inducing tides on Earth is the:

moon's gravitational pull

At the equatorial ocean basins, sea surface temperatures may reach 30 degrees C or greater; at the sea floor 5 km below, the temperature is:

near freezing (2-4 C)

A wave will disturb the water to a depth equal to:

one-half of its wavelength

Longshore currents flow:

parallel to the shoreline

Which type of continental coastline features a much broader continental shelf?

passive continental margins

Wave crests:

refract (bend) so as to impact the shore in a nearly parallel manner

Due to the Coriolis effect, surface currents in the ocean are always pulled to the ______ in the northern hemisphere as compared to the prevailing wind direction.

right

What is downwelling?

surface water being drawn downward

Global circulation of ocean water is influenced by _____

surface winds, coastal upwelling and downwelling, and sinking of cold and saline water

Tidal reach is affected by:

the position of the Sun

A shoreline is more likely to consist of a tidal flat than a beach if ______

the shore is protected from strong waves

The magnitude of tidal effect (lateral extent of the intertidal zone between high and low tides) is affected by:

the slope of the coastline, and the position of the Sun

Rogue waves arise from constructive interference of multiple convergent waves; these waves can occasionally be more than 100 feet high. T/F

true