Probabilistic Tsunami Hazard Analysis for Vancouver Island Coast Using Stochastic Rupture Models for the Cascadia Subduction Earthquakes
Tsunami hazard analysis is an essential step for designing buildings and infrastructure and for safeguarding people and assets in coastal areas. Coastal communities on Vancouver Island are under threat from the Cascadia megathrust earthquakes and tsunamis. Due to the deterministic nature of current...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-06-01
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| Series: | GeoHazards |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2624-795X/4/3/13 |
| _version_ | 1827726049293631488 |
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| author | Katsuichiro Goda |
| author_facet | Katsuichiro Goda |
| author_sort | Katsuichiro Goda |
| collection | DOAJ |
| description | Tsunami hazard analysis is an essential step for designing buildings and infrastructure and for safeguarding people and assets in coastal areas. Coastal communities on Vancouver Island are under threat from the Cascadia megathrust earthquakes and tsunamis. Due to the deterministic nature of current megathrust earthquake scenarios, probabilistic tsunami hazard analysis has not been conducted for the coast of Vancouver Island. To address this research gap, this study presents a new probabilistic tsunami hazard model for Vancouver Island from the Cascadia megathrust subduction events. To account for uncertainties of the possible rupture scenarios more comprehensively, time-dependent earthquake occurrence modeling and stochastic rupture modeling are integrated. The time-dependent earthquake model can capture a multi-modal distribution of inter-arrival time data on the Cascadia megathrust events. On the other hand, the stochastic rupture model can consider variable fault geometry, position, and earthquake slip distribution within the subduction zone. The results indicate that the consideration of different inter-arrival time distributions can result in noticeable differences in terms of site-specific tsunami hazard curves and uniform tsunami hazard curves at different return period levels. At present, the use of the one-component renewal model tends to overestimate the tsunami hazard values compared to the three-component Gaussian mixture model. With the increase in the elapsed time since the last event and the duration of tsunami hazard assessment, the differences tend to be smaller. Inspecting the regional variability of the tsunami hazards, specific segments of the Vancouver Island coast are likely to experience higher tsunami hazards due to the directed tsunami waves from the main subduction zone and due to the local underwater topography. |
| first_indexed | 2024-03-10T22:43:48Z |
| format | Article |
| id | doaj.art-dd0dcc3706f54e2aabca91d274ed379a |
| institution | Directory Open Access Journal |
| issn | 2624-795X |
| language | English |
| last_indexed | 2024-03-10T22:43:48Z |
| publishDate | 2023-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | GeoHazards |
| spelling | doaj.art-dd0dcc3706f54e2aabca91d274ed379a2023-11-19T10:54:27ZengMDPI AGGeoHazards2624-795X2023-06-014321723810.3390/geohazards4030013Probabilistic Tsunami Hazard Analysis for Vancouver Island Coast Using Stochastic Rupture Models for the Cascadia Subduction EarthquakesKatsuichiro Goda0Department of Earth Sciences, Western University, London, ON N6A 3K7, CanadaTsunami hazard analysis is an essential step for designing buildings and infrastructure and for safeguarding people and assets in coastal areas. Coastal communities on Vancouver Island are under threat from the Cascadia megathrust earthquakes and tsunamis. Due to the deterministic nature of current megathrust earthquake scenarios, probabilistic tsunami hazard analysis has not been conducted for the coast of Vancouver Island. To address this research gap, this study presents a new probabilistic tsunami hazard model for Vancouver Island from the Cascadia megathrust subduction events. To account for uncertainties of the possible rupture scenarios more comprehensively, time-dependent earthquake occurrence modeling and stochastic rupture modeling are integrated. The time-dependent earthquake model can capture a multi-modal distribution of inter-arrival time data on the Cascadia megathrust events. On the other hand, the stochastic rupture model can consider variable fault geometry, position, and earthquake slip distribution within the subduction zone. The results indicate that the consideration of different inter-arrival time distributions can result in noticeable differences in terms of site-specific tsunami hazard curves and uniform tsunami hazard curves at different return period levels. At present, the use of the one-component renewal model tends to overestimate the tsunami hazard values compared to the three-component Gaussian mixture model. With the increase in the elapsed time since the last event and the duration of tsunami hazard assessment, the differences tend to be smaller. Inspecting the regional variability of the tsunami hazards, specific segments of the Vancouver Island coast are likely to experience higher tsunami hazards due to the directed tsunami waves from the main subduction zone and due to the local underwater topography.https://www.mdpi.com/2624-795X/4/3/13probabilistic tsunami hazard analysisstochastic rupture modelstime-dependent earthquake occurrenceCascadia subduction zoneVancouver Island |
| spellingShingle | Katsuichiro Goda Probabilistic Tsunami Hazard Analysis for Vancouver Island Coast Using Stochastic Rupture Models for the Cascadia Subduction Earthquakes GeoHazards probabilistic tsunami hazard analysis stochastic rupture models time-dependent earthquake occurrence Cascadia subduction zone Vancouver Island |
| title | Probabilistic Tsunami Hazard Analysis for Vancouver Island Coast Using Stochastic Rupture Models for the Cascadia Subduction Earthquakes |
| title_full | Probabilistic Tsunami Hazard Analysis for Vancouver Island Coast Using Stochastic Rupture Models for the Cascadia Subduction Earthquakes |
| title_fullStr | Probabilistic Tsunami Hazard Analysis for Vancouver Island Coast Using Stochastic Rupture Models for the Cascadia Subduction Earthquakes |
| title_full_unstemmed | Probabilistic Tsunami Hazard Analysis for Vancouver Island Coast Using Stochastic Rupture Models for the Cascadia Subduction Earthquakes |
| title_short | Probabilistic Tsunami Hazard Analysis for Vancouver Island Coast Using Stochastic Rupture Models for the Cascadia Subduction Earthquakes |
| title_sort | probabilistic tsunami hazard analysis for vancouver island coast using stochastic rupture models for the cascadia subduction earthquakes |
| topic | probabilistic tsunami hazard analysis stochastic rupture models time-dependent earthquake occurrence Cascadia subduction zone Vancouver Island |
| url | https://www.mdpi.com/2624-795X/4/3/13 |
| work_keys_str_mv | AT katsuichirogoda probabilistictsunamihazardanalysisforvancouverislandcoastusingstochasticrupturemodelsforthecascadiasubductionearthquakes |