A spring is a place where water moving underground finds an opening to the land surface and emerges, sometimes as just a trickle, maybe only after a rain, and sometimes in a continuous flow. Spring water can also emerge from heated rock underground, giving rise to hot springs.
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Water cycle components » Atmosphere · Condensation · Evaporation · Evapotranspiration · Freshwater lakes and rivers · Groundwater flow · Groundwater storage · Ice and snow · Infiltration · Oceans · Precipitation · Snowmelt · Springs · Streamflow · Sublimation · Surface runoff
What is a spring?
A spring is a water resource formed when the side of a hill, a valley bottom, a lakebed, or other excavation intersects groundwater at or below the local water table, below which the subsurface material is saturated with water. A spring occurs when an aquifer fills to the point where groundwater spills out into a lake or river or onto the land surface. They range in size from intermittent seeps, which flow only after much rain, to huge pools flowing hundreds of millions of gallons daily.
Springs are not limited to the Earth's surface, though. Recently, scientists have discovered hot springs at depths of up to 2.5 kilometers in the oceans, generally along mid-ocean rifts (spreading ridges). The hot water (over 300 degrees Celsius) coming from these springs is also rich in minerals and sulfur, which results in a unique ecosystem where unusual and exotic sea life seems to thrive.
How are springs formed?
Springs may be formed in any sort of rock. Large springs are rare but small ones are found in many different places. In Missouri, the largest springs are formed in limestone and dolomite, two types of rock found in the karst topography of the Ozarks, a mountain range in the southern-central US. Both dolomite and limestone fracture relatively easily. When weak carbonic acid (formed by rainwater percolating through organic matter in the soil) enters these fractures it dissolves bedrock. When it reaches a horizontal crack or a layer of non-dissolving rock such as sandstone or shale, it begins to cut sideways. As the process continues, the water hollows out more rock, eventually admitting an airspace, at which point the spring stream can be considered a cave. This process often takes tens to hundreds of thousands of years to complete.
Springs can also form in other landforms and other rock types, essentially anywhere that the water table intersects land surface and where water can flow more easily than elsewhere.
Water flow from springs
The amount of water that flows from springs depends on many factors, including the size of the sand or gravel or fissures or caverns within the rocks, the water pressure in the aquifer, the size of the area providing water to the spring, and the amount of rainfall. Human activities also can influence the volume of water that discharges from a spring. Groundwater withdrawals near a spring can cause water levels in the aquifer to drop, ultimately decreasing the flow from the spring. Most people probably think of a spring as being like a pool of water—and sometimes that is the case. But springs can occur when geologic, hydrologic, or human forces cut into the underground layers of soil and rock through which groundwater is flowing.
Spring water is not always clear
Water from springs usually is remarkably clear. Water from some springs, however, may be "tea-colored." This picture shows a natural spring in southwestern Colorado. Its red iron coloring and metals enrichment are caused by groundwater coming in contact with naturally occurring minerals present as a result of ancient volcanic activity in the area.
In Florida, many surface waters contain natural tannic acids from organic material in subsurface rocks, and the color from these streams can appear in springs. If surface water enters the aquifer near a spring, the tannin-stained water can move quickly through the aquifer and discharge at the spring vent.
This water is cold and clear—is it fit to drink?
Credit: Briant A Kimball
The quality of the water in the local groundwater system will generally determine the quality of spring water. The quality of water discharged by springs can vary greatly because of several factors, including the quality of the water that recharges the aquifer that supplies the spring, the type of rocks through which groundwater flows and is in contact, the time for water to flow between aquifer recharge and spring discharge. The rate of flow and the length of the flowpath through the aquifer affects the amount of time the water is in contact with the rock, and thus, the amount of minerals that the water can dissolve.
So, should you feel confident about whipping out your canteen and filling it with cool and refreshing spring water? No, you should be cautious. Water from some springs is very old and of excellent drinking quality, whereas water issuing from other springs may have microorganisms, viruses, bacteria, toxic algae, and other toxic chemicals that could make you very sick.
Thermal springs
Credit: Wikipedia
Thermal springs are ordinary springs except that the water is warm and, in some places, hot, such as in the bubbling mud springs in Yellowstone National Park, Wyoming. Many thermal springs occur in regions of recent volcanic activity and are fed by water heated by contact with hot rocks far below the surface. Even where there has been no recent volcanic action, rocks become warmer with increasing depth. In such areas water may migrate slowly to considerable depth, warming as it descends through rocks deep in the Earth. If it then reaches a large crevice that offers a path of less resistance, it may rise more quickly than it descended. Water that does not have time to cool before it emerges forms a thermal spring. The famous Warm Springs of Georgia and Hot Springs of Arkansas are of this type.
Below are other science topics associated with the water cycle.
Streamflow and the Water Cycle
Groundwater Storage and the Water Cycle
Snowmelt Runoff and the Water Cycle
Groundwater Flow and the Water Cycle
Freshwater (Lakes and Rivers) and the Water Cycle
Ice, Snow, and Glaciers and the Water Cycle
Infiltration and the Water Cycle
Oceans and Seas and the Water Cycle
Springs and the Water Cycle
Surface Runoff and the Water Cycle
Precipitation and the Water Cycle
Evaporation and the Water Cycle
A spring is a place where water moving underground finds an opening to the land surface and emerges, sometimes as just a trickle, maybe only after a rain, and sometimes in a continuous flow. Spring water can also emerge from heated rock underground, giving rise to hot springs.
• Water Science School HOME • Groundwater topics • Surface Water topics • The Water Cycle •
Water cycle components » Atmosphere · Condensation · Evaporation · Evapotranspiration · Freshwater lakes and rivers · Groundwater flow · Groundwater storage · Ice and snow · Infiltration · Oceans · Precipitation · Snowmelt · Springs · Streamflow · Sublimation · Surface runoff
What is a spring?
A spring is a water resource formed when the side of a hill, a valley bottom, a lakebed, or other excavation intersects groundwater at or below the local water table, below which the subsurface material is saturated with water. A spring occurs when an aquifer fills to the point where groundwater spills out into a lake or river or onto the land surface. They range in size from intermittent seeps, which flow only after much rain, to huge pools flowing hundreds of millions of gallons daily.
Springs are not limited to the Earth's surface, though. Recently, scientists have discovered hot springs at depths of up to 2.5 kilometers in the oceans, generally along mid-ocean rifts (spreading ridges). The hot water (over 300 degrees Celsius) coming from these springs is also rich in minerals and sulfur, which results in a unique ecosystem where unusual and exotic sea life seems to thrive.
How are springs formed?
Springs may be formed in any sort of rock. Large springs are rare but small ones are found in many different places. In Missouri, the largest springs are formed in limestone and dolomite, two types of rock found in the karst topography of the Ozarks, a mountain range in the southern-central US. Both dolomite and limestone fracture relatively easily. When weak carbonic acid (formed by rainwater percolating through organic matter in the soil) enters these fractures it dissolves bedrock. When it reaches a horizontal crack or a layer of non-dissolving rock such as sandstone or shale, it begins to cut sideways. As the process continues, the water hollows out more rock, eventually admitting an airspace, at which point the spring stream can be considered a cave. This process often takes tens to hundreds of thousands of years to complete.
Springs can also form in other landforms and other rock types, essentially anywhere that the water table intersects land surface and where water can flow more easily than elsewhere.
Water flow from springs
The amount of water that flows from springs depends on many factors, including the size of the sand or gravel or fissures or caverns within the rocks, the water pressure in the aquifer, the size of the area providing water to the spring, and the amount of rainfall. Human activities also can influence the volume of water that discharges from a spring. Groundwater withdrawals near a spring can cause water levels in the aquifer to drop, ultimately decreasing the flow from the spring. Most people probably think of a spring as being like a pool of water—and sometimes that is the case. But springs can occur when geologic, hydrologic, or human forces cut into the underground layers of soil and rock through which groundwater is flowing.
Spring water is not always clear
Water from springs usually is remarkably clear. Water from some springs, however, may be "tea-colored." This picture shows a natural spring in southwestern Colorado. Its red iron coloring and metals enrichment are caused by groundwater coming in contact with naturally occurring minerals present as a result of ancient volcanic activity in the area.
In Florida, many surface waters contain natural tannic acids from organic material in subsurface rocks, and the color from these streams can appear in springs. If surface water enters the aquifer near a spring, the tannin-stained water can move quickly through the aquifer and discharge at the spring vent.
This water is cold and clear—is it fit to drink?
Credit: Briant A Kimball
The quality of the water in the local groundwater system will generally determine the quality of spring water. The quality of water discharged by springs can vary greatly because of several factors, including the quality of the water that recharges the aquifer that supplies the spring, the type of rocks through which groundwater flows and is in contact, the time for water to flow between aquifer recharge and spring discharge. The rate of flow and the length of the flowpath through the aquifer affects the amount of time the water is in contact with the rock, and thus, the amount of minerals that the water can dissolve.
So, should you feel confident about whipping out your canteen and filling it with cool and refreshing spring water? No, you should be cautious. Water from some springs is very old and of excellent drinking quality, whereas water issuing from other springs may have microorganisms, viruses, bacteria, toxic algae, and other toxic chemicals that could make you very sick.
Thermal springs
Credit: Wikipedia
Thermal springs are ordinary springs except that the water is warm and, in some places, hot, such as in the bubbling mud springs in Yellowstone National Park, Wyoming. Many thermal springs occur in regions of recent volcanic activity and are fed by water heated by contact with hot rocks far below the surface. Even where there has been no recent volcanic action, rocks become warmer with increasing depth. In such areas water may migrate slowly to considerable depth, warming as it descends through rocks deep in the Earth. If it then reaches a large crevice that offers a path of less resistance, it may rise more quickly than it descended. Water that does not have time to cool before it emerges forms a thermal spring. The famous Warm Springs of Georgia and Hot Springs of Arkansas are of this type.
Below are other science topics associated with the water cycle.
Streamflow and the Water Cycle
Groundwater Storage and the Water Cycle
Snowmelt Runoff and the Water Cycle
Groundwater Flow and the Water Cycle
Freshwater (Lakes and Rivers) and the Water Cycle
Ice, Snow, and Glaciers and the Water Cycle
Infiltration and the Water Cycle
Oceans and Seas and the Water Cycle
Springs and the Water Cycle
Surface Runoff and the Water Cycle
Precipitation and the Water Cycle