THE VIRGINIAN-PILOT
Copyright (c) 1995, Landmark Communications, Inc.
DATE: Thursday, August 31, 1995 TAG: 9508310420
SECTION: LOCAL PAGE: B1 EDITION: FINAL
SOURCE: BY MIKE MATHER AND JAMES SCHULTZ, STAFF WRITERS
DATELINE: VIRGINIA BEACH LENGTH: Medium: 73 lines
An unusual combination of atmospheric conditions and wind direction allowed residents in Hampton Roads and North Carolina to hear and feel a Navy bombing exercise 40 miles off the Virginia coast Wednesday.
The atmosphere was configured in such a way that the sounds and shock waves generated by the blasts of 1,000-pound bombs were channeled through North Carolina's Outer Banks, Virginia Beach, Norfolk and parts of the Peninsula.
The explanation came long after the bombing runs, and many Hampton Roads residents thought they were feeling earth tremors or remnants of a sonic boom.
More than 150 calls poured into the Virginia Beach 911 center and 30 more rang into Norfolk's communications complex to report strange tremors, shock waves and rumbles, police said.
At first, police and fire officials thought the tremors were from the demolition of an old radar-tower foundation at the Oceana Naval Air Station. That theory was later discounted and replaced by the bombing explanation.
``Under the right temperature and wind conditions, it's possible to get pretty freaky sound propagation, particularly low-frequency sounds from bombs,'' said Kevin Shepherd, a NASA acoustics expert who works at Langley Research Center in Hampton.
``Basically, the sound levels don't decrease with distance as they would under normal weather conditions. It's particularly noticeable at low frequencies, and low frequencies will cause houses to vibrate.''
The Navy spent several hours guessing what happened beforeclaiming credit Wednesday afternoon and blaming an unusual temperature inversion and winds blowing from ocean to shore for carrying the shock waves much farther than normal.
The offshore bombing exercise was routine, a Navy spokesman said. There were no reports of damage or injures.
It began shortly after 9 a.m. when three A-6 Intruders dropped 18 bombs on floating targets. Moments later, phones began ringing at 911 centers.
The shock waves, felt most strongly in Virginia Beach, rolled as far west as York County.
Virginia Beach residents in the Red Mill Farm and Oceana areas gave graphic reports of the stirrings.
``It was like you could hear it coming, and all of a sudden the house started shaking,'' said Katherine Benton, of Red Mill Farm. ``We have glass shelves with crystal on them, and they were rattling. Fortunately, nothing fell off.''
Another Red Mill Farm resident said she timed the rumblings. The tremors rattled Peggy Farrar's home Wednesday morning at 9:25, 9:27, 9:30, 9:49, 9:52 and 9:56.
Some Virginia Beach residents reported as many as nine separate tremors. No one reported any significant damage. A few residents said sudden gusts of air accompanied some of the rumblings.
``I was lying in my bed when the whole house shook,'' said Raine Lightner, 20-year-old Oceana-area resident. Lightner said he was awakened by things falling off a shelf. ``I thought our next-door neighbors were jumping around like they usually do.'' MEMO: Staff writers Larry Brown, Jack Dorsey and Beacon editor Kevin
Armstrong contributed to this report.
ILLUSTRATION: BAD VIBRATIONS
Graphic
Text by JAMES SCHULTZ/Staff Writer
Graphic by JOHN EARLE
SOURCE: U.S.Navy/NASA
by CNB