In tribute to Sen. Rick Santorum's deeply principled support for teaching "intelligent design" in our public schools, I will first turn to a faith-based explanation about how a flooded underground river would "manifest itself." Because the Bible, as we know, contains the answer to all things. You just have to be willing to look very, very hard.
I'm in debt for the material that follows to the Journal of the Adventist Theological Society; I've no doubt that the information is wholly reliable. True, I came across this story while amusing myself on the Internet one day, but hey -- relying for scientific information on the Internet makes as much sense as relying on the Old Testament book of Leviticus, say, for moral guidance about homosexuality. Yet Rick Santorum does that all the time.
In a fine 2001 article by Ted and Ken Noel -- note the Christmas-sounding last name, unbelievers -- the JATS explains that an underground river, or "aquifer," may have caused Noah's great flood. They go to considerable trouble to prove this, which is surprising, given how much they take for granted. Ask how Noah could feed all the animals on the ark, for example, and they blithely explain: "The ark is clearly a miraculous singularity, and all elements of it may properly be attributed to the miracle." Oh. Silly me.
I should explain that the definition of an aquifer appears to be among the few points of agreement between faith and science: Both say an aquifer is an underground layer of porous rock that can absorb and hold water. Essentially, the Noels theorize that before the Flood, a huge amount of water was stored in an underground aquifer that fed the rivers of the day. That explains how there could be enough water to inundate the world.
What happened was this: The planet Earth -- which had been standing straight up on its North/South axis -- suddenly slumped over, tilting to its current angle of 23.5 degrees off center. The molten rock below the earth's crust acted "like a skating rink," with landmasses sliding around like runny eggs on a hot griddle. Then, the Noels say, "Ocean waters and [water from the] aquifer exposed to the mantle would then flash into steam," which shot into the air and condensed into rain.
So according to Scripture, a flooding aquifer would manifest itself thusly: "[A]ll the fountains of the great deep were broken up and the windows of heaven were opened. And the rain was upon the earth forty days and forty nights."
The scientific answer, if you care, is that aquifers don't flood. For starters, it's not really a river as we think of it; it's a layer of earth sandwiched between solid bedrock and clay. Water does move through Pittsburgh's aquifer, but very slowly: a couple miles a day, compared to a few miles an hour for even a fairly lazy river on the surface.
Pittsburgh's aquifer is known as the "Wisconsin Glacial Flow," and as the name suggests, it's a remnant of Ice Age glaciers that once scoured the landscape and then retreated, leaving gravel deposits in their wake tens of thousands of years ago. I'm assuming you believe the earth is really that old, heretic.
The resulting aquifer runs from the Great Lakes to Pittsburgh, much like the Allegheny itself. (In many places, in fact, the Allegheny runs right over it, separated from the "fourth river" by a few feet of clay.) But at its most shallow, it runs dozens of feet below the surface, so only a few enterprising well-diggers notice it.
The aquifer doesn't flood because flooding would begin long before water from the surface could filter down to it. The ground above would have been saturated, and streams and rivers would have swollen their banks long before.
Of course, that's only if science is true. As Rick Santorum himself recently wrote in the Pittsburgh Post-Gazette, "Ultimately, academic freedom is at stake" here; we must be free to consider other points of view. So either aquifers don't flood because of basic geological principles, or a tip of the earth's axis is all that separates us from Biblical disaster. Six of one, half a dozen of the other.
I've reported. You decide.