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Geology in action: A mid-ocean ridge you can visit on vacation! Answered

UPDATE Jun 2011:  ScienceNews has a very nice feature about Afar, with an excellent narrative summary of items since the current spreading event began in 2005.

UPDATE Nov 2009:  Science magazine only keeps their news articles free for a short time.  The link below requires paid access to read.  Wikipedia has an article on the volcano.

A news article in this week's (May 2009) Science magazine online reports on a very unusual volcano. Located directly in the center of east Africa's Great Rift Valley, it is spewing a unique kind of lava.

The Great Rift Valley is a place where one of Earth's tectonic plates is actively dividing in two -- the eastern tip of Africa and the Arabian peninsula is separating from the rest of Africa. In several million years there will be a brand new ocean (not a "sea") like the Atlantic, and the Great Rift Valley will become its mid-ocean ridge.

This African volcano is essentially an example of the undersea volcanoes that run down the spreading center along the middle of the Atlantic (Iceland is a set of them that are above the ocean surface). If you want to see what was happening when the Atlantic Ocean was forming, and Brazil was being broken away from West Africa, go visit Ol Doinyo Lengai in Tanzania.

ADDED:  Besides the world's only active (on land!) natrocarbonatite volcano, the Great Rift Valley also has examples of sheeted dikes forming and breaking through to the surface.


Very cool, and in the ScienceNews link there is some really neat stuff on RNA rewriting too :-)  also an interest of mine....

|Your link in the OP gives me this message (Subscribe/Join AAAS or Buy a Site Pass to View Full Text. The content you requested requires a AAAS member subscription to this site or ScienceNOW Site Pass purchase. If you already have a user name and password, please sign in below.

  However, I don't see ANY text from the article, there.

ARGH.  Okay, so I've learned something.  They only keep the "news" articles free for a finite time.  I'll update the topic text above, and also see if I can find an alternative writeup (possibly in ScienceNews).  Sorry for the inconvenience.

NP,  I looked around for at least some of the info elsewhere, just so I could print off a bit and read at my leisure.  

8 years ago

You could also go to Iceland

True enough!  The difference, though, is that Iceland is "merely" an exposure of the existing mid-Atlantic ridge above the current sea surface level.  The activity in Afar (and the Great Rift Valley in general) is demonstrating how new mid-ocean ridges form during the fragmentation of a existing crustal plate.

This is absolutely correct, but to see a mid ocean ridge (plume as well maybe?) I'd go to Iceland, to see rifting, IN THE DESERT, which is double awesome, I'd definitely go to the Afar. It's semantics really, I suppose. I was just surprised when I saw the mid ocean ridge thing in the thread title that it wasn't about Iceland.

The reason they're describing it as "like a mid-ocean ridge" is because the volcano is producing carbonate magma, rather than the usual silicate magma.  That's characteristic of the vulcanism along the mid-ocean ridge.  Also (see my posting below from 4 Nov), there are sheeted dikes forming in the same area.  Those are unique to mid-ocean ridges.

The whole situation is really awesome, no matter what your semantics :-)

A followup.  In the same region, a sheeted dike (the characteristis feature of mid-ocean ridges) formed in the course of just a few days in 2005!


The though occurs to me that some Africans might be a bit more concerned about whether they'll have anything to eat today or be dead tomorrow. It's nice that we can think of geology...


Ah, that one. It's moved quite a bit "recently" - good link. L