Two sources of same info.
https://strangesounds.org/2019/07/north-carolina-methane-field-activity-video.html
“Evidence of a “seep field” off the island was first detected on sonar in 2012, but the expedition this month marked the first time visual proof was established that the seeps remains active and plentiful, officials said.”
or
Start at 1:55 to skip all the intro stuff.
h/t IJumpInIt