Tides, Waves & Currents

Tides are caused by

• the spin of the Earth on its axis.

• the gravitational pull of the moon only.

• the gravitational pull of the sun only.

• the gravitational pull of the moon & sun.

The highest tide of the month is referred to as a

• spring tide.

• longshore tide.

• neap tide.

• trough.

Which of the following is true about waves?

• A wave is the movement of water along the surface of the ocean.

• A wave period is the distance between two successive wave crests.

• The bottom of a passing wave is called a trough.

• A wavelength is the time it takes for one wave to pass a given point.

Which of the following does NOT cause a tsunami?

• Earthquakes

• Meteorites

• Tides

• Glacial collapse

Which of the following is true of gyres in the Northern Hemisphere?

• They move in a counter-clockwise direction.

• They move in a clockwise direction.

• They can move either clockwise or counter-clockwise.

• They all move towards the equator.

The current created by the returning water from a wave breaking on the beach is called a(n)

• upwelling.

• tidal current.

• whirlpool.

• undertow.

Compared to the position of the moon, where will a low tide occur on Earth?

• At a 90^o angle to the moon’s position.

• Directly opposite the moon’s position.

• Directly beneath the moon’s position.

• At a 45^o angle to the moon’s position.

A lone wave formed by the incoming tide where the mouth of a river is sloped is called a

• whitecap.

• rogue wave.

• tidal bore.

• swell.

The direction gyres move is caused by the ____________ and is/are called ____________.

• rotation of the Earth, the Coriolis Effect

• revolution of the Earth, the Coriolis Effect

• gravitational pull of the moon, countercurrents

• gravitational pull of the sun, countercurrents

A vertical subsurface current that brings up cold, nutrient-rich sediments from the deep ocean is called a(n)

• undertow.

• rip current.

• turbidity current.

• upwelling.