TY - JOUR
T1 - Laboratory results indicating complex and potentially unstable frictional behavior of smectite clay
AU - Saffer, Demian M.
AU - Frye, Kevin M.
AU - Marone, Chris
AU - Mair, Karen
PY - 2001/6/15
Y1 - 2001/6/15
N2 - A central problem in explaining the apparent weakness of the San Andreas and other plate boundary faults has been identifying candidate fault zone materials that are both weak and capable of hosting earthquake-like unstable rupture. Our results demonstrate that smectite clay can be both weak and velocity weakening at low normal stress (<30 MPa). Our data are consistent with previous work, which has focused on higher normal stress conditions (50 MPa and greater) and found only velocity strengthening. If natural fault zones contain significant smectite, one key implication of our results is that localized zones of high pore pressure, which reduce effective normal stress, could be important in controlling potential sites of earthquake nucleation. Our experiments indicate that friction of smectite is complex, and depends upon both sliding velocity and normal stress. This complexity highlights the need for detailed experiments that reflect in-situ conditions for fault gouges.
AB - A central problem in explaining the apparent weakness of the San Andreas and other plate boundary faults has been identifying candidate fault zone materials that are both weak and capable of hosting earthquake-like unstable rupture. Our results demonstrate that smectite clay can be both weak and velocity weakening at low normal stress (<30 MPa). Our data are consistent with previous work, which has focused on higher normal stress conditions (50 MPa and greater) and found only velocity strengthening. If natural fault zones contain significant smectite, one key implication of our results is that localized zones of high pore pressure, which reduce effective normal stress, could be important in controlling potential sites of earthquake nucleation. Our experiments indicate that friction of smectite is complex, and depends upon both sliding velocity and normal stress. This complexity highlights the need for detailed experiments that reflect in-situ conditions for fault gouges.
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U2 - 10.1029/2001GL012869
DO - 10.1029/2001GL012869
M3 - Article
AN - SCOPUS:0035874888
SN - 0094-8276
VL - 28
SP - 2297
EP - 2300
JO - Geophysical Research Letters
JF - Geophysical Research Letters
IS - 12
ER -