Ocean Dynamics

How many high and low tides are there each day?

2

How often does the level of the ocean change?

2 times a day.

How long does it take for the moon to complete it's orbit around the earth?

4 weeks

How long does it take deep-ocean water to travel from the poles to the equator and back again?

500-2000 years.

What direction do the water molecules travel in, in a wave?

A circular path.

Gyres

A circular rotation of wind or water that moves clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere.

Current

A mass of water or air that is moving in a consistent direction.

Barrier island

A thin island near the ocean that parallels the coast .

What is a tidal bore?

A wall of water that moves up and down the bay as the tide comes in and goes out.

Does the tidal bulge stay the same?

As the moon moves in its orbit, so does the tidal bulge of the oceans.

How does wind blowing across the water's surface cause a wave?

As the wind blows, there is friction between the air and the underlying water. The friction transfers energy from the wind to the water to create a wave.

How do waves erode the shore?

As waves pound against the shore, they break up the rocks into smaller and smaller sediments, which is an example of weathering.

Where is the water-land boundary?

At the coastal zone.

What are the three distinct zones of the water-land boundary?

Beach, Shore and Shoreline

Name two places that coastal upwelling occurs.

California coast and the Galapagos Islands.

What is one cold water current?

Canary current

What does wind blowing across the ocean's surface produce?

Currents

What does salinity, temperature and density cause?

Deep ocean currents.

Thermohaline circulation

Deep-sea currents that occur because of differences between the salinity and temperature characteristics of water masses.

How do the physical and chemical properties of seawater affect ocean water circulation?

Differences in temperature, salinity, and density drive deep-ocean circulation.

What is the outward movement of water called?

Ebb current

What does the wind "give" to the water to produce waves and currents?

Energy

What moves when a wave travels?

Energy, not the water molecules.

What is the inward movement of water called?

Flood current

Which direction do surface waters travel?

From the equator to the poles.

Which direction do deep-ocean currents travel?

From the poles to the equator.

What are some warm water currents?

Gulf Stream, North Atlantic, and North Equatorial)

What are the circular rotation patters of currents called?

Gyres

Spring tides

Higher high tides, and lower low tides because the solar and lunar bulges are aligned.

Where are tides the highest?

In the bulges.

Waves

In the ocean, energy traveling along the interface between ocean and atmosphere; the medium, of wave travel is the ocean water.

What effect does coastal upwelling have?

It brings nutrient - and - oxygen rich water to the surface, which helps marine life thrive.

What will longer fetches create?

Larger waves.

What will longer lasting winds create?

Larger waves.

What are tidal currents?

Long-period gradual waves.

What do circulation patterns do for the ocean water?

Mix the ocean's waters, distributing important nutrients throughout the world's oceans. They also distribute heat energy and influence coastal geology.

Neap tide

Reduced tidal range because the lunar and solar bulges are perpendicular to each other.

What happens when the solar and lunar bulges are opposite of each other?

Reduces the tidal range to milder variations called neap tides.

What is the affect of the sun on tides called?

Solar tidal bulge.

What will higher winds create?

Stronger waves.

What can cause upwelling?

Surface currents

What are the three things that "drive" deep-ocean currents?

Temperature, salinity and density.

Beach

The accumulation of sediment (sand) on the land side of an ocean or lake, beaches consist of flat portions called berms that gradually slope from the shore up to a marked change in landform, such as a cliff or dunes.

Where do the tidal bulges line up with?

The center of the moon.

Longshore current

The eroding of one area of shore and the building up (deposition) of other areas of shore.

Tidal Currents

The flow of water accompanying the rise and fall of the tides.

How does gravity affect ocean water circulation?

The gravitational influences of the moon and sun pull on the earth's oceans, thereby causing daily and monthly deviations in the ocean surfacewthe tides.

What is a fetch?

The length of the area over which the wind blows.

Shoreline

The line of contact between the water and the land, shoreline migrates with changes in the daily tides.

What "stretches" the ocean layer into an oblong shape?

The moon's gravity pulling on the earth.

What are temperature, salinity and density called?

The physical, and chemical properties of water.

Tides

The rise and fall of water levels due to gravitational forces.

What causes the tides to shift daily?

The rotation of the earth.

Shore

The shore is the narrow strip of land immediately bordering any body of water. It is the zone between high water and low water.

What determines the strength of the wave?

The strength of the wind, the duration of the wind and the length of the area over which the wind blows.

Why are longshore currents important?

They build narrow islands called barrier islands along the coast which provide protection for the coastline from storm damage and create a key habitat for wildlife.

What happens to deep-ocean currents when they warm up?

They move to the surface and then follow the surface currents.

What are tides?

Tides are the slow rise and fall of the ocean level that occurs twice a day.

What does gravity cause?

Tides.

What happens when the solar and lunar bulges align?

Twice a month, the solar and lunar tidal bulges align and reinforce each other, creating wide tidal variations called spring tides (higher high tides and lower low tides).

What are wave currents, deep-ocean currents and tides?

Types of ocean circulation.

What is vertical movement of water called?

Upwelling

What does wind cause?

Wave currents.

What builds and erodes coastal zones?

Waves and currents.

What is the difference between waves and currents?

Waves are surface movement of the water, currents are deeper movements of ocean water.

How are shoreline features eroded?

Waves can erode shoreline features such as dunes and beaches, especially after a storm. When wind and waves strike the shore at an angle, the wave action moves sand particles along the shoreline and creates currents of sediment-laden water called longshore currents.

How can surface currents cause upwelling?

When prevailing winds push surface currents parallel to the shore and then away from the shore this causes cold, dense water from below to come to the surface to replace the water that was pulled away from the shore.

What produces a wave?

Wind blowing across the water's surface.

What causes the circular nature of the gyre?

Wind patterns and earth's rotation. (Coriolis effect)

What are the three things that cause ocean circulation?

Wind, gravity and the physical and chemical properties of seawater.

How does wind affect ocean water circulation?

Winds blowing across the water produce surface circulation in the form of waves and currents.

Does the sun have any affect on tides?

Yes but the solar effects are weaker because the sun is so much farther away than the moon.