Chapter 15- Oceans And Coasts

How deep are the abyssal plains?

2.5 and 3.5 miles deep

What is a barrier island?

A long, narrow, offshore deposit of sand or sediments that parallel the coastline.

On a barrier island, what direction is sand moving?

Along the shoreline downwind and perpendicular to the shoreline

What caused the tsunami on Indonesian coast?

An earthquake caused by the violent movement at the Java trench

What is thermohaline circulation?

Changes in heat and salt content change the density of the ocean water. Saltier and colder waster is denser, which is heavier and sinks. This water returns to the surface (where it is warmed) through mixing and wind-driven upwelling.

If the Earth warmed, why would some area of the Earth have a greater rise in sea level than others?

Gravity is different across the globe; cooling ocean water would slow down the conveyor system causing water to stack up; some area of the Earth are rising and falling causing relative sea level to be different in different places

What is the tallest mountain in the world?

Hawaiian Islands

What is a spit? Is it a depositional or erosional feature?

A ridge of sand carried by longshore drift that extends out from the mainland across a bay; depositional

Is the plate margin at a convergent plate boundary active or passive?What about active at a transform plate boundary?

Active; active

Japan, which has lots of earthquakes and volcanoes, is located on which kind of plate boundary, active or passive? How do you know?

Active; the earthquakes and volcanoes are evidence of tectonic activity, which is by definition, an active plate boundary

What is marine snow?

Algae, bits of poop, and parts of tiny dead animals

How can you use the Hawaiian Islands to tell how fast the ocean floor is moving?

By looking at the difference in age between the youngest versus oldest of the islands. The time difference and the distance between the youngest and the oldest tell how fast the plate is moving.

Within a deep ocean wave, water molecules follow a _____ path, with the radius becoming ____ with depth.

Circular; smaller

What is a mid-ocean ridge?

Crust split apart at a divergent plate boundary where molten material from the mantle rises to the surface

How are submarine canyons made?

During ice ages, glaciers lock up ocean water, resulting in sea level fall. Rivers that once flowed gently to the sea, after sea levels fall, must drop hundreds of feet to reach the ocean, gouging deep ravines. After the ice age ends and ocean levels rise, the ravines are submerged. These are now submarine canyons.

Give 2 examples of passive continental margins?

East coast of North America and west coast of Africa

How is Hawaii formed?

Hot Spot

What is the Continental shelf?How deep is it? How wide is it?

It is shallow ledge that surrounds the continents; on average 440 ft below the surface; approximately 50 miles wide

What is the deepest trench?

Marianas Trench

Are all stacks formed from the collapse of a sea arch?

No, some stacks form as the coastline around them erodes

Were the Grand Canyon and Monterey created by the same agent?

No, the Grand Canyon was carved by water and Monterey was carved by mass movements (debris flows and turbidity currents).

What kind of tectonic activity would you expect at a passive plate margin?

None, that is why they are called "passive".

What are the deepest parts of the ocean?

Oceans Trenches

Have you ever been to the beach, played in the water, and found yourself being moved down the beach by the current? This is longshore drift. The direction of longshore drift is controlled by the direction of waves which is influenced by ____ _____.

Prevailing winds

What does Gray's Reef National Marine Sanctuary do?

Protects a live-bottom reef that is home to more than 200 species of fish

From the book: Wave ____ occurs when waves approach the shore at an angle.

Refraction

What is the Green Bridge of Wales? How did it form?

Sea Arch; sea eroded the weaker bands of rock then it eroded the cracks when form an arch.

If all the ice on Antarctica melted, what would be the effect on sea level?

Sea level would rise

What is the effect of acidification on Pacific Oysters?

Shells are dissolving, reducing the number of oysters available for harvesting and so affect local businesses.

What is effect of acidification on planktonic organisms?

Shells dissolve and so the amount of plankton could be significantly reduced. They are a major food source for many organisms and are a main source of oxygen in the atmosphere.

Is the Cascadia subduction zone stable?

no

What is riprap or a groyne used for?

To keep sediment from eroding and moving in the direction of longshore drift

What was the cause of the red tidal bloom in Florida?

Too much fertilizer and sewage in the water caused the red algae to reproduce

What are seamounts?

Undersea mountains formed by volcanic activity.

What are black smokers?

Underwater volcanic chimneys, with water reaching 750 degrees F, billowing out black smoke, located on the oceanic ridges

From the book: At some point in the depth of the wave, water molecules are not moving. This point is called the ______.

Wave base

What is "acidification"?

When CO2 is absorbed by the ocean, a series of chemical reactions occur resulting in the increased concentration of hydrogen ions. This increase causes the seawater to become more acidic.

Why do we have currents? Name 2 reasons.

Wind and thermohaline circulation

What is a wave cut platform?

platform or flat sheet of rock (cut by waves) with a sea cliff in front of it.

What is the theory called for barrier island formation?

submerged beach ridge theory

Ocean waves begin because of the ____.

wind

How do the organisms live in association with black smokers?

They use bacteria in their bodies to derive energy from the chemicals spewing out the black smokers

How does the size of Monterey compare with the Grand Canyon?

They are about the same size

What causes headlands?

They are made of rock harder than the surrounding land so they are not eroded as fast as the surrounding softer rocks

How much carbon dioxide from the atmosphere is absorbed in ocean water?

25%

How deep are these trenches?

3.7-6.8 miles below the surface

What percent of the world's volcanoes are on under water?

70%

Water makes up what percentage of the Earth's surface?

71%

What is the heat source for the hydrothermal field of the Lost City?

new sea floor that looks like stalagmites that are formed by water reacting with chemicals in the rocks causing heat.

Trieste is a Swiss-designed, Italian-built deep-diving research bathyscaphe which reached a record depth of about 10,911 meters in the Challenger Deep of the Mariana Trench near Guam in the Pacific. On 23 January 1960, Jacques Piccard and US Navy Lieutenant Don Walsh achieved the goal of Project Nekton. Have you ever heard of another Picard?

Jean-Luc Picard of the USS Enterprise. Or perhaps you know of Auguste Antoine Piccard (28 January 1884 - 24 March 1962), Jacque's father, a Swiss physicist, inventor and explorer, known for his record-breaking helium-filled balloon flights, with which he studied the Earth's upper atmosphere. Auguste was also known for his invention of the first bathyscaphe, FNRS-2, with which he made a number of unmanned dives in 1948 to explore the ocean's depths.

What is the smoke?

Liquid containing minerals such as metal sulfides

Where is the continental slope?

Located on the edge of the continental shelf

What endangered species are protected here?

Loggerhead sea turtles and North Atlantic right whales

What processes act on barrier beaches?

Longshore drift, inlets migration, summer/winter change, overwash fans

Why are big cities typically found along a passive plate boundary?

The area is stable and not tectonically active

What caused the death of the ecosystem?

The decay of the algae used up all the oxygen in the water, and so everything suffocated

What causes tides?

The gravitational pull of the moon and sun on Earth.

What is the global ocean conveyor belt and where does it exist?

The sinking and rising of ocean water moves cold water from the poles to the equator where it is warmed.

Monserrat volcano lies on what kind of plate boundary?

The volcano is the result of a convergent plate boundary where the North American plate meets and is subducted under the Caribbean plate at the Puerto Rico Trench.

Are there other dead zones in the world besides the one in the Gulf of Mexico?

Yes , Dead zones occur in many areas of the country, particularly along the East Coast, the Gulf of Mexico, and the Great Lakes, but there is no part of the country or the world that is immune.

Has the ocean become more acidic in the last 200 years?

Yes, 25-30%

Would you expect to see tectonic activity, like earthquakes and volcanoes, at an active plate boundary?

Yes, that is why it is called active

Are seamounts abundant across the earth?

Yes, very abundant

Does the terrain of Monterey Canyon ever change? Why? What has carved this canyon?

Yes; Large sediment transport events occur frequently involving both debris flows and turbidity currents.

What is a tombolo?

a spit that connects an island to the mainland

If the top of a sea arch collapses, what is the landform that is left behind?

a stack

When the land surface intersects the wave base, the top of the wave is moving faster than the base of the wave. This friction causes the wave to become a ____.

breaker