New map of the Earth's stress field in the Permian Basin, west Texas and southeast New Mexico. Black lines represent measured directions of maximum horizontal stress. The colored background represents whether the Earth's crust is extensional or compressional. Blue areas to the west indicate that normal (extensional) faults are potentially active, yellow (mostly out of view to the northeast) represents strike-slip faulting (more compressional), and green means that both normal and strike-slip faults are potentially active. Earthquake locations are shown as colored dots. In recent years, several new clusters of earthquakes (red dots) have occurred in the southern Delaware Basin, near the town of Fort Stockton, and another cluster has occurred near Midland. In contrast, older events (orange dots) are concentrated on the Central Basin Platform.