U.S. Water News Online
HAMPTON, Va. --This summer, the U.S. Geological Survey
(USGS) is drilling a big hole in NASA's backyard. As it turns out,
NASA Langley at Hampton, Va. sits near the edge of a 51-mile-wide
impact crater created 35 million years ago when a meteor or comet
slammed into the ocean near the present-day mouth of the Chesapeake
"People living in southeastern Virginia are affected by this
ancient cataclysm daily," said Greg Gohn, USGS Chief of the
Chesapeake Bay Impact Crater Project. "The impact severely disrupted
the rock units that today are important aquifers providing drinking
water to the Hampton Roads area. We believe that large areas within
the crater are unsuitable for future water-supply development.
Drilling this exploratory bore hole and others in the next few years
will help in understanding how to best develop and manage the
region's ground-water supply," said Gohn.
This USGS research effort, hosted by NASA, involves drilling a
2,700-foot-deep hole in the Earth, bringing up a core (underground
sediment and rock) for analysis, and setting off underground,
firecracker-like blasts to perform a seismic reflection survey across
the crater's margin. Drilling associated with the crater project
began on July 23 and will continue throughout the summer. The seismic
survey will begin in mid-August.
Some of the data gathered by the scientists will be incorporated
into the regional groundwater flow model that was developed by USGS
water resources specialists in Virginia. Results of the project,
which is supported and partially funded by the Hampton Roads Planning
District Commission (HRPDC) and the Virginia Department of
Environmental Quality (VA DEQ), will assist local and state water
resources managers in making better decisions concerning the
availability and use of groundwater, an important water supply in
Joel S. Levine, a senior research scientist at NASA Langley, looks
forward to the shared science and agency cooperation at the local,
state, and federal levels. "The USGS drilling project will permit a
detailed investigation of a very significant event in the history of
our planet that affected all four components of the Earth system --
the atmosphere, ocean, land, and biosphere," said Levine. "We're
working closely with USGS scientists to assess what we can learn
about the Earth's early atmosphere from analysis of the cores
obtained from drilling."
At the time of the impact 35 million years ago, sea level along
the East Coast was higher and most of eastern Virginia was submerged.
According to USGS scientist, David Powars, the object -- meteor or
comet -- "sliced through the water and thousands of feet of
underlying sediment, colliding violently with continental bedrock
several miles beneath the surface."
Powars added that the surrounding region was engulfed in
widespread devastation and, "within minutes, millions of tons of
water, sediment, and shattered rock were cast high into the
atmosphere for hundreds of miles along the East Coast." An enormous
seismic sea wave, or tsunami, rushed westward, engulfing the land and
possibly even overtopping the Blue Ridge Mountains.
In 1993, T. Scott Bruce of VA DEQ, and David S. Powars and C.
Wylie Poag of the USGS found evidence of these startling events.
Earlier this year, these scientists received the Thomas Jefferson
Award from the Virginia Museum of Natural History in recognition of
their discovery of the Chesapeake Bay Impact Crater. Research
drilling and related studies have been conducted across the region
for the past several years.
For more information on the Chesapeake Bay Impact Crater, visit
the following web sites:
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