Vince/ SLAM/index.htm

construction image

Seismo-lineament along the Dog Valley Fault Zone near Truckee, California.

Resources for the Seismo-Lineament Analysis Method (SLAM)

The seismo-lineament analysis method is a tool to spatially correlate a shallow-focus earthquake to the surface trace of the fault that generated it. SLAM is the intellectual property and work product of Vince Cronin, and has been developed with assistance from Catherine Hobart, Brandon Rasaka, Victoria Worrell, Jeremy Ashburn, Luke Pajer, Brian Bayliss, Chris Breed, Bruce Byars, Ryan Campbell, David Cleveland, Jon Cook, Kelly Cronin, Jordan Dickinson, Daniel Lancaster, Ryan Lindsay, Mark Millard, Shane Prochnow, Tyler Reed, Stephen Secrest, Lauren Seidman Robinson, Keith Sverdrup and Lisa Zygo, with funds from AAPG, Association of Environmental and Engineering Geologists (AEG), Baylor University, Colorado Scientific Society, Ellis Exploration, Ft. Worth Geological Society, Geological Society of America (GSA), Gulf Coast Association of Geological Societies (GCAGS), Samson Resources, Roy Shlemon Scholarship Fund, Sigma Xi, and SIPES.

Full papers describing SLAM

Cronin, V.S., 2014, Seismo-Lineament Analysis Method (SLAM), using earthquake focal mechanisms to help recognize seismogenic faults, in Grutzner, C., Choi, J-H., Edwards, P., and Kim, Y-.S., [editors], Proceeding of the 5th International INQUA Meeting on Paleoseismology, Active Tectonics and Archeoseismology , 21-27 September 2014, p. 28-31, ISBN 9791195344109 93450; available via

Cronin, V.S., Millard, M., Seidman, L, and Bayliss, B., 2008, The Seismo-Lineament Analysis Method (SLAM) -- A Reconnaissance Tool to Help Find Seismogenic Faults: Environmental and Engineering Geology, v. 14, no. 3, p. 199-219. Available via GeoScience World at
If you do not have access to the paper online, please contact Vince Cronin directly for a copy:

Typical SLAM workflow

  1. Acquire earthquake data
  2. Acquire DEM data. A suitable DEM dataset is a flat file (text file; e.g., and Arc ASCII GRID file) with a 6-record header and a rectangular matrix of elevation data.
    — Video about getting a DEM and hillshade map from
  3. Use the SLAM code to define the seismo-lineament boundaries
  4. Conduct the structural-geomorphic analysis of the area within the seismo-lineament boundaries, using hillshade maps with low illumination angle in directions nearly perpendicular to the strike of the fault-plane solution. Use the highest-resolution DEMs for this purpose.
  5. Consult all available fault maps of the area, created by reliable sources, to evaluate whether the earthquake occurred on a known fault. Start with
    — the Quaternary Fault and Fold Database of the United States at or, and
    — the National Geologic Map Database at
  6. Are there other earthquakes with focal mechanisms/moment tensors in the catalog that might have seismo-lineaments that overlap with your subject earthquake?
  7. Are there other earthquakes that might be related to the subject earthquake — foreshocks and aftershocks, for example? If so, consider doing a 3-D planar regression to find a best-fit plane through the hypocenter point cloud.
  8. Develop hypotheses for the location of possible fault traces that might correlate with the subject earthquake.
  9. Design a field study to test those hypotheses. For example, go to the area, look along any lineaments identified in the structural-geomorphic study to find evidence of recent faulting. In particular, look for shear surfaces whose striae are approximately parallel to the slip vector of the fault-plane solution. If there are no suitable outcrops, consider EM and resistivity surveys across suspected fault traces to evaluate whether there appears to be subsurface evidence of faulting. Then (safely) trench suspected fault traces.
  10. Interpret the results. Be mindful not to extend beyond a reasonable interpretation of the data.

Current SLAM codes

Note. These are research codes that are the intellectual property of Vince Cronin. You can use them, but you cannot adapt them for sale as a proprietary commercial code.

Current versions of the SLAM code in Mathematica

A larger, higher-res version of the DEM file is available at DogValleyFull27.dat (71.3 MB)

Other potentially useful codes

None of the Mathematica codes written by Cronin are particularly user-friendly — they are research codes.

Some SLAM Thesis References

Ashburn, Jeremy, 2015, Investigation of a lineament that might mark the ground-surface trace of the Dog Valley fault, Truckee area, northern California : B.S. thesis, Baylor University, accessible via

Bayliss, Brian, 2007, Test of a method for recognizing unmapped seismogenic faults : M.S. thesis, Baylor University, accessible via

Dickinson, Jordan, 2015, A seismo-lineament study of magnitude 3.3-5.3 earthquakes near Trinidad, Colorado : B.S. thesis, Baylor University, accessible via

Hobart, Catherine, 2021, Selecting locations for future geophysical surveys in search of the Dog Valley fault using earthquake, LiDAR, and GPS data: M.S. thesis, Baylor University, accessible via

Hobart, Catherine, 2021, Selecting locations for future geophysical surveys in search of the Dog Valley fault using earthquake, LiDAR, and GPS data: M.S. thesis, Baylor University, accessible via

Lancaster, Daniel, 2011, Correlation of earthquakes with seismogenic faults along the Northern Arizona Seismic Belt, southwestern margin of the Colorado Plateau : M.S. thesis, Baylor University, accessible via

Lindsay, Ryan, 2012, Seismo-lineament analysis of selected earthquakes in the Tahoe-Truckee area, California and Nevada : M.S. thesis, Baylor University, accessible via

Millard, Mark, 2007, Linking onshore and offshore data to find seismogenic faults along the Eastern Malibu coastline : M.S. thesis, Baylor University, accessible via

Rasaka, Brandon, 2016, Correlation of selected earthquakes with seismogenic faults, central Oklahoma : M.S. thesis, Baylor University, accessible via

Reed, Tyler, 2014, Spatial correlation of earthquakes with two known and two suspected seismogenic faults, north Tahoe-Truckee area, California: M.S. thesis, Baylor University, accessible via

Seidman, Lauren, 2007, Seismo-lineament analysis of the Malibu Beach quadrangle, Southern California : M.S. thesis, Baylor University, accessible via

Strasser, Matthew, 2017, Spatial Correlation of Selected Earthquakes with the Dog Valley Fault in Northern California using LiDAR and GPS Data: M.S. thesis, Baylor University, accessible via

Worrell, Victoria, 2014, The Seismo-Lineament Analysis Method (SLAM) applied to the South Napa Earthquake and antecedent events: M.S. thesis, Baylor University, accessible via Download from

Some documents from past SLAM presentations

An Adobe Acrobat PDF file of Vince Cronin's presentation at the INQUA PATA meeting in Busan, South Korea, is accessible via , and provides a visual introduction to SLAM.

An Adobe Acrobat PDF file of the oral presentation about SLAM at the Latin American Geological Congress in Medellin, Colombia, on August 31, 2011, is accessible via (~1.2 MB)

A poster describing tests of SLAM that has been presented at the IRIS workshop "Geophysical Hazards and Plate Boundary Processes in Central America, Mexico and the Caribbean" in October 2010 is accessible via (~8 Mb).

The PowerPoint file of the Cronin and others presentation "Finding probable seismogenic faults using EarthScope data and SLAM" at the AEG meeting in South Lake Tahoe (2009) is accessible via . The first half is an overview of EarthScope, and an example of a preliminary application of SLAM in the Lake Tahoe area is at the end of the presentation.

SLAM Bibliography (in approximate superposed chronological order; probably incomplete)

If you have any questions or comments about this site or its contents, drop an email to the humble webmaster .

All of the original content of this website is © 2022 by Vincent S. Cronin