SPACE.com -- Geologists to Inspect Huge Crater Beneath NASA's Langley Research Center

New Crater Found Down Under

Sudden Increase In Asteroid Impacts May Have Fueled Life

Yucatan Crater May Harbor Clues to Dinosaur Extinction

Prospecting for Oil? Look In an Asteroid Crater


	Geologists to Inspect Huge Crater Beneath NASA's Langley Research Center By Craig Linder Special to SPACE.com posted: 12:00 am ET 30 July 2000

langley_drilling_000728

WASHINGTON, July 28 -- When NASA built its Langley Research Center in Hampton, Virginia, it thought that all the interesting science would be taking place in the skies above the facility, not in the ground below it.

But geologists are now drilling a 2,700-foot- (825-meter-) deep hole at the center to explore a 35 million-year old crater. Langley sits on the edge of the 56-mile- (90-kilometer-) wide crater, which helped create Chesapeake Bay.

Scientists from the U.S. Geological Survey (USGS) will use the samples they pull from the crater to help track the quality of ground water in the coastal region of Virginia, project chief Gregory Gohn said.

The white lines on this satellite image show the inner and outer rims of the buried crater. The area inside the inner rim suffered the full brunt of impact, compressing and vaporizing rock and leaving the deepest hole.

"People living in southeastern Virginia are affected by this ancient cataclysm daily," he said in a statement. "We believe that large areas within the crater are unsuitable for future water-supply development. Drilling this exploratory bore-hole...will help in understanding how to best develop and manage the region's groundwater supply."

Extracting water

As the scientists bore the hole, their hydraulic drill rig pulls samples of earth from each of the crater's layers, 10 feet (3 meters) at a time. Samples are photographed and cataloged at the Hampton site. Researchers at a USGS lab in Reston, Virginia then clean 6- to 8-inch (15- to 20-centimeter) segments of the sample and squeeze the segments to extract any water.

Using this technique, called "pour-water squeezing," the geologists expect to find that the water from the crater's layers will be saltier than seawater. Gohn said that other scientists could use the data from the experiment to determine the makeup of the ancient oceans.

The USGS scientists will also study the crater's seismic reflection by setting off controlled explosions deep within the hole. Data from the seismic reflection can tell researchers the geologic makeup of the crater's rocks.

Set off tsunami

The crater was created 35 million years ago when a meteorite or comet crashed into the Atlantic Ocean at 50,000 miles (80,465 kilometers) per hour, landing underwater on the continental shelf. The impact produced tsunamis that could have reached as far inland as what are today the Blue Ridge Mountains and set off wildfires in the East.

The impact helped create the Chesapeake Bay and the geography of eastern Virginia -- the areas closest to the crater.

"This was the most traumatic and dramatic geologic event ever to hit North America," said Joel S. Levine, the senior research scientist in NASA's atmospheric sciences division.

Drilling into the crater has also sparked the interest of NASA scientists. A team led by Levine will be taking small portions of the USGS sample and trying to extract ancient gases.

Scientists at Langley will crush the samples of rock inside a vacuum compartment and analyze any gases that are released. They hope that gas trapped millions of years ago will provide a peek into Earth's ancient history.

NASA hopes to "see if we can shed light on the geological evolution of the Earth's atmosphere over time," Levine said.

Natural collaboration

Though Levine is not optimistic about his project's chances for success -- he puts them at less than 1 percent -- he said that working with the USGS was a natural collaboration as long as they were at Langley.

"What we are trying to do is maximize science return and leverage what USGS is doing," he said.

Levine said that atmospheric scientists don't normally have much opportunity to work with geologists, but then the USGS team sought to work at the space center.

USGS' drilling project will be going on for about the next two months, but NASA officials say that it should not disrupt work at the Langley facility.

"If you didn't know better, you'd think it was some construction going on," center spokesman Chris Rink said. "It's good for USGS, it's nice for NASA."

Levine noted that the Langley center shares an interest in history with its neighbor, Colonial Williamsburg, the popular attraction where tourists can learn about the history of the 1700s.

But at Langley, he said, "we are going to be looking at history from 35 million years ago."