Doug Smylie

Professor Emeritus and Senior Scholar in Geophysics

Department: Earth & Space Science & Engineering

Phone Number: (416) 736-2100 x 66438

Email Address:doug@core.yorku.ca

Website: www.yorku.ca/smylie/




Douglas Edwin Smylie began his scientific career by studying Engineering
Physics at Queen’s University from which he graduated in 1958. He then
went on to do a Master’s degree in Applied Mathematics at the University of
Toronto. After a year working at Ontario Hydro as a programmer-systems
analyst on the second computer in Canada, a Univac 2, he returned to grad-
uate school to do a doctorate in geophysics at the University of Toronto.
His thesis topic was to calculate the contribution of geomagnetic core-
mantle coupling to the excitation of the Chandler wobble, a free motion
of the pole of rotation with a 14-month period. The thesis was negative.
Shortly after, he began his first academic appointment in the Department of
Geophysics at the University of Western Ontario. Another new appointment
there, the brilliant young seismologist, Lalu Mansinha, told him how the
great Alaskan earthquake of March 1964 had been observed on strain metres
by Frank Press of MIT as far away as Hawaii. This suggested that the dis-
placement fields of great earthquakes might be very extensive and that the
mass redistribution might contribute to the excitation of the Chandler wob-
ble. Indeed, both calculations based on the elasticity theory of dislocations
and study of the pole paths confirmed the effect of earthquakes on the polar
motion (Mansinha and Smylie, 1968). Of much interest was the observation
that changes in the polar motion generally preceded earthquakes. This led
to a lot of publicity for this research (even reported in Time magazine) and
a NATO Advanced Study Institute was held at the University of Western
Ontario in June 1969 with more than one hundred participants. Modern
observations of the polar motion by the very long baseline (VLBI) technique
are more than a thousand times more accurate and a recent analysis (Smylie,
Henderson and Zuberi, 2015) has confirmed the effect of earthquakes on the
pole path including the fact that the effect on the polar motion generally pre-
cedes the earthquake. As a result of this early work, Smylie was promoted
to a position in the Department of Geophysics and Astronomy at the Uni-
versity of British Columbia and both he and Mansinha were awarded Senior
Research Fellowships of the National Academy of Sciences at Goddard Space
Center in Greenbelt, Maryland in 1970-71.
In 1972 Smylie was recruited by York University to start the Earth and
Environmental Science Programme which evolved into the Department of
Earth and Atmospheric Science and then into the present Department of
Earth and Space Science and Engineering.
At York, interest in earthquake displacement fields evolved into gravime-
try and the detection of motions in the inner and outer cores of the Earth
(Smylie, Szeto and Rochester, 1984). In particular, long period motions
below seismic frequencies were considered and the subseismic wave equa-
tion was derived as the governing equation and a variational principal was
demonstrated for its solution (Smylie, Jiang, Brennan and Sato, 1992). The
Product Spectrum was developed to find common features in the spectra of
several observatories. This led to the detection of the three translational
modes of the inner core and the measurement of the viscosity at the bottom
of the outer fluid core (Smylie, 1992). A doctoral student, Xianhua Jiang,
through his variational calculations discovered the prograde free nutation
and his thesis won the Canadian Association of Graduate Schools Doctoral
Dissertation Prize for all fields in Canada in 1994 and the 1995 Annual Dis-
sertation Award of the Northeastern U. S. Association of Graduate Schools.
Another brilliant doctoral student Hong Ma, won the Governor General’s
Gold Medal as the best graduating student at York University in all fields
in 1996. Andrew Palmer, a doctoral student, using singular value decompo-
sition, found both the prograde and retrograde nutations in the unequally
spaced VLBI observations, and from the ring down of the two modes, was
able to measure the viscosity at the top of the fluid outer core (Palmer and
Smylie, 2005). Vadim Brazhkin, at the Moscow Institute for High Pressure
Physics, found very close values of viscosity at the bottom and top of the
outer core, and this led to a collaboration over the internet to produce a joint
paper published in Physics-Uspekhi (Smylie, Brazhkin and Palmer, 2009).

Research Interests

With my doctoral student, Andrew Palmer, I have been engaged in the spectral analysis of the Free Core Nutations using Very Long Baseline Interferometric observations of the celestial pole. We have implemented the Parseval criterion for deciding the number of singular values to eliminate in the Singular Value Decomposition of the coefficient matrix for fitting the discrete Fourier transform to the non-equispaced observations. We have found the Prograde Free Core Nutation (PFCN), predicted numerically by Jiang, in his prize winning 1993 doctoral thesis. We have also found that both the PFCN and the classical Retrograde Free Core Nutation (RFCN) are in free decay, allowing the viscosity at the top of the liquid outer core to be measured.

Selected Publications

  •  D. E.Smylie, G. A. Henderson and Midhat Zuberi, Modern observations of
    the efffect of earthquakes on the Chandler wobble, Journal of Geodynamics,
    83, 85-91, 2015.
  • D. E. Smylie, Earth Dynamics – Deformations and Oscillations of the Rotating Earth, Cambridge University Press, 543 pp., 2013.
  • D. E. Smylie and Midhat Zuberi, Free and Forced Polar Motion and Modern Observations of the Chandler Wobble, Journal of Geodynamics, 48, 226-229, 2009.
  • Midhat Zuberi and D. E. Smylie, Spectral Analysis of the VLBI Pole Path, Journal of Geodynamics, 48, 230-234, 2009.
  • D. E. Smylie, V. V. Brazhkin and Andrew Palmer, Direct Observations of the Viscosity of the Outer Core and Extrapolation of Measurements of the Viscosity of Liquid Iron, Physics-Uspekhi, 52(1), 79‑92, 2009.
  • D. E. Smylie, V. V. Brazhkin and Andrew Palmer, Russian language paper, Uspekhi Fizicheskikh, 179(1), 91‑105, 2009.
  • D. E. Smylie and Andrew Palmer, Viscosity of Earth’s Outer Core, arXiv:0709.3333v1, [physics.geo-ph], 30pp., 2007.
  • Andrew Palmer and D. E. Smylie, VLBI Observations of Free Core Nutations and Viscosity at the Top of the Core, Phys. Earth Planet. Inter., 148, 285‑301, 2005.
  • D. E. Smylie, O. Francis and J. B. Merriam, Beyond Tides – Determination of Core Properties from Superconducting Gravimeter Observations, J. Geodet. Soc.
    , 47, 364-372, 2001.
  • D. E. Smylie and D. G. McMillan, The Inner Core as a Dynamic Viscometer, Phys. Earth Planet. Inter., 117, 71-79, 2000.
  • D. E. Smylie, Viscosity near Earth’s Solid Inner Core, Science, 284, 461-463, 1999.
  • D. E. Smylie, Observation of the Inner Core Translational Triplet and the Density near Earth’s Center, Science, 255, 1678-1682, 1992.
  • D. E. Smylie, Xianhua Jiang, B. J. Brennan and Kachishige Sato, Numerical Calculation of Modes of Oscillation of the Earth’s Core, Geophys. J. Int., 108, 465-490, 1992.
  • D. E. Smylie, A. M. K. Szeto and M. G. Rochester, The dynamics of the Earth’s Inner and Outer Cores, Rep. Prog. Phys., 47, 855-906, 1984.
  • Smylie, D. E., G. K. C. Clarke and T. J. Ulrych, Analysis of Irregularities in Earth’s Rotation, Methods in Computational Physics, 13, 391-430, B. Adler, S. Fernbach and B. A. Bolt, eds., Academic Press, 1973.
  • Mansinha, L. and D. E. Smylie, The Displacement Fields of Inclined Faults, Bull. Seism. Soc. Am., 61, 1433-1440, 1971.
  • Smylie, D. E. and L. Mansinha, The Elasticity Theory of Dislocations in Real Earth Models and Changes in the Rotation of the Earth, Geophys. J. R. astr. Soc., 23, 329-354, 1971.
  • Johnson, I. M. and D. E. Smylie, An Inverse Teory for the Calculation of the Electrical Conductivity of the Lower Mantle, Geophys. J. R. astr. Soc., 22, 41-53, 1970.
  • Mansinha L. and D. E. Smylie, Effect of Earthquakes on the Chandler Wobble and the Secular Polar Shift, Science, 161, 1127-1129, 1968.