Kaj Johnson Crustal Deformation Department of Geological Sciences Indiana University

1001 E. 10^th St. Bloomington, IN 47405 (812) 855-3612 Email: kajjohns at indiana.edu

Research Interests:

I am a geophysicist who works primarily with geodetic data and numerical and analytical modeling to investigate active deformation of the lithosphere. In particular, I study how deformation within plate boundary zones is accommodated by faulting and folding in the crust and viscous flow in the lower crust and upper mantle.

The types of research questions that motivate my current work and will continue to drive future research include:

(1) What physical processes are involved in the “earthquake cycle” at plate boundary settings consisting of relatively steady interseismic deformation punctuated by sudden earthquakes and rapid transient postseismic deformation?

(2) What controls the location and timing of large earthquakes on faults? To what extent can faults be characterized as consisting of locked patches that rupture unstably in large earthquakes and creeping patches that slide stably? Can we identify these patches and predict the location of future large earthquakes?

(3) How can observations from geology, geomorphology, seismology, and geodesy be combined to constrain a single mechanical model of crustal deformation over multiple time scales?

(4) How does short time-scale, recoverable elastic deformation transform into permanent, inelastic deformation in the lithosphere, and to what extent can this permanent deformation be recognized in the contemporary deformation field?

Quick jump to:

Curriculum Vitae

Research Projects

Publications with links to abstracts and pdf copies

Matlab scripts for deformation analysis

Crustal Deformation Group Members Faculty member: Kaj Johnson Graduate Students: Ray Chuang, PhD, plate boundary deformation, southern California, Taiwan Mehmet Kokum, MS, North Anatolian Fault Ying-Feng Chen, new student, TBD Austin Hodge, fault related folding in Montana Jeremy Mauer, new student, TBD Visiting Student: Yi-Rong Yang, National Taiwan University Former members: Abbie Enneking, MS, volcano deformation, now working in Houston Shibaji Chatterjee, MS, deformation in Tibet, now working in India Chinaemerem Kanu, MS 2010, fault friction (now at Colorado School of Mines) Jun’ichi Fukuda, post-doc 2006-2009, now Assistant Professor, Earthquake Research Institute, University of Tokyo, Japan Owen (Wen-Jeng) Huang, post-doc 2006-2008, now Assistant Professor at National Central University, Taiwan Kuo-En Ching, post-doc 2009-2010, now post-doc at Academia Sinica, Taipei, Taiwan

The Group in 2010 Left to right: Owen, Yi-Rong, Kaj, Ray, Mehmet The Group in 2008 Left to right: Ray, Kaj, Shibaji, Kanu, Abbie, Junichi (Fukuda-san)

If you are a prospective student looking for a graduate program in crustal deformation studies, please contact me about joining our group!!

We also work closely with Michael Hamburger and Gary Pavlis:

Geophysics & Tectonics at Indiana

Active Research Projects  

Links to descriptions of active projects:

Crustal stress in Japan and M9 Tohoku earthquake

Southern California crustal deformation

Shallow fault creep at Parkfield

Deep fault creep at Parkfield

Mountain building in Taiwan

Mountain building in Taiwan

The goal of this project is to integrate seismic, GPS, paleoseismic, and geomorphic data into a model for the contemporary and Holocene time-scale deformation in Taiwan. The main research questions are: What are the slip rates on active faults in Taiwan? What lithospheric deformation processes are responsible for the present-day GPS velocity field? To what extent does the GPS-derived velocity field reflect the long-term evolution of the mountain range? What is the importance of topographic load on deformation? To what extent does erosion influence contemporary deformation?

Collaborators: Wen-Jeng Huang (Indiana University Postdoc), Ruey-Juin Rau (Professor, National Cheng Kung University, Taiwan), Kuo-En Ching (PhD student, National Cheng Kung University, Taiwan).

Funding: (current) NSF EAR-0609620, Toward Dynamic Models of contemporary plate boundary deformation with application to Taiwan

Afterslip and fault friction

In this work we are using transient deformation recorded with high rate and standard GPS data following several earthquakes to infer the spatial distribution of frictional properties on faults. We are investigating the 2004 Parkfield earthquake, the 2002 Denali, Alaska earthquake, the 2003 Tokachi-oki, Japan earthquake and the 2003 Cheng-Kung, Taiwan earthquake. We incorporate laboratory-derived rate-and-state dependent friction laws into numerical models to simulate the evolution of afterslip. The main objective of this research is to determine whether or not afterslip occurs on areas of the fault that are nominally frictionally stable and unable to spontaneously rupture in earthquakes, or on nominally unstable areas that do rupture in earthquakes. These findings will have important implications to our knowledge of the extent to which slip on faults is partitioned into stable creeping regions and unstable stick-slip regions.

collaborators: Junichi Fukuda (Indiana University Postdoc), Paul Segall (Professor, Stanford University), Shinichi Miyazaki (Assistant Professor, ERI University of Tokyo), Kristine Larson (Professor, University of Colorado)

Funding: (current) USGS NEHRP No. 07HQGR0110, Inferring Rate- and state-dependent frictional parameters at Parkfield, CA, using numerical models and geodetic data

(current) NSF EAR-0635741, Collaborative Research: Utilizing GPS Measurements of postseismic deformation to infer spatial distribution of frictional properties on faults (with Paul Segall, Stanford)

Interseismic deformation and lithosphere rheology

We are using GPS, triangulation, and paleoseismic data with interseismic earthquake cycle models to infer slip rates on faults and rheology of the lithosphere. As we recently showed in Johnson et al. (2007), it is necessary to estimate fault slip rates and rheology simultaneously because fault slip rate estimates are strongly dependent on rheology. We are applying 2D and 3D models to data in the San Francisco Bay Area, California, Taiwan, Tibet, and southern California.

collaborators: Junichi Fukuda (Indiana University Postdoc), Paul Segall (Professor, Stanford University), George Hilley (Assistant Professor, Stanford), Roland Bürgman (Professor, UC Berkeley)

Funding: (recently expired) USGS NEHRP No. 06HQGR0034, Refining estimates of lithosphere rheology and earthquake parameters along the San Andreas fault

(recently expired) USGS NEHRP No. 05HQGR0127 Refining estimates of fault slip rates and earthquake recurrence times in the San Francisco Bay Area using 3D viscoelastic cycle models and GPS data

(current) Southern California Earthquake Center (SCEC), Reconciling geodetic and geologic estimates of fault slip rates in southern California

Postseismic processes and lithosphere rheology

We are using GPS measurements of postseismic deformation following the 2002 M7.9

Denali, Alaska Earthquake to infer lithosphere rheology in southern Alaska. We are modeling the deformation as coupled processes of afterslip governed by rate-dependent friction on a fault in an elastic crust overlying distributed viscous flow in the lower crust and upper mantle. We are using the model and observations to infer the relative contributions of flow and afterslip to deformation and infer the first-order lithosphere rheology.

collaborators: Roland Bürgman (Professor, UC Berkeley), Jeffrey Freymueller (Professor, University Alaska, Fairbanks)

Funding: none – this is a continuation of my postdoctoral research at UC Berkeley that was supported by a grant awarded to Roland Bürgmann.

Growth of fault-related folds:

Blind reverse faults underlying actively growing anticlines pose significant seismic hazard in places like Los Angeles, California. Contrary to the prevailing view in the literature, we have shown that a significant contribution to the growth of these anticlines may be folding by buckling of strata rather than slip on the buried fault. In this work we have developed boundary element models of folding of a medium containing many elastic layers and a fault to show that folds produced by slip on faults may be significantly amplified by buckling of the multilayer.

collaborators: Wen-Jeng Huang (Indiana University Postdoc)

Funding: none right now

Probabilistic Inverse theory

We are developing inversions schemes caste in a fully probabilistic, Bayesian framework. We have developed a method to objectively select smoothing in fault slip inversions. We are also developing Bayesian inversions for mixed linear/nonlinear problems. A number of common and seemingly different inverse problems, including standard damped least squares, can be solved with this method with the relative weighting of data fit and damping determined objectively. In this approach, all information on data, priors, and model uncertainty is expressed as probability distributions.

collaborators: Junichi Fukuda (Postdoc, Indiana University)

Funding: none specific to this work, but this work permeates all of my funded work

Publications

Published

Shelly, D., and K. M. Johnson (2011), Tremor reveals stress shadowing, deep postseismic creep, and depth-dependent slip recurrence on the lower-crustal San Andreas fault near Parkfield, Geophys. Res. Lett., doi:10.1029/2011GL047863, pdf.

Chuang, R. and K. M. Johnson, 2011, Reconciling geologic and geodetic fault-slip-rate discrepancies in southern California: consideration of non-steady mantle flow and lower crustal fault creep, Geology, doi: 10.1130/G32120.1

Ching, K.-E., K. M. Johnson, R.-J. Rau, R. Y. Chuang, L.-C. Kuo, and P.-L. Leu (2011), Inferred Fault geometry and slip distribution of the 2010 Jiashian, Taiwan, earthquake is consistent with a thick-skinned deformation model, Earth and Planetary Science Letters, 31, 1-2, p. 78-86

Ching, K.E., and M.-L. Hsieh, K.M. Johnson, K.-H. Chen, R.-J. Rau, and M. Yang (2011), Modern vertical deformation rates and mountain building in Taiwan from precise leveling and continuous GPS observations, 2000-2008, Journal Geophysical Research (accepted manuscript)

Sun, J., K. M. Johnson , Z. Cao , Z.-K Shen , R. Bürgmann , X. Xu (2011), Mechanical constraints on inversion of co-seismic geodetic data for fault slip and geometry: example from InSAR observation of the 6 October 2008 Mw 6.3 Dangxiong-Yangyi (Tibet) earthquake, J. Geophys. Res., 116, B01406, doi:10.1029/2010JB007849

Kanu, C. and K. M. Johnson (2011), Arrest and Recovery of Frictional Creep on the southern Hayward fault triggered by the 1989 Loma Prieta, California earthquake and Implications for Future Earthquakes, J. Geophys. Res., 116, B04403, doi:10.1029/2010JB007927.

Johnson, K. M., and J. Fukuda (2010), New methods for estimating the spatial distribution of locked asperities and stress-driven interseismic creep on faults with application to the San Francisco Bay Area, California, J. Geophys. Res., 115, B12408, doi:10.1029/2010JB007703.

Fukuda, J. and Johnson, K. M. (2010), Mixed linear–non-linear inversion of crustal deformation data: Bayesian inference of model, weighting and regularization parameters. Geophysical Journal International, 181: 1441–1458. doi: 10.1111/j.1365-246X.2010.04564.x. pdf

Huang, W.-J., K. M. Johnson, J. Fukuda, and S.-B. Yu (2010), Insights into active tectonics of eastern Taiwan from analyses of geodetic and geologic data, J. Geophys. Res., 115, B03413, doi:10.1029/2008JB006208. pdf

Fukuda, J., K. M. Johnson, K. M. Larson, and S. Miyazaki, 2009. Fault friction parameters inferred from the early stages of afterslip following the 2003 Tokachi-oki earthquake, J. Geophys. Res., doi:10.1029/2008JB006166, pdf

Johnson, K.M., Burgmann, R., and J.T. Freymueller, 2009. Coupled afterslip and viscoelastic flow following the 2002 Denali Fault, Alaska Earthquake, Geophys. Journal Int., 176, 3, doi:10.1111/j.1365-246X.2008.04029.x, pdf

Hilley, G. E., Johnson, K. M., Shen, Z.-K., Wang, M., and Bürgmann, R., 2009, Earthquake-Cycle Deformation and Fault Slip Rates in Northern Tibet, Geology, v. 37; no. 1, p. 31–34, doi: 10.1130/G25157A.1. pdf, supplementary materials

Huang, W.J., and Johnson, K.M., Growth of fault-cored anticlines by combined mechanisms of fault slip and buckling, Journal Geophysical Research, submitted 7/26/07.

Fukuda, J., and Johnson, K.M., 2008. A fully Bayesian inversion for spatial distribution of fault slip with objective smoothing, Bulletin Seismological Society of America, v. 98, no. 3; p. 1128-1146; doi: 10.1785/0120070194. pdf

Johnson, K.M., Hilley, G.E., and Burgmann, R., 2007. Influence of lithosphere viscosity structure on estimates of fault slip rate in the Mojave region of the San Andreas fault system, Journal Geophysical Research, 112, B07408, doi:10.1029/2006JB004842. pdf

Johnson, K.M., R. Bürgmann, and K. Larson, 2006. Frictional properties on the San Andreas Fault near Parkfield, California, Inferred from Models of Afterslip following the 2004 Earthquake. Bulletin of the Seismological Society of America, Vol. 96, No. 4B, pp. S321-S338, doi: 10.1785/0120050808. pdf

Johnson K. M., P. Segall, S. B. Yu, 2005. A viscoelastic earthquake cycle model for Taiwan, J. Geophys. Res., 110, B10404, doi:10.1029/2004JB003516. pdf

Johnson, K.M., and Segall, P., 2004. Viscoelastic earthquake cycle models with deep stress-driven creep along the San Andreas Fault, Journal of Geophysical Research, 109, 10.1029/2004JB003096. pdf

Johnson, K.M., and Segall, P., 2004. Imaging the ramp-décollement geometry of the Chelungpu fault using coseismic GPS displacements from the 1999 Chi-Chi, Taiwan earthquake. Tectonophysics, 378, 123-139. pdf

Johnson, K.M, Hsu, Y.J., Segall, P., and Yu, S.B., 2001. Fault geometry and slip distribution of the 1999 Chi-Chi, Taiwan earthquake imaged from inversion of GPS data, Geophysical Research Letters, 28, 11, 2285-2288. pdf

Johnson, K.M., and Johnson, A.M., 2002, Mechanical models of trishear-like folds, Journal of Structural Geology, 24, 277-287. pdf

Johnson, K.M., and Johnson, A.M., 2002, Mechanical analysis of the geometry of forced-folds, Journal of Structural Geology, 24, 401-410. pdf

Johnson, K.M., and Johnson, A.M. 2000. Localization of layer-parallel faults in San Rafael Swell, Utah and other monoclinal folds, Journal of Structural Geology 22, 1455-1468.

Hooper, A., Segall, P., Johnson, K.M., and Rubinstein, J., 2002. Reconciling seismic and geodetic models of the 1989 Kilauea south flank earthquake GRL, 29, Vol. 29, No. 22, 2062, doi:10.1029/2002GL016156, 2002. pdf

Cervelli, P., Segall, P., Johnson, K.M., Lisowski, M., and Miklius, A., 2002. Sudden aseismic fault slip on the south flank of Kilauea Volcano. Nature, 415, p.1014-1018.

Johnson, A.M., Johnson, K.M., Durdella, J., Sozen, M., and Gur, T., 2002. An emendation of elastic rebound theory: Main rupture and adjacent belt of right-lateral distortion detected by Viaduct at Kaynasli, Turkey 12 November 1999 Duzce Earthquake. Journal of Seismology, 6, p. 329-346.

Matlab Scripts

I am making available some Matlab programs I have generated for modeling crustal deformation. Feel free to contact me if you have any questions about the codes

2D deformation programs:

Anti-plane strain (strike-slip)

Nur and Mavko (1974) model for postseismic relaxation [download]

Savage and Prescott (1978) model for periodic earthquakes – version 1 – no interseismic creep [download]

Savage and Prescott (1978) model for periodic earthquakes – version 2 – with interseismic creep [download]

Johnson and Segall (2004) model for periodic earthquakes on a fault with stress-driven creep below the locking depth [download]

Plane strain (dip-slip)

Postseismic deformation due to dislocation in elastic layer over Maxwell viscoelastic halfspace [download]

Interseismic deformation due to periodic earthquakes on dipping fault in elastic layer over Maxwell viscoelastic halfspace [download]

3D deformation programs:

Layered elastic half-space models (dislocation and mogi source) [download]

Rectangular dislocation in an elastic layer overlying a viscoelastic half-space [download]