The bones of the earth; a new perspective

[fivemack]

The Shuttle Radar Topography Mission is one of the esoteric topics I'm most prone to enthuse about; I think of it as the last major donation made by the military-industrial complex to the sum of human knowledge before 9/11, and so possibly the last for some time. Using a fortnight of time on the Space Shuttle, Earth was mapped to 90-metre resolution in position and about one-metre in height.

This is a very interesting resolution; water erosion is the main visible feature, you can see some of the moderate-scale processes of geology (are the long linear features dykes?), and you can't see humanity at all.

ESDI is the best interface to the data I've found so far, though it dispenses data in TIFF-format files, one square degree per file and one 32-bit float per pixel; these aren't viewable in standard software.

If you pull out hexdump, gcc, python and gimp in some order, however, you can get something like



I'll be very impressed if anyone knows the shape of my country well enough to be sure of where that is.

I've got a full-scale version (5MB .PNG) or a version with labels (5.5MB .PNG); I'd recommend downloading these to anyone with the connectivity. The labels come, I think, from a full dump of the National Geospatial Intelligence Agency's GNIS database; coordinates there are rounded to the arc-minute, which is about a mile, so I've positioned them randomly within a two-arc-minute square aroud the given position. This may mean North Wallop is positioned south of South Wallop; sorry.

If anyone's aware of a better freely-available gazetteer, please tell me.

Comments

[fivemack.livejournal.com]

They're located west-south-west of Ironbridge, so it's not quite into Wales, and I realise I don't know the name, beyond 'Welsh borders', of that area with Wroxeter, Shrewsbury, Quatford - basically from the Malverns across into Wales. If I had a car, and could figure out a sensible way to navigate along roads towards a GPS position, I'd be very tempted to drive over and see what they look like in ground truth. I suspect they're a signature of a truly spectacular fissure eruption a few hundred megayears ago; it looks as if the spheres were carved out by water escaping from between the dyke and the escarpment.

But I am more ignorant of geography than a worm is of wind-surfing. I've pointed Tim Bond, a geologist at ICL (OK, specialising more in Venus than in Earth at the moment, but one presumably trains long on Earth before proceeding outwards) at this page, and expect him to post something amazingly clear and vastly erudite.