The rifting of Africa

Lava flows from the 2005 Mando Hararo eruption in Ethiopia.

Alright, I had been attempting to ignore this story because it was, well, a little uninteresting at first, but it apparently has legs so I will tackle it.

Slashdot has a post proclaiming:

‘Volcanic activity may split the African continent in two, creating a new ocean, say experts. This is due to a recent geological crack which has appeared in northeastern Ethiopia.’

OK. Where do I start?

This is based on a recent study published in Geophysical Research Lettersthat found that the recent volcanism in Ethiopia is related to the active rifting up and down the east side of the continental – an area already known as the Ethiopian/East African Rift. The continent is known to be pulling apart, forming the valleys and deep lakes (like Lake Malawi and Victoria) that have active volcanoes like Oldoinyo Lengai in them. This is nothing new, we’ve known that Africa is splitting apart for decades – and the rifting has been going on for millions of years.

From what I can gather from the study, the real find is that the fissures formed during the 2005 eruptions at Mando Hararo in Ethiopia are actually part of that rifting – i.e., the crack is part of the “crack” that is splitting the continent. This is not to say that the rifting is starting NOW due to the crack – rather that the fissure is a new manifestation of the active rifting between Africa and the Arabian subcontinent. As with most fissures in actively rifting area, magma came up the cracks – always nice to have ready-made conduits – so this process of cracking and erupting is akin to what we might expect at a mid-ocean ridge (except, at this point, on a continent).

So yes, at some point in the future, water from likely the Red Sea (also an actively rifting and growing ocean) will spill into the East African Rift system and create a new “ocean.” However, this process has been going on for millions of years and to come out and misconstrue the study by Ayele and others in GRL as saying that the activity in 2005 started the rifting or that the crack is the “start” of a new ocean just shows that the mainstream media (a) doesn’t know how to read science beyond what other media are saying about it and (b) how quickly the real findings of a study can be lost in the murk of speculation.