Horizontal polarization of ground motion in the Hayward fault zone

We investigate shear wave polarization in the Hayward fault zone near Niles Canyon, Fremont,
CA. Waveforms of 12 earthquakes recorded by a seven-accelerometer seismic array around
the fault are analysed to clarify directional site effects in the fault damage zone. The analysis
is performed in the frequency domain through H/V spectral ratios with horizontal components
rotated from 0◦ to 180◦, and in the time domain using the eigenvectors and eigenvalues of the
covariance matrix method employing three component records. The near-fault ground motion
tends to be polarized in the horizontal plane. At two on-fault stations where the local strike
is N160◦, ground motion polarization is oriented N88 ± 19◦ and N83 ± 32◦, respectively.
At a third on-fault station, the motion is more complex with horizontal polarization varying
in different frequency bands. However, a polarization of N86 ± 7◦, similar to the results at
the other two on-fault stations, is found in the frequency band 6–8 Hz. The predominantly
high-angle polarization from the fault strike at the Hayward Fault is consistent with similar
results at the Parkfield section of the San Andreas Fault and the Val d’Agri area (a Quaternary
extensional basin) in Italy. In all these cases, comparisons of the observed polarization
directions with models of fracture orientation based on the fault movement indicate that the
dominant horizontal polarization is near-orthogonal to the orientation of the expected predominant
cracking direction. The results help to develop improved connections between fault
mechanics and near-fault ground motion.

Argus, D.F. & Gordon, R.G., 2001. Present tectonic motion across the Coast
ranges and San Andreas fault system in central California, Bull. seism.
Soc. Am., 113, 1580–1592.
Bakun, W.H., 1999. Seismic activity of the San Francisco Bay region, Bull.
seism. Soc. Am., 89, 764–784.
Barchi, M., Amato, A., Cippitelli, G., Merlini, S. & Montone, P., 2007.
Extensional tectonics and seismicity in the axial zone of the Southern
Apennines, Boll. Soc. Geol. It., Special Issue 7, 47–56.
Ben-Zion, Y., 1998. Properties of seismic fault zone waves and their utility
for imaging low-velocity structures, J. geophys. Res., 103(B6), 12 567–12
585.
Ben-Zion, Y. & Aki, K., 1990. Seismic radiation from an SH line source
in a laterally heterogeneous planar fault zone, Bull. seism. Soc. Am., 80,
971–994.
Ben-Zion, Y. & Sammis, C.G., 2003. Characterization of fault zones, Pure
appl. Geophys., 160, 677–715.
Ben Zion, Y. & Shi, Z., 2005. Dynamic rupture on a material interface with
spontaneous generation of plastic strain in the bulk, Earth planet. Sci.
Lett., 236, 486–496.
Ben-Zion, Y. et al., 2003. A shallow fault-zone structure illuminated by
trapped waves in the Karadere-Duzce branch of the North Anatolian
Fault, western Turkey, Geophys. J. Int., 152, 699–717.
Bonamassa, O. & Vidale, J.E., 1991. Directional site resonances observed
from aftershocks of the 18 October Loma Prieta earthquake, Bull. seism.
Soc. Am., 81(5), 1945–1957.
Boness, N.L. & Zoback, M.D., 2006. Mapping stress and structurally controlled
shear velocity anisotropy in California, Geology, 34(10), 825–828.
Burjanek, J., Gassner-Stamm, G., Poggi, V., Moore, J.R. & Fah, D., 2010.Ambient vibration analysis of an unstable mountain slope, Geophys. J.
Int., 180, 820–828, doi:10.1111/j.1365-246X.2009.04451.x.
Caine, J.S., Evans, J.P. & Forster, C.B., 1996. Fault zone architecture and
permeability structure, Geology, 24, 1025–1028
Calderoni, G., Rovelli, A. & Di Giovambattista, R., 2010. Large amplitude
variations recorded by an on-fault seismological station during the
L’Aquila earthquakes: evidence for a complex fault-induced site effect,
Geophys. Res. Lett., 37, L24305, doi:10.1029/2010GL045697.
Cello, G., Gambini, R., Mazzoli, S., Read, A., Tondi, E. & Zucconi, V.,
2000. Fault zone characteristics and scaling properties of the Val d’Agri
fault system, Southern Apennines, Italy, J. Geodyn., 29(3–5), 293–307.
Cello, G., Tondi, E., Van Dijk, J.P., Mattioni, L., Micarelli, L. & Pinti,
S., 2003. Geometry, kinematics and scaling properties of faults and
fractures as tools for modelling geofluid reservoirs: examples from
the Apennines, Italy, Geol. Soc. London Spec. Publ., 212, 7–22,
doi:10.1144/GSL.SP.2003.212.01.02.
Cultrera, G., Rovelli, A., Mele, G., Azzara, R., Caserta, A. & Marra, F.,
2003. Azimuth dependent amplification of weak and strong ground motions
within a fault zone, Nocera Umbra, Central Italy, J. geophys. Res.,
108(B3), 2156–2170, doi:10.1029/2002JB001929.
Di Giulio, G., Cara, F., Rovelli, A., Lombardo, G. & Rigano, R., 2009.
Evidences for strong directional resonances in intensely deformed
zones of the Pernicana fault, Mount Etna, Italy, J. geophys. Res., 114,
doi:10.1029/2009JB006393.
Dor, O., Rockwell, T.K. & Ben-Zion, Y., 2006. Geologic observations of
damage asymmetry in the structure of the San Jacinto, San Andreas and
Punchbowl faults in southern California: a possible indicator for preferred
rupture propagation direction, Pure appl. Geophys., 163, 301–349,
doi:10.1007/s00024-005-0023-9.
Dor, O., Yildirim, C., Rockwell, T.K., Ben-Zion, Y., Emre, O., Sisk, M. &
Duman, T.Y., 2008. Geologic and geomorphologic asymmetry across the
rupture zones of the 1943 and 1944 earthquakes on the North Anatolian
Fault: possible signals for preferred earthquake propagation direction,
Geophys. J. Int., 173, 483–504, doi:10.1111/j.1365-246X.2008.03709.x.
Falsaperla, S., Cara, F., Rovelli, A., Neri, M., Behncke, B. & Acocella, B.,
2010. Effects of the 1989 fracture system in the dynamics of the upper
SE flank of Etna revealed by volcanic tremor data: the missing link? J.
geophys. Res., 115(B11306), doi:10.1029/2010JB007529.
Fletcher, J.B., Fumal, T., Liu, H.-P. & Carroll, L.C., 1990. Near-surface
velocities and attenuation at two boreholes near Anza, California, from
logging data, Bull. seism. Soc. Am., 80, 807–731.
Graymer, R. W., Sarna-Wojcicki, A.M., Walker, J.P., McLaughlin, R.J. &
Fleck, R.J., 2002. Controls on timing and amount of right-lateral offset
on the East Bay fault system, San Francisco Bay region, California, Bull.
geol. Soc. Am., 114, 1471– 1479.
Graymer, R.W., Ponce, D.A., Jachens, R.C., Simpson, R.W., Phelps,
G.A. & Wentworth, C.M., 2005. Three-dimensional geologic map
of the Hayward fault, northern California: correlation of rock units
with variations in seismicity, creep rate and fault dip, Geology, 33,
521–524.
Griffith, A., Sanz, P.F. & Pollard, D., 2009. Influence of outcrop scale fractures
on the effective stiffness of fault damage zone rocks, Pure appl.
Geophys., 166, 1595–1627.
Harding, T.P., 1974. Petroleum traps associated with wrench faults, Bull.
Am. Ass. Petrol. Geol., 60, 365–378.
Harding, T.P. & Lowell, J.D., 1979. Structural styles, their plate tectonic
habitats & hydrocarbon traps in petroleum provinces, Am. Assoc. Petrol.
Geol. Bull., 63, 1016–1058.
Hobbs, B.E., Means, W.D. & Williams, P.P., 1976. An Outline of Structural
Geology, Wiley, New York, NY, 571 pp.
Improta, L. & Bruno, P.P., 2007. Combining seismic reflection with multifold
wide-aperture profiling: an effective strategy for high-resolution
shallow imaging of active faults, Geophys. Res. Lett., 34, L20310,
doi:10.1029/2007GL031893.
Jaeger, J.C., Cook, N.G.W. & Zimmerman, R.W., 2007. Fundamentals of
Rock Mechanics, Blackwell, Malden, MA, 475 pp.
Jurkevics, A., 1988. Polarization analysis of three component array data,
Bull. seism. Soc. Am., 78, 1725–1743.Kanasewich, E.R., 1981. Time Sequence Analysis in Geophysics, University
of Alberta Press, Edmonton, 477 pp.
Kelson, K.I. & Simpson, G.D., 1995. Late Quaternary deformation of
the Southern East Bay Hills, Alameda County, California, Am. Assoc.
Petrol. Geol. Bull., Abstracts with Programs, Pacific Section Convention,
p. 37.
La Rocca, M., Galluzzo, D., Saccorotti, G., Tinti, S., Cimini, G.B. & Del
Pezzo, E., 2004. Seismic signals associated with landslides and with
a tsunami at Stromboli volcano, Italy, Bull. seism. Soc. Am., 94(5),
1850–1867, doi:10.1785/012003238.
Lawson, A.C., 1908. The earthquake of 1868, in The California Earthquake
of April 18, 1906: Report of the State Earthquake Investigation Commission,
Volume I, pp. 434–448, ed. Lawson, A.C., Carnegie Institution of
Washington Publication No. 87.
Li, Y.G. & Leary, P.C., 1990. Fault zone trapped seismic waves, Bull. seism.
Soc. Am., 80, 1245–1271.
Li, Y.G., Leary, P.C., Aki, K. & Malin, P., 1990. Seismic trapped modes
in the Oroville and San Andreas fault zones, Science, 249, 763–765,
doi:10.1126/science.249.4970.763.
Li, Y.L., Ellsworth, G.W., Thurber, C.H., Malin, P.E. & Aki, K., 1997.
Observations of fault zone trapped waves excited by explosions at the
San Andreas fault, central California, Bull. seism. Soc. Am., 87, 210–221.
Lienkaemper, J.J., Galehouse, J.S. & Simpson, R.W., 2001. Long-term monitoring
of creep rate along the Hayward fault and evidence for a lasting
creep response to 1989 Loma Prieta earthquake, Geophys. Res. Lett., 28,
2265–2268.
Liu, Y., Teng, T.L. & Ben-Zion, Y., 2005. Near-surface seismic anisotropy,
attenuation and dispersion in the aftershock region of the 1999 Chi-Chi
earthquake, Geophys. J. Int., 160(2), 695–706.
Liu, Y., Zhang, H. & Thurber, C., 2008. Shear wave anisotropy in the crust
around the San Andreas fault near Parkfield: spatial and temporal analysis,
Geophys. J. Int., 172, 957–970, doi:10.1111/j.1365-246X.2007.03618.x.
Lewis, M. & Ben-Zion, Y., 2010. Diversity of fault zone damage and trapping
structures in the Parkfield section of the San Andreas Fault from
comprehensive analysis of near fault seismograms, Geophys. J. Int., 183,
1579–1595, doi:10.1111/j.1365-246X.2010.04816.x.
Lewis, M.A., Peng, Z., Ben-Zion, Y. & Vernon, F.L., 2005. Shallow seismic
trapping structure in the San Jacinto fault zone near Anza, California,
Geophys. J. Int., 162, 867–881, doi:10.1111/j.1365-246X.2005.
02684.x.
Lienkaemper, J.J., 1992. Map of recently active traces of the Hayward fault,
Alameda and Contra Costa Counties, California, scale 1:24,000. U.S.
Geol. Surv. Misc. Field Stud. Map MF-2196, 13 pp.
Lienkaemper, J.J., Borchardt,G.&Lisowski,M., 1991. Historic creep rate&
potential for seismic slip along the Hayward fault, California, J. geophys.
Res., 96, 18 261–18 283.
Mamada, Y., Kuwahara, Y., Ito, H. & Takenaka, H., 2004. Discontinuity of
the Mozumi–Sukenobu fault low-velocity zone, central Japan, inferred
from 3-D finite-difference simulation of fault zone waves excited by
explosive sources, Tectonophysics, 378(3–4), 209–222.
Mandl, G., 2000. Faulting in Brittle Rocks, Springer, London, 434 pp.
Maschio, L., Ferranti, L. & Burrato, P., 2005. Active extension in Val d’Agri
area, Southern Apennines, Italy: implications for the geometry of the
seismogenic belt, Geophys. J. Int., 162(2), 591–609.
Menardi Noguera, A. & Rea, G., 2000. Deep structure of the Campanian-
Lucanian Arc (Southern Apennine, Italy), Tectonophysics, 324(4),
239–265.
Mizuno, T. & Nishigami, K, 2004. Deep structure of theMozumi-Sukenobu
fault, central Japan, estimated from the subsurface array observation of
fault zone trapped waves, Geophys. J. Int., 159(2), 622–642.
Pastori, M., Piccinini, D., Margheriti, L., Improta, L., Valoroso, L., Chiaraluce,
L. & Chiarabba, C., 2009. Stress aligned cracks in the upper crust
of the Val d’Agri region as revealed by shear wave splitting, J. geophys.
Res., 179, 601–614.
Peng, Z. & Ben-Zion, Y., 2004. Systematic analysis of crustal anisotropy
along the Karadere-D¨uzce branch of the north Anatolian fault, Geophys.
J. Int., 159, 253–274, doi:10.1111/j.1365-246X.2004.02379.x.
Peng, Z. & Ben-Zion, Y., 2006. Temporal changes of shallow seismicvelocity around the Karadere-Duzce branch of the North Anatolian Fault
& strong ground motion, Pure appl. Geophys., 163, 567–600.
Peng, Z., Ben-Zion, Y.,Michael, A.J. & Zhu, L., 2003. Quantitative analysis
of fault zone waves in the rupture zone of the Landers, 1992, California
earthquake: evidence for a shallow trapping structure, Geophys. J. Int.,
155, 1021–1041.
Pischiutta, M., 2010. The polarization of horizontal ground motion: an
analysis of possible causes, Ph.D. thesis, Universit`a di Bologna ‘Alma
Mater Studiorum’, 172 pp.
Pischiutta, M., Rovelli, A., Fletcher, J.B., Salvini, F. & Ben-Zion, Y., 2010.
Study of ground motion polarization in fault zones: a relation with brittle
deformation fields? American Geophysical Union, Fall Meeting 2010,
abstract #S13A-1960.
Pischiutta, M., Rovelli, A., Vannoli, P. & Calderoni, G., 2011. Recurrence
of horizontal amplification at rock sites: a test using H/V based ground
motion prediction equations, in Effects of Surface Geology on SeismicMotion,
Proceedings of 4th IASPEI/IAEE International Symposium, 2011
August 23–26, University of California Santa Barbara.
Pitarka, A., Collins, N., Thio, H.K., Graves, R. & Somerville, P., 2006. Implication
of rupture process and site effects in the spatial distribution and
amplitude of the near-fault ground motion from the 2004 Parkfield earthquake,
In Proceedings, SMIP06 Seminar on Utilization of Strong motion
Data, California Strong Motion Instrumentation Program, Sacramento,
CA, pp. 19–40.
Provost, A.-S. & Houston, H., 2003. Stress orientations in northern and
central California: evidence for the evolution of frictional strength along
the San Andreas plate boundary system, J. geophys. Res., 108(B3), 2175,
doi:10.1029/2001JB001123.
Riedel,W., 1929. Zur mechanik geologischer Brucherscheinungen. Zentralblatt,
Mineral Geol Palaont B, 354–368.
Rigano, R., Cara, F., Lombardo, G. & Rovelli, A., 2008. Evidence of ground
motion polarization on fault zones of Mount Etna volcano, J. geophys.
Res., 113, doi:10.1029/2007JB005574.
Rovelli, A., Caserta, A., Marra, F. & Ruggiero, V., 2002. Can seismic waves
be trapped inside an inactive fault zone? The case study of Nocera Umbra,
central Italy, Bull. seism. Soc. Am., 92, 2217–2232.
Salvini, F., Billi, A. &Wise, D.U., 1999. Strike-slip fault-propagation cleavage
in carbonate rocks: the Mattinata Fault Zone, Southern Apennines,
Italy, J. Struct. Geol., 21, 1731–1749.
Savage, J.C. & Lisowski, M., 1993. Inferred depth of creep on the Hayward
fault, central California, J. geophys. Res., 98, 787–793.
Savage,M.K., Peppin,W.A.&Vetter,U.R., 1990. Shear-wave anisotropy and
stress direction in & near Long Valley Caldera, California, 1979–1988, J.
geophys. Res., 95, 11 165–11 177.
Seeber, L., Armbruster, J.G., Ozer, N., Aktar,M., Baris, S., Okaya, D., Ben-
Zion, Y. & Field, E. 2000. The 1999 earthquake sequence along the North
Anatolia Transform at the juncture between the two main ruptures, in
The 1999 Izmit & Duzce Earthquakes: Preliminary Results, pp. 209–223,
eds Barka, A., Kazaci, O., Akyuz, S. & Altunel, E., Istanbul Technical
University.
Spudich, P. & Olsen, K.B., 2001. Fault zone amplified waves as a possible
seismic hazard along the Calaveras Fault in central California, Geophys.
Res. Lett., 28(13), 2533–2536, doi:10.1029/2000GL011902.
Spudich, P. & Xu, L., 2003. Documentation of software package ISOSYN:
isochrone integration programs for earthquake ground motion calculations,
CD accompanying IASPEI Handbook of Earthquake & Engineering
Seismology, 72pp.
Spudich, P., Hellweg, M. & Lee, M.H., 1996. Directional topographic site
response at Tarzana observed in aftershocks of the 1994 Northridge California
earthquake: implications formainshocks motions, Bull. seism. Soc.
Am., 86, 193–208.
Storti, F., Salvini, F. & McClay, K., 1997. Fault related folding in sandbox
analogue models of thrust wedges, J. Struct. Geol., 19, 583–602.
Yu, E.&Segall, P., 1996. Slip in the 1868 Hayward earthquake from the analysis
of historical triangulation data, J. geophys. Res., 101, 16 101–16 118.
Wakabayashi, J., 1999. Distribution of displacement on and evolution of a
young transform fault system: the northern San Andreas fault system,
California, Tectonics, 18, 1245–1274.Wakabayashi, J., Hengesh, J.V. & Sawyer, T.L., 2004. Four-dimensional
transform fault processes: progressive evolution of step-overs and bends,
Tectonophysics, 392, 279– 301.
Williams, P.L., 1992. Geologic record of southern Hayward Fault earthquakes,
in Proceedings of the Second Conference on Earthquake Hazards
in the Eastern San Francisco Bay Area, eds Borchardt, G. et al., Spec.
Publ. Calif. Div. Mines Geol. 113, pp. 171–179.
Williams, R.A., Simpson, R.W., Jachens, R.C., Stephenson,W.J.,Odum, J.K.
& Ponce, D.A., 2005. Seismic reflection evidence for a northeast-dipping
Hayward fault near Fremont, California: implications for seismic hazard,
J. geophys. Res., 114, doi:10.1029/2005GL023113.