Naked Science Forum

Non Life Sciences => Geology, Palaeontology & Archaeology => Topic started by: yeldas on 08/05/2008 08:29:46

Title: How do you find water underground?
Post by: yeldas on 08/05/2008 08:29:46

yeldas asked the Naked Scientists:
hi

This is Yeldas. I am very much interested in how you find underground water?


What do you think?

Title: How do you find water underground?
Post by: Bass on 08/05/2008 23:14:34

Hi Yeldas

Hydrology is the branch of geology devoted to water and water cycles.  JimBob has much more experience, but I'll give it a go:

Underground water (ground water) is formed when rainfall percolates into the ground.  The water moves downward from the surface through an unsaturated zone (voids are not completely filled with water) until it finally reaches the saturated zone.  The boundary between the unsaturated and saturated zones is called the water table.

The water continues to move downward and laterally along favorable geologic horizons called aquifers.  Aquifers must be both porous (have pore space) and permeable (the pore spaces must be connected).  Aquifers can be either open to the surface, or they can be confined (capped by impermeable rocks).

As you can guess, your question "how do you find ground water" is not always simple.  In areas covered with young gravels (such as river and stream valleys), finding ground water is often as simple as drilling a hole deep enough to hit the water table.  In other areas, knowledge of the local geology and aquifers, and the services of a hydrologist, are indispensable.  Subsurface hydrology and geology can be determined from nearby outcrops, wells, and geophysical methods.

Of course, there are people that claim to be able to find water using branches or metal rods, called water dowsers.  I've known dowsers that are able to predict water very well, and those who are complete frauds.  I don't know that anyone really knows the science behind dowsing (there's a prior thread on dowsing somewhere in TNS).

Title: How do you find water underground?
Post by: JimBob on 09/05/2008 01:47:41

Actually, for a hard rocker, ( it is my taste in music, not geology) you did quite well. I see nothing that needs to be added.

Let me guess - you have been at one time or another, dealing with subsurface water entering your mines.

Title: How do you find water underground?
Post by: Bass on 09/05/2008 20:38:53

More like tracing indicator elements in groundwater to try to find deposits.

Title: How do you find water underground?
Post by: JimBob on 10/05/2008 01:24:19

OK, much more sophisticated stuff than I realized. Bravo - you know what a sand is !!!

Title: How do you find water underground?
Post by: thedoc on 18/06/2008 13:13:28

Listen to this question on our podcast by clicking here (http://www.thenakedscientists.com/HTML/podcasts/show/2008.06.15/)

Title: How do you find water underground?
Post by: neilep on 18/06/2008 14:37:55

Hang On !!

The answer is simple....send a probe across millions of miles to Mars and find out !!

QED