Some Current Research Projects

*I am actively recruiting PhD students for all of these projects, so if any or all of these interest you, please contact me.


 

Incremental fault slip rates and paleo-earthquake ages and displacements of the Marlborough fault system, New Zealand – Towards an understanding of the collective behavior of plate-boundary fault systems

Driving in to the trailhead to work on the eastern Clarence fault, Inland Kaikōura Range (Zinke et al., 2018, in prep.). That’s Rob Zinke in the lead fording the ford (in a Ford). Mount Tapuaenuku (2900 m) dominates the skyline.

This ongoing (2010-present) project aims to generate the data necessary to dissect the inner workings of relative plate motions at time scales ranging from the most recent earthquakes to the latest Pleistocene (~15 ka). Our primary goal in this effort (collaborative with Ed Rhodes at Sheffield/UCLA, and Russ Van Dissen and Rob Langridge at GNS Science in New Zealand) is to advance our understanding of the collective behavior of regional fault networks, particularly the importance of emergent phenomena such as earthquake clusters and strain transients that may not be expected in our current understanding of earthquake physics and that are not accounted for in current seismic hazard assessment strategies.

Progressively offset fluvial terraces at our Saxton River study site along the Awatere fault, Marlborough fault system, New Zealand. See Zinke et al. (2017 GRL).

 

We have been using tectonic geomorphic and structural analysis (both field and lidar-based) and paleoseismic trenching to determine rates and dates of fault slip on the main faults of the MFS, which collectively accommodate 80-85% of the total relative Australia-Pacific plate motion in northern South Island, New Zealand. Thus far, our studies reveal wide variations in slip rate spanning multiple millennia, and demonstrate previously hidden interactions between the major MFS faults in which the faults appear to “trade off” displacement amongst themselves. These observations raise a host of questions about the structural evolution of fault zones, the detailed mechanics of moving one plate past another, the limits, predictability, and causes of system-level behavior, and the implications of all of these findings for seismic hazard assessment.

 

Incremental slip rate record of the Awatere fault since c. 12-13 ka at the Saxton River site (Zinke et al., 2017). Note the extreme variations in rate, with the very fast mid-Holocene rate superseded by much-slower slip rates during the past 4,000 years. Similar data sets from all of the other major faults of the Marlborough system are forthcoming, and will allow us to document the collective behavior of the entire fault system, which in the upper crust of this part of New Zealand, accommodates ~85% of the total Pacific-Australia relative plate motion.

Restorations of offset fluvial terrace risers at the Saxton River site. Dating with the newly developed post-IR-IRSL225 luminescence technique (Rhodes, 2015) allows us to precisely constrain the ages of these offsets. Zinke et al. (2017 GRL); lidar data from Dolan & Rhodes (2016) available on OpenTopography website.

(A) Lidar hillshade of northern Kekerengu fault study area showing three potential incremental offset sites that we will map and date. (B) 25-30 m dextral offset of terrace riser at Bluff Station house, where 2016 offsets were 10-12 m. Stars in A & B show location of inset photo of house, which was dragged off its foundation by 6 m; view to NE (lidar courtesy of GNS Science).

How’s this for a field area? That horizontal bench crossing ridge in the middle distance is the easternmost geomorphic expression of the Clarence fault, one of the five main faults that accommodate most relative plate motion within the Marlborough fault system. And it just ends. Right here. Hmmm. There are some really interesting kinematic puzzles related to the structural evolution and growth of faults in this area remaining to be sorted out.

 

Here are some recent publications on these topics (** denotes student co-author under my supervision)(* denotes other student co-author) (we have six more pubs in the works at the moment!):

Zinke, R. W.**, Dolan, J. F., Rhodes, E.J., Van Dissen, R.J., McGuire, C.P.*, Hatem, A.E.**, and Brown, N.D.*, 2018 in review, , Multi-millennial incremental slip rate variability of the Clarence fault at the Tophouse Road site, Marlborough fault system, New Zealand: Geophysical Research Letters, September, 2018.

Zinke, R.**, Dolan, J.F., Rhodes, E.J., Van Dissen, R., and McGuire, C.P.*, 2017, Highly variable latest Pleistocene–Holocene incremental slip rates on the Awatere fault at Saxton River, South Island, New Zealand, revealed by lidar mapping and luminescence dating: Geophysical Research Letters, v. 44, doi:10.1002/2017GL075048.

Ellis, S., Van Dissen, R., Eberhart-Phillips, D., Reyners, M., Dolan, J.F., and Nicol, A., 2017, Detecting hazardous cryptic faults by mapping discontinuities at seismogenic depths: Earth and Planetary Science, doi.org/10.1016/j.epsl.2017.01.038

Langridge, R.M., Ries, W.F.*, Dolan, J. F., Schermer, E., and Siddoway, C., 2017, Slip rate estimates for the Alpine fault (Calf Paddock), New Zealand: New Zealand Journal of Geology and Geophysics, doi: 10.1080/00288306.2016.1275707.

 


Long-distance and long-term fault interactions in southern California – How do the Garlock and San Andreas faults and the faults of the Eastern California Shear Zone work together to move the North American Plate past the Pacific Plate?

Our previous research on these major fault systems suggests both long-term and long-distance fault interactions that are neither well-understood nor accounted for in current seismic hazard assessment strategies. But the details of how Pacific-North America plate motions are accommodated on these fault systems in time and space remain incompletely understood, and we are actively working to flesh out our record of potential long-distance and long-term fault interactions in this area. These results suggest previously unknown forms of interaction, and we are actively working with geodynamicist colleagues to model potential controls on the observed behaviors.

 

Hand digging a trench across a subtle fluvial bar offset left-laterally by 26 m along the Garlock fault south of Searles Lake (see Dolan et al., 2016). The distant peak near center is Telescope Peak (3400 m) in the Panamint Range, with Death Valley on the other side. L to R: James Hollingsworth, Ed Rhodes, Steve Okubo, and Lee McAuliffe.

Spectacularly well-constrained 38 m left-lateral offset of a mid-Holocene alluvial fan (orange) along the central Garlock fault at our Summit Range East site (Dolan et al., 2018 in prep.). The central and eastern sections of the Garlock fault exhibit some of the world’s best geomorphic markers of strike-slip faulting. Truly amazing stuff, both in the NSF-funded GeoEarthScope lidar data, as here, and in the field.

The emerging incremental slip-rate record for the central Garlock fault (Dolan et al., 2015; 2016; in prep. 2018). Note the highly variable slip rate, which we ascribe to a combination of three independent loading mechanisms associated with the behavior of all of the other faults in this kinematically complex section of the Pacific-North America plate boundary (Hatem & Dolan, 2018). There’s lots more to do out there as we continue to sort out how the Garlock and related faults work collectively to accommodate plate motions in this complicated neck of the woods.

We (Sally McGill [Cal State San Bernardino] and Ed Rhodes [Sheffield University/UCLA], and I) have recently been funded by the NSF to continue our work on these fault systems, with a goal of more tightly constraining the past behavior of the major faults, using field and lidar-based tectonic geomorphic and structural mapping, paleoseismic trenching, and luminescence dating to document incremental fault slip rates and paleo-earthquake ages and displacements.

Some recent publications on these topics (** denotes student co-author under my supervision)(* denotes other student co-author):

 

Hatem, A.**, and Dolan, J.F., 2018, A model for the initiation, evolution, and controls on seismic behavior of the Garlock fault, California: Geochemistry, Geophysics, Geosystems, v. 19, https://doi.org/10.1029/2017GC007349

Dolan, J.F., McAuliffe, L.J.**, Rhodes, E.J., McGill, S.F., and Zinke, R.**, 2016, Extreme multi-millennial slip rate variations on the Garlock fault, California: Strain super-cycles, potentially time-variable fault strength, and implications for system-level earthquake occurrence: Earth & Planet, Sci. Lett., http://dx.doi.org/10.1016/j.epsl.2016.04.011.

McAuliffe, L.**, Dolan, J. F., Kirby, E., Rollins, C.**, Haravitch, B.**, Alm, S., and Rittenour, T. M., 2013, Paleoseismologic evidence for late Holocene earthquakes on the southern Panamint Valley fault zone: Implications for earthquake clustering in the Eastern California Shear Zone north of the Garlock fault: Jour. Geophys. Res., v. 118, 1-21, doi:10.1002/jgrb.50359.

Ganev, P.N.**, Dolan, J.F., McGill, S.F., and Frankel, K.L., 2012, Constancy of geologic slip rate along the central Garlock fault: Implications for strain accumulation and release in southern California: Geophysical Journal International, doi: 10.1111/j.1365X.2012.05494.x.

Madden Madugo, C.*, Dolan, J. F., and Hartleb, R. D.**, 2012, New paleoearthquake ages from the western Garlock fault: Implications for regional earthquake occurrence in southern California: Bulletin of the Seismological Society of America, v. 102, p. 2282-229, doi: 10.1785/0120110310.

Roder, B.*, Lawson, M.,* Rhodes, E. J., Dolan, J. F., McAuliffe, L.**, and McGill, S., 2012, Assessing the potential of luminescence dating for fault slip rate studies on the Garlock fault, Mojave Desert, California, USA: Quaternary Geochronology, v. 10, p. 285-290, doi: 10.1016/j.quageo.2012.03.013.

Frankel, K. L.** (deceased 2011), Owen, L.A., Dolan, J.F., Knott, J.R., Lifton, Z.*, Finkel, R.C., and Wasklewicz, T., 2015, Timing and rates of Holocene normal faulting along the Black Mountains fault zone, Death Valley: Lithosphere, doi:10.1130/L464.1.

Frankel, K. L.**, Dolan, J. F., Owen, L. A., Ganev, P.**, and Finkel, R. C., 2011, Spatial and temporal constancy of seismic strain release along an evolving segment of the Pacific-North America plate boundary: Earth and Planetary Science Letters, v. 304, p. 565-576.

Owen, L. A., Frankel, K. L.**, Knott, J. R., Reynhout, S., Finkel, R. C., Dolan, J. F., and Lee, J., 2011, Beryllium-10 terrestrial cosmogenic nuclide surface exposure dating of landforms in Death Valley: Geomorphology, v. 125, p. 541-557, doi:10.1016/j.geomorph.2010.10.024.

Ganev, P.N.**, Dolan, J.F., Frankel, K.L., and Finkel, R.C., 2010, Rates of extension along the Fish Lake Valley fault and transtensional deformation in the eastern California shear zone: Lithosphere, v. 2, p. 33-49; Data Repository 2009285, doi: 10.1130/L51.1.

Ganev, P.N.**, Dolan, J.F., Oskin, M., Blisniuk, K.*, and Owen, L.A., 2010, Paleoseismologic evidence for multiple Holocene earthquakes on the Calico fault: Implications for earthquake clustering in the Eastern California Shear Zone: Lithosphere, v. 2; no. 4; p. 287–298; doi: 10.1130/L82.1; Data Repository 2010217.

Dolan, J. F., Bowman, D. D., and Sammis, C. G., 2007, Long-range and long-term fault interactions in southern California: Geology, v. 35, p. 855-858.

Frankel, K. L.**, Dolan, J. F., Finkel, R. C., Owen, L.A., and Hoeft, J.S.**, 2007a, Spatial variations in slip rate along the Death Valley-Fish Lake Valley fault system determined from LiDAR topographic data and cosmogenic 10Be geochronology: Geophysical Research Letters, v. 34, L18303, doi:10.1029/2007GL030549.


How is surface deformation in large-magnitude earthquakes made manifest in the landscape? Implications of sub-pixel image correlation results for the structural evolution of faults and the predictability of future ground-deformation hazards

In another long-term (2011-present) and ongoing project we (James Hollingsworth [Universite du Grenoble] and my graduate students and I) have been using sub-pixel image correlation tools to document the detailed patterns of surface deformation in past large-magnitude earthquakes. Our goal is to generate a sufficient number of such data to facilitate their use in a predictive sense in next-generation probabilistic fault displacement hazard analysis. We are already in the early stages of using these data as points of comparison with measurable features of faults (e.g., structural complexity, cumulative displacement, local kinematics), and the shallow crust in which the faults are embedded (e.g., sediment thickness and composition, slope angle, distance to bedrock), to evaluate the predictability of patterns and magnitudes of ground deformation hazards in future large-magnitude earthquakes. These comparisons will eventually help to form the basis for next-generation probabilistic fault displacement hazard studies (PFDHA), micro-zonation maps for mitigating damage to the built environment in future large-displacement events, and a more thorough understanding of detailed, site-specific patterns of strong ground motions.

Surface deformation maps generated by sub-pixel image correlations using COSI-Corr for the 1992 Mw=7.3 and 1999 Mw=7.1 Hector Mine earthquakes in the eastern California shear zone in the Mojave Desert of California (Milliner et al., 2016). (a) is N-S motion, (b) is E-W motion. (c) shows displacement measurements (spaced every 138 m along each fault) from the correlation maps (1058 measurements for Landers and 470 for Hector Mine). (d) strain maps computed from the correlation maps.

Wow! You want complicated faulting? We got complicated faulting. Tectonic setting and major faults that ruptured to the surface (red) during the 2016 Mw=7.8 Kaikōura earthquake (Zinke et al. 2018); faults that did not rupture to the surface, including some of the fastest-slipping faults in this part of the Pacific-Australia plate boundary, shown in black.

This is a brand new and rather amazing data set. Moving beyond 2D for the first time in a complex rupture, this shows the full 3D surface deformation field for the Kaikōura earthquake (Zinke et al. 2018). The details of fault kinematics and patterns of distributed versus localized strain revealed by these correlations is truly exceptional.

Some recent publications on these topics (** denotes student co-author under my supervision)(* denotes other student co-author):

 

Zinke, R. W.**, Hollingsworth, J. C., Dolan, J. F., Van Dissen, R., in review 2018, 3D surface deformation in the 2016 MW 7.8 Kaikōura, New Zealand earthquake from optical image correlation: Implications for strain localization and long-term evolution of the Pacific-Australian plate boundary: Geochemistry, Geophysics, Geosystems, August 2018.

Milliner, C.**, Dolan, J. F., Hollingsworth, J. C.#, Leprince, S., and Ayoub, F., 2016, Comparison of near-field and off-fault deformation patterns of the 1992 Mw = 7.3 Landers and 1999 Mw = 7.1 Hector Mine earthquakes: Implications for controls on distribution of surface strain: Geophys. Res. Lett., doi: 10.1002/2016GL069841.

  • Milliner, C.**, Sammis, C., Allam, A.A., Dolan, J.F., Hollingsworth, J., Leprince, S., and Ayoub, F., 2016, The fractal nature of coseismic slip and the relation to fault structure: Nature Scientific Reports, 6:27201, DOI: 10.1038/srep27201.
  • Xu, X.*, Tong. X., Sandwell, D. T., Milliner, C.W.D.**, Dolan, J.F., Hollingsworth. J.#, Leprice, S., and Ayoub, F., 2016, Refining the magnitude of the shallow slip deficit: Jour. Intnl., v. 204, p. 1867-1886, doi: 10.1093/gji/ggv563.
  • Zinke, R.**, Dolan, J. F., Van Dissen, R., Grenader, J. R.**, Rhodes, E. J., McGuire, C.P.*, Langridge, R., Nicol, A., and Hatem, A.**, 2015, Progressive geomorphic and structural manifestation of fault slip as a function of cumulative displacement: A comparison of the Wairau and Awatere faults, South Island, New Zealand: Geology, doi:10.1130/G37065.1, Data Repository item 2015341.
  • Milliner, C.**, Dolan, J. F., Hollingsworth, J. C.#, Leprince, S., Ayoub, F., and Sammis, C.G., 2015, Quantifying near-field and off-fault deformation patterns of the 1992 Mw3 Landers earthquake: Geochemistry, Geophysics, Geosystems, Doi 10.1002/2014GC005693.
  • Zinke, R. W.**, Hollingsworth, J. C., and Dolan, J. F., 2014, Surface slip and off-fault deformation patterns in the 2013 Mw7 Balochistan, Pakistan earthquake: Geochemistry, Geophysics, Geosystems, doi: 10.1002/2014GC005538.

Dolan, J. F., and Haravitch, B. D.**, 2014, How well do surface slip measurements track slip at depth in large strike-slip earthquakes? The importance of structural maturity in controlling on-fault versus off-fault deformation: Earth and Planetary Science Letters, http://dx.doi.org/10.1016/j.epsl.2013.11.043.

Elliott, A. J. **, Dolan, J. F., and D. D. Oglesby, 2009, Evidence from coseismic slip gradients for dynamic control on rupture propagation and arrest through stepovers: Jour. Geophys. Res., 114, B02313, doi:10.1029/2008JB005969.

 


The structural evolution, geomorphic manifestation, and seismic hazards of blind thrust faults and their associated folds

The Puente Hills blind thrust fault. Described by some as LA’s “doomsday fault”. Big fault (we’ve shown that it generates Mw7+ earthquakes) in a bad place (directly beneath downtown LA and most of the rest of the northern LA metropolitan area) with the worst-possible geometry (updip directivity will send seismic energy directly towards downtown LA and funnel it into the Los Angeles Basin. All in all, not good. See Shaw et al. (2002) Pratt et al. (2002), Dolan et al. (2003), and Leon et al. (2007).

Together with my long-term collaborator John Shaw (Harvard) and Ed Rhodes (Sheffield/UCLA), my group is continuing our explorations of numerous features and processes associated with blind thrust faults and their associated folds. These studies range from hard-core fold-thrust belt structural geology, to the acquisition and interpretation of high-resolution seismic reflection data at a wide range of depth scales, to tectonic geomorphologic and sedimentologic studies of the interactions between active faulting and fold growth and the Earth’s surface, to analysis of patterns of past seismic events generated by these structures.

These efforts at understanding how blind thrust fault work and how they are expressed in the landscape are ongoing, with a new project recently funded by the Southern California Earthquake Center (collaborative with Amanda Hughes and Roy Johnson [Arizona] and John Shaw and Ed Rhodes) to study the White Wolf fault system, a major blind thrust that generated the 1952 Mw~7.3 Kern County earthquake. In addition, we are continuing our studies of the major blind thrust systems that underlie much of the metropolitan Los Angeles region (including both my office and my house), as well as our studies of even larger reverse faults in the central and western Transverse Ranges (e.g., San Cayetano-Ventura-Pitas Point fault system; Sierra Madre-Cucamonga fault zone). Some specific goals of these efforts include refining the ages and displacements in past blind thrust earthquakes on the multiple systems we’re currently studying, understanding the structural evolution of the thrust faults and associated folds at scales ranging from a few earthquakes to a million-plus years, documenting the geomorphic expression of these folds and their evolving relationships to rivers and alluvial fans, and the use of all of these data in determining the seismic threat posed by these faults.  So if you’re interested in fold-thrust belt structural geology, the tectonic geomorphology of folds, studying some of the worst deterministic seismic hazards in the entire United States, and working on these issues as your dissertation project(s), then drop me a line.

Pesky gophers acting up again? Try our patented Gopher-B-gone rodent suppression system. Oops. Sorry, wrong caption. Actually, that’s Tom Pratt (USGS) on the left and John Shaw (Harvard) on the right flanking me in the middle. We’re acquiring high-resolution seismic reflection data across the locus of most-recent folding above the central, Santa Fe Springs segment of the Puente Hills blind thrust fault east of downtown LA. See Pratt et al. (2002), Shaw et al. (2002), Dolan et al. (2003), and Leon et al. (2007) for the resulting data (and a lot more).

An example of how we use seismic reflection data of various resolutions and depths to document the entire depth range of folding above blind thrust faults. These nested data sets allow us to document the entire system all the way up into the shallowest levels of folding that developed in the most-recent few earthquakes, into the depth range where we can directly examine the folded strata with continuously cored boreholes.

That’s Lorraine Leon on the right (USC PhD 2009) describing cores from a borehole transect across the zone of most-recent folding above the Compton blind thrust fault southwest of downtown LA. Erik Frost (USC PHD 2009) helping out on the left. See Leon et al. (2009).

If you set out to draw cartoon of the expected geometry of growth stratigraphy deposited across a growing fold, this is what you’d get. Except that these are actual data derived from a transect of continuously cored boreholes collected above the tip of the growth triangle above the Compton blind thrust fault (see photo above). Check out, in particular, the upper inset showing the details of the most recent folding event. The orange sand doesn’t change thickness across the fold, indicating that it was deposited in the absence of a fold scarp and was subsequently folded during the MRE. Now note the geometry of the next sand to be deposited – the brown unit that pinches out (buttresses) against the brand-new fold scarp created in the most recent earthquake. See Leon et al. (2009) for more details.

 

 

Here are some recent publications on these topics (** denotes student co-author under my supervision)(* denotes other student co-author):

Bergen, K.J.*, Shaw, J.H., Leon, L.A.**, Dolan, J.F., Pratt, T.L., Ponti, D.J., Morrow, E., Barerra, W.*, Rhodes, E.J., Murari, M.K., and Owen, L.A., 2017, Accelerating slip rates on the Puente Hills blind-thrust fault system beneath metropolitan Los Angeles, California: Geology.

 

  • McAuliffe, L.**, Dolan, J.F., Rhodes, E.J., Hubbard, J.F.*, Shaw, J.H., Pratt, T.L., 2015, Paleoseismologic evidence for large-magnitude (Mw≥7.5) earthquakes on the Ventura blind thrust fault: Implications for multi-fault ruptures in the Transverse Ranges of southern California: Geosphere, doi:10.1130/GES01123.1

 

Hubbard, J.*, Shaw, J. H. Dolan, J. F., 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: Bulletin of the Seismological Society of America, v. 104, p. 1070-1087, doi: 10.1785/0120130125.

Leon, L. A.**, Dolan, J. F., Shaw, J. H., and Pratt, T. L., 2009, Evidence for large-magnitude Holocene earthquakes on the Compton blind thrust fault, Los Angeles, California: Jour. Geophys. Res., doi:  10.1029/2008JB006129.

 

Leon, L. A.,**, Christofferson, S. A.**, Dolan, J. F., Shaw, J. H., and Pratt, T. L., 2007, Earthquake-by-earthquake fold growth above the Puente Hills blind thrust fault, Los Angeles, California: Implications for fold kinematics and seismic hazard: Jour. Geophys. Res. – Solid Earth, 112, B03S03, doi:10.1029/2006JB004461

Dolan, J. F., and Avouac, J., 2007, Introduction to special section: Active Fault-Related Folding: Structural Evolution, Geomorphologic Expression, Paleoseismology, and Seismic Hazards, Jour. Geophys. Res., 112, B03S01, doi:10.1029/2007JB004952.

Dolan, J. F., Christofferson, S.**, and Shaw, J. H.,2003, Recognition of paleoearthquakes on the Puente Hills blind thrust fault, Los Angeles, California:  Science, v. 300, p. 115-118.

Shaw, J. H., Plesch, A., Dolan, J. F., Pratt, T., and Fiore, P.*, 2002, Puente Hills blind-thrust system, Los Angeles basin, California:  Bulletin of the Seismological Society of America, v. 92, p. 2946-2960.

Pratt, T. L., Shaw, J. H., Dolan, J. F., Christofferson, S.**, Williams, R. A., Odum, J. K. and Plesch, A., 2002, Shallow folding imaged above the Puente Hills blind-thrust fault, Los Angeles, California:  Geophysical Research Letters, v. 29, 10.1029/2001GL014313, p. 18-1 to 18-4 (May 8, 2002).