Deep Methane Maxima in the Northwest Caribbean Sea: Possible Seepage Along the Jamaica Ridge

Methane concentrations as great as 30,000 nanoliters per liter were measured on two cruises in the northwest Caribbean Sea. Such concentrations are three orders of magnitude higher than Bunsen solubilities would predict. Although shallow maxima may result from in situ microbial activity, the deeper maxima appear to result from massive seepage (estimated at 1 x 10(8) to 10 x 10(8) liters per day) along the Jamaica Ridge.