Haiti - no more concrete?

Awful tragedy in Haiti, from an earthquake. The folk there have everyone's deepest sympathy and need all the help we can muster. But the job after that is to see that tragedy on this scale does not happen there again.

You cannot, pray or curse as much as you like, stop earthquakes. But it was not basically the earthquake that killed and injured so many folk in Haiti. It was falling concrete.

Barack Obama, who has responded very well, (10/10 for that)and is sending all the help he can, said "this is cruel and incomprehensible."

It is unfortunately neither cruel nor incomprehensible and it is perhaps worth getting this straight. If he wants to blame his pet sky god, fine, but he does not have to. No conscious agency was involved in setting off the earthquake. You can look at the world map of the shape of the sea beds, and see immediately that around Haiti is a nightmare. Port Au Prince, the capital, is a tectonic nightmare's nightmare. Two massive tectonic plates are in collision, and Haiti is the crumpling fender. To the south is the massive South American plate, and to the north is the equally vast North American plate. With Haiti not merely on the boundary, but on a twisted and stressed part of that boundary. The two American plates are moving westwards, but at different rates. Haiti is on the tear line. Tear as in both senses of the word.

Have a look first at this map, of the planet's plate tectonics


Click on the map for a bigger image.

Haiti is half of the oval island due north of the most northerly tip of South America. It's location does not look particularly alarming, at that scale. But have a look at the following Google Earth image. It shows the capital, Port Au Prince, but it also shows the shape of the seabed around the island.


Click on the map for a bigger image.

The two dark blue lines in the sea, the curved one to the east of the island and the straight one stretching west to the Yucatan Peninsula, are massive ocean trenches, on the boundary between the two big tectonic plates. And, to make a bad situation worse, the line of the southern edge of the western trench runs right through Port Au Prince.

What follows is that there will be earthquakes there for the next fifty million years, minimum.

What is cruel and does involve conscious thought is the utterly absurd habit of putting up concrete buildings in such places as Haiti. Such places are Japan, southern Italy, Crete, Turkey, Greece, San Francisco, Northern China, the Solomon islands, etc. where the plate tectonics get savage and will always be so.

Construction with concrete should be made illegal in every one of those.

Here is a vast opportunity to be useful, for the steel industry. Promote the replacement of concrete buildings with safer steel ones. Clad them with corrugated iron, or foam sandwiches, or whatever. But not with concrete. The stuff is too heavy. Even if the building stands in a quake, the concrete will fall off and hurt people. If you bolt steel sheeting on properly, it will not fall off. Very simple.

And there is a bonus for the folk who still hang onto the quaint old notion that CO2 is changing the climate, and not deep-seated geological processes. Concrete manufacturing produces vast quantities of greenhouse gases. OK, so does the manufacture of steel, but hey, the greenhouse gassers are bloody damn good at looking the other way, or they would have by now noticed their hockey stick has snapped in the middle. So, just don't talk about that, because a lot of peoples' lives are at stake here. For real, this time.