what is the groom lake bed?

probably a stupid question but its confusing to hear dry and lake in the same title for something,so wahat is it consisting of water or sand?
-GTB

it's dry. it's an ancient lake that has totally dried up.
usually such places are used as landing sites for planes, space shuttles.....etc. namely because they are usually extremely flat. they are also used for testing cars,trucks,motorcycles etc.. for landspeed records and other things.

The playa known as Groom Lake is the dried remnant of a lake that last held water during the Pleistocene Age. Sediments deposited in the lake consisted largely of reworked silt and clay that were first deposited in an older and larger lake that occupied the same basin during the Pliocene Age (ending about a million years ago).

When the lake dried up, starting about 10,000 years ago, it left a clay deposit. The light-colored, fine-grained sediments fill the basin to an unknown depth and have been compacted to the point where the surface hardness easily supports the weight of an airplane during takeoff and landing operations.

Heavy rains cause the lakebed to soften and retain water for months at a time. When this happens, copepods (a kind of brine shrimp) emerge from the mud and enjoy their life cycle until the lakebed dries out again.

wow,thanks that explains alot .
-GTB

There are numerous lake beds throughout the Great Basin. Great Salt Lake, Pyramid Lake in NV, and Honey Lake in CA are ancient lakes that just haven't dried up yet.

Very nice explanation Shadowhawk.


Here's a pic that shows a dry lake bed that's a couple hundred miles S/E of Groom Lake.

The cannon shown - more correctly a mortar, but we call em cannons - fire bowling balls a half mile where they land undamaged.
The finger holes make an interesting whistling sound as they fly, the sound rises and falls in pitch as the ball rotates during flight.

A typical load is 1/4 pound of blackpowder.

wow thats crazy,now i can also understand better why they do bomb tests there:
1:because its a secret area[duh]
2:because the ground is so strong if it makes a huge impact such as the sedan crater the effect of the blast could be bigger in a normal area
-GTB

[edit on 10/7/2006 by gregthebunny]

This particular dry lake is typical of the desert dry lakes I've been on and I expect Groom Lake would be no different.

When dry, the surface is quite hard and 3/4 ton pickups - Ford 250 and the like - with large campers don't sink into the dry surface.
They just smooth out the cracked areas and leave tracks that aren't very deep.
Perhaps 1/8" - 1/4" and an area with lots of traffic getes smooth, but the smooth areas aren't very deep and still about parallel with the undisturbed areas next to the well traveled areas.

This particular lake floods over most rainy seasons, but it dries up quite hard.
When it's wet, you can get stuck very quickly.

There can be slight differences mineral-wise between the dry lakes, but for the most part their makeup is fairly similar.
I'm sure ShadowHawk could elaborate on that.

I do know that when you cross the edges of some of them that are still wet or have running water on the edge, the liquid will discolor aluminum such as found on a dirt bike's spoked wheels.
Our guess is that the water is quite alkaline and that's what does the number on aluminum.

Aside from the famed 20 Mule Teams of the Borax Corporation that bring in borax - from hills that have washed down to the lake bed and left deposits from what I understand - dry lake beds are also mined for talcum.

One thing I've always thought about these lake beds and I'm hoping ShadowHawk will elaborate upon is that they are the first stages of a salt lake.
Enough evaporation of rainwaters over millennia seems like it would eventually start to lay down a layer of salt.
Said salt can be quite deep.
Bonneville Salt Flats are fairly thin in places due to potash mining over the years, but there is an effort that's underway and has been for several years now to restore the lakebed.
They are gaining salt thickness, but as you would expect, not very fast.

If I remember right, Bonneville's salt crust used to range from 3' - 6' thick.

Lake Gairdner in Australia - about 20 x 100 miles in size has salt deposits ranging down to 10' deep and beyond from what I understand.
The hot rodders in Oz trek to Lake Gairdner every year for their Land Speed Trials.
And like many things Australian, it's a tough trek with the last 200 miles being very unimproved dirt road . . . not to mention the black flies when you get there.

Things in Oz - like major cities - are a long way apart.
About 2000 miles between major cities in most cases and in one instance I believe the distance is 3000 miles.
Roads between these cities are fairly well maintained gravel roads and are not paved like you'd find in the US.

The distances quoted may be in kilometers as are most things in Oz, but my Australian friend who quoted the distances did say miles . . . probably for my benefit since I don't use the metric system much at all.

Actually it's a great question!

Groom Lake is the remains of an anchient lake bed. Many scientist think it was probably created from a time when the area may have been connected to a sea (which no longer exists). As the Sea disappeared, a pocket of concentrated salt water was trapped in a low lying area of the mountains. Slowly over hundreds or thousands of years, the water evaporated. As the water evaporated, it left a heavy deposit of salt behind on the desert floor. The sun baked the drying salt into the hard desert floor, which is why Groom Lake has a whitish color to it.

Hope that fills in all the blanks.

Tim

[edit on 7-10-2006 by ghost]

And from the sun baking it, it is hard as asphalt.