Validation of linearity assumptions for using tsunami waveforms in joint inversion of kinematic rupture models : application to the 2010 Mentawai Mw 7.8 tsunami earthquake
Tsunami observations have particular importance for resolving shallow offshore slip in finite-fault rupture model inversions for large subduction zone earthquakes. However, validations of amplitude linearity and choice of subfault discretization of tsunami Green's functions are essential when i...
| Main Authors: | , , , , , , , , , |
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| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
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2015
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| Online Access: | https://hdl.handle.net/10356/107268 http://hdl.handle.net/10220/25577 |
| _version_ | 1826117408568377344 |
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| author | Sieh, Kerry Kongko, Widjo Yue, Han Lay, Thorne Li, Linyan Yamazaki, Yoshiki Cheung, Kwok Fai Rivera, Luis Hill, Emma M. Muhari, Abdul |
| author2 | Earth Observatory of Singapore |
| author_facet | Earth Observatory of Singapore Sieh, Kerry Kongko, Widjo Yue, Han Lay, Thorne Li, Linyan Yamazaki, Yoshiki Cheung, Kwok Fai Rivera, Luis Hill, Emma M. Muhari, Abdul |
| author_sort | Sieh, Kerry |
| collection | NTU |
| description | Tsunami observations have particular importance for resolving shallow offshore slip in finite-fault rupture model inversions for large subduction zone earthquakes. However, validations of amplitude linearity and choice of subfault discretization of tsunami Green's functions are essential when inverting tsunami waveforms. We explore such validations using four tsunami recordings of the 25 October 2010 Mentawai Mw 7.8 tsunami earthquake, jointly inverted with teleseismic body waves and 1 Hz GPS (high-rate GPS) observations. The tsunami observations include near-field and far-field deep water recordings, as well as coastal and island tide gauge recordings. A nonlinear, dispersive modeling code, NEOWAVE, is used to construct tsunami Green's functions from seafloor excitation for the linear inversions, along with performing full-scale calculations of the tsunami for the inverted models. We explore linearity and finiteness effects with respect to slip magnitude, variable rake determination, and subfault dimensions. The linearity assumption is generally robust for the deep water recordings, and wave dispersion from seafloor excitation is important for accurate description of near-field Green's functions. Breakdown of linearity produces substantial misfits for short-wavelength signals in tide gauge recordings with large wave heights. Including the tsunami observations in joint inversions provides improved resolution of near-trench slip compared with inversions of only seismic and geodetic data. Two rupture models, with fine-grid (15 km) and coarse-grid (30 km) spacing, are inverted for the Mentawai event. Stronger regularization is required for the fine model representation. Both models indicate a shallow concentration of large slip near the trench with peak slip of ~15 m. Fully nonlinear forward modeling of tsunami waveforms confirms the validity of these two models for matching the tsunami recordings along with the other data. |
| first_indexed | 2024-10-01T04:27:08Z |
| format | Journal Article |
| id | ntu-10356/107268 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T04:27:08Z |
| publishDate | 2015 |
| record_format | dspace |
| spelling | ntu-10356/1072682020-09-26T21:28:50Z Validation of linearity assumptions for using tsunami waveforms in joint inversion of kinematic rupture models : application to the 2010 Mentawai Mw 7.8 tsunami earthquake Sieh, Kerry Kongko, Widjo Yue, Han Lay, Thorne Li, Linyan Yamazaki, Yoshiki Cheung, Kwok Fai Rivera, Luis Hill, Emma M. Muhari, Abdul Earth Observatory of Singapore DRNTU::Science::Geology::Volcanoes and earthquakes Tsunami observations have particular importance for resolving shallow offshore slip in finite-fault rupture model inversions for large subduction zone earthquakes. However, validations of amplitude linearity and choice of subfault discretization of tsunami Green's functions are essential when inverting tsunami waveforms. We explore such validations using four tsunami recordings of the 25 October 2010 Mentawai Mw 7.8 tsunami earthquake, jointly inverted with teleseismic body waves and 1 Hz GPS (high-rate GPS) observations. The tsunami observations include near-field and far-field deep water recordings, as well as coastal and island tide gauge recordings. A nonlinear, dispersive modeling code, NEOWAVE, is used to construct tsunami Green's functions from seafloor excitation for the linear inversions, along with performing full-scale calculations of the tsunami for the inverted models. We explore linearity and finiteness effects with respect to slip magnitude, variable rake determination, and subfault dimensions. The linearity assumption is generally robust for the deep water recordings, and wave dispersion from seafloor excitation is important for accurate description of near-field Green's functions. Breakdown of linearity produces substantial misfits for short-wavelength signals in tide gauge recordings with large wave heights. Including the tsunami observations in joint inversions provides improved resolution of near-trench slip compared with inversions of only seismic and geodetic data. Two rupture models, with fine-grid (15 km) and coarse-grid (30 km) spacing, are inverted for the Mentawai event. Stronger regularization is required for the fine model representation. Both models indicate a shallow concentration of large slip near the trench with peak slip of ~15 m. Fully nonlinear forward modeling of tsunami waveforms confirms the validity of these two models for matching the tsunami recordings along with the other data. Published version 2015-05-18T05:06:23Z 2019-12-06T22:27:40Z 2015-05-18T05:06:23Z 2019-12-06T22:27:40Z 2015 2015 Journal Article Yue, H., Lay, T., Li, L., Yamazaki, Y., Cheung, K. F., Rivera, L., et al. (2015). Validation of linearity assumptions for using tsunami waveforms in joint inversion of kinematic rupture models : application to the 2010 Mentawai Mw 7.8 tsunami earthquake. Journal of geophysical research : solid earth, 120(3), 1728-1747. 2169-9313 https://hdl.handle.net/10356/107268 http://hdl.handle.net/10220/25577 10.1002/2014JB011721 en Journal of geophysical research : solid earth © 2015 American Geophysical Union. This paper was published in Journal of Geophysical Research and is made available as an electronic reprint (preprint) with permission of American Geophysical Union. The paper can be found at the following official DOI: [http://dx.doi.org/10.1002/2014JB011721]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law. application/pdf |
| spellingShingle | DRNTU::Science::Geology::Volcanoes and earthquakes Sieh, Kerry Kongko, Widjo Yue, Han Lay, Thorne Li, Linyan Yamazaki, Yoshiki Cheung, Kwok Fai Rivera, Luis Hill, Emma M. Muhari, Abdul Validation of linearity assumptions for using tsunami waveforms in joint inversion of kinematic rupture models : application to the 2010 Mentawai Mw 7.8 tsunami earthquake |
| title | Validation of linearity assumptions for using tsunami waveforms in joint inversion of kinematic rupture models : application to the 2010 Mentawai Mw 7.8 tsunami earthquake |
| title_full | Validation of linearity assumptions for using tsunami waveforms in joint inversion of kinematic rupture models : application to the 2010 Mentawai Mw 7.8 tsunami earthquake |
| title_fullStr | Validation of linearity assumptions for using tsunami waveforms in joint inversion of kinematic rupture models : application to the 2010 Mentawai Mw 7.8 tsunami earthquake |
| title_full_unstemmed | Validation of linearity assumptions for using tsunami waveforms in joint inversion of kinematic rupture models : application to the 2010 Mentawai Mw 7.8 tsunami earthquake |
| title_short | Validation of linearity assumptions for using tsunami waveforms in joint inversion of kinematic rupture models : application to the 2010 Mentawai Mw 7.8 tsunami earthquake |
| title_sort | validation of linearity assumptions for using tsunami waveforms in joint inversion of kinematic rupture models application to the 2010 mentawai mw 7 8 tsunami earthquake |
| topic | DRNTU::Science::Geology::Volcanoes and earthquakes |
| url | https://hdl.handle.net/10356/107268 http://hdl.handle.net/10220/25577 |
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