Software for slip-tendency analysis in 3D: A plug-in for Coulomb

Slip-tendency analysis is a valuable tool in fault reactivation evaluation and seismic hazard assessment as it provides a means of quantifying the slip potential on mapped or suspected faults in a known or inferred stress field. We developed an interactive graphic tool to perform slip-tendency analysis. The application is written in MATLAB in the form of plug-ins for COULOMB, a graphic-rich deformation and stress change open-source software. In addition to identifying the faults most prone to reactivation, we compute and plot synthetic focal mechanisms from the direction and sense of likely slip. This allows compatibility between focal mechanisms and geological structures to be verified. Both individual faults and fault networks can be considered in three dimensions. The potential for slip depends on the prevailing stress field, the fault surface orientation and the coefficient of friction. These parameters are given interactively in a Windows environment. The application thus offers an easy-to-use graphical interface with the possibility of fast parameter modification and 3D visualization of the results.

[1]  M. Bott,et al.  The Mechanics of Oblique Slip Faulting , 1959, Geological Magazine.

[2]  Walter H. F. Smith,et al.  Free software helps map and display data , 1991 .

[3]  Yoshio Fukao,et al.  Thrust faulting at a lithospheric plate boundary the Portugal earthquake of 1969 , 1973 .

[4]  L. Pinheiro,et al.  Tsunamigenic-seismogenic structures, neotectonics, sedimentary processes and slope instability on the southwest Portuguese Margin , 2003 .

[5]  Giorgio Minelli,et al.  A mechanical model for complex fault patterns induced by evaporite dehydration and cyclic changes in fluid pressure , 2007 .

[6]  Robert E. Wallace,et al.  Geometry of Shearing Stress and Relation to Faulting , 1951, The Journal of Geology.

[7]  C. Pascal,et al.  Interaction of faults and perturbation of slip: influence of anisotropic stress states in the presence of fault friction and comparison between Wallace-Bott and 3D Distinct Element models , 2002 .

[8]  Marco Ligi,et al.  Source of 1755 Lisbon earthquake and tsunami investigated , 2001, Eos, Transactions American Geophysical Union.

[9]  Cristiano Collettini,et al.  A slip tendency analysis to test mechanical and structural control on aftershock rupture planes , 2007 .

[10]  Alan P. Morris,et al.  The importance of the effective intermediate principal stress (σ′2) to fault slip patterns , 2009 .

[11]  Y. Okada.  Internal deformation due to shear and tensile faults in a half-space , 1992, Bulletin of the Seismological Society of America.

[12]  J. F. Luis,et al.  Mirone: A multi-purpose tool for exploring grid data , 2007, Comput. Geosci..

[13]  Mourad Bezzeghoud,et al.  Seismic Sources on the Iberia-African Plate Boundary and their Tectonic Implications , 2004 .

[14]  David D. Pollard,et al.  Stress inversion methods: are they based on faulty assumptions? , 1993 .

[15]  José Morales,et al.  Source analysis of the February 12th 2007, Mw 6.0 Horseshoe earthquake: Implications for the 1755 Lisbon earthquake , 2007 .

[16]  Rui Neves,et al.  Flexure and seismicity across the ocean–continent transition in the Gulf of Cadiz , 2009 .

[17]  J. Angelier,et al.  Determination of the mean principal directions of stresses for a given fault population , 1979 .

[18]  Mark D. Zoback,et al.  Faulting patterns in north‐central Nevada and strength of the crust , 1980 .

[19]  W. Dunne,et al.  Palaeostress analysis of small-scale brittle structures , 1994 .

[20]  Elisa Buforn,et al.  Seismicity, source mechanisms and tectonics of the Azores-Gibraltar plate boundary , 1988 .

[21]  Alan P. Morris,et al.  Slip-tendency analysis and fault reactivation , 1996 .

[22]  G. King,et al.  STATIC STRESS CHANGES AND THE TRIGGERING OF EARTHQUAKES , 1994 .

[23]  Jian Lin,et al.  Stress triggering in thrust and subduction earthquakes and stress interaction between the southern San Andreas and nearby thrust and strike-slip faults , 2004 .

[24]  William Sassi,et al.  Homogeneous stress hypothesis and actual fault slip: a distinct element analysis , 1993 .

[25]  A. Etchecopar,et al.  An inverse problem in microtectonics for the determination stress tensors from fault striation analysis , 1981 .

[26]  N. Zitellini,et al.  Eastern segment of the Azores-Gibraltar line (central-eastern Atlantic) : An oceanic plate boundary with diffuse compressional deformation , 1994 .

[27]  Gustavo Tolson,et al.  A graphical technique to predict slip along a pre-existing plane of weakness , 1998 .

[28]  D. Bamford,et al.  Lithospheric structural contrasts across the Caledonides of northern Britain , 1979 .

[29]  Serkan B. Bozkurt,et al.  Forecasting the evolution of seismicity in southern California : Animations built on earthquake stress transfer : Stress transfer, earthquake triggering, and time-dependent seismic hazard , 2005 .

[30]  Diego Córdoba,et al.  Crustal architecture and tectonic evolution of the Gulf of Cadiz (SW Iberian margin) at the convergence of the Eurasian and African plates , 2003 .

[31]  Giorgio Ranalli,et al.  Critical stress difference, fault orientation and slip direction in anisotropic rocks under non-Andersonian stress systems , 1992 .

[32]  F. Chierici,et al.  Neogene Through Quaternary Tectonic Reactivation of SW Iberian Passive Margin , 2004 .

[33]  M. Astiz,et al.  Magnetotelluric survey in the bradyseismic area of Phlegraean Fields , 1984 .

[34]  H. Philip,et al.  Modern tectonic stress field in the Mediterranean region: evidence for variation in stress directions at different scales , 1992 .

[35]  Enrico Serpelloni,et al.  Kinematics of the Iberia–Maghreb plate contact from seismic moment tensors and GPS observations , 2006 .

[36]  Christophe Pascal,et al.  SORTAN: a Unix program for calculation and graphical presentation of fault slip as induced by stresses , 2004, Comput. Geosci..

[37]  Andrés Maldonado,et al.  Structure and evolution of the “Olistostrome” complex of the Gibraltar Arc in the Gulf of Cádiz (eastern Central Atlantic): evidence from two long seismic cross-sections , 2004 .

[38]  John W. Gephart,et al.  An improved method for determining the regional stress tensor using earthquake focal mechanism data: Application to the San Fernando Earthquake Sequence , 1984 .

[39]  Richard J. Lisle,et al.  Test of the frictional reactivation theory for faults and validity of fault-slip analysis , 2004 .