A good aquifer is one that carries a large amount of water and recharges quickly. Some aquifers are even under pressure so that little if any work is required to bring water to the surface. An aquifer is any body of groundwater into which a well can be dug.Continue Reading
Aquifers are buried porous rocks or masses of unconsolidated material, such as gravel, sand or silt, that are saturated with water. When one digs into such a rock or mass of material, water seeps into the hole, forming a well. When the layer of water-bearing material has porous materials above or beneath it, it's not under much pressure, and energy must be used to obtain the water. In artesian wells, however, the layer of water-bearing material is sandwiched between non-permeable materials, such as granite or clay. In these cases, the water is under pressure.
Aquifers have limited supplies of water and rely on precipitation to be refilled. Different aquifers refill at different rates depending on the amount of precipitation and the nature of the overlying materials. Human overuse of aquifers can deplete them or, in the case of coastal aquifers, cause saltwater to seep in, rendering them unusable for drinking or agriculture.Learn more about Layers of the Earth
Moving water that flows through the porous rock of an aquifer is filtered by the tiny pore spaces in the rock. The pore size determines the size of the particulate matter that flows through; smaller pore sizes are helpful for filtering bacteria and other solid matter. Clay particles and other minerals slow down or stop dissolved substances so they don't travel with the water, providing another layer of filtration.Full Answer >
In an artesian aquifer system, the weight of the water from the upper part of the aquifer exerts pressure in the lower part of the system, which contains the artesian well, the only opening through which water can escape. This forces the water to rise in the well.Full Answer >
Temperatures in the Earth's mantle are as high as 4,000 degrees Fahrenheit at its furthest depth and as low as 1,600 F in its uppermost layer. The Earth's mantle is made up of extremely hot, dense rock that is constantly flowing and stretches 1,800 miles from top to bottom, making it the thickest layer on the planet.Full Answer >
The outer core of the Earth begins about 1,800 miles below the Earth's surface and is between 1,370 and 1,430 miles thick. It is composed of liquid iron and nickel with some trace elements.Full Answer >