A 3.7 magnitude earthquake recorded off the coast of Florida was likely triggered by a man-made explosion, in order to test the seaworthiness of a new US Navy vessel.

Asked about the reported earthquake on Monday, a public information officer for the Navy’s Sea Systems Command in Washington, DC said the agency was working on a statement it expects to release this week.

The United States Geological Survey reported the 3.7 magnitude to have been detected by seismographs on Saturday afternoon, July 16, when it struck about 104 miles northeast of Daytona Beach.

Seismographs as far away as Minnesota, Texas and Oklahoma reacted as well, as did others along the coasts of Florida, Georgia and North Carolina.

A similar 3.7 magnitude “earthquake”was recorded on June 10, which happened at the same time the Navy reported conducting a shock trial on the USS Jackson for testing, according to the Daytona Beach News-Journal.

The trials are being done to test the ship’s ability to withstand the effects of underwater explosions and remain seaworthy.

The USS Jackson is a new class of combat ship, which will conduct anti-submarine surface and mine countermeasure operations around the globe, according to the Navy.

They’re “designed to defeat threats in coastal waters where increasingly capable submarines, mines and swarming small craft operate,” said the Navy.

The New Journal discovered the Navy had already notified the National Oceanic and Atmospheric Administration’s National Marine Fisheries Service that another shock trial would be conducted between July 16 and 20.

Upon seeing the photo of the shock-trail on the News-Journal’s website, a geophysicist and shift supervisor at the USGS in California, Bruce Presgrave, said, “That’s a smoking gun, isn’t it?”

Presgrave was planning to contact the Navy to learn more about the charges they were detonating. A large underwater explosion “would almost certainly be detected as an earthquake,” he said.

A permit from the Fisheries Service for Navy maneuvers between 2013 and 2018 stated explosions to conduct shock trials east of Jacksonville could include a 10,000 pound charge and a 40,000 pound charge.

According to its permit, the vessel is required to have at least 10 marine mammal observers on board during the exercise, to watch for injuries or mortalities or marine mammal strandings.

Last week, a federal appeals court in San Francisco ruled the Navy’s sonar levels may harm whales and other marine mammals in the world’s oceans, and they must be scaled back.

According to the decision by the Ninth US Circuit Court in San Francisco on Friday, US officials wrongly allowed the Navy to use sonar at levels that harmed marine mammals, and the Navy would have to scale back low-frequency sonar in the Atlantic, Pacific and Indian Oceans as well as the Mediterranean Sea, under authority granted in 2012.

The Navy uses sonar to detect enemy submarines and claims no other type of sonar can fulfill its needs.

Environmental groups, led by the Natural Resource Defense Council (NRDC), challenged the government in a 2012 lawsuit, arguing the Obama administration had approved emissions at sound levels that violated the Marine Mammal Protection Act. The National Marine Fisheries Service then approved the Navy’s plan to deploy 18 deepwater loudspeakers over a five-year period.