UMass Geomechanics

Ayla Heinze Fry and Karl Grette present their undergraduate theses

Congratulations! (photos by J Brigham-Grette)

New paper in Journal of Structural Geology

We dcument fault propagation around restraining bendswithin wet kaolin and demonstrate that the fault evolve to increase efficiency. Cooke, M. L., M. T. Schottenfeld and S. W. Buchanan (2013), Evolution of Fault Efficiency at Restraining Bends within Wet Kaolin, Journal of Structural Geology, doi:10.1016/j.jsg.2013.01.010.

Quicktime animation of strike-slip fault growth in our restraining bend analog experiments

The bright pink highlight regions of high shear strain. The image at right shows a snapshot towards the end of the experiment. On the left side of the restraining bend, two echelon faults are active. The inner fault is dying out while the outer fault picks up activity.

The geomechanics group will have several presenations at the upcoming AGU meeting

• T13D-2644. The influence of complex fault geometry on uplift patterns in the Coachella Valley and Mecca Hills of Southern California
  Laura Fattaruso; Michele L. Cooke
• T13E-2657. The Work Budget of Rough Faults
  Patrick J. Newman; William A. Griffith; Michele L. Cooke
• T14C-07. Testing restoration-based fracture prediction methods using field studies of fracturing in syn-tectonic strata
  John R. Shackleton; Michele L. Cooke; Gareth Johnson; Antonino Cilona
• T23D-2699. Evolution of Fault Efficiency at Restraining Bends within Wet Kaolin Analog Experiments
  Michele L. Cooke; Mariel Schottenfeld; Steve Buchanan
• T23D-2708. Using the Work of Fault Generation in the Laboratory to Predict Fault Evolution 
  Justin W. Herbert; Michele L. Cooke

New paper in the Bulletin of the Seismological Society of America

Justin shows that slip distribution along faults changes with rather small changes in fault geometry. In the figure above, Justin shows that variations in tectonic loading may favor either strike-slip along the San Andreas fault or the Eastern California Shear Zone.

Herbert, Justin and Michele L. Cooke, 2012. Sensitivity of the southern San Andreas fault system to tectonic boundary conditions, Bulletin of the Seismological Society of America, vol. 105, 2046-2062, doi: 10.1785/0120110316

2012 Southern California Earthquake Center meeting Sept 9-12

Justin Herbert, Laura Fattaruso and Ohilda Difo did an awesome job presenting their posters at the meeting. In this photo they are enjoying a gondola ride up Mt San Jacinto before the meeting

Over the summer, the Physical Modeling Lab got a bit of a makeover

More light, more space and more storage for the win. The uniaxial rig moved in.

We upgraded some furniture and we are readyto run more analog experiments.