The latest in our series of earth fissure maps has been released for the North Sulfur Springs Valley study area in Cochise County in southern Arizona. The map is available for free viewing and download at our online document repository - http://repository.azgs.az.gov/sites/default/files/dlio/files/nid1562/dm-ef-26_fissuremap.pdf, and the fissures are viewable at the online interactive statewide map viewer of all earth fissures - http://services.azgs.az.gov/OnlineMaps/EarthFissureViewer/. [Right, index map showing fissure areas outlined in red, superimposed over basin subsidence map from ADWR]
This is one of a series of earth fissure maps prepared by the Arizona Geological Survey (AZGS)
in accordance with Ariz. Rev. Stat. § 27-152.01(3). AZGS collected location information from
previously conducted earth fissure studies, reviewed available remote-sensing aerial and satellite
imagery, and conducted surface site investigations throughout the study area. A reasonable
effort was made to identify all earth fissures in the study area. Nonetheless, some fissures may
remain unmapped as a result of one or more of the following:
1) Existing fissures may have been masked by construction or agricultural activities.
2) Incipient fissures may lack clear surface expression.
3) The surface expression of fissures changes constantly as new earth fissures develop and
old earth fissures fill in. A blank area on the map does not guarantee earth fissures are not
present. However, blank areas within the study area boundary have been investigated,
and no surface evidence of fissures was found as of the date of map publication.
Determining the presence or absence of a fissure at any specific site may require
additional mapping and/or geotechnical analysis.
4) Some earth fissures mapped in this study area were previously referred to as
"combination earth fissure-desiccation cracks" (Harris, 2004). Based on similar
appearance, morphology, and depth of surface crack to nearby known earth fissures,
these features are depicted here as earth fissures. Other shallow polygonal surface crack
networks within the study area were interpreted to be giant desiccation cracks and are not
individually depicted on this map. However, zones of desiccation cracks are outlined.
Ref: Arizona Geological Survey, 2014, Earth Fissure Map of the North Sulphur Springs Valley Study Area, Cochise County, Arizona. Arizona Geological Survey Digital Map Series - Earth Fissure Map 26 (DM-EF-26), map scale 1:24,000.
[The report description is taken from the AZGS Document Repository]