Underground Rivers - University of New Mexico

Mirror Lake
Chapter 26 -- Subterranean Water Bodies
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Lake of the Clouds
At the lowest point in the cavern, 300 meters below the surface, Lake of the Clouds is 3 meters
deep, has no apparent drainage, and its level remains nearly constant. The regional groundwater
table is some 30 meters lower.
Mean residence times estimated from bromide tracer loss range from less than a year for
Rookery Pool and Devil’s Spring to 16 years for Lake of the Clouds.
In the 1940s, when the military was testing the
feasibility of Carlsbad Cavern as an emergency
fallout shelter, Green Lake was observed for
ripples caused by a nuclear bomb test hundreds
of kilometers away. None appeared.
The Fall of Water
Carlsbad artwork by Kimberly Simon
A cavern extending entirely through the earth is old-hat in Boys Club fiction and likewise old-hat
to physics students. To be discussed in Chapter 45, Subterranean Geophysics, the earth's
interior temperature reaches several thousand degrees and the pressure approaches 300 million
times greater than that on the suerface, but we'll ignore the practicality our ride..
The nearer we are to the earth's center, the smaller is the pull of gravity. If we pour frictionless
water down a shaft that passes from one side of our earth to the other -- the trip's known in
physics as the Graviity Express -- the water will arrive at zero velocity on the other side -- China
being the proverbial destination -- in 42 minutes, having accelerated to 7900 meters/second at
midpoint, a calculation communicated by Robert Hooke to Isaac Newton. Unless it's grabbed at
China, the water will fall back to where we poured it and then again descend.
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