Questions or comments please contact education @ unavco.org. Ground Motions, Earthquakes, and Volcanoes in the Four Corners region Arizona, Utah, Colorado, New Mexico Using: UNAVCO GPS Velocity Viewer http://www.unavco.org/software/visualization/GPSVelocityViewer/GPSVelocityViewer.html This map shows three types of data (legend is below the map): • Ground motion vectors (Length and direction of the arrow shows the velocity of the ground at that point as measure by GPS). Stable North America is fixed (‘not moving’). • Earthquakes (magenta diamond shapes) • Volcanoes (black triangles with orange tear drops)