June 20 – Martyrs' Day in Eritrea

Posted on June 20, 2016

I've talked a bit about the 30-year war of independence in Eritrea in an earlier post. Today is set aside to remember the tens of thousands of people who died during that generation-long struggle.

Unfortunately, the two nations involved in that war -- Ethiopia and Eritrea -- are still skirmishing along the border! Like, when I googled “Eritrea” just now, there was a news item about a deadly battle from just a few hours ago!

When-oh-when will peace reign in that region?

Rather than go back through the depressing stuff about humans vs. humans, with way too much killing along the border, I thought I would talk about the Danakil Depression, on the border between Eritrea and Ethiopia.

The Danakil Depression has nothing to do with the sad kind of depression, nor with killing (despite its name). Instead, it is a very low-lying area, a depression in the Earth's crust.

The Depression is there because, in the Horn of Africa, where Eritrea is located, several tectonic plates are moving apart from one another, more quickly than is usual for geological movement. The Horn of Africa is eventually going to be ripped off of the rest of Africa, and we are witnessing the birth of a new ocean.

You probably know that the rocky crust of the Earth is not solid, but rather made up of plates of different sizes and shapes. They slo-o-o-o-o-owly ride on top of the hotter, more mobile mantle.

In some places, two plates are pulling away from each other, moving apart. Magma rushes in to fill the widening gap. When this happens on a continent, like Africa, a low rift valley is formed. Eventually, most rift valleys fill up with water and eventually eventually most become steadily widening oceans!

Here you can see some of the directions in which plates are pulling apart in that part of Africa.

The Danakil Depression is the hottest place on Earth, when you look at year-round average temperatures. It is one of the lowest places on Earth (330 feet below sea level, or 100 feet below sea level), and it has no rainfall most of the year.

It sounds a bit like hell, doesn't it? But...when you look at the magma crater lakes in the Danakil Depression's active volcano, and you consider the fact that the hot springs smell like sulfur...

I mean, come on! Look at this place!!!

There's not much life in this tectonically active region. Any microorganisms that live there are extremophiles (organisms that love extreme environments), most of them thermophiles (organisms that love really hot environments).

Still, even though the Danakil Depression isn't exactly lush with lifeforms, understanding the biology going on there may be helpful in understanding the sorts of lifeforms we might find on other planets and moons. Also, this area is called the cradle of the hominids because Donald Johanson and his colleagues discovered the famous Australopithecus skeleton we call Lucy there.

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