We develop an adjoint‐state full‐waveform inversion procedure to recover the initial water elevation of a tsunami event. Traditional finite‐fault tsunami source inversion methods suffer from the uncertainty of fault parameters or crustal rigidity. Moreover, the heavy computational burden of calculating Green's functions results in limited spatial resolution and hinders the real‐time applicability of the traditional methods to tsunami early warning. In this work, we apply the adjoint‐state full‐waveform inversion method to the tsunami source inversion. The benefits of the adjoint inversion are twofold: (1) independence of fault parameters, and (2) high computational efficiency, especially for dense tsunami arrays and high‐resolution grids. We validate this approach with synthetic tsunami sources and apply it to the 2014 Chile‐Iquique tsunami event. Both synthetic and real‐data results show that the adjoint‐state method is of high efficiency and high resolution, outperforming the traditional tsunami source inversions.
We explore the potential of the adjoint‐state tsunami inversion method for rapid and accurate near‐field tsunami source characterization using S‐net, an array of ocean bottom pressure gauges. Compared to earthquake‐based methods, this method can obtain more accurate predictions for the initial water elevation of the tsunami source, including potential secondary sources, leading to accurate water height and wave run‐up predictions. Unlike finite‐fault tsunami source inversions, the adjoint method achieves high‐resolution results without requiring densely gridded Green's functions, reducing computation time. However, optimal results require a dense instrument network with sufficient azimuthal coverage. S‐net meets these requirements and reduces data collection time, facilitating the inversion and timely issuance of tsunami warnings. Since the method has not yet been applied to dense, near‐field data, we test it on synthetic waveforms of the 2011
- PAR ID:
- 10482072
- Publisher / Repository:
- DOI PREFIX: 10.1029
- Date Published:
- Journal Name:
- Earth and Space Science
- Volume:
- 10
- Issue:
- 12
- ISSN:
- 2333-5084
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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