Yearly Archives: 2016

In Memoriam of Lee M. Allison

In honor and remembrance of Arizona’s late state geologist, Lee M. Allison, several colleagues and friends have organized a special event including an afternoon field trip and an evening dinner event. The afternoon field trip event is still being organized and will be on the afternoon of November 19, 2016. The dinner event is planned on November 19, 2016 at  Tohono Chul Park, 7366 N. Paseo del Norte, Tucson, Arizona. There is no cost to this event as it is sponsored by:

AEG – Association of Environmental & Engineering Geologists
AGS – Arizona Geological Society
AZGS – Arizona Geological Survey
AIPG – American Institute of Professional Geologists
ARPA – Arizona Rock Products Association
SABC – Southern Arizona Business Coalition

Evening Event: Celebrating the life of Lee Allison @ Performance Garden of Tohono Chul Park

Day / Time: November 19, 6:00–10:00 pm
Light dinner and drinks provided (cash bar)

Those planning to attend the evening celebration, please RSVP to Kristi Sagar.

Field Trip: Debris-Flow Hazards of the Santa Catalina Mountains and Quaternary Evolution of Piedmont Fans

Day / Time: November 19, 12:30–5:30 pm
Leaders: Ann Youberg and Phil Pearthree of the Arizona Geological Survey
Transportation: TBD
Field trip guide provided gratis by Arizona Geological Survey

Those planning to attend the afternoon field trip, please RSVP to


Posted in Field Trips, Meetings, News

2016 Southwest Geo-Hazards Symposium– Early Bird Special

2016 Southwest Geo-Hazard Symposium

November 14, 2016

Desert Willow Conference Center
4340 E Cotton Center Boulevard, Suite 100
Phoenix, AZ  85040

Please visit the AzSCE website for more details on registration, sponsorship opportunities and a listing of topics and speakers. The symposium flyer can be found here.

 Register before October 21 for Early Bird Special!!!

Posted in News

October 2016 Dinner Meeting


Our next dinner meeting will be held Wednesday October 5, 2016 at McFate Brewing Company located on Scottsdale Road, south of McDowell Road, in Scottsdale (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 and discussion starting shortly after dinner.

This months meeting sponsor is Resilient Drilling.

Meeting Sponsor!

Our presenter is Dr. Phil Pearthree, Interim Director for Arizona Geological Survey (AZGS). Dr. Pearthree will be giving an update on the status of AZGS, as well as a discussion on the landslide database available through AZGS. See October 2016 AEG Meeting flyer for additional details.

We will also present the new AEG Phoenix Chapter leadership, including:

Jessica Castleton, Southwest Regional Director
Ashley Evans, Chair
Danielle Smilovsky, Vice Chair
Maren Henley, Secretary
Tiana Rasmussen, Treasurer

Please RSVP by Monday, October 3, by email to 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.

Posted in Meetings, News


Posted in News

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.


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

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

AZGS Contact Information:
Michael Conway –  520.209.4146 ph

Posted in News

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 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.

Posted in Meetings, News