____ km3 of water is returned to the sea by run-off from the land.
the __ ___ is the process by which water travels in a sequence from the air to Earth and returns to the atmosphere.
____ ____ is the driving force behind the water cycle
____ sets the water cycle in motion
During ____, precipitation is absorbed by vegetation, dead organic matter on the ground, and urban structures and streets.
Precipitation moves into the ground through ____.
During heavy rains when the soil is saturated, excess water flows across the surface of the ground as ___ ___.
Some water entering the soil seeps down to an impervious layer of clay or rock to collect as ______.
___ is the evaporation of water from internal surfaces of leaves, stems, and other living parts.
The total amount of evaporating water from the surfaces of the ground and vegetation is called ____.
High plains ogallala aquifer
The ___ ___ ___ ___ underlies an area of approximately 174,000 square miles that extends through 8 states. It is the principal source of water in one of the major agricultural regions of the US.
water has polar ____ bonds.
When hydrogen atoms act as connecting links between water molecules, ____ ___ occurs.
___ ___ is the number of calories necessary to raise 1 gram of water 1 degree Celsius. The value of water is 1.
The energy released or absorbed in transforming water from one state to another is called ___ ____.
Due to H bonding, water molecules tend to stick firmly to each other, resisting external forces that break these bonds. This property is called ____.
Water molecules on the surface are drawn downward, resulting in a surface that is taut like an inflated balloon. This condition is called ___ __ and is important in the lives of aquatic organisms.
___ is the property of a material that measures the force necessary to separate the molecules and allow an object to pass through the liquid. It is the source of frictional resistance to objects moving through water.
The density of water is about ___ times greater than that of air.
If a body submerged in water weighs less than the water it displaces, if is subjected to an upward forced called ___.
pressure increases 1 atm for each __ m in depth.
___ leads to constraints on movement and a need for streamlined creatures.
The region of the vertical depth profile where the temperature declines most rapidly is called the ____. Its depth depends on the input of solar radiation to the surface waters and on the degree of vertical mixing.
The thermocline is located between an upper layer of warm, lighter (less dense) water called the ____ and a deeper layer of cold, dense water called the ____.
Compounds that consist of electrically charged atoms or groups of atoms are called ____.
practical salinity units
Determination of the most abundant element, chlorine, is used as an index of salinity, which is expressed in ___ ___ ___ represented as 0/00 and measured as grams of chlorine per kilogram of water.
___ is the general tendency of molecules to move from a region of high concentration to one of lower concentration.
The solubility of a gas (O2) in water ___ as the temperature of the water increases.
Solubility of a gas ___ as atmospheric pressure increases.
Solubility of a gas ____ as salinity increases, which is not significant in freshwater.
gases diffuse ___ times slower in water than in air.
Water eliminates most red light in __ meters depth. More than half of blue light makes it to ___ meters.
___ is a limiting factor for aquatic life. It determines where and which species of organisms can live in each body of water. Amount of this dissolved increases as water temperature increases.
The abundance of H ions in solution is a measure of ___.
__ solutions are those that have a large # of OH- and few H+ ions.
When deep-water currents meet in the equatorial waters of the ocean, they form a region of ____ where the deep waters move up to the surface, closing the pattern of ocean circulation. This provides oxygen and nutrients to life in the photic zone.
Dissolved __ buffers pH change in water
Na+ and Cl- form about __% of sea salt.
The are lying between the water lines of high and low tide, referred to as the ___ ____, is an environment of extremes. It undergoes dramatic shifts in environmental conditions with the daily patterns of inundation and exposure. Tides strongly affect life in these areas.
salinity ___ as depth increases
The place where freshwater joins and mixes with the saltwater is called an ___.
The seawater on the surface tends to to sink as lighter freshwater rises, and mixing takes place from the surface to the bottom. The phenomenon is called ____ ____.