Paleoseismologic evidence for large-magnitude (M-w 7.5-8.0) earthquakes on the Ventura blind thrust fault: Implications for multifault ruptures in the Transverse Ranges of southern California

Article English OPEN
McAuliffe, L. J. ; Dolan, J. F. ; Rhodes, E. J. ; Hubbard, J. ; Shaw, J. H. ; Pratt, T. L. (2015)
  • Publisher: Geological Society of America

Detailed analysis of high-resolution seismic reflection data, continuously cored boreholes\ud and cone penetrometer tests (CPTs), and luminescence and 14 C dates from Holocene strata folded\ud above the tip of the Ventura blind thrust fault constrain the ages and displacements in the two\ud most recent earthquakes. These two earthquakes are recorded by a prominent surface fold scarp\ud and a stratigraphic sequence that thickens across an older buried fold scarp, and occurred soon\ud after about 700-900 years ago (most recent event) and between 3-5 ka (penultimate event).\ud Minimum uplift in these two scarp-forming events was ~6 m for the most recent earthquake and\ud ~4.5 meters for the penultimate event. Individual uplifts of this amount require large magnitude \ud earthquakes, probably in excess of Mw7.5 and likely involving rupture of the Ventura fault\ud together with other Transverse Ranges faults to the east and west. The proximity of this large\ud reverse-fault system to major population centers, including the greater Los Angeles region, and\ud the potential for tsunami generation during ruptures extending offshore along the western parts\ud of the system, highlight the importance of understanding the complex behavior of these faults for\ud probabilistic seismic hazard assessment.
  • References (22)
    22 references, page 1 of 3

    Biasi, G.P., and Weldon II, R.J., 2006, Estimating surface rupture length and magnitude of paleoearthquakes from point measurements of rupture displacement: Seismological Society of America Bulletin, v. 96(5), p. 1612-1623.

    Buylaert, J.P., Jain, M., Murray, A.S., Thomsen, K.J., Thiel, C., and Sohbati, R., 2012, A robust feldspar luminescence dating method for Middle and Late Pleistocene sediments: Boreas, v. 41, p. 435-451. DOI:10.1111/j.1502-3885.2012.00248.x

    Dolan, J.F., Sieh, K., Rockwell, T.K., Yeats, R.S., Shaw, J., Suppe, J., Huftile, G.J., and Gath, E.M., 1995, Prospects for Larger or More Frequent Earthquakes in the Los Angeles Metropolitan Region: Science, v. 267, p. 199-205.

    Donnellan, A., Hager, B.H., and King, R.W., 1993a, Rapid north-south shortening of the Ventura basin, southern California: Nature, v. 366, p. 333-336.

    Donnellan, A., Hager, B.H., King, R.W., and Herring, T.A., 1993b, Geodetic measurement of deformation in the Ventura basin, southern California: Journal of Geophysical Research, v. 98, p. 21727-21739.

    Hager, B.H., Lyzenga, G.A., Donnellan, A., and Dong D., 1999, Reconciling rapid strain accumulation with deep seismogenic fault planes in the Ventura basin, California: Journal of Geophysical Research, v. 104(B11), p. 25,207-25,219.

    Hanks, T.C., and Bakun, W.H., 2002, A bilinear source-scaling model for M-logA observations of continental earthquakes: Seismological Society of America Bulletin, v. 92, p. 1841- 1846.

    Hanks, T.C., and Bakun, W.H., 2008, M-log A observations of recent large earthquakes: Seismological Society of America Bulletin, v. 98, p. 490-494.

    Hornafius, J.S., Luyendyk, B.P., Terres, R.R., and Kamerling, M.J., 1986, Timing and extent of Neogene tectonic rotation in the western Transverse Ranges, California: Geological Society of America Bulletin, v. 97, p. 1476-1487, doi: 10.1130/0016- 7606(1986)97<1476:TAEONT>2.0CO;0.

    Hubbard, J., Shaw, J.H., Dolan, J., Pratt, T.L., McAuliffe, L., and Rockwell, T.K., 2014, Structure and seismic hazard of the Ventura Avenue anticline and Ventura fault, California: Prospect for large, multi-segment ruptures in the Western Transverse Ranges: Seismological Society of America Bulletin, v. 104, p. 1070-1087.

  • Related Research Results (1)
  • Metrics
    views in OpenAIRE
    views in local repository
    downloads in local repository

    The information is available from the following content providers:

    From Number Of Views Number Of Downloads
    White Rose Research Online - IRUS-UK 0 29
Share - Bookmark