Latest Global Temp. Anomaly (December '23: +0.83°C)
How Much Ocean Heating is Due To Deep-Sea Hydrothermal Vents?
January 29th, 2024 by Roy W. Spencer, Ph. D.
I sometimes see comments to the effect that recent ocean warming could be due to deep-sea hydrothermal vents. Of course, what they mean is an INCREASE in hydrothermal vent activity since these sources of heat are presumably operating continuously and are part of the average energy budget of the ocean, even without any long-term warming.
Fortunately, there are measurements of the heat output from these vents, and there are rough estimates of how many vents there are. Importantly, the vents (sometimes called “smokers”) are almost exclusively found along the mid-oceanic ridges, and those ridges have an estimated total length of 75,000 km (ref).
So, if we had (rough) estimates of the average heat output of a vent, and (roughly) know how many vents are scattered along the ridges, we can (roughly) estimate to total heat flux into the ocean per sq. meter of ocean surface.
Direct Temperature Measurements Near the Vents Offer a Clue
A more useful observation comes from deep-sea surveys using a towed sensor package which measures trace minerals produced by the vents, as well as temperature. A study published in 2016 described a total towed sensor distance of ~1,500 km just above where these smokers have been located. The purpose was to find out just how many sites there are scattered along the ridges.
https://www.drroyspencer.com/2024/01/how-much-ocean-heating-is-due-to-deep-sea-hydrothermal-vents/
