Sunday, October 28, 2007

GSA: everyday science

There are stories about a session at the American Geophysical Union in 1966, when it finally became clear to the audience that sea-floor spreading was real and that the continents really did move. Apparently some other recent AGU meetings have had that sort of feel in sessions about climate change - Chris Mooney describes one in Storm World. But the Geological Society of America meetings that I've attended... they just haven't been like that.

Every talk is fifteen minutes long. Fifteen minutes, in which to make a case that one's ideas or data should change the way we interpret things. Fifteen minutes to convince a room of structural geologists that we really should start with equations of conservation of momentum, as Dave Pollard tried this afternoon. Fifteen minutes to try to explain why rotations determined from paleomagnetic data don't fit those predicted from estimates of strike-slip motion along Laramide structures. (If the model never fits the interpretations of the field data, something's got to be going on - either we don't understand the structures, or we don't understand what kind of rotation the structures should cause.) It's enough time to raise a few questions, maybe even to make a well-constructed argument... and then it's on to the next.

In part, it's the nature of science: most of what we do is incremental, fitting new data into existing models, tweaking the ideas here and there when the data don't quite fit with previous understanding. In part, it's the way the talks work: they are progress reports, ways to raise questions before submitting the long version of the research for rigorous peer review.

So what's the most interesting thing I saw today? Well, there was one talk (in a structure modeling session) testing a hypothesis for entraining layers of debris in the toe of a glacier... which concluded that, no, thrust faults couldn't form in a glacier. (It's nice to see someone come to a conclusion that, no, a model doesn't work.) And I learned, little by little, about mechanical modeling - but I didn't come away with the conclusion that my explanations for a certain group of structures have been totally wrong all this time.

My biggest conclusion for the day is that I need to do a better job of teaching quantitative skills in structural geology. Which isn't really a new conclusion at all.

But perhaps that is not so unsual.

And maybe, if I had wanted to have some paradigms shifted, I should have sat in the Mars sessions. (There will be another one tomorrow. I'm going to go, at least for a while.)

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