eTextbook: Oceanography: An Invitation to Marine Science - Ebooks

Approximately what percentage of the Earth's surface is covered by the world ocean?

Approximately $71\%$.

What percentage of the Earth's surface water is contained within the ocean?

Approximately $97\%$, with the remaining $3\%$ found in ice, groundwater, and lakes.

What is the average depth of the world's ocean?

Approximately $3,700\,meters$ ($12,100\,feet$).

What is the scientific theory that describes the large-scale motion of the Earth's lithosphere?

Plate Tectonics.

What geological feature is typically created at a divergent plate boundary on the seafloor?

A mid-ocean ridge.

What process occurs at a convergent boundary where one tectonic plate is forced down into the mantle?

Subduction.

What is the average salinity of seawater expressed in parts per thousand?

$35\,ppt$ (parts per thousand) or $35\,g/kg$.

What is the term for the ocean layer where water density increases rapidly with depth?

Pycnocline.

What is the term for the ocean layer where temperature degrees decrease rapidly with depth?

Thermocline.

What is the term for the ocean layer where salinity changes rapidly with depth?

Halocline.

In which direction does the Coriolis effect deflect moving objects in the Northern Hemisphere?

To the right.

What is the primary driving force for surface ocean currents?

Wind.

What global-scale ocean circulation system is driven by differences in density, temperature, and salinity?

Thermohaline circulation.

What type of tide occurs when the sun, moon, and Earth are in a straight line, resulting in the highest tidal range?

Spring tide.

What type of tide occurs when the moon and sun are at right angles to the Earth, resulting in the lowest tidal range?

Neap tide.

What is the name of the upper layer of the ocean where there is sufficient light for photosynthesis?

The photic zone.

What term refers to the microscopic, photosynthetic organisms that form the base of the marine food web?

Phytoplankton.