When are Non-Double-Couple Components of Seismic Moment Tensors Reliable?
DOI:
https://doi.org/10.26443/seismica.v2i1.241Keywords:
Non-double-couple components, moment tensors, moment tensor catalogsAbstract
There has been considerable discussion as to how to assess when non-double-couple (NDC) components of seismic moment tensors represent real source processes. We explore this question by comparing moment tensors (MTs) of earthquakes in three global catalogs, which use different inversion procedures. Their NDC components are only weakly correlated between catalogs, suggesting that they are largely artifacts of the inversion. A monotonic decrease in the NDC components' standard deviation with magnitude indicates increased reliability of the NDC components for larger earthquakes. The standard deviation begins to decrease for large NDC components exceeding 60%, suggesting that they represent real source processes. Randomly generated NDC components with the same mean and standard deviation as in the MT catalogs only reproduce some of this decrease. Thus NDC components of large earthquakes and NDC components that exceed 60% are likely to represent real source processes.
References
Adamová, P., & Šílený, J. (2010). Non-double-couple earthquake mechanism as an artifact of the point-source approach applied to a finite-extent focus. Bulletin of the Seismological Society of America, 100(2), 447–457.
Ammon, C. J., Lay, T., Velasco, A. A., & Vidale, J. E. (1994). Routine estimation of earthquake source complexity: The 18 October 1992 Colombian earthquake. Bulletin of the Seismological Society of America, 84(4), 1266–1271.
Beyreuther, M., Barsch, R., Krischer, L., Megies, T., Behr, Y., & Wassermann, J. (2010). ObsPy: A Python toolbox for seismology. Seismological Research Letters, 81(3), 530–533.
Chapman, M. C. (2013). On the rupture process of the 23 August 2011 Virginia earthquake. Bulletin of the Seismological Society of America, 103(2A), 613–628.
Cohee, B. P., & Beroza, G. C. (1994). Slip distribution of the 1992 Landers earthquake and its implications for earthquake source mechanics. Bulletin of the Seismological Society of America, 84(3), 692–712.
Dziewonski, A. M., & Woodhouse, J. (1983). An experiment in systematic study of global seismicity: centroid-moment tensor solutions for 201 moderate and large earthquakes of 1981. Journal of Geophysical Research, 88(B4), 3247–3271.
Ekström, G., Nettles, M., & Dziewonski, A. (2012). The global CMT project 2004-2010: Centroid-moment tensors for 13,017 earthquakes. Physics of the Earth and Planetary Interiors, 200–201, 1–9.
Frohlich, C. (1992). Triangle diagrams: ternary graphs to display similarity and diversity of earthquake focal mechanisms. Physics of the Earth and Planetary Interiors, 75(1–3), 193–198.
Frohlich, C. (1994). Earthquakes with non-double-couple mechanisms. Science, 264(5160), 804–809.
Frohlich, C., & Davis, S. D. (1999). How well constrained are well-constrained T, B, and P axes in moment tensor catalogs? Journal of Geophysical Research, 104(B3), 4901–4910.
Giardini, D. (1984). Systematic analysis of deep seismicity: 200 centroid-moment tensor solutions for earthquakes between 1977 and 1980. Geophysical Journal International, 77(3), 883–914.
Gudmundsson, M. T., Jónsdóttir, K., Hooper, A., Holohan, E. P., Halldórsson, S. A., Ófeigsson, B. G., Cesca, S., Vogfjörd, K. S., Sigmundsson, F., Högnadóttir, T., Einarsson, P., Sigmarsson, O., Jarosch, A. H., Jónasson, K., Magnússon, E., Hreinsdóttir, S., Bagnardi, M., Parks, M. M., Hjörleifsdóttir, V., … Aiuppa, A. (2016). Gradual caldera collapse at Bárdarbunga volcano, Iceland, regulated by lateral magma outflow. Science, 353(6296).
Hamling, I. J., Hreinsdóttir, S., Clark, K., Elliott, J., Liang, C., Fielding, E., Litchfield, N., Villamor, P., Wallace, L., Wright, T. J., d’Anastasio, E., Bannister, S., Burbridge, D., Denys, P., Gentle, P., Howarth, J., Mueller, C., Palmer, N., Pearson, C., … Stirling, M. (2017). Complex multifault rupture during the Mw 7.8 Kaikōura earthquake, New Zealand. Science, 356(6334).
Hayes, G. P., Briggs, R. W., Sladen, A., Fielding, E. J., Prentice, C., Hudnut, K., Mann, P., Taylor, F. W., Crone, A. J., Gold, R., Ito, T., & Simons, M. (2010). Complex rupture during the 12 January 2010 Haiti earthquake. Nature Geoscience, 3(11), 800–805.
Hayes, G. P., Rivera, L., & Kanamori, H. (2009). Source inversion of the W-Phase: real-time implementation and extension to low magnitudes. Seismological Research Letters, 80(5), 817–822.
Hudson, J. A., Pearce, R. G., & Rogers, R. M. (1989). Source type plot for inversion of the moment tensor. Journal of Geophysical Research: Solid Earth, 94(B1), 765–774.
Jost, M. U., & Herrmann, R. B. (1989). A student’s guide to and review of moment tensors. Seismological Research Letters, 60(2), 37–57.
Kanamori, H. (1977). The energy release in great earthquakes. Journal of Geophysical Research, 82(20), 2981–2987.
Kanamori, H., & Given, J. W. (1982). Analysis of long-period seismic waves excited by the May 18, 1980, eruption of Mount St. Helens - A terrestrial monopole? Journal of Geophysical Research, 87(B7), 5422–5432.
Kawakatsu, H. (1991). Insignificant isotropic component in the moment tensor of deep earthquakes. Nature, 351(6321), 50–53.
Miller, A. D., Foulger, G. R., & Julian, B. R. (1998). Non-double-couple earthquakes 2. Observations. Reviews of Geophysics, 36(4), 551–568.
Nettles, M., & Ekström, G. (1998). Faulting mechanism of anomalous earthquakes near Bárdarbunga Volcano, Iceland. Journal of Geophysical Research: Solid Earth, 103(B8), 17973–17983.
Okal, E. A., Saloor, N., Kirby, S. H., & Nettles, M. (2018). An implosive component to the source of the deep Sea of Okhotsk earthquake of 24 May 2013: Evidence from radial modes and CMT inversion. Physics of the Earth and Planetary Interiors, 281, 68–78.
Pang, G., Koper, K. D., Mesimeri, M., Pankow, K. L., Baker, B., Farrell, J., Holt, J., Hale, J. M., Roberson, P., Burlacu, R., Pechmann, J. C., Whidden, K., Holt, M. M., Allamm, A., & DuRoss, C. (2020). Seismic analysis of the 2020 Magna, Utah, earthquake sequence: Evidence for a listric Wasatch fault. Geophysical Research Letters, 47(18).
Rodríguez-Cardozo, F., Hjörleifsdóttir, V., K., J., Iglesias, A., Franco, S. I., Geirsson, H., Trujillo-Castrillón, N., & M., H. (2021). The 2014-2015 complex collapse of the Bárðarbunga caldera, Iceland, revealed by seismic moment tensors. Journal of Volcanology and Geothermal Research, 416.
Rösler, B., & Stein, S. (2022). Consistency of Non-Double-Couple Components of Seismic Moment Tensors with Earthquake Magnitude and Mechanism. Seismological Research Letters, 93(3), 1510–1523.
Rösler, B., Stein, S., & Spencer, B. D. (2021). Uncertainties in Seismic Moment Tensors Inferred from Differences Between Global Catalogs. Seismological Research Letters, 92(6), 3698–3711.
Ross, A., Foulger, G. R., & Julian, B. R. (1996). Non-double-couple earthquake mechanisms at the Geysers geothermal area, California. Geophysical Research Letters, 23(8), 877–880.
Ruhl, C. J., Morton, E. A., Bormann, J. M., Hatch-Ibarra, R., Ichinose, G., & Smith, K. D. (2021). Complex Fault Geometry of the 2020 Mww 6.5 Monte Cristo Range, Nevada, Earthquake Sequence. Seismological Research Letters, 92(3), 1876–1890.
Saloor, N., & Okal, E. A. (2018). Extension of the energy-to-moment parameter Θ to intermediate and deep earthquakes. Physics of the Earth and Planetary Interiors, 274, 37–48.
Sandanbata, O., Kanamori, H., Rivera, L., Zhan, Z., Watada, S., & Satake, K. (2021). Moment tensors of ring-faulting at active volcanoes: Insights into vertical-CLVD earthquakes at the Sierra Negra caldera, Galápagos Islands. Journal of Geophysical Research: Solid Earth, 126(6).
Scognamiglio, L., Tinti, E., Casarotti, E., Pucci, S., Villani, F., Cocco, M., Magnoni, F., Michelini, A., & Dreger, D. (2018). Complex fault geometry and rupture dynamics of the Mw 6.5, 30 October 2016, Central Italy earthquake. Journal of Geophysical Research, 123(4), 2943–2964.
Shuler, A., Ekström, G., & Nettles, M. (2013). Physical mechanisms for vertical-CLVD earthquakes at active volcanoes. Journal of Geophysical Research: Solid Earth, 118(4), 1569–1586.
Shuler, A., Nettles, M., & Ekström, G. (2013). Global observation of vertical-CLVD earthquakes at active volcanoes. Journal of Geophysical Research: Solid Earth, 118(1), 138–164.
Silver, P. G., & Jordan, T. H. (1982). Optimal estimation of scalar seismic moment. Geophysical Journal International, 70(3), 755–787.
Sipkin, S. A. (1986). Interpretation of non-double-couple earthquake mechanisms derived from moment tensor inversion. Journal of Geophysical Research: Solid Earth, 91(B1), 531–547.
Stierle, E., Bohnhoff, M., & Vavryčuk, V. (2014). Resolution of non-double-couple components in the seismic moment tensor using regional networks - II: application to aftershocks of the 1999 Mw 7.4 Izmit earthquake. Journal of Geophysical Research: Solid Earth, 196(3), 1878–1888.
Vavryčuk, V. (2001). Inversion for parameters of tensile earthquakes. Journal of Geophysical Research: Solid Earth, 106(B8), 16339–16355.
Vavryčuk, V. (2002). Non-double-couple earthquakes of 1997 January in West Bohemia, Czech Republic: evidence of tensile faulting. Geophysical Journal International, 149(2), 364–373.
Vavryčuk, V. (2011). Tensile earthquakes: theory, modeling, and inversion. Journal of Geophysical Research: Solid Earth, 116(B12).
Wald, D. J., & Heaton, T. H. (1994). Spatial and temporal distribution of slip for the 1992 Landers, California, earthquake. Bulletin of the Seismological Society of America, 84(3), 668–691.
Yang, J., Zhu, H., Lay, T., Niu, Y., Ye, L., Lu, Z., Luo, B., Kanamori, H., Huang, J., & Li, Z. (2021). Multi-fault opposing-dip strike-slip and normal-fault rupture during the 2020 Mw 6.5 Stanley, Idaho earthquake. Geophysical Research Letters, 48(10).
Additional Files
Published
How to Cite
Issue
Section
License
Copyright (c) 2023 Boris Rösler, Seth Stein, Bruce D. Spencer
This work is licensed under a Creative Commons Attribution 4.0 International License.
