平野史朗 (博士・理学)
Shiro Hirano, PhD,
Assistant Professor, Dept. of Phys. Sci.,
College of Sci. & Eng., Ritsumeikan Univ., Japan

Research Interests

Mathematical modeling of earthquake fault mechanics
Dynamic rupture along and crossing with a material interface
Earthquake energy estimation based on inversion analyses
Determination mechanisms of rupture velocity
Unilateral rupture along very long reverse faults
Slip/stress heterogeneity and foreshock-mainshock-aftershock sequences
Source time functions based on a stochastic differential equation
Seismicity data analysis
Objective threshold determination of a matched-filter technique for seismic event detection based on the extreme value theory and an information criterion
Seismic event-pair detection by similarity thresholding.
Laboratory seismology
Dynamic opening/shear rupture in a photoelastic medium
Elastodynamics and rheorogy of sand after strong vibration or water injection

Academic Positions & Education

Assistant professor, Apr. 2015 -- present
Department of Physical Science, College of Science and Engineering, Ritsumeikan University, Japan
Teaching Earth Science/Laboratory Works in Earth Science
Postdoctoral fellow, Oct. 2013 -- Mar. 2015
Mega Quake Risk Management Project / Faculty of Engineering, Information and Systems, Tsukuba University, Japan
PhD course, Apr. 2009 -- Sep. 2013
Earthquake Research Institute / Department of Earth and Planetary Science, Graduate School of Science, University of Tokyo, Japan
supervised by Teruo Yamashita and Nobuki Kame
Internship, Jul. 2011 -- Aug. 2011
School of Engineering and Applied Science, Harvard University, U.S.
research assistant of James R. Rice
Master's course, Apr. 2007 -- Mar. 2009
Earthquake Research Institute / Department of Earth and Planetary Science, Graduate School of Science, University of Tokyo, Japan
supervised by Teruo Yamashita
Undergraduate course, Apr. 2003 -- Mar. 2007
Department of Mathematics, Faculty of Science, Tokyo University of Science, Japan
supervised by Keiichi Kato

Publications

Peer-reviewed journal papers

Naoi, M., & Hirano, S.. (2024)
Efficient similar waveform search using short binary codes obtained through a deep hashing technique
Geophys. J. Int., 273(1):607--621, doi:10.1093/gji/ggae061
Yagi, Y., Okuwaki, R., Hirano, S., Enescu, B., Chikamori, M., & Yamaguchi, R. (2024)
Barrier-induced rupture front disturbances during the 2023 Morocco earthquake
Seismol. Res. Lett., XX:1--8, doi:10.1785/0220230357
Ohara, K., Yagi, Y., Yamashita, S., Okuwaki, R., Hirano, S., & Fukahata, Y. (2023)
Complex evolution of the 2016 Kaikoura earthquake revealed by teleseismic body waves
Prog. Earth Planet. Sci., 10:35, doi:10.1186/s40645-023-00565-z
Hirano, S., Kawakata, H. & Doi, I. (2022)
A matched-filter technique with an objective threshold
Sci. Rep., 12:22090, doi:10.1038/s41598-022-25839-2
大嵜雅人, 吉光奈奈, 平野史朗, 福山英一 (EN: Osaki, M., Yoshimitsu, N., Hirano, S., & Fukuyama, E.) (2022)
注水による誘発地震発生場を模擬した寒天ゲルを用いた光弾性実験手法 (EN: Photoelastic experimental approach using agar gel to simulate a stress field of fluid injection induced earthquakes)
地震 第2輯 (Zisin: Journal of Seismological Society of Japan), 75:83--91, doi:10.4294/zisin.2021-17 (Japanese text with English abstract.)
Hirano, S. (2022)
Source time functions of earthquakes based on a stochastic differential equation
Sci. Rep., 12:3936, doi:10.1038/s41598-022-07873-2
Numerical results in an ascii format: OSF: Open Science Framework, doi:10.17605/OSF.IO/VUXJ6
Nakayama, M., Kawakata, H., Hirano, S., & Doi, I. (2021)
Development of a laboratory monitoring system for elastic waves transmitted through sand under dry and saturated conditions
Earth Planet Space, 73(25), doi:10.1186/s40623-020-01346-4
Hirano, S., & Itou, H. (2020)
Parameter interdependence of dynamic self-similar crack with distance-weakening friction
Geophys. J. Int., 223(3):1584--1596, doi:10.1093/gji/ggaa392
Erratum

eq. (7) must be $L(x) = \displaystyle \log\left|\frac{1-x}{1+x}\right|$ (absolute value symbol was missing)

$\Delta \sigma_b$ in eqs.(C1)(C5)(C6)(C7) and next line to eq.(C9) must be $\sigma_b$.

Okuwaki, R., Hirano, S., Yagi, Y., & Shimizu, K. (2020)
Inchworm-like source evolution through a geometrically complex fault fueled persistent supershear rupture during the 2018 Palu Indonesia earthquake
Earth Planet. Sci. Lett., 547(2020):116449, doi:10.1016/j.epsl.2020.116449
EarthArXiv Preprints, doi:10.31223/osf.io/j4cas
OSF: Open Science Framework, doi:10.17605/OSF.IO/8AZ3G
Hirano, S. (2019)
Modeling of unilateral rupture along very-long reverse faults
J. Geophys. Res., 124(1):1057--1071, doi:10.1029/2018JB016511.
Okuwaki, R., Kasahara, A., Yagi, Y., Hirano, S. & Fukahata, Y. (2019)
Backprojection to image slip
Geophys. J. Int., 216(3):1529--1537, doi:10.1093/gji/ggy505.
Tamaribuchi, K., Yagi, Y., Enescu, B. & Hirano, S. (2018)
Characteristics of foreshock and aftershock activity inferred from the JMA earthquake catalog improved by automatic processing
Earth Planet Space, 70:90, doi:10.1186/s40623-018-0866-9.
Hirano, S. & Yagi, Y. (2017)
Dependence of seismic and radiated energy on shorter wavelength components
Geophys. J. Int., 209(3):1585--1592, doi:10.1093/gji/ggx108.
Hirano, S. & Yamashita, T. (2016)
Modeling of interfacial dynamic slip pulses with slip-weakening friction
Bull. Seism. Soc. Am. 106(4):1628--1636, doi: 10.1785/0120150208.
Erratum

$\displaystyle \frac{1}{1+S}$ in eqs. (19)(20)(22) must be $\displaystyle - \frac{1}{1+S}$ (minus sign was missing)

Self archive of a pre-copyedit version
Hirano, S. & Yamashita, T. (2015)
Dynamic anti-plane rupture propagation crossing a material interface: modelling with BIEM
Geophys. J. Int. 200(2):1220--1233, doi:10.1093/gji/ggu471.
Erratum

eq. (26) must be $\Psi_l(X) = \displaystyle \sqrt{X^2-\beta_l^{-2}} \arctan{\frac{\eta_l}{\sqrt{X^2-\beta_l^{-2}}}} - \eta_l$ (subscript $l$ of $\beta$ was missing)

Okuwaki, R., Yagi, Y. & Hirano, S. (2014)
Relationship between High-frequency Radiation and Asperity Ruptures, Revealed by Hybrid Back-projection with a Non-planar Fault Model
Sci. Rep., 4:7120, doi:10.1038/srep07120.
Yagi, Y., Okuwaki, R., Enescu, B., Hirano, S., Yamagami, Y., Endo, S. & Komoro, T. (2014)
Rupture process of the 2014 Iquique Chile earthquake in relation with the foreshock activity
Geophys. Res. Lett., 41(12):4201--4206, doi: 10.1002/2014GL060274.
Hirano, S. & Yamashita, T. (2011)
Analysis of the static stress field around faults lying along and intersecting a bimaterial interface
Geophys. J. Int. 187(3):1460--1478, doi:10.1111/j.1365-246X.2011.05202.x.

Peer-reviewed proceeding papers

Hirano, S. (2020)
Friction vs. damage: dynamic self-similar crack growth revisited
In: Itou, H. et al. (eds) Mathematical Analysis of Continuum Mechanics and Industrial Applications III. CoMFoS18. Mathematics for Industry, Springer, doi:10.1007/978-981-15-6062-0_12
Self archive of a pre-copyedit version
Nakayama, M., Kawakata, H., Hirano, S., Doi, I., & Takahashi, N. (2018)
Propagation characteristics of elastic waves transmitted through sand soils under dry and saturated conditions
Progress in Acoustic Emission XIX, Jpn. Soc. Non-Destructive Inspection, 163--167.
Hirano, S. (2018)
Integral representation and its applications in earthquake mechanics: a review
In: van Meurs, P. et al. (eds) Mathematical Analysis of Continuum Mechanics and Industrial Applications II. CoMFoS 2016. Mathematics for Industry, vol 30. Springer, Singapore, doi:10.1007/978-981-10-6283-4_9.
Self archive of a pre-copyedit version
Hirano, S. (2017)
Propagation velocity of pulse-like rupture along earthquake faults
In: Itou, H. et al. (eds) Mathematical Analysis of Continuum Mechanics and Industrial Applications. Mathematics for Industry, vol 26. Springer, Singapore, doi:10.1007/978-981-10-2633-1_10.
Self archive of a pre-copyedit version

Book

Itou, H., Hirano, S., Kimura, M., Kovtunenko, V.A., & Khludnev, A.M. (Eds.) (2020)
Mathematical Analysis of Continuum Mechanics and Industrial Applications III. CoMFoS18. Mathematics for Industry, Springer, doi:10.1007/978-981-15-6062-0

Misc.

Hirano, S., & Okuwaki, R. (2020)
Note on “Backprojection to image slip”
OSF: Open Science Framework, doi:10.17605/OSF.IO/PB7HK
Endo, S., Nakao, A., Hirano, S. & Yagi, Y. (2017)
The 2013 Sea of Okhotsk deep earthquake: A complex rupture within the Ringwoodite stability zone
Earth Evol. Sci., 11:23--30.
桑野修, 平野史朗, 藤田哲史, 日下部哲也, 小寺祐貴, 亀伸樹, 中谷正生, 安藤亮輔 (2011)
寒天(アガロースゲル)を用いた断層の動的破壊実験
日本地震学会ニュースレター Vol.22 No.6, 表紙

International Conferences

Hirano, S.
Modeling of slip on a fault during an earthquake: point-source approximation
RIMS Workshop "Some approaches on ill-posed problems -theory and practice-", Kyoto, Japan, January 11, 2023 (Oral)
Yasumoto, R., Hirano, S., & Kawakata, H.
Effect of bay topography on surface waves
American Geophysical Union 2023 Fall Meeting, San Francisco, December 12, 2023 (Poster)
Inanishi, T., Kwakata, H., & Hirano, S.
Source parameters of AE events in uniaxial compression tests of cement mortar specimens
American Geophysical Union 2023 Fall Meeting, San Francisco, December 12, 2023 (Poster)
Hirano, S.
Stochastic source time functions with double corner frequencies
American Geophysical Union 2023 Fall Meeting, San Francisco, December 11, 2023 (Poster)
Hirano, S.
Statistics and variability of source time functions based on a stochastic differential equation
American Geophysical Union 2021 Fall Meeting, New Orleans and Online, December, 2021 (Oral)
Okuwaki, R., Yagi, Y., Shimizu, K., Fukahata, Y., Hirano, S., Hicks, S.P., Craig, T.J., Fan, W., Goes, S.D.B., & Wright, T.J.
Accounting epistemic uncertainty in finite-fault inversion: development of a potency-density tensor approach to investigate complex earthquake rupture processes
American Geophysical Union 2021 Fall Meeting, New Orleans and Online, December, 2021 (Oral, Invited)
Hirano, S.
Various inverse problems in seismology: seismic tomography, hypocenter location, earthquake source kinematics, and Earth's crustal stress.
Control and inverse problems on waves, oscillations and flows - Mathematical analysis and computational methods -, Online, September, 2021 (Oral)
Hirano, S.
Theoretical properties of source time functions based on a stochastic differential equation
Joint Scientific Assembly IAGA-IASPEI 2021, Online, August 26, 2021 (Flash talk & Poster)
Okuwaki, R., Hirano, S., Yagi, Y., & Shimizu, K.
Source evolution through a geometrically complex fault system controls supershear rupture during the 2018 Palu earthquake
FRINGE 2021 (Advances in the Science and Applications of SAR Interferometry and Sentinel-1 InSAR), Online, May 31--June 04, 2021 (Oral)
Hirano, S., & Itou, H.
Dynamic antiplane self-similar crack with distance-weakening friction: an analytical solution for source parameter estimation
American Geophysical Union 2020 Fall Meeting, Online, December 16, 2020 (Flash talk & Poster)
Go to the poster page.
Hirano, S.
An empirical PDE for slip along earthquake faults
The Second Russia-Japan Workshop "Mathematical analysis of fracture phenomena for elastic structures and its applications" - 20th Conference of Continuum Mechanics Focusing on Singularities (CoMFoS20), Online, December 15, 2020 (Oral)
Hirano, S.
A nonlinear integro-differential equation for earthquake faulting
RIMS Workshop on Analysis of inverse problems through partial differential equations and related topics, Kyoto, Japan, January 09, 2020 (Oral)
Hirano, S.
An observation-based differential equation of spatio-temporal slip distribution
American Geophysical Union 2019 Fall Meeting, San Francisco, U.S., December 13, 2019 (Poster)
Kakutani, T., Kawakata, H., & Hirano, S.
Seismic response change of a sand soil after strong motion, revealed by a transmission laboratory experiment
American Geophysical Union 2019 Fall Meeting, San Francisco, U.S., December 11, 2019 (Poster)
Nakayama, M., Kawakata, H., Hirano, S., & Doi, I.
Propagation characteristic changes of elastic waves transmitted through a sand soil in water injection and drainage processes
American Geophysical Union 2019 Fall Meeting, San Francisco, U.S., December 10, 2019 (Poster)
Hirano, S.
Dynamic growth of a self-similar anti-plane crack during earthquakes
Russia-Japan Workshop "Mathematical analysis of fracture phenomena for elastic structures and its applications", Novosibirsk, Russia, November 12, 2019 (Oral)
Hirano, S.
Energy dissipation during dynamic antiplane self-similar crack growth
CoMFoS19:Mathematical Analysis of Continuum Mechanics and Industrial Applications, Kanazawa, Japan, July 15, 2019 (Oral)
Hirano, S.
Analytical solution of dynamic self-similar crack growth under distance-weakening friction
Numerical Modeling of Earthquake Motions: Waves and Ruptures, Smolenice, Slovakia, July 01--03, 2019 (Poster)
Hirano, S., Kawakata, H., & Doi, I.
Foreshock activity detection by a threshold-free matched-filter technique
Japan Geoscience Union Meeting, Chiba, Japan, May 26, 2019 (Oral)
Hirano, S.
Aftershocks and the GR law due to a heterogeneous slip model
American Geophysical Union 2018 Fall Meeting, Washington D.C., U.S., December 14, 2018 (Oral)
Nakayama, M., Kawakata, H., Hirano, S., Doi, I., & Takahashi, N.
24-hours broadband measurements of elastic waves transmitted through sand soils under dry and saturated conditions to investigate differences in propagation characteristics
American Geophysical Union 2018 Fall Meeting, Washington D.C., U.S., December 10, 2018 (Poster)
Nakayama, M., Kawakata, H., Hirano, S., Doi, I., & Takahashi, N.
Propagation characteristics of elastic waves transmitted through sand soils under dry and saturated conditions
24th International Acoustic Emission Symposium, Sapporo, Japan, November 07, 2018 (Oral)
Hirano, S., Toyomoto, Y., Kawakata, H., & Doi, I.
Application of Extreme Value Theory to a Matched-Filter Analysis
10th ACES International Workshop, Awaji Island, Japan, September 27, 2018 (Poster)
Hirano, S.
Friction vs. damage: dynamic self-similar crack growth revisited
CoMFoS18:Mathematical Analysis of Continuum Mechanics and Industrial Applications, Kyoto, Japan, June 13, 2018 (Oral)
Hirano, S., Toyomoto, Y., Kawakata, H. & Doi, I.
Objective matched-filter analysis for dertecting small events
International Symposium on Earthquake Forecast / 5th International Workshop on Earthquake Preparation Process, ~Observation, Validation, Modeling, Forecasting~, Chiba, Japan, May 25, 2018 (Poster)
Wakamatsu, S., Kawakata, H. & Hirano, S.
Observed seismic and infrasonic signals around the Hakone volcano -Discussion based on a finite-difference calculation-
American Geophysical Union 2017 Fall Meeting, New Orleans, U.S., December 15, 2017 (Poster)
Hirano, S.
Mathematical modeling and numerical simulation of unilateral dynamic rupture propagation along very-long reverse faults
American Geophysical Union 2017 Fall Meeting, New Orleans, U.S., December 14, 2017 (Poster)
Nakayama, M., Kawakata, H., Hirano, S., Doi, I. & Takahashi, N.
Improvement in transmission experiment of elastic waves through partially saturated porous sand soil
American Geophysical Union 2017 Fall Meeting, New Orleans, U.S., December 14, 2017 (Poster)
Yoneda, N., Kawakata, H., Hirano, S., Yoshimitsu, N. & Takahashi, N.
Extraction of AE events to estimate their b values under a triaxial compressive condition ~Examination using continuous broadband records~
American Geophysical Union 2017 Fall Meeting, New Orleans, U.S., December 14, 2017 (Poster)
Hirano, S.
Unilateral dynamic rupture propagation along earthquake faults
CoMFoS17:Mathematical Analysis of Continuum Mechanics and Industrial Applications, OIST, Japan, September 21, 2017 (Oral)
Hirano, S.
Energy estimation of earthquake faulting based on a wavefield inversion
RIMS workshop on "Singularity and asymptotic behavior of solutions for partial differential equations with conservation law", Kyoto, Japan, June 08, 2017 (Oral)
Hirano, S.
Integral equation for mechanics of earthquakes
RIMS workshop on "Inverse problems for partial differential equations and related areas", Kyoto, Japan, January 26, 2017 (Oral)
Nakayama, M., Kawakata, H., Hirano, S., Doi, I., & Takahashi, N.
Transmission experiment of elastic waves with short wavelengths through a highly porous sand soil during water injection
American Geophysical Union 2016 Fall Meeting, San Francisco, U.S., December 15, 2016 (Poster)
Toyomoto, Y., Kawakata, H., Hirano, S. & Doi, I.
Foreshock search over a long duration using a method of setting appropriate criteria
American Geophysical Union 2016 Fall Meeting, San Francisco, U.S., December 15, 2016 (Poster)
Tsujimura, Y., Kawakata, H., Fukuyama, E., Yamashita, F., Xu, S., Mizoguchi, K, Takizawa, S. & Hirano, S.
Spatio-temporal foreshock activity during stick-slip experiments of large rock samples
American Geophysical Union 2016 Fall Meeting, San Francisco, U.S., December 13, 2016 (Poster)
Hirano, S., Yamashita, T. & Hatano, T.
Behavior of pulse-like rupture with velocity-time-dependent friction from a granular layer model
American Geophysical Union 2016 Fall Meeting, San Francisco, U.S., December 12, 2016 (Oral)
Hirano, S.
Integral representation and its applications of the mechanics of earthquakes
CoMFoS16:Mathematical Analysis of Continuum Mechanics and Industrial Applications, Kyushu University, Japan, October 23, 2016 (Oral)
Hirano, S. & Yamashita, T.
Propagation velocity of pulse-like rupture with a time-weakening friction law
American Geophysical Union 2015 Fall Meeting, San Francisco, U.S., December 18, 2015 (Poster)
Iwata, K., Kawakata, H., Hirano, S., & Doi, I.
Estimation of Seismic Attenuation beneath Tateyama Volcano, Central Japan by Using Peak Delay
American Geophysical Union 2015 Fall Meeting, San Francisco, U.S., December 17, 2015 (Poster)
Imahori, A., Kawakata, H., Hirano, S., Yoshimitsu, N., & Takahashi, N.
Travel Times of Later Phases for Transmitting Waves through a Fracturing Westerly Granite Sample under a Triaxial Compressive Condition
American Geophysical Union 2015 Fall Meeting, San Francisco, U.S., December 16, 2015 (Poster)
Hirano, S.
Propagation velocity of pulse-like rupture along earthquake fault
CoMFoS15:Mathematical Analysis of Continuum Mechanics and Industrial Applications, Kyushu University, Japan, November 16, 2015 (Oral)
Hirano, S. & Yagi, Y.
Dependence of seismic energy on higher wavenumber components
American Geophysical Union 2014 Fall Meeting, San Francisco, U.S., December 19, 2014 (Poster)
Yagi, Y., Okuwaki, R., Enescu, B. & Hirano, S.
Rupture process of the 2014 Iquique Chile earthquake in relation with the foreshock activity
American Geophysical Union 2014 Fall Meeting, San Francisco, U.S., December 17, 2014 (Poster)
Okuwaki, R., Yagi, Y. & Hirano, S.
Relationship between High-frequency Radiation and Asperity Rupture,Revealed by Hybrid Back-projection with Non-planer Fault
Seismological Society of America Annual Meeting, Anchorage, U.S., May 01, 2014 (Poster)
Hirano, S. & Yamashita, T.
BIEM Simulation for Anti-Plane Dynamic Rupture Propagation across a Bimaterial Interface
Seismological Society of America Annual Meeting, Anchorage, U.S., April 30, 2014 (Oral)
Hirano, S.
An integral representation and numerical simulation of dynamic earthquake faulting occurring in a two-layered medium
Conference on Diffusion in Heterogeneous Media and Related Topics, Tokyo, Japan, March 06, 2014 (Oral)
Hirano, S. & Yamashita, T.
Off Fault Stress Distribution around Dynamic Slip Pulse on a Bimaterial Interface
The 7th ACES International Workshop, Otaru, Japan, October 04, 2010 (Poster)
Hirano, S. & Yamashita, T.
Theoretical analysis of static mode-II crack in two-layered medium - interfacial fault and intersecting fault
Workshop -Earthquake Source Dynamics: Data and Data-constrained Numerical Modeling, Smolenice Castle, Slovakia, June 28, 2010 (Poster)
Hirano, S. & Yamashita, T.
Mathematical and numerical analysis of non-planar static mode-II crack in a two-layered medium
American Geophysical Union 2009 Fall meeting, San Francisco, U.S., December 17, 2009 (Poster)
Hirano, S. & Yamashita, T.
Mathematical and numerical analyses of arbitrarily oriented static mode-II crack in a two-layered medium
The 7th General Assembly of Asian Seismological Commission and The 2008 Fall meeting of Seismological Society of Japan, Tsukuba, Japan, November 27, 2008 (Poster)

Award & Grants

Award

Mar. 2019
The Young Scientist Award of Seismological Society of Japan for Extension of Mathematical Seismology

Grants

Apr. 2022 -- Mar. 2025
Growth and termination of dynamic rupture revealed by a stochastic fault model
The JSPS Grant-in-Aid for Scientific Research(C) Program No. 22K03782
Principal Investigator
Apr. 2022 -- Mar. 2025
Elastodynamics for strongly heterogeneous material: experiment, numerical simulation, and theory
The JSPS Grant-in-Aid for Scientific Research(B) Program No. 22H01336
Co-Investigator (PI: Kawakata, H., Ritsumeikan Univ.)
Apr. 2021 -- Mar. 2024
Understanding the physics of foreshocks based on dense seismic observation and seismicity model
The JSPS Grant-in-Aid for Scientific Research(B) Program No. 21H01191
Co-Investigator (PI: Naoi, M., Kyoto Univ.)
Apr. 2018 -- Mar. 2022
SDE modeling for diversity and heterogeneity of earthquake ruptures
The JSPS Grant-in-Aid for Early-Career Scientists Program No. 18K13637
Principal Investigator
Apr. 2017 -- Mar. 2021
Mathematical modeling and analysis of discontinuous phenomena in continuum body
The JSPS Grant-in-Aid for Scientific Research(B) Program No. 17H02857
Co-Investigator (PI: Kimura, M., Kanazawa Univ.)

Contributions

Journal Reviewer
Bulletin of Seismological Society of America
Computers and Mathematics with Applications
Earth Planets Space
Environmental Earth Sciences
European Journal of Environmental and Civil Engineering
Geophysical Journal International
Journal of Geophysical Research: Solid Earth
Journal of Japan Association for Earthquake Engineering
Tectonophysics
Grant Reviewer
Israel Science Foundation
Conference Management
Program committee for The 10th International Congress on Industrial and Applied Mathematics. Waseda University, Tokyo, Japan, August 20-25, 2023
Organizing committee for CoMFoS18:Mathematical Analysis of Continuum Mechanics and Industrial Applications, Kyoto, Japan, June 13--15, 2018
Projects
Earthquake and Volcano Hazards Observation and Research Program (Co-investigator, 2015-)
Mega Quake Risk Management project at University of Tsukuba (Postdoctoral fellow, 2013-2014)
AE measurements in deep South African gold mines: Phase II - monitoring of rock mass damage by underground cavities and prediction of rockbursts (Research assistant, 2009-2011)