[meteorite-list] Drill and Crew Begin Search For Insight Into Chesapeake Bay Crater

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Tue Sep 13 13:07:14 2005
Message-ID: <200509131652.j8DGqWr01604_at_zagami.jpl.nasa.gov>

http://www.timesdispatch.com/servlet/Satellite?pagename=RTD%2FMGArticle%2FRTD_BasicArticle&c=MGArticle&cid=1031785022526&path=!news&s=1045855934842

Drill and crew begin search for insight into bay crater
Project is researching explosion that created 56-mile-wide hollow

BY A.J. HOSTETLER
RICHMOND TIMES-DISPATCH
September 13, 2005

It's a busy construction season, even for an 80-foot-tall rig headed for
some late-summer work along the Chesapeake Bay.

The crew and drill rig operated by Major Drilling Inc. was greeted by a
handful of U.S. Geological Survey researchers when it arrived at the
Eastern Shore on Saturday, a few days late to start drilling on Sunday.
The USGS is participating in a $1.3 million international project to
drill nearly 1.4 miles below Cheriton to understand the catastrophic
explosion that carved out a 56-mile-wide crater buried below the
Chesapeake Bay.

The drill will look for traces of a 2-mile-wide asteroid or comet whose
explosion over the Atlantic Ocean, geologists say, sent a shock wave
about 7 miles underground, melted rock, briefly exposed the seafloor and
vaporized water.

Greg Gohn, the USGS researcher directing the project, said the team
spent the weekend and yesterday setting up a crane and other equipment
from five flatbed trucks. The coring - bringing up tubes of long-buried
dirt - could start late today after another flatbed truck arrives with
additional gear.

"These things, ugh, the start of drill jobs are pretty notorious for
starting late, so I'm not surprised," Gohn said.

The drill site was prepped in July with a shallow water well 412 feet
deep, into which was placed a steel casing to stabilize the hole. The
water cools the big drill as it goes deeper and deeper, and the
resulting mud acts as a lubricant for the machinery to pump and raise
the cores.

The crater is the largest one in the United States and the sixth-largest
in the world.

It sits below about 1,000 feet of rubble and sediment beneath the lower
part of the Chesapeake Bay, its surrounding peninsulas, and the inner
continental shelf of the Atlantic.

Tropical Storm Ophelia should not hinder the project unless it brings
high winds, lightning and a deluge to the Eastern Shore, Gohn said.

"It's just a matter of when folks are tired of standing out in a downpour."

The drill, involving about 49 scientists, will go night and day for the
next three months to reach 7,200 feet. The USGS plans to return next
spring to core the top 412 feet so that the record will be complete.
Received on Tue 13 Sep 2005 12:52:31 PM PDT