Comparison of statistical low-frequency earthquake activity models
Abstract Slow earthquakes are slow fault slip events. Quantifying and monitoring slow earthquake activity characteristics are important, because they may change before large earthquakes occur. Statistical seismicity models are useful for quantifying seismicity characteristics. However, no standard s...
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| Format: | Article |
| Language: | English |
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SpringerOpen
2024-04-01
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| Series: | Earth, Planets and Space |
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| Online Access: | https://doi.org/10.1186/s40623-024-02007-6 |
| _version_ | 1797199605817933824 |
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| author | Tomoaki Nishikawa |
| author_facet | Tomoaki Nishikawa |
| author_sort | Tomoaki Nishikawa |
| collection | DOAJ |
| description | Abstract Slow earthquakes are slow fault slip events. Quantifying and monitoring slow earthquake activity characteristics are important, because they may change before large earthquakes occur. Statistical seismicity models are useful for quantifying seismicity characteristics. However, no standard statistical model exists for slow earthquake activity. This study used a high-quality catalog of low-frequency earthquakes (LFEs), a type of slow earthquake, in the Nankai subduction zone from April 2004 to August 2015 and conducted the first comparison of existing statistical LFE activity models to determine which model better describes LFE activity. Based on this comparison, this study proposes a new hybrid model that incorporates existing model features. The new model considers the LFE activity history in a manner similar to the epidemic-type aftershock sequence (ETAS) model and represents the LFE aftershock rate (subsequent LFE occurrence rate) with a small number of model parameters, as in the Omori–Utsu aftershock law for regular earthquakes. The results show that the proposed model outperforms other existing models. However, the new model cannot reproduce a feature of LFE activity: the sudden cessation of intense LFE bursts. This is because the new model superimposes multiple aftershock activities and predicts extremely high seismicity rates during and after the LFE bursts. I suggest that reproducing and successfully predicting the sudden cessation of intense LFE bursts is critical for the further improvement of statistical LFE activity models. In addition, the empirical equations formulated in this study for the LFE aftershock rates may be useful for future statistical and physical modeling of LFE activity. Graphical Abstract |
| first_indexed | 2024-04-24T07:18:25Z |
| format | Article |
| id | doaj.art-5414618c65cc4e2e809a045edbedfc98 |
| institution | Directory Open Access Journal |
| issn | 1880-5981 |
| language | English |
| last_indexed | 2024-04-24T07:18:25Z |
| publishDate | 2024-04-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | Earth, Planets and Space |
| spelling | doaj.art-5414618c65cc4e2e809a045edbedfc982024-04-21T11:11:52ZengSpringerOpenEarth, Planets and Space1880-59812024-04-0176112110.1186/s40623-024-02007-6Comparison of statistical low-frequency earthquake activity modelsTomoaki Nishikawa0Disaster Prevention Research Institute, Kyoto UniversityAbstract Slow earthquakes are slow fault slip events. Quantifying and monitoring slow earthquake activity characteristics are important, because they may change before large earthquakes occur. Statistical seismicity models are useful for quantifying seismicity characteristics. However, no standard statistical model exists for slow earthquake activity. This study used a high-quality catalog of low-frequency earthquakes (LFEs), a type of slow earthquake, in the Nankai subduction zone from April 2004 to August 2015 and conducted the first comparison of existing statistical LFE activity models to determine which model better describes LFE activity. Based on this comparison, this study proposes a new hybrid model that incorporates existing model features. The new model considers the LFE activity history in a manner similar to the epidemic-type aftershock sequence (ETAS) model and represents the LFE aftershock rate (subsequent LFE occurrence rate) with a small number of model parameters, as in the Omori–Utsu aftershock law for regular earthquakes. The results show that the proposed model outperforms other existing models. However, the new model cannot reproduce a feature of LFE activity: the sudden cessation of intense LFE bursts. This is because the new model superimposes multiple aftershock activities and predicts extremely high seismicity rates during and after the LFE bursts. I suggest that reproducing and successfully predicting the sudden cessation of intense LFE bursts is critical for the further improvement of statistical LFE activity models. In addition, the empirical equations formulated in this study for the LFE aftershock rates may be useful for future statistical and physical modeling of LFE activity. Graphical Abstracthttps://doi.org/10.1186/s40623-024-02007-6Low-frequency earthquakeStatistical modelSeismicityNankai TroughSubduction zoneSlow earthquake |
| spellingShingle | Tomoaki Nishikawa Comparison of statistical low-frequency earthquake activity models Earth, Planets and Space Low-frequency earthquake Statistical model Seismicity Nankai Trough Subduction zone Slow earthquake |
| title | Comparison of statistical low-frequency earthquake activity models |
| title_full | Comparison of statistical low-frequency earthquake activity models |
| title_fullStr | Comparison of statistical low-frequency earthquake activity models |
| title_full_unstemmed | Comparison of statistical low-frequency earthquake activity models |
| title_short | Comparison of statistical low-frequency earthquake activity models |
| title_sort | comparison of statistical low frequency earthquake activity models |
| topic | Low-frequency earthquake Statistical model Seismicity Nankai Trough Subduction zone Slow earthquake |
| url | https://doi.org/10.1186/s40623-024-02007-6 |
| work_keys_str_mv | AT tomoakinishikawa comparisonofstatisticallowfrequencyearthquakeactivitymodels |