Earth Fissure Mapping Update: Maricopa County Complete
& Moving into Cochise County | AZGS STAFF

With release of four new Earth Fissure Study Area Maps, AZGS’s Earth Fissure Mapping program is ahead of schedule.   The maps published in June 2009 include:

Friendly Corners
Pinal County
Maricopa County
Signal Peak
Pinal County
Tator Hills
Pinal County

The four county Earth Fissure Planning maps, which identify the 23 earth fissure study areas, were published in 2007.  Since then 14 study areas have been mapped; the maps are available as PDFs at .   A shape file containing all published earth fissure map is available there, too.


Completion of the Harquahala study area, marks the end of earth fissure mapping in Maricopa County.  Other earth fissure study area maps in that county, include: Chandler Heights, Luke, Mesa, Scottsdale, Wintersburg and Apache Junction, the latter co-resides in Pinal County.

Tator Hills south of Arizona City is home to more than a dozen fissures.   Several fissures range from ½ mile to over 1 mile in length, and one particularly prominent fissure is two-thirds of a mile long, 3 to 10 ft wide, and up to 15 ft deep.  Fissures here are largely confined to unimproved lands or to agricultural fields.

Signal Peak, located about 6 miles north-northeast of Casa Grande, hosts six fissures, one of which slices for nearly a mile through a housing addition west of Signal Peak.

Friendly Corners, eight miles east of Picacho Peak and consisting entirely of agricultural lands, hosts one confirmed and several unconfirmed earth fissures.


When AZGS was first charged with comprehensive mapping of earth fissures in 2006, the work was scheduled from 2007-2011, with regular updates to follow on a five-year cycle.  Areas rapidly changing from rural to urban – e.g., Chandler Heights, Apache Junction – were scheduled first with agricultural areas to follow.  By July 2009, and just two years into the program, more than 50 percent of the study areas are mapped including the largest area, Picacho Basin.   

The Willcox Basin of Cochise County and Greene Reservoir of Pinal County are next up for mapping.  The image displayed here shows a well head perched about 1-meter above the subsiding basin floor of the Willcox Playa.   (Photo by Todd Shipman, August 2009.)

The AZGS Earth Fissure Mapping team is managed by Dr. Todd Shipman and includes Mike Mahan, Mimi Diaz, and Mike Conway. 

2 FIGURES   1) EF Mapping Pic – thumbprint and interior pic;  
2) Tator Hills6-09 (W caption:  Tator Hills Earth Fissure Map) – should appear to the top and right side of page.

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