Editor’s note: I live minutes from where this happened off the coast.
Just last weekend, Floridians social media erupted with the news about an earthquake off the coast of Daytona Beach. However, it turns out that the “earthquake” (reported as a 3.7 magnitude) detected on Saturday by seismographs, as far away as Venezuela and across the United States and Caribbean, was actually triggered by a manmade explosion designed to test the seaworthiness of a new U.S. Navy vessel.
https://www.youtube.com/watch?v=yogCyjApkPI
And this isn’t the first time. A similar 3.7 magnitude “earthquake” was reported by the U.S. Geological Survey on June 10, 156 nautical miles east-northeast of Ormond-by-the-Sea, the same day the Navy reported conducting a shock trial (which tests a ship’s ability to withstand the effects of underwater explosions and remain seaworthy) on the USS Jackson, headquartered at Mayport for testing.
So, what is going on with this testing? Well, the Navy plans to release a statement this week. But, they may not be done. The Navy notified the National Oceanic and Atmospheric Administration’s National Marine Fisheries Service that there may be another shock trial coming, depending on weather, between July 16 and July 20.
Sound travels much further in a layer of ocean water called the SOFAR channel, which is short for Sound Fixing and Ranging Channel. Because the shock trials happen underwater, the SOFAR channel is a very good amplifier, which is likely the reason that this last one sent seismographs as far away as Minnesota, Texas and Oklahoma, as well as along the coast of Florida, Georgia, and North Carolina, into a tizzy. A permit from the Fisheries Service for Navy maneuvers between 2013 and 2018 stated explosions to conduct shock trials on vessels east of Jacksonville could include a 10,000-pound charge and a 40,000-pound charge.
From the article:
“A permit from the Fisheries Service for Navy maneuvers between 2013 and 2018 stated explosions to conduct shock trials on vessels east of Jacksonville could include a 10,000-pound charge and a 40,000-pound charge.
The USS Jackson, commissioned last December, is one of the Navy’s new Independence class of littoral combat ships, which will conduct anti-submarine, surface and mine countermeasure operations around the globe, the Navy has reported. They’re “designed to defeat threats in coastal waters where increasingly capable submarines, mines and swarming small craft operate.”
Thankfully, according to the permit, the Navy is required to have at least 10 marine mammal observers on board aircraft or multiple vessels during the exercise. This ensures that no marine mammals will be stranded due to sonar issues. We don’t have word yet of any strandings but the Fisheries Service reported that a team of observers found no mortalities, injuries to or strandings of marine mammals or sea turtles in 2008, during similar testing on the USS Mesa Verde. Let’s hope we have the same results this time around.
This video is old but if you’d like to know what a shock trial looks like, check it out:
Source: The Daytona Beach News Journal
