Chapter 10 - The World Ocean Flashcards
What are waves that move through water deeper than one half their wavelength known as?
a. Shallow water waves
b. deepwater waves
c. transitional waves
d. big waves
b. Deepwater race
Dense, cold, saline North Atlantic Deep Water (NADW) originates at several sites near the surface of the South Atlantic.
true or false
False
What is the general order of events for the evolution of an island to atoll?
a. subsidence and upward reef growth Emmy: rapid extrusion of lava; continued subsidence (fringing reef becomes barrier reef)
b. subsidence (fringing reef becomes barrier reef); continued its subsidence and upward reef growth; rapid extrusion of lava
c. substance and upward reef growth; continued subsidence (fringing reef becomes barrier reef); rapid extrusion of lava
d. rapid extrusion of lava; subsidence (fringing reef becomes barrier reef); continued subsidence and upward reef growth
d. rapid extrusion of lava; subsidence (fringing reef becomes barrier reef); continued subsidence and upward reef growth
A draft bottle is tossed into the ocean off the coast of Peru. Three years later the bottle is recovered on a beach in Northern California. describe the most likely path of the bottle from Peru to California, assuming it to have been transported solely by the ocean surface currents.
Peru current; South equatorial current; North equatorial current; Kuroshio Current; North Pacific current; California current
Surface ocean waves receive their energy from winds that blow across the water surface
true or false
True
Where are the highest ocean surface salinities found?
In areas where evaporation is greater than precipitation
What is the rising of cold water from deeper layers (to replace warmer surface water) known as?
Upwelling
What would a ship feel if a tsunami passed beneath it in the open ocean?
Nothing
The Coriolis effect causes all moving bodies to be deflected to the right in the southern hemisphere and to the left in the northern hemisphere
true or false
False
What are currents within the surface on the follow parallel to the shore known as?
Longshore currents
Estuaries occur where fresh and salt water mix in the coastal environment
true or false
True
Plants and animals living in the uppermost water of the ocean occupy which zone?
The pelagic zone
El Niño occurs every few years on the tradewinds and their associated currents weaken or even reverse
true or false
True
Tsunami is a waterway that is generated by strong winds
true or false
False
Deep ocean circulation is driving by variations in water temperature and salinity. What is this called?
Thermohaline circulation
About how long has earth had liquid water on a surface?
4 billion years
One of the most important contributions of the ocean to the Earth system is its moderating influence on climate
true or false
True
where is the lowest ocean surface salinity found?
In areas where there is a lot of sea ice melt
What causes a wave approaching the beach at an angle to break parallel to the beach?
Refraction
Explain the differences in winter temperatures at the same latitudes along the Atlantic boundaries of England and Canada
England receives cold air from the north in Canada receives warm air from the sales according to the north Atlantic gyre
How much of Earth’s surface is a covered by seawater?
70.8%
Most of the water is contained in three interconnected basins, what are they?
Pacific, Atlantic, and Indian oceans
What is the greatest ocean depth?
The greatest ocean depths is Mariana trench reaching nearly 11,000 m
How long has earth had liquid water on its surface?
4 billion years
How old is the ocean?
4.4 billion years old
What is the theory on where water came from?
While uncertain, there are two theories:
carbonaceous chondrites: contain water as hydrous minerals, suggesting some water originated from accretion and volcanic steam
Icy comets: bombarded early earth, bringing with them frozen water
Salinity of ocean water is related to latitude, but also:
- Evaporation
- precipitation of rain and snow
- in flow of fresh river water
- freezing of sea ice
The ocean has three major depth zones, what are they?
Surface zone: 100 to 500 m
Thermocline, Halocline, or Pynocline
Deep Zone: contains 80% of ocean water
Which zone do plants and animals live in?
Plants and animals living in the uppermost water occupy the pelagic zone.
Benthonic organisms live on or within the bottom sediment
Define surface ocean currents
Broad, slow drifts of surface water caused by friction between the ocean and air flowing over it
- 50 to 100 m deep
- solar radiation provides heat energy, nonuniform heating generates winds, which drive the movement of surface ocean water
Ocean current directionIs influenced by ____ ___________ ______
The Coriolis force
What is the NADW?
North Atlantic Deep Water (NADW) originates at the surface of the North Atlantic, flows downward and spread southward to the South Atlantic.
Flowing beneath this is the colder, denser and Antarctic Bottom Water (AABW)
the sinking of dense, cold, saline surface water propels a global thermohaline circulation system.
Where to surface waves receive their energy from?
wind
What is the size of a wave determined by?
Windspeed, duration, and fetch (distance)
What are important dimensions of waves?
The height (from crest to trough)
and wavelength (from crest to crest or crest to trough)
what is a tsunami?
A seismic sea wave generated by sudden movements on the seafloor such as:
an earthquake
submarine or coastal landslide
large volcanic eruption
Five characteristics of a tsunami
- Travels at speeds up to 950 km/h
- wavelengths measured in kilometres
- height is only 1 to 2 m
- periodicity can be 20 min to 1 hr
- as the crest moves on shore, water can pile up rapidly to a height of 30 m and travel great distances inland, as the trough moves on shore, it causes drawdown
What are ocean tides?
Rhythmic, twice-daily rise and fall of ocean water along coastlines that are caused by gravitational attraction between the earth and the moon, and to a lesser extent, the sun
What is submergence?
The rise of water level relative to the land
What is emergence?
A lowering of water level relative to the land
What are cycles of emergence and submergence related to
Cycles of emergence and submergence are related to the buildup and decay of vast Ice Age glaciers systems
