I heard a 50 min talk yesterday by Kerry Sieh on Sumatra...and took some notes. I may post details later, but the important thing is for me to first correct things that I posted: I thought that the M7.9 quake in September that followed the M8.4 filled half the Mentawai (sp) gap between quakes (south of equator). I assumed that the aftershocks were showing the extent of the rupture. But, the 7.9 broke a relatively small part of the subduction zone and a M7.0 quake afterwards just broke an unconnected patch off the the north. So, there is a big gap that Kerry expects could be filled by a M8.8 or 8.9 in the next couple of decades...or could be a half dozen M8.4s. He is using accumulated strain since 1833 or 1861 (would have to check my notes). Using corals, he can see uplift events that show that 2 or 3 quakes can cause uplift in the same spot. Also, as strain is accumulating on locked parts of subduction zones and other parts creep, you get horizontal motions seen on GPS and vertical motions that corals record. He may not have explicitly said that the following is the reason there were not really large tsunamis from the 8.4 (or 8.7 March 2005), but he did say that those quakes did not rupture all the way up to the seafloor.

Also heard the latter part of a talk that said climate change in the Arctic is worse than climate models had predicted: things are happening much more quickly. The speaker (another special 50 minute talk) thought that the Arctic Ocean would be ice free in summer by 2030 rather than the 2100 that had been predicted, and said that someone else had predicted it would be ice free by 2013. In response to a question: conserve and adapt.
Chris