Sea-Floor Sunday #70: Black Sea submarine channel system
This week’s Sea-Floor Sunday image* is from the Black Sea side of the Bosphorous Strait and, as always, shows sea floor bathymetry (hot colors are shallower water and cooler colors are deeper water). Note the prominent channel carving its way into deeper water and then possibly splitting into smaller channels. Or maybe those are overspill channels? Pretty awesome I say.
credit: The Daily Mail
I blogged about this channel system in June 2009 and showed a similar, although much less colorful, image in this post.
The image above and the following quote are from this article in The Daily Mail.
The undersea river – the only active one to have been found so far – stems from salty water spilling through the Bosphorus Strait from the Mediterranean into the Black Sea, where the water has a lower salt content. This causes the dense water from the Mediterranean to flow like a river along the sea bed, carving a channel and deep bank.
The second sentence of that statement is a good one — it explains the mechanism for the origin of this submarine channel system (i.e., saline density currents that hug the sea bottom) and mentions it forms a geomorphic feature similar to a terrestrial river. But the first sentence causes my inner nerd to itch a bit. Firstly, submarine channels are not “undersea rivers” — at least, I’ve never heard anyone else who studies these features call them that. The quote from the researcher included in the piece is simply painting a picture for a general reader that the geomorphology is similar to a river. Secondly, what exactly is meant by “the only active one to have been found so far”? If they mean the active submarine channel systems then, no, this is not the only active one — there are numerous submarine canyon-channel systems that have transmitted density currents in recent decades (e.g. Monterey, Var, Hueneme, Congo, etc.). Perhaps they mean the only active system in which a saline current is the dominant agent? I’m not sure about that — maybe some of my readers could comment on that.
Don’t get me wrong, a discussion about what aspects of submarine channels are similar to rivers and what aspects are different from rivers is a discussion very much worth having. In fact, having that discussion helps us understand these features much better. But, I’m not ready to let the mainstream press and the general public simply call these ‘undersea rivers’ and be done with it — there’s still far too much to learn.
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* pointed out by @jeffersonite last week
Clastic Detritus 
Great image! I am looking forward to read the papers as well, not just the press releases.
Regarding “undersea rivers” — I actually like metaphors that help non-specialists understand fairly complicated phenomena… Even if the analogy is not too precise.
I guess by “active” they meant that this is the only known submarine channel with an always-on and (almost) steady density current in it. If somebody explained how different types of density differences drive rivers, turbidity currents and saline density underflows, the article or press release would be more interesting and more informative… But maybe we are expecting too much from press releases and ‘The Daily Mail’ – type science journalism.
I am tickled that something like this is even featured in mainstream press — and likening it to a river helps paint a picture for the general public no doubt.
This is a very nice image.
Getting anything vaguely scientifically accurate in the pages of the Daily Mail has to be considered a win – it is most well-known for vaccine scare-mongering and trying to frame everything in terms of whether it causes or cures cancer.