NARRAGANSETT, R.I. (WPRI) – As state investigators search for answers as to what caused a blast at Salty Brine Beach over the weekend, local scientists say the cause is likely something man-made.

Three earth science professors interviewed by Target 12 all say it is highly unlikely something geological caused the incident that reportedly sent a woman through the air, landing on the rocks of a jetty.

State officials have said they are looking at every possible angle, including shifting rocks and gas buildup. Rhode Island State Police Lt. Col. Todd Catlow said the State Fire Marshal’s office did not find any evidence of an incendiary device at the beach.

“This is not a geological event in any way, shape or form,” said Dr. Jon Boothroyd, a geology professor emeritus at the University of Rhode Island. “Rocks don’t explode in that manner.”

Dr. Bryan Oakley, an associate professor of earth science at Eastern Connecticut State University, said that like many people, he initially thought the blast was a buried firework that detonated. He said he shares the feelings of his academic colleagues that it is unlikely it was a geological event.

“I don’t think it would have made a large resounding boom which would have exploded and caused a woman to go into the air, which some reports are claiming,” Oakley said.

A seismograph at Bryant University did not register any unusual activity from the time of the incident.

“I can think of one natural phenomenon that was possible, but none that were probable,” said Dr. Stephen Porder, an associate professor of ecology and evolutionary biology at Brown University.

“The possible one, although highly improbable, would be an accumulation of methane [gas],” he said. “But there would be several things that have to happen and most of those things, I don’t think of those happening in a beach environment.”

Both Porder and Oakley say methane would have to be generated from something decomposing, like seaweed. But Porder said it would have to be trapped, then suddenly get exposed to oxygen and a spark.

“That’s a lot that has to happen,” Proder said.

Oakley said whatever the cause of the explosion – whether man-made or Mother Nature – it was likely a rare event and beachgoers shouldn’t be overly concerned that it will happen again.

“I’ve been doing this a while – I think most people are aware that beaches generally don’t explode,” Oakley said. “I think there’s probably a good chance they’ll have a great day at the beach and not get blown up.” Tim White( twhite@wpri.com ) is the Target 12 investigative reporter for WPRI 12 and Fox Providence. Follow him on Twitter: @TimWhiteRI