Discovery of a large earth fissure in the southern Picacho Basin, Pinal County, Arizona

Sometime between Mar. 2014 and Dec. 2014, a mile-long, north-south trending earth fissure opened near the Tator Hills, 13 miles south of Arizona City. The fissure extended an additional ¾ mile to the south sometime after March 2016. The sudden appearance of this deep, jagged fissure in an area of modest but continuous rate of land subsidence (up to 1 inch or 3 cm annually over the past decade), and otherwise without active fissure formation since the early 1990s, was surprising. Arizona Geological Survey (AZGS) geoscientists used this opportunity to couple repeat aerial photography, available via Google Earth, with drone technology to complement sub-meter field mapping in order to better understand the timing and geomorphological expression of the fissuring process.Documents in the AZGS Documents Repository collection are made available by the Arizona Geological Survey (AZGS) and the University Libraries at the University of Arizona. For more information about items in this collection, please contact azgs-info@email.arizona.edu)