Page 40 - The 'X' Chronicles Newspaper - February 2014 Edition

Earthquake Booms, Seneca Guns & Others Earthquake Booms, Geological Survey, Washington D.C., p. 203- averaging perhaps half an hour. From that time Seneca Guns, and Other 528" is perhaps the most comprehensive until 9:30 p.m. occasional and very slight scientific document that compiles seemingly spasmodic tremors of an instant's duration Sounds credible accounts from numerous sources. accompanied the detonation. I endeavored to Dutton these determine the direction from which the sounds objectively sums USGS interviews/observations with the following: came, but no two individuals agreed. They "According to the testimony of some, the seemed to me to come from the northwest. They Introduction & Basics first intimation of the disturbance was a strange were much like, but somewhat more muffled sound or murmur. Others say that with the than peals of thunder at distance of half a mile Earthquake "booms" have been reported for a sound they felt the trembling, and that both or more, or perhaps more like the discharge of long time, and they tend to occur more in the increased, at first steadily, but by perceptible a blast in a mine or quarry at a little distance." Northeastern US and along the East Coast. Of stages, and then suddenly or by swift degrees, to course, most "booms" that people hear or the full roar and energy of the climax. Dr. Seneca Guns experience are actually some type of cultural Manigault resides in a very quiet street near the The term “Seneca guns” is just a name, noise, such as some type of explosion, a large Battery, and but a few hundred yards from the not an explanation. It does not tell us anything vehicle going by, or sometimes a sonic boom, estuary of the Ashley River. He was engaged in about what causes these noises and shakings. but there have been many reports of "booms" a game of chess, and a member of his family The name originated in a short story that James that cannot be explained by man-made sources. was sitting by an open window. The latter, Fennimore Cooper wrote during the 1800’s. The No one knows for sure, but scientists speculate surprised or perhaps alarmed by the prolonged name refers to booms that have been heard on that these "booms" are probably small shallow sound, arose, crossed the room, entered the hall, the shores of Lake Seneca and Lake Cayuga in earthquakes that are too small to be recorded, and passed out into the open air before the New York State. The name has been applied to but large enough to be felt by people nearby. doctor became aware of anything unusual. The similar noises along the coasts of North As it turns out....there are many factors sound appeared to come across the water of Carolina, South Carolina, and Virginia. Similar that contribute to the "sound' that an earthquake Ashley River from the west-southwest. Another booms are called Barisol guns in coastal India. makes. To begin to understand these factors we observer of intelligence was seated in the park These phenomena have also occurred in three have to understand the different types of waves, at the Battery, near the statue of Jasper. He widely separated places around the world. the speed they travel through the earth, and the suddenly became conscious of a deep murmur, That’s about all we know about the Seneca speed that sound travels through the air. which swelled in volume, and which appeared guns. Perhaps the best way to understand to come from the open bay, lying southeastward. earthquake sounds are from an actual Very soon there was a sound of agitation in the What might be the cause experiment that took place back in the 80's in leaves of the trees overhead, and at the same California by David Hill. Dr. Hill's team instant, he thinks, he became aware of a tremor The thing that comes closest to matching all of recorded sounds that came out of the earth in the ground. Springing to his fee, there the observations is sonic booms from military (from nearby small earthquakes between suddenly broke upon his ear a rapid swell in the aircraft. The article from www.farshores.org/ magnitude 2.0 and 3.0) and simultaneously sound, which became a mighty roar, and with summarizes reports of Seneca guns from coastal measured the arrival of the P wave on a the roar came a shock." South Carolina. seismograph. Researchers also reported hearing It is apparent from these observations The article in a sound before the S waves were recorded; this that, at least for the main shock, people heard www.unknowncountry.com/ reports on one loud turned out to be the arrival of the P wave. See the actual low frequency motions of the boom that was heard in Myrtle Beach, SC on this Alaska Science Forum article entitled damaging earthquake waves as they rolled Dec. 14 of an unspecified year. The sound was "Earthquake Waves Outrace Sound" for a across the region and right down their so loud that it shook a window and the sofa that description of that experiment. street.....the "roar' came with the "shock". the person was sitting on, and she felt the shock As for scientific evidence for loud from the sound. Thus, a loud enough boom can Observations of Earthquake Sounds sounds that preceded the 1886 Charleston, SC be felt. Earthquake, there is none. To our knowledge, In the Myrtle Beach case, the Air Force there were no seismographs or barographs that claimed responsibility and said that they had Spokane, Washington recorded the earthquake. The only data that was The most recent documented earthquake been conducting training exercises at the time. sounds were from a swarm of small earthquakes collected that could have scientific significance The seismologist whom I called in Virginia (aside from tide gauge and other water surface that unnerved the city of Spokane, WA in 2001. measurements, was from large clocks that reported that, during the 1970’s, Seneca guns Many of the Spokane quakes were definitely stopped due to ground motions. Unfortunately were heard on the coast of Virginia. Reporters accompanied by "booming sounds". The quakes none of these clocks were precisely and seismologists investigated for several in Spokane were shallow, sometimes only a weeks but were unable to determine the cause. mile or two deep. This probably contributed to synchronized so those data are of poor quality. Finally the Navy admitted that one of their For several weeks after the Charleston all the noise they made. Higher-frequency Earthquake (8/31/1886) there were many planes had caused a sonic boom. The problem vibrations make the booming sound, and when aftershocks that were reportedly accompanied with sonic booms is that they cannot explain quakes are deeper, those vibrations are gone by by "loud detonations". But there was little Seneca guns that occurred before supersonic the time they reach the surface. Sometimes the jets. quakes boom even when no vibration is felt. mention of sounds occurring before an event. Naval ships firing their guns offshore The earth was in a fairly continuous state of might have produced some of the booms. Under agitation and it would be difficult to relate a certain atmospheric conditions, sounds can New Madrid, Missouri There are accounts of "artillery"-like specific sound to a specific earthquake. The travel farther than usual so that they might be sounds that were said to have occurred before or following account from the Dutton report is heard onshore as loud booms. Naval firing during the New Madrid earthquakes of 1811- particularly informative: might explain some of the Seneca guns that "For several weeks following the 1812. occurred before jet planes were in wide use. In principal disturbance minor shocks continued particular, naval gunfire might have caused to be felt at frequent intervals. Many of them some of the booms that were heard during the Charleston, S. Carolina would have been considered very forcible and As with most historical earthquakes, alarming and they not been greatly disparaged 1800’s and early 1900’s, when it might have details about sounds and the actual level of by the convulsion of August 31. Almost all of been more common for ships to fire within a ground motion related to the Charleston, SC them were accompanied by loud detonations. few miles of shore. However, naval gunfire Earthquake (1886) are somewhat sketchy and Mr. McGee thus describes several which he cannot explain the Seneca guns inland, around hard to authenticate. "Dutton, Clarence E., experienced. Seneca Lake and Cayuga Lake. 1889: "The Charleston Earthquake of August I reached Summerville about 5 o'clock 31, 1886," Ninth Annual Report, 1887-88, U.S. Continued on Page 42 p.m. Detonations were heard at intervals