Imaging the Japan Earthquake From 5000 Miles Away
The disastrous magnitude 9 Japanese earthquake of 2011 caused much damage along the northeastern coast of mainland Japan, but the energy from this earthquake reached every corner of the world. The recordings of the earthquake in North America by nearly 500 seismometers, therefore, contain valuable information about the earthquake such as how it started and why it became so large. We unravel the data to reconstruct how the magnitude 9 earthquake happened as seen from 5000 miles away. In particular, data from the Transportable Array, a group of 400 seismic stations covering a strip extending from the Canadian border to the Mexican border and is continuously migrating eastward, are rich in complex signals. The Transportable Array acts as a powerful telescope that shows us the details and mysteries associated with this earthquake. One of the surprising results is the cascading failure of different faults in the region before, during and after the earthquake. This suggests that the event could have been much larger, at magnitude 9.2, releasing twice as much energy and potentially more hazardous than the already devastating event on March 11th.
Dr. Miaki Ishii
Associate Professor of Earth and Planetary Sciences
Harvard Seismology Group
Harvard University, Cambridge, Massachusetts
2003 Ph.D. (Geophysics), Harvard University
1998 Hon.B.Sc. (Physics), University of Toronto
2010-current Associate Professor of Earth and Planetary Sciences, Harvard University
2006-2010 Assistant Professor of Earth and Planetary Sciences, Harvard University
2003-2005 Green Scholar (Postdoctoral Fellow), Scripps Institution of Oceanography, UCSD
2003 Visiting Scientist, University of California Los Angeles
1994 Summer Intern, Chalk River National Laboratory, Atomic Energy of Canada Limited
2009 James B. Macelwane Medal, American Geophyical Union
2009 American Geophysical Union Fellow
2008 Charles F. Richter Early Career Award, Seismological Society of America
2007 Most Cited Authors, Physics of Earth and Planetary Interiors
2004 Alice Wilson Award, Royal Society of Canada
2000-2002 Julie Payette Scholar (Earth Sciences), Natural Sciences and Engineering Research Council of Canada
1999 Outstanding Student Paper Award, American Geophysical Union
1998 Outstanding Student Paper Award, American Geophysical Union
1995 Summer Research Studentship, Natural Sciences and Engineering Research Council of Canada
1994-1998 Canada Scholar, Industry Canada
- Kiser, E., Ishii, M., Langmuir, C.H., Shearer, P.M., & Hirose, H., 2011.
Insights into the mechanism of intermediate-depth earthquakes from source properties as imaged by back-projection of multiple seismic phases.
J. Geophys. Res., doi:10.1029/2010JB007831.
- Kiser, E., & Ishii, M., 2011.
The 2010 Mw 8.8 Chile earthquake: Triggering on multiple segments and frequency‐dependent rupture behavior.
Geophys. Res. Lett. 38, L07301, doi:10.1029/2011GL047140.
- Latychev, K., Mitrovica, J.X., Ishii, M., Chan, E., & Davis, J.L., 2009.
Body tides on a 3-D elastic Earth: Toward a tidal tomography.
Earth Planet. Sci. Lett. 277, 86--90, doi:10.1016/j.epsl.2008.10.008.
- Ishii, M., Shearer, P.M., Houston, H., & Vidale, J.E., 2007.
Teleseismic P wave imaging of the 26 December 2004 Sumatra-Andaman and 28 March 2005 Sumatra earthquake ruptures using the Hi-net array.
J. Geophys. Res. 112, B11307, doi:10.1029/2006JB004700.
- Ishii, M., 2007.
Seismological constraints on the structure of the Earth's core.
in Superplume: Beyond Plate Tectonics, edited by D. Yuen, S. Karato, S. Maruyama, and B.F. Windley, 31--68, Kluwer Academic Press, New York.
- Peng, Z., Vidale, J.E., Ishii, M., & Helmstetter, A., 2007.
Seismicity rate immediately before and after main shock rupture from high-frequency waveforms in Japan.
J. Geophys. Res. 112, B03306, doi:10.1029/2006JB004386.
- Walker, K., Ishii, M., & Shearer, P.M., 2005.
Rupture details of the 28 March 2005 Sumatra Mw 8.6 earthquake imaged with teleseismic P waves.
Geophys. Res. Lett. 32(24), L24303, doi:10.1029/2005GL024395.
- Davis, P., Ishii, M., & Masters, G., 2005.
An assessment of the accuracy of GSN sensor response information.
Seism. Res. Lett. 76(6), 678-683.
- Ishii, M., & Dziewonski, A.M., 2005.
Constraints on the outer core tangent cylinder using normal-mode splitting measurements.
Geophys. J. Int. 162(3), 787-792, doi:10.1111/j.1365-246X.2005.02587.x.
- Ishii, M., Shearer, P.M., Houston, H., & Vidale, J.E., 2005.
Extent, duration and speed of the 2004 Sumatra-Andaman earthquake imaged by the Hi-Net array.
Nature 435(7044), 933-936, doi10.1038/nature03675.
- Pysklywec, R.N., & Ishii, M., 2005.
Time dependent subduction dynamics driven by the instability of stagnant slabs in the transition zone.
Phys. Earth Planet. Inter. 149(1-2), 115-132.
- Lay, T., Heinz, D., Ishii, M., Shim, S., Tsuchiya, J., Tsuchiya, T., Wentzcovitch, R., & Yuen, D., 2005.
Multi-disciplinary impact of the lower mantle perovskite phase transition.
EOS Trans. AGU 86(1), 1-5.