I had a great conference, I networked, had job interviews, presented my postdoctoral work, and met with collaborators and most importantly I was immersed in new science expanding my knowledge in Critical Zone processes. The best thing I saw at AGU was the session on Critical Zone Science Union (U53A: The Critical Zone: Revealing the Structure, Function, and Evolution of Earth’s Living Skin). It took place on Friday afternoon, but was worth the wait. It was well attended and is available through AGU on-demand at: https://vts.inxpo.com/scripts/Server.nxp?LASCmd=AI:1;S:17;F:QP!14100&EventKey=201126&EventAttendeeKey=18768642&ShowKey=33780&EventScreenCaptureMode=NULL&RandomValue=1484073070905
There were several interesting talks in this union, but I will focus on just two. Bill Dietrich (UC Berkeley) and Steven Holbrook (University of Wisconsin) focused their talks on the deep critical zone. Bill, spoke about the need to define and locate the layer of fresh bedrock, as the reactions there strongly influence earth surface processes. He outlined various hillslope theories which could be utilised to map the bedrock surface underlying the landscape, which he referred to as the next topographic revolution. Then, Steven Holbrook, a geophysicist, presented some novel techniques to measure the depth to bedrock in the field. As well, he spoke about a model which was able to predict the depth to bedrock through surface observations, from a 2015 Science paper by St. Clair et al. (http://science.sciencemag.org/content/350/6260/534). As a critical zonist, with a speciality in earth surface processes, river biogeochemistry, and catchment hydrology, I found this topic quite interesting, because the behaviour at the surface that I measure is influenced by the deeper critical zone structure, thus gained a greater appreciation for the deep critical zone.