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Abstract The 1 January 2024, moment magnitude 7.5 Noto Peninsula earthquake ruptured in complex ways, challenging analysis of its tsunami generation. We present tsunami models informed by a 6‐subevent centroid moment tensor (CMT) model obtained through Bayesian inversion of teleseismic and strong motion data. We identify two distinct bilateral rupture episodes. Initial, onshore rupture toward the southwest is followed by delayed re‐nucleation at the hypocenter, likely aided by fault weakening, causing significant seafloor uplift to the northeast. We construct a complex multi‐fault uplift model, validated against geodetic observations, that aligns with known fault system geometries and is critical in modeling the observed tsunami. The simulations can explain tsunami wave amplitude, timing, and polarity of the leading wave, which are crucial for tsunami early warning. Upon comparison with alternative source models and analysis of 2000 multi‐CMT ensemble solutions, we highlight the importance of incorporating complex source effects for realistic tsunami simulations.
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Influence of Tsunami Aspect Ratio on Near and Far-Field Tsunami Amplitude
This study presents a numerical investigation of the source aspect ratio (AR) influence on tsunami decay characteristics with an emphasis in near and far-field differences for two initial wave shapes Pure Positive Wave and N-wave. It is shown that, when initial total energy for both tsunami types is kept the same, short-rupture tsunami with more concentrated energy are likely to be more destructive in the near-field, whereas long rupture tsunami are more dangerous in the far-field. The more elongated the source is, the stronger the directivity and the slower the amplitude decays in the intermediate- and far-fields. We present evidence of this behavior by comparing amplitude decay rates from idealized sources and showing their correlation with that observed in recent historical events of similar AR.
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- Award ID(s):
- 1716156
- PAR ID:
- 10295525
- Date Published:
- Journal Name:
- Geosciences
- Volume:
- 11
- Issue:
- 4
- ISSN:
- 2076-3263
- Page Range / eLocation ID:
- 178
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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The January 1st, 2024, moment magnitude (Mw) 7.5 Noto Peninsula earthquake ruptured in complex ways, challenging timely analysis of the tsunami generation. We present rapid and accurate tsunami models informed by a 6-subevent centroid moment tensor (CMT) model that we obtain by inverting teleseismic and strong motion data and validation against geodetic observations. We identify two distinct bilateral rupture episodes, including six subevents and a re-nucleation episode at its hypocenter 20 seconds after its initiation, likely aided by fault weakening. We construct a complex uplift model that aligns with known fault system geometries and is critical in modeling the observed tsunami. Our tsunami simulation can explain wave amplitude, timing, and polarity of the leading wave, which are crucial for tsunami early warning. Analyzing a 2000 multi-CMT solution ensemble and comparing to alternative rapid source models, we highlight the importance of incorporating complex source effects for realistic tsunami simulations.more » « less
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.3390/geosciences11040178
