The Hydrological Cycle and World Waters

Comprehensive vocabulary flashcards covering the hydrological cycle, oceanography, inland water systems, and water resource management.

Hydrological Cycle

The continuous movement of water on, above, and below the surface of the Earth, functioning as a closed system where the total amount of water remains constant.

Solar Energy

A main driver of the hydrological cycle that provides the heat necessary for evaporation.

Transpiration

The process by which plants release water vapor through their leaves.

Infiltration & Percolation

Processes where water soaks into the soil and moves down into aquifers.

Global Water Distribution (Saltwater)

Approximately $97.5\%$ of the Earth's water, found in oceans.

Freshwater Distribution

Approximately $2.5\%$ of Earth's water, mostly stored in glaciers and ice caps, with less than $1\%$ being accessible.

World Ocean

A continuous body of saltwater that covers approximately $71\%$ of the Earth's surface.

Pacific Ocean

The largest and deepest ocean, featuring the Mariana Trench.

Marginal Seas

Seas located at the edges of continents, such as the North Sea.

Inland (Mediterranean) Seas

Seas almost entirely surrounded by land, such as the Red Sea or Mediterranean Sea.

Salinity

The total amount of dissolved salts in seawater, measured in parts per thousand (\text{\textperthousand}), with a global average of 35\text{\textperthousand}.

Thermocline

A vertical ocean layer where temperature drops rapidly with depth.

Thermohaline Circulation

The global conveyor belt driven by differences in water density, which is determined by temperature and salinity.

Seawater Freezing Point

Because of salt content, seawater freezes at approximately $-1.9\,^\circ\text{C}$ rather than $0\,^\circ\text{C}$.

Tsunami

A special type of wave with long wavelengths caused by underwater earthquakes, volcanic eruptions, or landslides.

Tides

The periodic rise and fall of sea levels caused by the gravitational pull of the Moon and the Sun.

Coriolis Effect

The deflection force caused by Earth's rotation that helps drive surface currents.

Phytoplankton

Marine organisms that produce $50\%$ to $80\%$ of the Earth's oxygen through photosynthesis.

Carbon Sink

The ocean's role in absorbing about $25\%$ of the carbon dioxide ($CO_2$) produced by human activities.

River Basin (Povodie)

The total area drained by a river and its tributaries.

Watershed / Drainage Divide

The boundary, usually a mountain ridge, separating two river basins.

Tectonic Lakes

Lakes formed in crustal rifts or faults, such as Lake Baikal or the African Great Lakes.

Oxbow Lakes (M\u0155tve ramen\u00e1)

U-shaped bodies of water formed when a wide meander from the main stem of a river is cut off.

Continental Glaciers

Massive ice masses covering more than $50,000\,km^2$, currently found in Antarctica and Greenland.

Ablation

The loss of ice from a glacier through melting or calving into the sea.

Aquifer

An underground body of permeable rock, like sand or gravel, that can contain or transmit groundwater.

Water Table

The boundary between the unsaturated zone (zone of aeration) and the saturated zone where all pores are filled with water.

Artesian Water

Groundwater trapped under pressure between two impermeable layers that rises to the surface without pumping when drilled.

Desalination

The process of converting seawater into drinking water by removing salt, commonly used in arid regions like the Middle East.

Water Protection Zones

Strictly limited areas around water sources where construction, farming, or chemical use is restricted to ensure clean water supply.