Whitney Houston took a car ferry from Britain to Ireland to attend her concert, rather than flying. Barack Obama has canceled his trip to a state funeral in Poland. A very large magical snake protects a canyon in south Africa. These things are connected a lot more closely than you might think.
Eyjafjallajoekull1 is the volcano in Iceland that is making all the mess in Europe, shutting down most Western European airports. Iceland as a whole is a volcanic feature that sits atop the Mid Atlantic Ridge.
The Atlantic Ocean is a huge rift valley, in some ways similar to the famous rift valleys of Africa, but very very wide. The African rifts sit on a continent, but were they to continue to spread, the space between the rift walls would become an ocean. There was a time when the Atlantic Ocean was a rift valley narrow enough to see across, presumably with lakes and dinosaur filled fern forests (or whatever) within. (The current Atlantic opened up starting about 65 million years ago.)
The continental level rifting can be seen in the basin structure of southern Africa as well. The seaward edge of the subcontinent tends to retain an upward slope. At one time, the faces of these slopes were the edges of rifts separating what is now Africa from South America and Antarctica. The upward slope is caused by the elevation that tends to accompany rift systems (which, in the case of Iceland, leads to Iceland sticking up out of the water, and along the mid Atlantic Ridge, leads to … it being a ridge.)
With the continent sloping upwards towards the sea, the interior was filled with giant inland bodies of water, which trapped the sediment that later would become, for instance, the Kalahari sands (which are a thick and major feature from the Orange River of South Africa to the left bank of the Congo River). Subsequent breaching by major rivers, typically forming modern day canyons or very deeply entrenched valleys, emptied those inland seas, and in some cases created huge off-shore deposits. The sand bar at St. Lucia, South Africa, formed in the Miocene of the output from the Limpopo River, is probably the largest sand bar in the world, measured in terms of volume of sand (this is subject to revision, but that is my impression).
Let me give an example that may be closer to home for some of you. If you live near the Hudson River, you may know about the Taconics and the Catskills. You would know of the Catskills as reasonably impressive mountains, and the Taconic Hills as a line of funny little bumps, large hills on the other side of the river from the Catskills. What you may not know is this: The Taconics are the basal remnants of uplift caused by an early closing up of the Atlantic ocean, that caused a huge mountain range to form much like the Himalayas have been formed by the closing of the gap between India and the rest of Asia. The ramming together of continents, as it were. To the west of those mountains formed a great sea, which was filled with sediment from erosion, that erosion being caused by the uplift. The Himalaya-size Taconics essentially eroded into the sea, forming a vast and complex region of sediments to the west. Subsequently, erosion has cut though those sediments and what is left behind is the Catskills. The Catskills are not really mountains … they are an eroded plain, and they are made up of relatively flat (considering how old they are) sediments from across the more recently formed Hudson.
Meanwhile, back in Africa, and much much earlier in time, one of the interior basins formed by rift-ridging around the edge of the continent was presumably breached by the Orange River, which flows all the way from the relatively better watered eastern side of the continent to the west. The river flows through the very arid lands of the southern Kalahari. Even if the river was not used in irrigation, it would still become smaller and smaller as it went west, because of evaporation. And, in reaching the sea, it cuts through a series of canyons.
One of those canyons starts with a high waterfall. The canyon below the waterfall is said to be the home of a giant snake, a very large powerful demonic snake. This snake is the main reasons people (who believe in the snake) will not travel through the area. That maybe somewhat less rational than air traffic controllers refusing to allow planes fly through the ash plume of Eyjafjallajoekull. So the connection, I admit, is tenuous at this level: The snake story and the grounding of the planes are both caused, directly or indirectly, by the rifting process.
But I find a different aspect of this to be more interesting. The average person spends their entire life living in, or frequently visiting, a region without knowing a single thing about it’s geology and related biogeography. Does any American who visits Jamaica or any of the Caribbean Islands know why those islands are there? Does the average Englishman know why the White Cliffs of Dover are in Dover, are white, or are cliffs? (Those may be three different questions … but the answer to one of them is related to rifting!) And now, all these people are wandering around a large chunk of Europe wondering when the ash is going to stop falling, when what they should really be doing is marveling at the fact that they are taking place in a major geological event! Granted, their role in the event is to become part of the sedimentary record (if they stop moving and the rate of ash fall increases enough!). And, in fact, as geological events go, this is not huge. But nonetheless, it is humbling and fascinating at the same time. If you let it be.
Like a big snow storm but you can put some of it in a small plastic box and keep it for your grand kids.
1Eyjafjallajoekull means “My fingers are on the wrong keys on the keyboard” in Icelandic.