A spring may be the result of karst topography where surface water
has infiltrated the Earth's surface (recharge area), becoming part
of the area groundwater. The groundwater then travels though a
network of cracks and fissures - openings ranging from
intergranular spaces to large caves. The water eventually emerges
from below the surface, in the form of a spring.
The forcing of the spring to the surface can be the result of a
confined aquifer in which the recharge area of the spring water
table rests at a higher elevation than that of the outlet. Spring
water forced to the surface by elevated sources are artesian wells.
This is possible even if the outlet is in the form of a 300-foot
deep cave. In this case the cave is used like a hose by the higher
elevated recharge area of groundwater to exit through the lower
elevation opening.
Non-artesian springs may simply flow from a higher elevation
through the earth to a lower elevation and exit in the form of a
spring, using the ground like a drainage pipe.
Still other springs are the result of pressure from an
underground source in the earth, in the form of volcanic activity.
The result can be water at elevated temperature such as a hot
spring.
Types of spring outlets
- Seepage or filtration spring. The term seep refers to springs
with small flow rates in which the source water has filtered into
permeable earth.
- Fracture springs, discharge from faults, joints, or fissures in
the earth, in which springs have followed a natural course of voids
or weaknesses in the bedrock.
- Tubular springs are essentially water dissolved and create
underground channels, basically cave systems.
Spring flow
Spring discharge, or resurgence, is determined by the "spring's"
recharge basin. Factors include the size of the area in which
groundwater is captured, the amount of precipitation, the size of
capture points, and the size of the spring outlet. Water may leak
into the underground system from many sources including permeable
earth, sinkholes, and losing streams. In some cases entire creeks
seemingly disappear as the water sinks into the ground via the
stream bed. Grand Gulf State Park in Missouri is an example of an
entire creek vanishing into the groundwater system. The water
emerges nine miles away, forming some of the discharge of Mammoth
Spring in Arkansas.
Classifications
Springs are often classified by the volume of the water they
discharge. The largest springs are called "first-magnitude,"
defined as springs that discharge water at a rate of at least 2800
liters or 100 cubic feet (2.8 m3) of water per second. Some
locations contain many first-magnitude springs, such as Central
Florida where there are 33[2] known to be that size, the southern
Missouri Ozarks (11 known of first-magnitude), and 11[3] more in
the Thousand Springs area along the Snake River in Idaho. The scale
for spring flow is as follows: 10 to 100 ft³/s
| Magnitude |
Flow (ft³/s, gal/min, pint/min) |
Flow (L/s) |
| 1st Magnitude |
> 100 ft³/s |
2800 L/s |
| 2nd Magnitude |
280 to 2800 L/s |
| 3rd Magnitude |
1 to 10 ft³/s |
28 to 280 L/s |
| 4th Magnitude |
100 US gal/min to 1 ft³/s (448 US gal/min) |
6.3 to 28 L/s |
| 5th Magnitude |
10 to 100 gal/min |
0.63 to 6.3 L/s |
| 6th Magnitude |
1 to 10 gal/min |
63 to 630 mL/s |
| 7th Magnitude |
1 pint to 1 gal/min |
8 to 63 mL/s |
| 8th Magnitude |
Less than 1 pint/min |
8 mL/s |
| 0 Magnitude |
no flow (sites of past/historic flow) |
To get credit
for this Earth Cache please follow TheBisch's EarthCache
Instructions (found at the bottom of this page) and answer the
questions below.
1) What type
of spring outlet is this?
2) What is the magntitude of the spring's flow?
3) How many rocks form the very top of the spring's basin?
Thanks for
playing one of TheBisch's EarthCaches. In order to be fair to
everyone, I place the same requirements on all my EarthCaches.
Basically I want you to prove that you were there on the day that
you posted your log. No armchair logging or "backlogging" (logging
my Earthcache when you visited a previous cache at the same spot)
is allowed.
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answer them CORRECTLY by sending me a message through
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little more lenient with your answers. Consider the photo like
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