In Wisconsin, United States
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Groundwater flows similar to surface water by flowing laterally from higher to lower areas and toward discharge points such as lakes and rivers. It also tends to flow toward areas where water is withdrawn, such as wells. Groundwater flow may move only a few inches per day. Or, on the other hand, in areas with porous, sandy soils, water may move quickly through the ground – as much as 100 feet per day.
This is the case with much of Ashland County. The northern half makes up the former lake bed of the ancient Lake Duluth. Glacial Lake Duluth was a proglacial lake that formed in the Lake Superior drainage basin as the Laurentian Glacier retreated. This created ideal conditions for artesian wells, such as the many found in Ashland and Washburn due to its abundant clay and sand deposits.
The Copper Falls Aquifer provides the water source for this artesian well. Porous stone is sandwiched between a top and bottom layer of an impermeable substance like clay or rock. This keeps the water pressure high, so that when you get to a point below the entryway of the flow, there is enough pressure (artesian pressure) to bring the water up. The water in the aquifer is also under enough pressure that, when the aquifer is tapped by a well such as this, the water rises up the well bore to a level that is above the top of the aquifer called the potentiometric surface.
The temperature of the water from artesian wells is generally constant because of its depth. Depending on the well depth the water temperature can be a few degrees above the annual mean temperature. The water temperature decreases about 1 °F for each 65 feet of depth to the well. The mean annual temperature for the Ashland, WI region is 41 °F. Some uses of these temperature differences have been to “heat” homes (heat pump) and or cool them.
TO LOG THIS CACHE: 1) Determine the output of the well in gallons per minute (gpm) and/or measure the temperature of the water (°F) compared to the ambient air temperature (list both temps in your email).
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Last Updated: on 5/2/2015 4:16:25 PM Pacific Daylight Time (11:16 PM GMT)
Coordinates are in the WGS84 datum