Malcolm J. S. Johnston
The focus of my research has been on the mechanics of failure of active faults and volcanoes.
My research focuses on the physical processes occurring prior to, during, and following earthquakes and volcanic eruptions and their implications in observations of ground displacement, strain, tilt, electric and magnetic fields using data from state-of-the-art borehole instrumentation. These data show the details of aseismic fault failure, preseismic, coseismic and postseismic deformation, earthquake nucleation, volcanic deformation and volcanic processes. Theoretical modeling of these processes suggests testable physical explanations in term of physics of failure, the role of fluids in the crust, strain redistribution, and likely properties of fault zone materials. Very near-field data on slow slip, earthquakes and dynamic rupture were obtained in fault zones at 3.6 km depth in South Africa, a few 10’s of meters from earthquakes from M=-4.5 to M=2.
Professional Experience
Research Geophysicist Emeritus - U.S. Geological Survey
1970-1972: Assistant Professor, Dept. Geology and Mineralogy, University of Michigan
1972: Visiting Lecturer (Assist Prof.), Department of Physics, University of Newcastle, England
1991-1996: Consulting Professor, Dept. of Geophysics, Stanford University
1983-Visiting Professor, University of Trieste, Trieste, Italy
1972-2013: Project Chief/Research Geophysicist U.S. Geological Survey, Menlo Park, CA
1979–1999: Visiting Scientist, US/China Exchange Program, Continuous Magnetic Field and Geodetic Arrays Along Active Faults in Yunnan and Near Beijing, China
2002: Visiting Scientist, Hawaii Volcano Observatory
Education and Certifications
Ph.D. (1970) Geophysics/Physics, University of Queensland, Australia
B.Sc(Hons) (1967) Physics/Geophysics, University of Queensland, Australia
B.Sc. (1965) Physics, University of Queensland, Australia
Affiliations and Memberships*
2001-present: Co-chairman and Executive Committee of International Union of Geology and Geophysics (IUGG) Working Group on Electromagnetic Studies of Earthquakes and Volcanoes (EMSEV)
1996 - Fellow, Japanese Society for Promotion of Science (JSPS), University of Tokyo
Science and Products
Rapid fluid disruption: A source for self-potential anomalies on volcanoes
Review of magnetic field monitoring near active faults and volcanic calderas in California: 1974-1995
Absence of earthquake correlation with Earth tides: An indication of high preseismic fault stress rate
Review of electric and magnetic fields accompanying seismic and volcanic activity
A slow earthquake sequence on the San Andreas fault
Near real-time monitoring of seismic events and status of portable digital recorders using satellite telemetry
Continuous borehole strain in the San Andreas fault zone before, during, and after the 28 June 1992, MW 7.3 Landers, California, earthquake
Increased pressure from rising bubbles as a mechanism for remotely triggered seismicity
Chapter C. The Loma Prieta, California, Earthquake of October 17, 1989 - Preseismic observations
Seismicity remotely triggered by the magnitude 7.3 landers, california, earthquake
Possible tectonomagnetic effect observed from mid-1989, to mid-1990, in Long Valley Caldera, California
Seismomagnetic effect generated by the October, 1989, ML, 7.1 Loma Prieta, California, Earthquake
Science and Products
- Publications
Filter Total Items: 63
Rapid fluid disruption: A source for self-potential anomalies on volcanoes
Self-potential (SP) anomalies observed above suspected magma reservoirs, dikes, etc., on various volcanoes (Kilauea, Hawaii; Mount Unzen, Japan; Piton de la Fournaise, Reunion Island, Miyake Jima, Japan) result from transient surface electric fields of tens of millivolts per kilometer and generally have a positive polarity. These SP anomalies are usually attributed to electrokinetic effects whereAuthorsM.J.S. Johnston, J. D. Byerlee, D. LocknerReview of magnetic field monitoring near active faults and volcanic calderas in California: 1974-1995
Differential magnetic fields have been monitored along the San Andreas fault and the Long Valley caldera since 1974. At each monitoring location, proton precession magnetometers sample total magnetic field intensity at a resolution of 0.1 nT or 0.25 nT. Every 10 min, data samples are transmitted via satellite telemetry to Menlo Park, CA for processing and analysis. The number of active magnetometeAuthorsR.J. Mueller, M.J.S. JohnstonAbsence of earthquake correlation with Earth tides: An indication of high preseismic fault stress rate
Because the rate of stress change from the Earth tides exceeds that from tectonic stress accumulation, tidal triggering of earthquakes would be expected if the final hours of loading of the fault were at the tectonic rate and if rupture began soon after the achievement of a critical stress level. We analyze the tidal stresses and stress rates on the fault planes and at the times of 13,042 earthquaAuthorsJ.E. Vidale, D.C. Agnew, M.J.S. Johnston, D. H. OppenheimerReview of electric and magnetic fields accompanying seismic and volcanic activity
New observations of magnetic, electric and electromagnetic field variations, possibly related to recent volcanic and seismic events, have been obtained on Mt. Unzen in Japan, Reunion Island in Indian Ocean, the Long Valley volcanic caldera in California, and for faults in China and Russia, California and several other locations. For volcanic events, contributions from different physical processesAuthorsM.J.S. JohnstonA slow earthquake sequence on the San Andreas fault
EARTHQUAKES typically release stored strain energy on timescales of the order of seconds, limited by the velocity of sound in rock. Over the past 20 years, observations and laboratory experiments have indicated that capture can also occur more slowly, with durations up to hours. Such events may be important in earthquake nucleation and in accounting for the excess of plate convergence over seismicAuthorsA. T. Linde, M. T. Gladwin, Malcolm J. S. Johnston, R. L. Gwyther, Roger BilhamNear real-time monitoring of seismic events and status of portable digital recorders using satellite telemetry
Near real-time monitoring of seismic events and status of portable 16-bit digital recorders has been established for arrays near Parkfield, Mammoth Lakes, and San Francisco, California. This monitoring system provides near real-time seismic event identification (rough location and magnitude) and a cost-effective means to maintain arrays at near 100% operational level. Principal objectives in the dAuthorsR.J. Mueller, Meei-You Lee, M.J.S. Johnston, Roger D. Borcherdt, G. Glassmoyer, S. SilvermanContinuous borehole strain in the San Andreas fault zone before, during, and after the 28 June 1992, MW 7.3 Landers, California, earthquake
High-precision strain was observed with a borehole dilational strainmeter in the Devil's Punchbowl during the 11:58 UT 28 June 1992 MW 7.3 Landers earthquake and the large Big Bear aftershock (MW 6.3). The strainmeter is installed at a depth of 176 m in the fault zone approximately midway between the surface traces of the San Andreas and Punchbowl faults and is about 100 km from the 85-km-long LanAuthorsM.J.S. Johnston, A. T. Linde, D.C. AgnewIncreased pressure from rising bubbles as a mechanism for remotely triggered seismicity
Aftershocks of large earthquakes tend to occur close to the main rupture zone, and can be used to constrain its dimensions. But following the 1992 Landers earthquake (magnitude M(w) = 7.3) in southern California, many aftershocks were reported in areas remote from the mainshock. Intriguingly, this remote seismicity occurred in small clusters near active volcanic and geothermal systems. For one ofAuthorsA. T. Linde, I. S. Sacks, M.J.S. Johnston, D. P. Hill, R.G. BilhamChapter C. The Loma Prieta, California, Earthquake of October 17, 1989 - Preseismic observations
The October 17, 1989, Loma Prieta, Calif., Ms=7.1 earthquake provided the first opportunity in the history of fault monitoring in the United States to gather multidisciplinary preearthquake data in the near field of an M=7 earthquake. The data obtained include observations on seismicity, continuous strain, long-term ground displacement, magnetic field, and hydrology. The papers in this chapter desSeismicity remotely triggered by the magnitude 7.3 landers, california, earthquake
The magnitude 7.3 Landers earthquake of 28 June 1992 triggered a remarkably sudden and widespread increase in earthquake activity across much of the western United States. The triggered earthquakes, which occurred at distances up to 1250 kilometers (17 source dimensions) from the Landers mainshock, were confined to areas of persistent seismicity and strike-slip to normal faulting. Many of the trigAuthorsD. P. Hill, P.A. Reasenberg, A. Michael, W.J. Arabaz, G. Beroza, D. Brumbaugh, J.N. Brune, R. Castro, S. Davis, D. Depolo, W.L. Ellsworth, J. Gomberg, S. Harmsen, L. House, S.M. Jackson, M.J.S. Johnston, L. Jones, Rebecca Hylton Keller, S. Malone, L. Munguia, S. Nava, J.C. Pechmann, A. Sanford, R. W. Simpson, R. B. Smith, M. Stark, M. Stickney, A. Vidal, S. Walter, V. Wong, J. ZollwegPossible tectonomagnetic effect observed from mid-1989, to mid-1990, in Long Valley Caldera, California
Precise measurements of local magnetic fields have been obtained with a differentially connected array of three proton magnetometers in the Long Valley caldera region since 1984. Two magnetometers are located inside the caldera with a third reference magnetometer located 26km southeast of the caldera. After correction for secular variation, it is apparent that an anomalous 2 nT decrease in the magAuthorsR.J. Mueller, M.J.S. Johnston, J. O. LangbeinSeismomagnetic effect generated by the October, 1989, ML, 7.1 Loma Prieta, California, Earthquake
A differentially connected array of proton magnetometers operated within the epicentral region of the October 18, 1989, ML 7.1 Loma Prieta earthquake for 12 years from 1974 to 1986. The closest magnetometer station was located 7.3 km from the epicenter of the earthquake and within 3 km of the site where anomalous ULF magnetic noise measurements were observed. Following the earthquake, the magnetomAuthorsR.J. Mueller, M.J.S. Johnston
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government