Megathrust earthquake sequences, comprising mainshocks and triggered aftershocks along the subduction interface and in the overriding crust, can impact multiple buildings and infrastructure in a city. The time between the mainshocks and aftershocks usually is too short to retrofit the structures; therefore, moderate\uffe2\uff80\uff90size aftershocks can cause additional damage. To have a better understanding of the impact of aftershocks on city\uffe2\uff80\uff90wide seismic risk assessment, a new simulation framework of spatiotemporal seismic hazard and risk assessment of future M9.0 sequences in the Cascadia subduction zone is developed. The simulation framework consists of an epidemic\uffe2\uff80\uff90type aftershock sequence (ETAS) model, ground\uffe2\uff80\uff90motion model, and state\uffe2\uff80\uff90dependent seismic fragility model. The spatiotemporal ETAS model is modified to characterise aftershocks of large and anisotropic M9.0 mainshock ruptures. To account for damage accumulation of wood\uffe2\uff80\uff90frame houses due to aftershocks in Victoria, British Columbia, Canada, state\uffe2\uff80\uff90dependent fragility curves are implemented. The new simulation framework can be used for quasi\uffe2\uff80\uff90real\uffe2\uff80\uff90time aftershock hazard and risk assessments and city\uffe2\uff80\uff90wide post\uffe2\uff80\uff90event risk management.
", "keywords": ["Mainshock-aftershock sequences", "550", "seismic risk", "Damage accumulation", "seismic hazard", "Cascadia", "City-wide seismic risk", "02 engineering and technology", "Wood-frame houses", "01 natural sciences", "aftershocks", "0201 civil engineering", "earthquake clustering", "13. Climate action", "Cascadia subduction earthquakes", "Spatiotemporal ETAS seismicity model", "earthquakes", "State-dependent aftershock fragility curves", "0105 earth and related environmental sciences"]}, "links": [{"href": "https://doi.org/10.1002/eqe.3286"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Earthquake%20Engineering%20%26amp%3B%20Structural%20Dynamics", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1002/eqe.3286", "name": "item", "description": "10.1002/eqe.3286", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1002/eqe.3286"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2020-06-21T00:00:00Z"}}, {"id": "10.1785/0120190121", "type": "Feature", "geometry": null, "properties": {"updated": "2026-07-27T16:20:39Z", "type": "Journal Article", "created": "2020-01-16", "title": "Variability of ETAS Parameters in Global Subduction Zones and Applications to Mainshock\u2013Aftershock Hazard Assessment", "description": "ABSTRACTMegathrust earthquake sequences can impact buildings and infrastructure due to not only the mainshock but also the triggered aftershocks along the subduction interface and in the overriding crust. To give realistic ranges of aftershock simulations in regions with limited data and to provide time-dependent seismic hazard information right after a future giant shock, we assess the variability of the epidemic-type aftershock sequence (ETAS) model parameters in subduction zones that have experienced M\uffe2\uff89\uffa57.5 earthquakes, comparing estimates from long time windows with those from individual sequences. Our results show that the ETAS parameters are more robust if estimated from a long catalog than from individual sequences, given individual sequences have fewer data including missing early aftershocks. Considering known biases of the parameters (due to model formulation, the isotropic spatial aftershock distribution, and finite size effects of catalogs), we conclude that the variability of the ETAS parameters that we observe from robust estimates is not significant, neither across different subduction-zone regions nor as a function of maximum observed magnitudes. We also find that ETAS parameters do not change when multiple M\uffc2\uffa08.0\uffe2\uff80\uff939.0 events are included in a region, mainly because an M\uffc2\uffa09.0 sequence dominates the number of events in the catalog. Based on the ETAS parameter estimates in the long time period window, we propose a set of ETAS parameters for future M\uffc2\uffa09.0 sequences for aftershock hazard assessment (K0=0.04\uffc2\uffb10.02, \uffce\uffb1=2.3, c=0.03\uffc2\uffb10.01, p=1.21\uffc2\uffb10.08, \uffce\uffb3=1.61\uffc2\uffb10.29, d=23.48\uffc2\uffb118.17, and q=1.68\uffc2\uffb10.55). Synthetic catalogs created with the suggested ETAS parameters show good agreement with three observed M\uffc2\uffa09.0 sequences since 1965 (the 2004 M\uffc2\uffa09.1 Aceh\uffe2\uff80\uff93Andaman earthquake, the 2010 M\uffc2\uffa08.8 Maule earthquake, and the 2011 M\uffc2\uffa09.0 Tohoku earthquake).
", "keywords": ["earthquake clustering", "550", "13. Climate action", "seismic hazard", "earthquakes", "01 natural sciences", "aftershocks", "0105 earth and related environmental sciences"]}, "links": [{"href": "https://doi.org/10.1785/0120190121"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Bulletin%20of%20the%20Seismological%20Society%20of%20America", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1785/0120190121", "name": "item", "description": "10.1785/0120190121", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1785/0120190121"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2020-01-14T00:00:00Z"}}, {"id": "10.1785/0220200428", "type": "Feature", "geometry": null, "properties": {"updated": "2026-07-27T16:20:40Z", "type": "Journal Article", "created": "2021-07-28", "title": "Comment on \u201cTwo Foreshock Sequences Post Gulia and Wiemer (2019)\u201d by Kelian Dascher-Cousineau, Thorne Lay, and Emily E. Brodsky", "description": "AbstractDascher-Cousineau et\uffc2\uffa0al. (2020) apply the so-called foreshock traffic-light system (FTLS) model proposed by Gulia and Wiemer (2019) to two earthquake sequences that occurred after the submission of the model: the 2019 Ridgecrest (Mw\uffc2\uffa07.1) and the 2020 Mw\uffc2\uffa06.4 Puerto Rico earthquakes. We show in this comment that the method applied by Kelian Dascher-Cousineau et\uffc2\uffa0al. (2020) deviates in at least six substantial and not well-documented aspects from the original FTLS method. As a consequence, they used for example in the Ridgecrest case only 1% of the data available to estimate b-values and from a small subvolume of the relevant mainshock fault. In the Puerto Rico case, we document here substantial issues with the homogeneity of the magnitude scale that in our assessment make a meaningful analysis of b-values impossible. We conclude that the evaluation by Dascher-Cousineau et\uffc2\uffa0al. (2020) is misrepresentative and a not a fair test of the FTLS hypothesis.
", "keywords": ["b-value", " foreshock traffic-light system", " FTLS", " forecasting models", " aftershocks", "01 natural sciences", "0105 earth and related environmental sciences"], "contacts": [{"organization": "Gulia, Wiemer,", "roles": ["creator"]}]}, "links": [{"href": "http://pubs.geoscienceworld.org/ssa/srl/article-pdf/92/5/3251/5390782/srl-2020428.1.pdf"}, {"href": "https://doi.org/10.1785/0220200428"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Seismological%20Research%20Letters", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1785/0220200428", "name": "item", "description": "10.1785/0220200428", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1785/0220200428"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2021-07-28T00:00:00Z"}}], "links": [{"rel": "self", "type": "application/geo+json", "title": "This document as GeoJSON", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=aftershocks&f=json", "hreflang": "en-US"}, {"rel": "alternate", "type": "text/html", "title": "This document as HTML", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=aftershocks&f=html", "hreflang": "en-US"}, {"rel": "collection", "type": "application/json", "title": "Collection URL", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main", "hreflang": "en-US"}, {"type": "application/geo+json", "rel": "first", "title": "items (first)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=aftershocks&", "hreflang": "en-US"}, {"rel": "last", "type": "application/geo+json", "title": "items (last)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=aftershocks&offset=3", "hreflang": "en-US"}], "numberMatched": 3, "numberReturned": 3, "distributedFeatures": [], "timeStamp": "2026-07-28T16:12:46.309033Z"}