I have been looking at Skafti Brynjólfsson's impressive doctorate thesis -- and was struck (not for the first time) by the "then and now" syndrome..........
The upper map is based on the field map made by Dave Sugden and myself in the valley of Kaldalon, NW Iceland, in 1960. We had no air photos to work with, and everything was done by hand, using a plane table an a telescopic alidade. Triangulation was the thing, out in the field in all weathers, and hours of painstaking work in the tent when the weather was too miserable to be out and about. I still have the original plane table map --but it was tidied up and simplified for the purposes of publication in the Geografiska Annaler in 1962.
Nowadays, with high resolution satellite imagery, in order to make a map like the one below, you don't even have to leave the comfort of your office or laboratory -- although every self-respecting glacial geomorphologist will of course get out into the field to confirm that the things you assume to be meltwater deposits, till spreads and scree banks are indeed what you think they are!
At the 1960 snout of the glacier
Google Earth 3D image, converted from verticalto oblique......... looking south
Dave working on the plane table map of the valley
Historic document -- primitive technology, but not at all bad in the circumstances.......
The pitted outwash area and the sandur, looking up the valley
1 comment:
The plane table is an amazing tool. I sent many days happily surveying earthworks in Dorset and other places in the days before we started chasing 2 or 3 decimal points, let alone deciding which bit of the slope we wanted to indicate.
Dave
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