Paul Johnson is a staff member at the Los Alamos National Laboratory in Los Alamos, New Mexico, USA. His interests are in the physics of faulting and fracturing, the elastic and nonlinear elastic and plastic properties of materials, and application of machine learning methods to geophysical problems. Johnson has published over 200 peer-reviewed papers, co-authored 9 book chapters, and co-authored a book (with R. A. Guyer) on the nonlinear elastic properties of Earth materials. Johnson holds