Revised Earth Fissure Maps Released – Cochise, Maricopa & Pinal Counties

NEWS RELEASE: Revised Earth Fissure Maps for Cochise, Maricopa and Pinal Counties released.

Immediate Release – 2/03/2016

Tucson, AZ – The Arizona Geological Survey (AZGS) continues to map, monitor, and inform the public regarding earth fissures in south-central and southeastern Arizona. Six freshly revised earth fissure maps are now available for parts of Maricopa, Pinal and Cochise Counties. A single new earth fissure map for just east of the Picacho Mountains in Pinal County was issued.

Updated earth fissure study area maps, include: Luke and Chandler Heights in Maricopa County; Picacho and Friendly Corners (3 map sheets) and Santa Rosa Wash in Pinal County; and North Sulphur Springs Valley and Dragoon Road study areas in Cochise County.

The maps and digital data are available at the Natural Hazards of Arizona viewer. Individual fissure study area maps are online at the Arizona Geological Survey’s Online Document Repository. A Google Earth .kmz file is available for viewing the fissures on Google Earth.

All new or revised earth fissure maps employ a base map displaying National Agriculture Imagery Program aerial photography and, when available, a local subsidence map, provided courtesy of the Arizona Department of Water Resources.

A new fissure line category (yellow lines) portrays select fissures as confirmed that were otherwise not mapped by AZGS’ fissure mapping team. These include fissures mapped by reliable sources and those identified on multiple aerial photographs. Previously, if fissures could not be identified during field checks, the fissure was reported as unconfirmed.

Besides posing a threat to infrastructure, fissures are frequently used for illegal dumping of tires, appliances, construction debris, manure and other sundry items.  Because fissures extend downward towards the groundwater table, they represent a potential conduit for surface runoff to contaminate aquifer resources.

AZGS’s earth fissure mapping team will continue to monitor existing earth fissures and map new ones as they form.  AZGS geologists collaborate with hydrologists from the Arizona Dept. of Water Resources to better understand where and when fissures will occur, and with local environmental and geological engineers on ways to mitigate and minimize the impact of earth fissures.

BACKGROUND INFORMATION

Earth fissures are cracks, seams, or separations in the ground produced during differential land subsidence that accompanies extensive groundwater harvesting.  The earliest appearance of fissures in Arizona was near Eloy in 1927.  Individual fissures range in length from hundreds of feet to miles, and in width from inches to tens of feet.  Currently, geoscientists believe that fissures initially form at the groundwater table and then propagate upwards hundreds of feet to the surface.  Because fissures are commonly oriented perpendicular to local drainages, they are capable of capturing surface runoff.  In-rushing waters may result in rapid erosion of sidewalls and gully development causing dramatic and sudden changes in fissure geometry — length, depth, and width.

Earth fissures are a geologic hazard in the arid valleys of central and south-central Arizona.  As urban and suburban centers encroach on subsiding areas of basins/valleys, residents and structures are placed in closer proximity to fissures. Property owners are encouraged to 1) set structures as far away from fissures as possible, and 2) prevent water from entering fissures.

Reports of earth fissures are confined to Cochise, Maricopa, Pima, and Pinal counties in central and south-central Arizona.  In 2007, AZGS released 1:250,000-scale planning maps of the four counties showing the approximate locations of earlier reported earth fissures. These earth fissure planning maps are available free, online at the Earth Fissure Center at www.azgs.az.gov/efc.

AZGS is charged by state statute with mapping earth fissures in Arizona.

AZGS Contact Information:
Michael Conway –  520.209.4146 ph
e-mail:   michael.conway@azgs.az.gov
http://www.azgs.az.gov
repository.azgs.az.gov




February 2016 Dinner Meeting

Our next meeting will be held Wednesday  February 3, 2016 at SunUp Brewing Company located on Camelback Road between Central Avenue and 7th Street in Phoenix (Google Map). We will start off at 5:30 pm with a hosted happy hour, followed by dinner at 6:30 pm and the presentation starting shortly after dinner. The meeting sponsor is AEG Arizona Section.

Our speaker is Gary S. Rasmussen, Engineering Geologist and President at Gary S. Rasmussen & Associates, Inc. His presentation is titled “Surface Ground Rupture from the 1992 Mw 7.3 Landers Earthquake as Observed from the Air and Ground “. See February 2016 AEG Meeting flyer for additional details.

Please RSVP by Tuesday, February 2, by email to aeg.arizona@gmail.com if you would like to attend. If you would like to sponsor a student dinner for an additional $10, please let us know in your RSVP as well.




2014-2015 Richard H. Jahns Distinguished Lecture

Our next meeting will be held Wednesday  September 9, 2015 at SunUp Brewing Company located on Camelback Road between Central Avenue and 7th Street in Phoenix (Google Map). We will start off at 5:30 pm with a hosted happy hour, followed by dinner at 6:30 pm and the presentation starting shortly after dinner.

Our speaker is Eldon Gath, Engineering Geologist and the 2014-2015 Richard H. Jahns Distinguished Lecturer. His presentation is titled “Tectonic Geomorphic and Paleoseismic Investigations for the Panama Canal“. See September 2015 AEG Meeting flyer for additional details.

Space is limited, so please RSVP to Zachary Shafer by latest Friday, September 4, if you would like to attend. If you would like to sponsor a student dinner for an additional $10, please let us know in your RSVP as well.

PLEASE NOTE OUR NEW MEETING LOCATION

More information about the Richard H. Jahns award can be found here.




July 2015 Dinner Meeting

Our next meeting will be held Thursday  July 23, 2015 at SunUp Brewing Company located on Camelback Road  between Central Avenue and 7th Street in Phoenix (Google Map). We will start off at 5:30 pm with a hosted happy hour, followed by dinner at 6:30 pm and the presentation starting shortly after dinner. The meeting sponsor is Geomechanics Southwest, Inc.

Our speaker is Ken Fergason, Senior Geologist at Amec Foster Wheeler and current President of AEG. His presentation is titled “The Geologic, Geohazard, and Geotechnical Field Investigation for the Hoover Dam Bypass Bridge“. See July 2015 AEG Meeting flyer for additional details.

Please RSVP to Zachary Shafer by Friday, July 20, if you would like to attend. If you would like to sponsor a student dinner for an additional $10, please let us know in your RSVP as well.

 

PLEASE NOTE OUR NEW MEETING LOCATION



Oak Creek-Mormon Lake Graben

The Geologic Field Trip Guide: Oak Creek-Mormon Lake Graben, North-Central Arizona by Paul Lindberg

This geologic field trip guide circumnavigates a loop of ~120 miles from Flagstaff to Sedona along Highway 89A and returns to Flagstaff along the Lake Mary Road.

The 12 geologic stops focus on recent faulting and the encroachment of Basin and Range extensional structures on the Colorado Plateau. Each stop is detailed in the text, which is amply illustrated with photographs and colored geologic sketches.

The guide is made available to the public courtesy of Paul Lindberg and the Arizona Geological Society.

 

Lindberg1

Cross section of the Oak Creek – Mormon Lake Graben (PL)

Lindberg2

Schnebly Hill sandstone deformed along Laramide-age, reverse Oak Creek fault

Lindberg3

Basalt lava flow capping volcanic tephra at junction of Stoneman Lake and Lake Mary Road

Lindberg4

Geologist Paul Lindberg at exposure of the Lake Mary Fault on Marshall Road adjacent to Upper Lake Mary




Grand Canyon – Geologic Tour of Central and Northern Arizona

The AEG 57th Annual Meeting Field Trip to the Grand Canyon Guidebook.

The authors and field trip leaders:
Phil Pearthree (Arizona Geological Survey)
Wayne Ranney (Geologist, Author, and Guide)
Guidebook Edited By: Chase White
Field Trip Sponsored By: Duane Kreuger

Grand Canyon National Park - Image credit: National Park Service

Grand Canyon National Park – Image credit: National Park Service




June 2015 AEG & AIPG Joint Dinner Meeting

Our next meeting will be held Wednesday June 3, 2015 at SunUp Brewing Company located on Camelback Road  between Central Avenue and 7th Street in Phoenix (Google Map). We will start off at 5:30 pm with a hosted happy hour, followed by dinner at 6:30 pm and the presentation starting shortly after dinner.

Our speaker is Jeffrey R. Keaton,Principal Engineering Geologist at Amec Foster Wheeler. His presentation is titled “The March 22, 2014, Oso Landslide: An Overview of the GEER Response“. See June 2015 AEG Meeting flyer for additional details.

Please RSVP to Zachary Shafer by Friday, May 29, if you would like to attend. If you would like to sponsor a student dinner for an additional $10, please let us know in your RSVP as well.

PLEASE NOTE OUR NEW MEETING LOCATION



10th Annual Arizona AEG Student Night

Please join the Arizona Section of the Association of Environmental and Engineering Geologists (AEG), the American Institute of Professional Geologists (AIPG), the Arizona Hydrological Society (AHS), and Geo-Institute (ASCE) at the 10th Annual Arizona AEG Student Night meeting on Thursday, April 30, 2015.

The event will begin at 6:00 pm and will be held in the Mohave Meeting Room of the Student Memorial Union on the Tempe campus of Arizona State University. For more information about Student Night, please see the Student Night Flyer.

RESERVE A SLIDE TO MARKET YOUR COMPANY!

Companies and agencies interested in a continuously running PowerPoint slide for advertising may reserve a slide for a cost of $100. The $100 cost will cover the display slide and dinner for one representative attending the meeting, and the much needed
support to help cover costs for student dinners.

PROFESSIONALS, SPONSOR A STUDENT DINNER!

You may sponsor a student for dinner at the time of the meeting or in advance for $30/student. Please extend your generosity and support to the next generation of professionals in our field.

The RSVP form for professionals can be found here. For reservations and to submit an abstract contact Tiana Rasmussen no later than Friday, April 17, 2015 Monday, April 20, 2015.

Student abstracts must be submitted by April 17, 2015.

DEADLINE EXTENDED TO APRIL 20!

DINNER FOR STUDENTS IS FREE!

Please contact Tiana Rasmussen or Nasser Hamdan with any questions.




ASU Presents: Great Debate Extinctions: Tragedy to Opportunity

If anyone is interested, ASU is having a talk, February 7th, on the the nature of extinction, from biology, and the great past extinctions, to culture, language, technology and the future of both our species and the Earth’s biosphere.  For more information about the event, please visit the event page




October Meeting

Come join us October 28th for a presentation by Dr. Ron C. Blakey.

Please visit out Section Events page for more details.