Active Tectonics, Quantitative Structural Geology, and Geomorphology



Welcome to the Active Tectonics, Quantitative Structural Geology, and Geomorphology website devoted to precariously balanced rocks (PBRs). This project, initiated in collaboration with Thomas C. Hanks of the U.S. Geological Survey (USGS) and the Southern California Earthquake Center (SCEC), will emphasize the study of the geology and geomorphology of PBRs and their situation in relatively low seismicity regions of Arizona and Southern California.

News & Updates
September 2012
Our paper on estimating the static stabilities of PBRs was just published in Geosphere!
July 2012
Our paper on the applications of airborne and terrestrial laser scanning to paleoseismology was just published in Geosphere!
April 2012
Pat Brennan from the Orange County Register posted a nice vignette on PBRs.

January 2012
We submitted a manuscript to Geosphere (published by the Geological Society of America) showcasing our PBRslenderness MATLAB program for determining the 2D static stability of PBRs from unconstrained digital photographs. The Supplementary Online Materials are located here.

December 2010
We presented a poster at the 2010 American Geophysical Union Fall Meeting in San Francisco, CA, about the latest results from our PBR slenderness program. Materials for this meeting can be accessed here.

October-November 2010
We presented an invited talk at the 2010 Geological Society of America Annual Meeting in Denver, CO, during Topical Session number 32 (Seeing the True Shape of Earth's Surface: Applications of Airborne and Terrestrial LiDAR in the Geosciences). The abstract and talk are available here.

September 2010
We presented a poster at the 2010 Southern California Earthquake Center's Annual Meeting in Palm Springs, CA. The abstract and poster are available here.

July 2010
The Arizona Geological Survey's online newsletter (Arizona Geology) just published an article that we contributed. The article explains LiDAR (TLS and ALSM) and how it was used in precarious rock research. It is freely available to the public here.

May 2010
Our final results were presented in the MS thesis defense of David Haddad on Wednesday May 12th, 2010 in room 566 of the Physical Sciences F-wing (ASU Tempe Campus) at 9:00 am.

January 2010
An updated version of our PBR slenderness analysis code is now available for users that do not have the MATLAB Image Processing Toolbox. Thanks to Matt Purvance for his suggestions that helped in writing the second version. Both versions can be downloaded here. We are still looking for volunteers to test the code using sample PBR photographs. For more information click here.

November 2009
We wrote a MATLAB progam that calculates the 2D static stability of PBRs from unconstrained digital photographs. The code, user manual, and sample PBR photographs are available here. We are searching for volunteers to test the code using sample PBR photographs. For more information, click here.

October 2009
We just completed preliminary processing of our newly acquired ALSM dataset for the Granite Dells! Click here to see a 0.25 m DEM generated from the dataset, among other products.

Click here to view our 2009 SCEC progress report that summarizes our research efforts and results to date.

September 2009
We submitted three abstracts for poster and podium presentations at the 2009 AGU Meeting in San Francisco. All material for this meeting can be accessed here.

Our ALSM data for the Granite Dells precarious rock zone were collected! Thanks to the NCALM pilots and crew for doing a great job and for showing us around their operations. We expect to have the raw point clouds ready for processing (and produce some sweet DEMs) before AGU. Here are some photos of the plane and scanner setup.

August 2009
We submitted two abstracts for poster presentations at the 2009 SCEC Annual Meeting in Palm Springs. We will present our latest results and methods in this project, including the collaborative effort between ASU and USGS Pasadena in documenting a precarious rock in Echo Cliffs, CA. Materials for this are available here.

We completed a terrestrial laser scanning expedition to scan some of our PBRs in the Granite Dells precarious rock zone. We used a Riegl LPM 800i (aka LPM 321) that was borrowed from our colleagues at the Cybermapping Lab of the University of Texas, Dallas. We scanned a single PBR and PBR-covered hillslopes. Here are some photos of the field set up

April 2009
We contributed an article to the April 2009 edition of the Arizona Geology newsletter (published by the Arizona Geological Survey) that describes research interests in the use of PBRs as natural seismometers.

March 2009
 Our proposal for a National Center for Airborne Laser Mapping (NCALM) seed grant to acquire ALSM data for one of our precarious rock zones was accepted! We expect to collect the data by the end of this summer, and begin processing them soon after to generate high-resolution DEMs. This will be the first application of ALSM technology to precariously balanced rocks research.

December 2008
We presented our research efforts at the 2008 AGU Fall Meeting, where David Haddad was awarded an Outstanding Student Paper. All materials for this meeting are available here.

September 2008
We presented a poster and two podium presentations at the 2008 SCEC meeting. All materials for this meeting can be accessed here.

July 2008
We completed our progress report that summarizes our PBR site-selection process.

April 2008
Here are some field photos from the Granite Dells precarious rock zone, near Prescott, AZ, taken on April 26, 2008 during a reconnaissance field trip with Thomas C. Hanks (USGS), Ramon Arrowsmith (ASU), David Haddad (ASU) and Matt Rossi (ASU).

Page maintained by: David E. Haddad.
Last modified: October 10, 2012.