Strain Energy Release from the 2011 9.0 Mw Tōhoku Earthquake, Japan

Kenneth M. Cruikshank, Curt D. Peterson

Department of Geology, Portland State University, Portland, USA.

DOI: 10.4236/ojer.2013.24008                

Abstract

The purpose of this paper is to compare the strain energy released due to elastic rebound of the crust from the tragic 2011 9.0 M_wTōhoku earthquake in Japan with the observed radiated seismic energy. The strain energy was calculated by analyzing coseismic displacements of 1024 GPS stations of the Japanese GEONET network. The value of energy released from the analysis is 1.75 × 10¹⁷J, which is of the same order of magnitude as the USGS-observed radiated seismic energy of 1.9 × 10¹⁷Nm (J). The strain energy method is independent of seismic methods for determining the energy released during a large earthquake. The analysis shows that although the energy release is concentrated in the epicentral region, about 12% of the total energy was released throughout the Japanese islands at distances greater than 500 km west of the epicenter. Our results also show that outside the epicentral region, the strainenergy was concentrated along known tectonic zones throughout Japan.

Keywords

Japan; Earthquake; Crustal Strain; GPS; Radiated Energy

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	H. F. Reid, “The California Earthquake of April 18, 1906: The Mechanics of the Earthquake,” The Carnegie Institution of Washington, Washington, D.C., 1908.
[2]	USGS, US Geological Survey, Vol. 2011, 2011.
[3]	H. Kanamori and E. E. Brodsky, “The Physics of Earthquakes,” Reports on Progress in Physics, Vol. 67, No. 8, 2004, pp. 1429-1496.
[4]	S. Stein and M. Wysession, “An Introduction to Seismology, Earthquakes, and Earth Structure,” Blackwell, Malden, 2003.
[5]	C. Hashimoto, A. Noda, T. Sagiya and M. Matsu’ura, “Interplate Seismogenic Zones along the Kuril-Japan Trench Inferred from GPS Data Inversion,” Nature Geoscience, Vol. 2, No. 2, 2009, pp. 141-144.
[6]	T. Harada and M. Shimura, “Horizontal Deformation of the Crust in Western Japan Revealed from First-Order Triangulation Carried out Three Times,” Tectonophysics, Vol. 52, No. 1-4, 1979, pp. 469-478.
[7]	Nuclear Waste Management Organization of Japan, “Evaluating Site Suitability for a HLW Repository (Scientific Background and Practical Application of NUMO’s Siting Factors),” Evaluating Site Suitability for a HLW Repository (Scientific Background and Practical Application of NUMO’s Siting Factors), Vol. NUMO-TR-04-04, 2004, pp. 29-39.
[8]	J. C. Jaeger, N. G. W. Cook and R. W. Zimmerman, “Fundamentals of Rock Mechanics,” Chapman and Hall, London, 2007.
[9]	T. Vincenty, “Direct and Inverse Solutions of Geodesics on the Ellipsoid with Application of Nested Equations,” Survey Review, Vol. 23, No. 176, 1975, pp. 88-93.
[10]	F. C. Frank, “Deduction of Earth Strains from Survey Data,” Bulletin of the Seismological Society of America, Vol. 56, No. 1, 1966, pp. 35-43.
[11]	L. E. Malvern, “Introduction to the Mechanics of Continuous Medium,” Prentice-Hall, Inc., Englewood Cliffs, 1969.
[12]	K. M. Cruikshank, A. M. Johnson, R. W. Fleming and R. Jones, “Winnetka Deformation Zone. Surface Expression of Coactive Slip on a Blind Fault during the Northridge Earthquake Sequence,” Open-File Report No. OF-96-698, 1996, p. 70.
[13]	Y. C. Fung, “Foundations of Solid Mechanics,” Prentice- Hall, Englewood Cliffs, 1965.
[14]	T. Hanks and H. Kanamori, “A Moment Magnitude Scale,” Journal of Geophysical Research, Vol. 84, No. B5, 1979, pp. 2348-2350.
[15]	W. D. Mooney, G. Laske and G. Masters, “CRUST5.1: A Global Crustal Model at 5 × 5 Degrees,” Journal of Geophysical Research, Vol. 103, 1998, pp. 727-747.
[16]	T. Sagiya, S. I. Miyazaki and T. Tada, “Continuous GPS Array and Present-Day Crustal Deformation of Japan,” Pure and Applied Geophysics, Vol. 157, No. 11-12, 2000, pp. 2303-2322.
[17]	G. Plafker, “Tectonics of the March 27, 1964 Alaska Earthquake,” Professional Paper No. 543-I, 1969, p. 74.
[18]	G. Plafker, “Alaskan Earthquake of 1964 and Chilean Earthquake of 1960: Implications for Arc Tectonics,” Journal of Geophysical Research, Vol. 77, No. 5, 1972, pp. 901-925.
[19]	ARIA, “Preliminary GPS Time Series Provided by the ARIA (Advanced Rapid Imaging and Analysis) Team at JPL and Caltech,” 2011. ftp://sideshow.jpl.nasa.gov/pub/usrs/ARIA/
[20]	B. Delaunay, “Sur la Sphère Vide,” Otdelenie Matemati- cheskikh i Estestvennykh Nauk, Vol. 7, 1934, pp. 793- 800.
[21]	G. C. P. King, R. S. Stein and J. Lin, “Static Stress Changes and the Triggering of Earthquakes,” Bulletin of the Seismological Society of America, Vol. 84, No. 3, 1994, pp. 935-953.