What is an artesian system? What three geologic conditions must ...

[Pea0909berry]

What is an artesian system? What three geologic conditions must exist for an artesian system to form? What will be an ideal response?

Question 2

What is a cone of depression, where is it found, and what causes it? Why can large cones of depression
  be a serious problem? What will be an ideal response?

[yeungji]

Answer to Question 1

In an artesian system, groundwater is confined and builds up high hydrostatic pressure. Water may
then rise above the level of the aquifer if a well is drilled through the confining layer, thereby reducing
pressure and forcing the water upward. The aquifer must be confined by aquicludes above and below,
the aquifer must be tilted to build up hydrostatic pressure and exposed at the surface to allow recharge,
and there must be sufficient precipitation to keep the aquifer filled.

Answer to Question 2

A cone of depression is where the water table is lower in a cone shape in the area around a well. It is
caused by excess groundwater pumping, that is, when discharge from a water well exceeds recharge or
the rate of groundwater flow. Large cones of depression are a problem because they can cause shallow
wells in the immediate vicinity to go dry.