What are the most pressing problems in applied geology and geophysics? David Hilbert's 23 problems in mathematics sustained several generations of researchers; today the Clay Mathematical Institute's Millennium Problems are similarly motivating. Perhaps a similar list of unsolved problems in earth science would help focus attention on the big problems, generate public interest, and even attract new funding to the discipline. A few lists have been compiled before — I've sifted through them to find the problems that linger, and I have conducted some crowdsourcing experiments to discover some more. I'll talk about what I've found, and discuss ways that we might grow and maintain a list like this so that it's useful, or at least interesting, to the community.

- Dr. Matt Hall, PhD PGeo, President of Agile Scientific