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Global Positioning System survey equipment operated by the National Oceanic and Atmospheric Administration overlooks buildings at the observatory.
Geophysicist Leroy Pankratz of Colorado is visiting the Fredericksburg Geomagnetic Observatory in Corbin to help celebrate its 50th anniversary. The facility in northern Caroline County was dedicated May 23, 1956.
Measuring equipment that once filled a room has been reduced in size to small components.
Leroy Pankratz looks at an aluminum tri-axial coil that generates |
By RUSTY DENNEN
The complex of small, white 1950s-era government-issue buildings sit in a time warp in a field in rural Caroline County.
And largely for that reason, the Fredericksburg Geomagnetic Observatory has done its arcane but important work for half a century. The observatory, one of 14 worldwide, measures Earth's magnetic field, providing key information to electric power producers, communications companies and the military.
Today, scientists will mark the 50th anniversary of the 180-acre site off State Route 2 in Corbin, south of New Post.
Geophysicist Leroy Pankratz travels here three or four times a year from the United States Geological Survey office in Denver, Colo., to update and calibrate the sensitive equipment and sensors. He arrived over the weekend to work and to prepare for the gathering.
"The whole idea is that there are no people here," Pankratz says of the property, which was purchased from, and is bordered by the U.S. Army's Fort A.P. Hill.
"To a certain extent, the equipment does much better when there are no people around. That's why we locate in the boonies--like here, Barrow, Alaska, Guam. It's pretty isolated," he said.
How long northern Caroline will remain rural is an issue: Percentage-wise, it's the nation's ninth fastest-growing county, according to the latest U.S. Census estimates.
When the Corbin center opened, then-U.S. Commerce Secretary Sinclair Weeks, speaking at the dedication ceremony on May 23, 1956, declared, "We could no more get along without the magnetic observatories than we could without weather stations, astronomic observatories and other institutions, which give us necessary information to maintain the commerce and technology of the country."
Corbin was chosen after the Cheltenham, Md., observatory was deemed obsolete and too small.
Precise readings on Earth's magnetic field, and its subtle changes due to solar activity and other factors, are needed for all kinds of civilian and military applications.
"Geomagnetism stuff is kind of technical," but essential, says Diane Noserale, spokeswoman for USGS in Reston. For example, any hiker, or ship's captain uses geographic information systems equipment calibrated by data gleaned from the observatories.
In the mid-50s Cold War era, for example, nuclear missiles' guidance systems relied on it.
Communications was another issue: High-frequency radio waves were affected by changes in Earth's magnetic field caused by solar flares.
Pankratz, 64, has been with USGS for 40 years and is familiar with the Corbin site's early work.
"Probably at its peak in the 1950s and '60s, there were 20-plus people here," he said.
They were needed to maintain and monitor equipment ensconced in sheds with double-width walls to maintain a steady temperature, and set on stone pilings sunk 15 feet deep, to eliminate vibration.
Today the Corbin observatory is a repository of obsolete gadgets with futuristic names.
For example, a sine galvanometer and proton vector magnetometer stored in one building were used until the mid-1990s. Electric current was passed through the galvanometer--a ceramic tube wrapped with wires--to measure the direction of magnetic fields. The magnetometer was used to calibrate magnetic sensors.
Early satellite sensors were calibrated here, Pankratz said.
For the most part, scientists worked quietly, with little fanfare or public attention.
There were exceptions.
"I was here in the '60s and the Navy had a Project Magnet," Pankratz said, in which planes' magnetometers were calibrated.
Super Constellations--large four-engine propeller aircraft--would swoop low over the grounds.
They'd do pass after pass.
He smiled, they were so close, "I can still hear the whispers from the propellers."
The observatory gradually evolved from analog to digital equipment.
Today, a Declination Inclination Magnetometer is used to take baseline readings. It's a nonmagnetic theodolite, which measures vertical and horizontal angles of the magnetic field.
Data from that and other instruments are fed into a main recording room in a building at the rear of the property. A wireless relay system sends that to the administration building, but that link is being converted to faster and more efficient fiber-optic cable.
Geomagnetic data accurate to the second are relayed to the National Oceanic and Atmospheric Administration's Space Environment Center in Colorado, the Air Force Weather Agency in Omaha, Pacific Marine Environment Laboratory, International Service of Geophysical Indices, and the GeoForschungsZentrum in Germany.
Satellites, which can cost hundreds of millions of dollars, are vulnerable to magnetic storms. Two satellites were disabled by the solar flares in 1989, so prompt warnings on magnetic field changes are crucial to protecting them.
"All it takes is for one to be on the [affected] side of the Earth. It can just fry them," Pankratz said.
Another practical side of the observations taken at Corbin have to do with the nation's electrical power grid.
Intense magnetic storms can create strong pulses of electrical energy in atmosphere, leading to power disruptions. New York and parts of Canada were among areas affected by such outages in recent years and early warning is critical.
In addition to the Corbin site, USGS has geomagnetic observatories in Alaska, Arizona, California, Colorado, Mississippi, Texas, Washington state, Guam, Puerto Rico and the Aleutian Islands.
USGS also maintains an Advanced National Seismic System station in Corbin, in cooperation with NOAA, to monitor earthquake activity anywhere in the world.
NOAA has had a presence as part of the National Geodetic Survey at Corbin since the early 1970s, and the Bureau of Indian Affairs has an Internet routing network for its reservation education programs.
Due to budget reductions and automation, the geomagnetic observatory operation now has one USGS employee working full time at Corbin. He maintains the grounds and does some observations. NOAA has four employees there and now jointly runs the site; the Indian affairs agency has one.
Some changes are on the way. Pankratz says that USGS will soon transfer all but about 45 acres to NOAA, which plans to expand its geodetic survey and training activities.
A new calibration and training center will support the national spatial reference system from which all official land boundary surveys are made. NOAA maintains a global positioning site and other survey equipment on the property.
Jack Townshend, special projects coordinator for the USGS Geomagnetism Group, says the Corbin site's geomagnetism and geodetic programs have racked up a number of achievements, among them:
U.S. and international magnetic standards were determined;
Scientists from around the world were trained in geometric observatory and field operations;
A NOAA scientist developed the Electronic Distance Measuring Instrument;
Hundreds of Global Positioning System antennas worldwide were calibrated at the facility.
Townshend, who has worked periodically at Corbin since it opened, wrote a history of the site and will be among those speaking at today's celebration.
To reach RUSTY DENNEN:
Email: rdennen@freelancestar.com
