Science: Pelagic Puzzle

The French liner France brought to port a deep sea puzzle for science. Eyewitnesses gave data:

A light fog clung to the flat, glassy sea between Ambrose Light and Fire Island, N. Y. Captain Maurice Aubert had just ordered a change in course, and for a horrid second, thought he had run aground when the France, with nothing but a limpid swell around her, listed with violent suddenness. Captain Aubert remembered his soundings of a moment before and knew the France could not possibly have touched bottom. This flash of certainty was verified as the ship’s sudden list reversed itself, became a sharp roll. Looking overside, Captain Aubert beheld the sea in a cold boil, an unaccountable churning that rolled the France steeply twelve times. Then all was calm. The France steamed on in peace.

Going below, Captain Aubert found his passengers picking themselves up, putting themselves to rights, after being tumbled about for three minutes as in a brutal storm. Fortunately, the only damage was minor bruises, sprains and a scratch in the left hand of right-handed Jean Borotra, Davis Cup tennis man from France.

Scientists pondered the phenomenon. Was it an earthquake? Seis-mographs sensitized to the slightest disturbance for thousands of miles had recorded nothing. A tidal wave? No wall of water had been visible on the surface. Many hours later a northward moving hurricane did bang that part of the Atlantic into a colossal lather, but what manner of hurricane forerunner would travel invisibly beneath the surface? A convulsive bottom current? A ponderous flotilla of mad leviathans? A freak pelagic tide-rip seething in the depths as masses of the Atlantic changed position?