Seneca Guns: The Booms of Summer
By Pam Smith
Coastal Review Online
The Seneca Guns - mysterious booms that rattle windows and nerves of coastal residents – were quiet this past summer.
The fearsome rumbles occur with no warning and leave no clues to reveal their origins.
be sure, the next Seneca Guns event will trigger frantic calls to local
emergency management agencies. It probably will rekindle front porch
debates about the source of the aberrations that have stymied
scientists for centuries.
boom theories abound: earthquakes, offshore storms, jets breaking the
sound barrier, Navy maneuvers, gaseous releases from the ocean floor,
shifts in tectonic plates, or even meteoric explosions.
convincing scientific conclusions, the strange soundings of the
so-called Seneca Guns have become the stuff of legends and
literature. In 1850, James Fennimore Cooper wove the phenomenon
into his short story, “The Lake Gun.” The story goes that for centuries
Seneca Lake in New York’s Finger Lakes region, emitted loud explosive
sounds, which white settlers said, came from “the lake gun.” Members of
the Seneca Tribe, however, considered the powerful sounds to be the
angry voice of their god, Manitou.
prevailing version of the legend holds that irate ghosts of Seneca
Indians fire their guns to disturb the descendants of the people who
drove them from their land.
Seneca Guns term has become synonymous with the unsettling salvos that
occur well beyond Upstate New York. The guns are heard up and
down the East Coast, but seem particularly concentrated off the
Carolinas, according to United States Geologic Survey, or USGS.
Similar booms occur along coastal India, where they are called Barisol
Dixon Varnam has experienced Seneca Gun episodes all of her
life. Growing up in Varnamtown, a Brunswick County fishing village
on the shores of Lockwoods Folly Inlet, the occasional rumbling folds
into other unexplained mysteries the ocean holds, she says.
Varnam owns and operates Carson Varnam Seafood Market, a business she and her late husband launched back in 1955.
a child I was curious about what they were. My first thought, of
course, was that there might be a storm. But, then, there would be no
clouds in the sky. Our house might shake, but I was never
frightened,” she recalls.
the years, we heard a lot different things that might be causing the
booms – earthquakes, part of the continental shelf slipping away and
jets breaking the sound barrier,” she says.
are no definitive answers, and the booms have become part of our
lives. We just go about our business when it happens. Some
mysteries you just can’t solve,” Varnam concludes.
may be right, says Jack C. Hall, professor of geology and chair of the
Department of Environmental Studies at the University of North
it is compelling – and fun – to explore the science behind the
ephemeral sounds. It may be less challenging to point to what the
Seneca Guns are not, says Hall.
safe to rule out tectonic plate movement. “The Mid-Atlantic Ridge is
not going anywhere. Its movement is so slow, it is not
measureable on seismic charts,” Hall explains.
scholars estimate that the Mid-Atlantic Ridge – the underwater mountain
range that splits the entire Atlantic Ocean nearly in half from north
to south - is spreading at an estimated 0.08 feet per year, or 15 miles
in a million years.
points out that seismic records don’t support the theory that Seneca
Guns events are indicative of continental shelf landslides. There
have been none recorded.
Nor do Seneca Gun episodes match seismic earthquake records.
definitely know when it’s the real deal, such as the earthquake that
occurred in August, 2011, in Virginia. Tremors were felt from
Connecticut to North Carolina. That’s because the quake struck in
the North American craton – the backbone of the continent. The shock
waves reverberated through the solid mass in many directions.” Hall
explains. “Most people heard it and felt it.”
Hall, with no measurable movement in the earth’s crust to attribute to
Seneca Guns, it makes more sense to look to the atmosphere for answers.
right atmospheric conditions, such as an inversion layer, can put a lid
on the atmosphere, so to speak. It would create a situation where
sound waves bounce from the ocean surface to the air layer and continue
to bounce back and forth until the wave of sound reaches the shore,”
Hall points out.
inversions occur in coastal areas when upwelling of cold water
decreases surface air temperature and the cold air mass stays under
warmer ones. What’s more, North Carolina’s coast juts out into
the Atlantic, essentially creating a microphone effect.
“Sound waves travel long distances and can generate a wall of sound like a base player at a Black Sabbath concert,” Hall quips.
that in mind, it seems feasible that Seneca Guns boom loudest when an
inversion layer amplifies a natural event, such storms far past the
horizon, or a man-made situation, such as breaking the sound barrier.
“It all comes down to stratification,” Hall surmises.
also inclined to attribute the occasional booms to military games
offshore as the source of an occasional eruption of Seneca Guns.
Of course, the military folks are not predisposed to commenting on
secret maneuvers,” Hall points out.
have suggested that much of the guessing about the source of Seneca
Guns bursts could be eliminated by installing an array of sensitive
seismic instruments along the coastline to record and analyze each
since there is no evidence that Seneca Guns do little more than rattle
windows and nerves, it’s unlikely to find institutions or individuals
willing to pick up the $20,000 tab for the equipment that may – or may
not - solve the mystery, Hall says.
story is provided courtesy of Coastal Review Online, the coastal news
and features service of the N.C. Coastal Federation. It is reprinted
from an Aug. 1 story. You can read other stories about the N.C. coast