Mysteries booming off east coast this week: No reason to panic

Several unusual events recorded off the east coast in Virginia and North Carolina have been tied together by mystery-mongering sites. Are the booming sounds, fish kill and dead dolphin related? Probably not but it’s awfully tempting to link it all into one narrative and promote it as a scary doom and gloom event.

Booming sounds off the coast of North Carolina are actually a fairly regular occurrence. That is, they happen occasionally, probably every year, and the explanation is not pinned down. So, there is a head scratcher there, no doubt. They could be caused by sonic booms, earth movements (shallow quakes or sediment compaction/settling), or atmospheric situations, among other possibilities. The unusual booms reported this week shook up local residents.

The Outer Banks Voice – Rumbles felt up the East Coast, but no earthquake recorded.

The U.S. Geological Survey wants to hear from coastal residents about two rumbles that shook houses from the Carolina coast to Delaware Monday, but the federal agency’s instruments detected no earthquakes in the region.

Unlike the occasional booms heard and felt along the Outer Banks from time to time, Monday’s rumbles lasted as long 20 seconds. The first occurred at 4:24 p.m., according to the U.S. Geological Survey, and the second at 6:24 p.m.

Offshore training exercises or a weather system are speculated as to the potential source of the event(s). Most of the responses reported to the USGS were from Kill Devil Hills, Kitty Hawk and Nags Head (Outer Banks), as well as some in Virginia. But we often never can pin down the source for sure. These things just happen. It’s unsettling but nothing to get panicked about.

Was it a sonic boom?

Was it a sonic boom?

The next day, dead fish appeared en masse along the Outer Banks of NC.

Dead marine life washes up along the Outer Banks.

A dolphin and thousands of dead fish have washed up on the beach on the Outer Banks over the past few days.

The dolphin was reportedly found Tuesday morning along Carova Beach.

The mammal was found in the area where locals have reported seeing thousands of dead fish wash up across miles of Carova Beach.

The fish have been identified as Atlantic Menhaden, said Charlton Godwin of the North Carolina Division of Marine Fisheries, which is investigating the kill off.

Photo NCDENR

Photo NCDENR

Mass die offs of menhaden are also relatively common (Google “menhaden fish kill” to see). Large schools of these fish can be corralled by predators and pushed into shallow waters where they die from lack of oxygen. Then they wash onshore. We’ve covered many such stories of fish kills that are perfectly natural. The dolphin, however, is a bit unusual. The common dolphin is not actually common in this area. However, if it was weak or injured (it was bitten), it could have gotten wrapped up in the fish cloud. Tests are being conducted.

The local Fish and Wildlife department sees such events quite a bit and didn’t find anything particularly worrisome about it. Though, people who observe such mass die offs often are concerned that something could be wrong in the environment. They also fear if it kills animals, it may be harmful to them. There is currently no indication that that is the case here.

There is also no connection to be made (except in time and location) with the booms. Coincidences happen! If there were some massive oceanic event that caused the boom and killed these fish, we would have seen other signs of it – more and different kinds of fish, other evidence washed up on shore, some sort of change in environmental measurements. We don’t see that. So, as usual, the mystery mongering sites spin a tale of fiction that is meant to frighten, not inform.

  8 comments for “Mysteries booming off east coast this week: No reason to panic

  1. Ronald H. Pine
    March 20, 2015 at 2:31 PM

    Whatever caused the booming sound or the fish kill, I doubt that it could have transported the dolphin to a place where that species is uncommon, so the fact that they are not common along the Outer Banks would seem to be irrelevant. The state of decomposition of the dolphin carcass could allow one to determine if it died at the same time as the fish. Whales and dolphins that are not common along the shore do wash up on the Outer Banks naturally. I was involved in extracting the skulls of a Fin Whale and a Sperm Whale in that area.

  2. BeenThereDoneThat
    March 21, 2015 at 12:21 AM

    Offshore supersonic training areas (sound of freedom) are likely the source of the booms (weather conditions impact footprint). Crab food cause could be one of many natural events. Correlation causation.

  3. Steve
    March 21, 2015 at 7:38 AM

    A quick theory – we know that major world powers have long experimented with ultra low frequency beamed into the water at high power and probably from several locations. The aim is to communicate with submarines. Perhaps there are sometimes nodal points where the amplitude “adds up” to a point where something like cavitation happens which might make the sound and also kill fish.
    Of course like all theories it may be way off beam (pardon the pun)but science will eventually win and we will know what causes this one day.

  4. March 21, 2015 at 9:46 AM

    Well, it’s not implausible. And we know military activities kill ocean life sometimes. But in this case, the simpler explanation seems perfectly adequate and there is no need to reach for another.

  5. TOF
    March 22, 2015 at 12:27 AM

    Usually, aircraft generated sonic booms are like a cannon shot, i.e., relatively short and sharp. Something cracking along at around Mach 3.0, e.g., a SR-71, will give a double boom (Ba-Boom). I have never experienced a Chelyabinsk kind of meteor; that’s in a much larger ball park when it comes to sonic booms. From what I’ve read, estimates of the Chelyabinsk meteor are in the neighborhood of 500 kt. That’s big. And it causes a lot of damage.

  6. Ronald H. Pine
    March 22, 2015 at 3:06 AM

    Actually, it was two Fin Whales, now that I think about it.

  7. knightofbob
    March 22, 2015 at 3:47 AM

    I was ground crew for fighters for many years, and I’m not sure what I can and can’t talk about to this day, but even on the Great Lakes, you’re not out of the “Offshore Supersonic Training Areas.” Those boys (and girls) have range. By NC, those jets could easily be from Florida, or even Texas, conservatively. I don’t know what the weather’s like down there, but if it’s the right humidity and right temperature, usually around this time of year, those sounds are definitely amplified over distance. My vote’s in for sonic boom.

  8. March 22, 2015 at 4:45 PM

    How often are sonic booms produced?

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