A review of the new understanding of fluid-rock deformation in the crack-critical earth

Shear-wave splitting (seismic birefringence) shows that fluid-saturated microcracks throughout the Earth's crust are so closely-spaced they verge on fracturing and hence are critical-systems. Such criticality imposes fundamental new properties on conventional sub-critical geophysics that resolve several previously inexplicable geophysical anomalies as well as implying a New Geophysics that has implications and applications for almost all solid-earth processes and operations including particularly hydrocarbon-production, carbon-sequestration, and forecasting-earthquakes, as well as suggesting new techniques for investigating currently-important solid-earth processes. This review summarises this new understanding of fluid-rock deformation where the new properties include: monitorability, calculability, predictability, universality, and extreme sensitivity to initial conditions. These new properties suggest that New Geophysics is a fundamental advance in solid-earth geoscience.