It's called the water table. In simplistic and non-scientific terms, it occurs when rain water (or snow water that has melted and run downstream) has seeped into the soil ... but at a certain depth (dependant upon a couple factors like tide and water quantity) the pressure that helps it flow down evens out (or most often in my experience it hits soild bedrock it can't pour through first) so it sits (or flows in the case of an underground river) instead of seeping further downward. The height of the water table can vary to extremes - sometimes it can be so near the surface that it creates land instability, erosion and sinkage. Sometimes it is hundreds of feet down, and unreachable by anything by modern oil drills. During my stint as an archaeologist in New Jersey, the table usually was 3 to 6 feet depending on how near we were to a march or river.
"The earliest wells are known from the Neolithic. In the submerged Pre-Pottery Neolithic B settlement of Atlit Yam in Israel, dated to 8100-7500 BC, a well has been found, which so far is the oldest known. Other PPNB wells (7-8 m deep) are known from Kissonerga-Mylouthkia on Cyprus and maybe shallower examples from Shillourokambos as well."
I theorize that underground water was accidentally discovered because the water table in some regions of Israel are quite shallow (near the Jordan river and near the Sea of Galillee) so even though these regions were more savannah-like at that time (its now much greener due to horticultural irrigation) it would have been easily discovered the first time someone dug deeply (possibly for burial, building, cooking, waste removal, etc ...)
"Wood-lined wells are known from the early Neolithic Linearbandkeramic culture, for example in Kückhoven, dated 5090BC and Eythra), dated 5200BC in Germany and Schletz in Austria. The early Mesolithic site of Friesack in Germany has yielded a shallow pit with the remains of a birch-bark container that may have been a shallow artificial well as well.
From the Iron Age onwards, wells are common archaeological features, both with wooden shafts and shaft-linings made from wickerwork."
In some places, like the entire Yucatan region, the land is made of porous limestone which cannot withstand any overland water. All water that sustained the Mayan people was found in underground cenotes. "Australian Aborigines relied on wells to survive the harsh Australian desert. They would dig down, scooping out sand and mud to reach clean water, then cover the source with spinifex to prevent spoilation. White people call these native wells, soaks or soakages."
2007-01-05 03:41:37
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answer #1
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answered by afnurik 2
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I live in Florida, and we have a lot of wells here. This answer is colored by this fact.
Fresh water in the ground comes from rain. some of it is very recent, and some of it may bave been there for thousands of years.
Water is heavy, MUCH heavier than air. Dirt has spaces in it, filled with air. So does cracked rock or deposits of gravel or sand. Water settles in through the spaces, displacing air up- and water moves down. It continues down untill something stops it. Then it sits there and accumulates- it can also spread out sideways, until it finds a way to get out of the dirt back to the ocean again.
Here in Florida, thre are springs off the coast in the atlantic and particularly in the gulf, where fresh water wells up. This is where fresh water is spreading OUT and finding outlets from the porus limestone layer of the state's underbedding. Sailing ships in the early days wopuld stop there for a while and let it kill the worms borrowing into the hull- they need salt water to live. Buckets would be lowered to dip fresh water from larger spring upwells to replentish shipboard supply, avoiding the need to go ashore to find good water.
so if you dig deep enough, you will find a layer of water, unless there is a special geological condition. A VERY dry place will not have water unless you drill VERY deep- and settled areas are drawing away this water much faster than nature replaces it, so it gets deeper every year. This is a big problem in southwestern states. Also, this water tends to be OLD, and may be very strongly laced with dissolved minerals, which is a problem all by itself.
However, you can also drill so deep you go past the water and into solid rock- and there's no water there at all. When you dig a well, you have to test now and then to make sure you are in a good layer, not only for quality, but for QUANTITY.
In North America, it's very unusual to find a place with NO water. Even in stone mountian areas, there are cracks in the rock with water in them. If you drill down INTO such a crack, you have a well. Try not to drill past it however...
In Florida, shallow wells are so easy to drill it is almost a child's game. You could rent a backhoe and do it, or get industrious with a shovel and strike paymud. Almost everyone has agarden well, with a surface mounted electric pump for the garden. These can only pull water up effectively from about 20 foot deep. This is not a problem in sandy soil areas. ROCK areas demand drilling or driving with special points- and a lot of work. But there are seams in the rock, with gravel, sand, and WATER in them. And a deep rock well can be VERY pure and delicious water- or if there is water soluable ore, poisonous. TEST WELL WATER before drinking it. It can look clear as a bell, and be dangerous.
Hope this was not too much.
2007-01-06 17:15:34
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answer #2
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answered by Anonymous
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In most places the ground is like a sponge. Just dig anywhere and you will probably hit some water when you get to what is known as the "water table".
2007-01-05 03:18:05
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answer #3
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answered by Anonymous
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Jerry P answered how water percolates into the ground, creating aquifers.
There are also, spring fed sources, artisian wells & oases, which is one way people would realize digging could lead to water. By trial & error or experience, persons would know which soils, areas, etc. might yield water. Giving rise to professional well diggers, with or without the "dousing rods"!
2007-01-05 03:33:29
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answer #4
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answered by S. B. 6
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Water flows downhill. That means that it can percolate down through porous soild until it hits a non-porous base of bedrock, where it may pool or flow like a river through the ground. Large underground water supplies are referred to as aquifers.
http://en.wikipedia.org/wiki/Aquifer
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2007-01-05 03:18:20
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answer #5
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answered by Jerry P 6
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besides the fact of using comps,past info, map readouts,
people find the water in whats known as a aquafier
theses are large bodies of water right under neath you.
These provide a back up supply for living and non living things
the water comes from seeping water,precipitaion,plates moving and stuff
2007-01-05 03:21:08
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answer #6
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answered by Buddha Boy 2
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properly, you're able to desire to presume plenty right here first. i'm assuming the lining of the hollow is a few variety of UBER-Plexiglas to hold back the magma and tens of millions of pounds of rigidity from the encompassing Earth. That being the case, a stone drop from one part of the Earth could advance up till it reached the middle of the Earth (with calculus you're able to desire to absolutely verify the value it may be going -- maximum possibly terminal velocity). Then because it comes up the different section it may be decelerating. All different issues being equivalent, the stone could come out the different section, come to a end at shoulder-point, and then fall back in. it may oscillate between the planet surfaces. in case you made the hollow promptly alongside the lean axis of the planet, it may try this continually -- in any different case i could wager that the Coriolis result could make it hit the wall of the hollow at last. sounds like a funky experience in case you inquire from me.
2016-10-06 11:49:30
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answer #7
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answered by ? 4
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i comes from and aquifer (underground river), and I'm sure it was discoverd by accident, like many other great discoveries.
2007-01-05 03:22:45
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answer #8
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answered by Just Gone 5
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