A coincidental occurrence today: A co-worker sent along a harrowing tale of Bill Menke, a seismologist, taking a truck down the 900ft deep caldera wall of Grimsvatn; and a discussion of some death-defying by geologists in the field. Don't miss the rockfall heading your way photos here.
I've found over the years that slopes aren't usually as impossible as they appear, and you'd be surprised at how you can climb and descend things you didn't think possible--it just takes time and effort. I did more dangerous things growing up in Boy Scouts and Explorers than in geology field courses.
And if you want some reading in which a man gets it right, nearly every time, read Bill's blog writings. Especially Cornucopians and Conservation