Friday's AGU wrapup

I'm pretty sure it was four years ago that I printed up a bunch of sheets of paper titled "Are You a Geoblogist?" that I posted on message boards (the physical kind) at the AGU meeting, inviting bloggers to make themselves known to me. I got a handful of contacts, but not one true blogger. And in 2003 on this very blog I was reporting the AGU meeting, into a vacuum. This year things are starting to hop, most notably the folks at RealClimate and ScienceBlogs. Something beautiful is starting to happen.

Anyway, this morning I picked up some good background on this year's breakthrough topic in mid-mantle studies, the presence of water far deeper than ever documented before. One speaker even modeled the presence of ice (the high-pressure form ice-X, that is) below the transition zone at 700-kilometer depths. This research is a struggle for me to understand, so it will be a while before I can write about it with any intelligence.

In the final afternoon of the meeting, I got to sit up and enjoy myself at two intimate gatherings. The first was one that went into geothermal exploration, another topic ready for a big rise in interest. I especially liked Douglas Walker's talk on his algorithm for finding new geothermal sites. We've been basically looking for steam, he says, which is no smarter than the first oil prospectors who looked for oil seeps (and incidentally the death of many of the world's geysers). His work points to efficient ways to produce more Earth energy. The second was a session on intraplate earthquakes, the handful of mysterious shocks that occur far from the usual subduction zones and other plate boundaries. The big concept in shallow-mantle studies, at least in my encounters this week, is the Farallon plate, long dead in California but still exerting its deep and subtle influence as North America plows over its sinking corpse. The Farallon plate is turning into the Pretty Boy Floyd of plate tectonics. The rise of the Sierra Nevada, the Laramide orogeny in the Rockies and the Neogene extension of the Basin and Range are added to its name. And now it's in the lineup with the other factors that are hypothesized to have caused the great 1811-1812 New Madrid earthquakes in the Midwest.