Malcolm J. S. Johnston

My research focuses on the physical processes occurring prior to, during, and following earthquakes and volcanic eruptions and their implications in observations of ground displacement, strain, tilt, electric and magnetic fields using data from state-of-the-art borehole instrumentation. These data show the details of aseismic fault failure, preseismic, coseismic and postseismic deformation, earthquake nucleation, volcanic deformation and volcanic processes. Theoretical modeling of these processes suggests testable physical explanations in term of physics of failure, the role of fluids in the crust, strain redistribution, and likely properties of fault zone materials. Very near-field data on slow slip, earthquakes and dynamic rupture were obtained in fault zones at 3.6 km depth in South Africa, a few 10’s of meters from earthquakes from M=-4.5 to M=2.