Oceanoraphy final

Sigma-t is the oceanographers short-hand for the density of seawater. It is defined as (density -1.0)*10^3. If the density of seawater is 1.02925g/cm3 the sigma-t value is

29.25

On December 15th, which of the following locations will receive the highest value of solar radiation?

30° S

Earth's age is estimated at ______ years

4.6*10^9

If a surface water wave has a wavelength of 200m and a 5 second period, its speed is ____

4000 cm/sec

How many calories must be removed from 5g of pure water at 10°C to convert the water to ice

450

If a sound pulse is sent vertically downward into the sea and its reflected echo from the seafloor returns 6 seconds later, the depth of the water is ____ meters

4500

Lithogenous sediment is

Derived from rocks

Which ocean basin is the deepest on average?

Pacific

During the Northern Hemisphere's summer solstice, the sun stand above

23 1/2° N

Seafloor spreading is continuing at a rate of approximatley

1 to 10 cm/year

The Big Bang occured roughly _________ years ago

13 billion

A water wave reaches an unstable breaking point when the steepness ratio, H/L reaches

1:7

Which cirlce of latitude or longitude has the smallest circumfrance?

80°S

The average movement of all water affected by the wind is ___ degrees to the ___ of the wind motion in the Southern Hemisphere.

90; left

Approximately what percentage of water on Earth is contained within the oceans?

97%

The mechanism causing lithospheric plates to move is thouhgt to be ____

A combination of convection in the mantle and "slab pull" caused by subducting lithosphere

The arguement of the hydrogen and oxygen atoms in a water molucue that causes the water molecule to

Be polar

The _____ wavelengths of light penetrate deepest into the ocean

Blue

The pH of seawater is regulated by

Carbon Dioxide

Water heated from below distributes the added heat by ______, whereas the still surface of water heated from above distributes the added heat by ____

Convection; Diffusion and conclusion

Volcanic activity occurs at all of the following except

Convergent boundaries between two continental plates

Which of the following is least likely to be a major comonent of marine sediments

Cosmogenous materials

The south pole is tilted toward the sun on what day?

December Solstice

The particle size of terrigenous sediments generally

Decreases

Thermohaline circulation is driven by changes in ___

Density

The sediments of the central deep-ocean basins of the North Pacific are formed chielfy from

Diatoms

The silica rich oozes of the Pacific Ocean are due to ______ at high latitudes and ____ at low latitudes

Diatoms, radiolarians

Water particle orbits for a shallow water wave are ____

Elliptic and faltten with depth

Antarctic bottom water has a very narrow range of both salinity and temperature; this water is nearly homogenous

False

Deep Earthquakes (below 100km or 60mi) are usually associated with oceanic ridges

False

Downwelling is produced by diverging surface currents

False

Earth's inner core is liquid whereas its outer core is solid

False

Passive continental margins are commonly associated with volcanic and earthquake activity

False

Red mud or brown clay deposits are found under oceanic regions of high biological productivity

False

The edge of an active continental margin bordered by a deep-sea trench is wide and shallow with deep deposits of land-derived sediments

False

The highly productive seas along the equator are the result of the tropical convergence located there

False

The steeper profile of Mid-Atlantic Ridge compared to the East Pacific Rise indicates that the Mid-Atlantic Ridge is the faster spreading center

False

The restoring force of a fully developed wind wave is____

Gravity

A water type having both high salinity and warm temperature but dense enough to be found at 1000m in the central North Atlantic has been formed ___

In the Red Sea

The density of Earth materials_____ as the core is approached

Increases

Waves occuring at the interface between layers of seawater and fresh water are called ____

Internal waves

The speed of a shallow water wave varies with ____

Its amplitude

A program of deep-sea drilling for cores from the ocean's bottom is carried out by the

JOIDES Resolution

When waves arrive at moinitoring stations set up long distances from a storm center, which waves arrive first

Long period waves

A storm tide is due to the ____

Low atmospheric pressure at a storm's center and strong winds creating a surface flow toawrd the shore

Hurricanes derive their energy from ___ preasure zones in the ___

Low; tropical

The deepest depth of the oceans is located in which trench?

Mariana

Gas hydrates are rich in

Methane

Trace elements in seawater are ______

Necessary for many marine life forms

Which of the following are found along subduction zones?

Oceanic trenches, Island arc systems, active earthquake zones

A local shore wind controlled only by daily temperature variation between land and water will blow ______ during the night

Offshore

The refraction of waves tends to concentrate wave energy _____ and disperse energy _____

On headlands; in bays

The ocean's oldest sediments are found

On top of the baslat layer, far from spreading centers

The orbital motion of a deep water wave extends to a depth equal to ___

One half the wavelength

During the Indian wet monsoon, the prevailing winds blow ____ in the ____

Onshore; summer

The concentration of carbon dioxide in surface water is low, whereas the concentration of oxygen is high becuase of the ______

Photosynthesis process

The coriolis effect deflects objects in the Northern Hemisphere to the ___ relative to their direction of motion

Right

Water transported shoreward in the surf zone is returned seaward by _____

Rip currents

The Coriolis effect arises primarily from the ____

Rotation of Earth around its axis

The seabed is presently being mined in the US for

Sand and gravel

Which processes cause surface seawater to increase in density

Sea ice formation and surface water evaporation

Extreme variation in the ocean's temperature is prevented by seawater's _____

Specific heat

The average wave energy of a wave is related to the square of its ____

Speed

Layering in the ocean occurs because___

Surface processes form water layers of differing combintions of salinity and temperature and atmospheric processes control conditions at the surface

Which of the following is NOT an example of a hydrogenous sediment

Tektities

If extremely cold fresh water is added on top of seawater, ____

The cold water will float at the surface

A rapid change in temperature with depth is called a ___

Thermocline

Plates move horizontally past each other along _____

Transform faults

Which latitudinal area tends to have the highest average surface salinity

Tropics (25°-30°)

Calcareous oozes of the open ocean are associated with midocean ridge and rise systems rather than the deep-ocean basin floor

True

Large particles sink faster than small particles of the same density

True

Oceanic-type crust is more dense than continental-type crust

True

Particles of a well-sorted sediment sample fall within a limited size range

True

Satelite radar alimeters measure sea surface topography

True

Shear waves do not pass through a solid-liquid boundary between Earth's layers. Comrpressional waves can pass through this type of boundary

True

Submarine canyons are features associated principally witht he continental slope; some are associated with past or present rivers

True

The flat-topped seamounts called guyouts found with their tops 1800m below the surface were flattened by erosion at the sea surface

True

Upwelling occurs along the coast of California when winds blow from the north

True

Usually temperature, salinity, and pressure distribution cause ocean water density to increase with depth

True

In a closed basin a single-node standing wave oscillation tends to have a wavelength that is ____ the basin length

Twice

Which phase change reaction requires the most energy?

Vaporization

Wave height of wind waves depends on

Windspeed and duration

The thermocline found in water above 500m at temperature latitudes disappears and the water column becomes neutral in

Winter

Determination of latitude requires that tim be kept very accuratley

false

On average the water in a river will have a longer residence time than water in the oceans

false

The residence time of water in the atmosphere equal to the residence time of water in the oceans

false

The coldest, deepest, densest water in the ocean

is Antarctic bottom water, formed around Antarctica, and flows north

Clouds _____ radiation

radiate longwave, intercept longwave, reflect longwave, absorb longwave

The residence time for water in any of Earth's principal reservoirs can be calculated by dividing______

reservoir volume by rate of water supply

Turbidity currents produce some

submarine cannons

Inactive volcanic seamounts on top of oceanic crusts will

subside with time

Changes in water density in the oceans create ____

the sofar channel, light refraction, sound shadows

Is radiometric dating based on rate at which a radioactive isotype decays

true

There is more land located in the Northern Hemisphere than in the Southern Hemisphere

true

When crossing the international dateline from east to west, the date increaes y by one day

true