Hydrosphere

Hydrosphere refers to that portion of Earth that is composed of water . The hydrosphere represents one component of Earth's system, operating in conjunction with the solid crust (lithosphere ) and the air that envelopes the planet (atmosphere). The derivation of the term hydrosphere, from the Greek words for water and ball, is truly descriptive of our world, as it reflects the abundance and importance of water on Earth.

On Earth, water exists in the three primary states of matter ; liquid, solid, and gas. The distance of Earth from the Sun , by fortunate coincidence, is such that the amount of energy arriving at the surface of most of the planet is sufficient to elevate the ambient temperature to levels above the freezing point of water, yet insufficient to cause all of the water to evaporate into the gaseous state. The capacity of water to store large quantities of heat energy heavily influences the nature of the global climate . The presence of large bodies of liquid water and the atmosphere restrict the range of temperature fluctuations on Earth. These conditions have allowed the existence of the fourth component of Earth's system, the biosphere .

Water is constantly being cycled through its various manifestations and through the components of Earth's systems by means of the hydrologic cycle . Driven by solar energy, water is evaporated from the ocean surface and distributed over the earth as water vapor. Precipitation returns the water, in liquid and solid forms, to other parts of the globe. Throughout the cycle, water may exist in a number of forms, interact with the atmosphere and lithosphere, or may be utilized by organisms within the biosphere.

One commonly cited statistic asserts that 71% of the surface area of our planet is covered by water, with the largest part covered by oceans. The total volume of sea-water, amounting to 97.2% of all the water on the planet, is 295,000,000 mi3 (1,230,000,000 km3). Usable freshwater constitutes less than 0.5% of all water on Earth. Water in all rivers , lakes and streams totals only 29,800 mi3 (124,200 km3). The amount of groundwater that is within 0.5 mi (0.8 km) of the surface is 960,000 mi3 (4,000,000 km3). Water also exists on Earth in the solid form as icecaps and glaciers , occupying a volume of 6,900,000 mi3 (28,600,000 km3). Straddling the division between hydrosphere and atmosphere is water vapor. A volume of 3,000 mi3 (12,700 km3) of water can be found in the atmosphere.

Hydrosphere

Hydrosphere refers to that portion of Earth that is composed of water. The operates in conjunction with the solid crust (lithosphere) and the air that envelopes the planet (atmosphere). The derivation of the term hydrosphere is from the Greek words for water and ball.

Water exists in the three primary states: liquid, solid, and gas. On Earth, the ambient temperature and pressure allows for water to exist in all three of these states and these state changes are important to the cycling of water throughout the hydrosphere. The capacity of water to store large quantities of heat energy, or its high specific heat capacity, heavily influences the global climate. The presence of large bodies of liquid water and water vapor in the atmosphere restrict the range of temperature fluctuations on Earth.

Water is constantly being cycled through its various states by means of the hydrologic cycle. Driven by solar energy, water is evaporated from the surfaces of oceans, lakes and rivers and redistributed around Earth as water vapor. Precipitation returns the water, in liquid and solid forms, to other parts of the planet. In the process, water may interact with the atmosphere and lithosphere, or may be utilized by organisms within the biosphere.

Approximately 70% of the surface area of Earth is covered by water, with the largest part covered by oceans. The total volume of seawater, amounting to 97.2% of all the water on the planet, is 295,000,000 mi³ (1,230,000,000 km³). Usable freshwater constitutes less than 0.5% of all water on Earth. Water in all rivers, lakes and streams totals 29,800 mi³ (124,200 km³). The amount of groundwater that is within 0.5 mi (0.8 km) of the surface is 960,000 mi³ (4,000,000 km³). Water also exists on Earth in the solid form as icecaps and glaciers, occupying a volume of 6,900,000 mi³ (28,600,000 km³). Water vapor in the atmosphere occupies a volume of 3,000 mi³ (12,700 km³).

hydrosphere The water on the surface of the earth. Some 74% of the earth's surface is covered with water, 97% (or some 10²¹ kilograms) of which is in the oceans. Icecaps and glaciers contain about 3 × 10¹⁹ kg, rivers about 10¹⁵ kg, lakes and inland seas about 2 × 10¹⁷ kg, and groundwater (down to 4000 metres) about 8 × 10¹⁹ kg. Water in the atmosphere contains only about 10¹⁶ kg.

hy·dro·sphere / ˈhīdrəˌsfir/ • n. (usu. the hydrosphere) all the waters on the earth's surface, such as lakes and seas, and sometimes including water over the earth's surface, such as clouds.

hydrosphere The whole of that body of water which exists on or close to the surface of the Earth. The hydrosphere formed as the Earth cooled and atmospheric water condensed.