Anne: So, Chris – how did your poster session go?

Chris: It went pretty well. The two key things that you want from a poster session are that you spend more time talking to people than you do standing and staring hopefully at everyone wandering past, and that the people you talk to don’t find glaring, basic flaws in the scientific story that you’re trying to present. Most people seemed to think that I had an interesting story about global ridge motions and how the EPR is fixed in the mantle, and I still had my voice at the end of it all. So I’m pretty satisfied.

Chris discusses his poster. Camera angle cunningly chosen to hide confused look on the face of his audience.

Anne: And did you get to those talks you wanted to see this afternoon during your poster session?

Chris: I got to the Gutenburg Lecture just after lunch. Thorne Lay gave a great overview of how seismic and geodetic data from continuous GPS receivers are being combined to great effect in studies of large subduction zone earthquakes, like the 2004 Sumatra earthquake and this years Tohuku earthquake off Japan (what he called ‘seismo-geodesy’). It was quite fun for me because a lot of the earthquakes he talked about were quite familiar to me through my blogging about them.

Sadly, a lengthy discussion at my poster prevented me from attending the rock magnetism talk I was planning to go to at the end of the day. By the time I’d finished talking, the lecture had already been going for 15 minutes.

Anne: Yeah, I know what you mean. I missed a whole hour of talks I meant to see, but had really good, useful conversations in that time instead. I’m starting to think that the poster hall has a serious gravity well associated with it. Every time I think I’m going to escape its orbit and go and listen to some talks in Moscone West, I get sucked back into the vortex by just one more interesting poster, or an encounter with a long-time acquaintance.

Chris: So any highlights from the poster hall vortex?

Anne: I had a couple of really good discussions about linking topographic form of watersheds to the geomorphic processes that shape them, which is directly related to the talk I’m giving tomorrow morning, so it was helpful to see what other people were thinking and doing in places ranging from endorheic basins in Chile to the mountains of Idaho.

But the definite highlight of my time in the poster vortex was running into a former undergraduate student of mine, who took my very first offering of hydrogeology. Now he’s completing a Masters degree in hydrogeology.

Chris: Very cool. My adventures in the vortex centered around the tectonics of subduction zones – particularly what happens when you try to subduct things like ridges and seamounts. I also had a good discussion of new data being collected along the Hikurangi subduction zone off New Zealand, which is a long-standing interest from my PhD research. But I did finally escape to Moscone West, where I sat in on an interesting series of talks about the role of tectonic inheritance in determining the structure of mountain belts. I’d never really appreciated this before, but if a continental collision is the end result of an ocean basin closing, then that ocean had to have first opened up by rifting; and it seems that the structures that formed during that rifting are very important when you get to the mountain building stage. So to truly understand mountain belts, you have to think quite long-term.

And you managed to escape to see some talks today, didn’t you?

Anne: Yes. I spent a good chunk of the afternoon in a hydrology session on ‘Landscape system response under change’, which had talks on the intersections between hydrology, geomorphology and biology. I especially liked Ellen Whol’s talk on the influence that headwater stream geomorphology plays on carbon storage in coarse wood in the floodplain and channel and in fine sediment. Beavers may play an important role in the carbon cycle!! It got me wondering about ways that urban stream hydrology and geomorphology may influence carbon dynamics.

Actually, Chris, it was all about allochthonous materials – at least as I understand them!

Chris: Well, there’s at least one word I understand! Once again, we both had very busy days which had very little in common with each other. It just goes to show just how much is going on at AGU. Bring on Wednesday!

[NB: This is a repost. A server failure at our hosts meant the original was lost.]

Chris: So how was your first day at AGU? You had a poster to present this morning, I think.

Anne: It wasn’t really my first day, you know. Yesterday I was at the Berkeley Catchment Science Symposium which was filled with really great talks on topics ranging from floods to metal isotopes, and lots of great discussions. It was a great way to get my head into the intense science week of AGU.

Chris: Alright, I’m a slacker.

Anne: But, yes, the poster. I was standing in for my graduate student Alea Tuttle and colleague Sara McMillan, who were unable to make it to the meeting. The poster presents some cool data on how stream restoration affects nitrogen dynamics at the stream-reach and individual structure scale. Alea did a great job putting the poster together so that it was very clear what she’d done and found, but I did get a few questions I wasn’t fully able to answer, so I’ll be going back to Charlotte with a few queries for Alea. I’m sure they are all things she’s thought of, and I’ll get a chance to learn some more nitrogen stuff as she explains things to me.

Chris: Excellent. What did you get up to when you weren’t manning your poster?

Anne: I saw a few talks – also on nitrogen, as it relates to hydrologic dynamics. And I caught up with old friends and made some new ones. After going to AGU for about 6 years, it’s amazing how much of a community it becomes.

How about you? You weren’t still working on a presentation, were you?

Chris: I got my poster done before getting on the plane, thank you very much. I’m presenting it tomorrow afternoon.

Anne: So, plenty of time to learn about interesting new science, then.

Chris: Yep. I ended up spending a lot of time today listening to talks discussing the interactions between convection in the mantle, plate tectonics, and topography – an area that my current research semi-overlaps with. I found it quite interesting how, depending on the research objectives, some people were using plate motions to drive mantle convection models, whereas other people were using the history of subduction encoded in the mantle’s temperature structure to refine plate motions. Several talks also emphasised how important mantle flow in response to subduction is in determining things like slab dip and deformation on the overiding plate.

In between talks, I visited the poster hall to look at the paleomagnetism contributions – experimental dynamos, Pangea reconstructions, the timing of the India-Asian collision, oh my! There were also a few interesting ones on dynamic stress triggering following large earthquakes – including a study that proposed that surface waves from a large main shock could circle the globe and trigger its own aftershocks. This falls into the ‘too cool not to be true’ category, although statistically it’s not quite a slam dunk yet,

Anne: Wow, that is cool. But are you sure we’re attending the same conference?

Chris: Well, we both turned up at the same Social Media Soiree.

Anne: Purely coincidence, I’m sure…

Chris: Maybe the next few days will expose some topics of converging interest for the Highly Allochthonous bloggers.

[NB: This is a repost. A server failure at our hosts meant the original was lost.]