In the network-based on-site earthquake early warning system (EEWS), the “blind zone”, namely the zone where the issued warning arrives later than the destructive S and surface waves, is one of the challenges affecting its effectiveness. The blind zone is determined by the interstation distance, or equivalently the density of seismic stations, of the network. In this paper, we suggest a practical approach according to which, when in a region a temporary increase of seismic hazard is declared, additional stations are deployed in such a way that the blind zone is temporarily reduced. In the procedure, the time-dependent neo- deterministic seismic hazard assessment (TD-NDSHA) plays a vital role in the identification of the regions potentially exposed to high macroseismic intensities. As a showcase example, we consider the scenario of year 2014 at the Sichuan-Yunnan border of southwest China. The TD-NDSHA is based on the standard NDSHA procedure at regional scale (bedrock conditions), with the “controlling earthquakes” defined on the basis of the Annual Consultation. We show that the blind zone can be reduced in the identified areas of interest (e.g., MMI ≥ VI), by deploying a limited number of additional seismic stations. In the case where false alarms can be tolerated, significant reduction of the blind zone can be implemented by moving from a network-based EEWS to a single-sensor-based EEWS and skipping the process of location and magnitude-determination/prediction procedures.

Earthquake early warning system empowered by time-dependent neo-deterministic seismic hazard assessment

Fabio Romanelli
;
Franco Vaccari;
2023-01-01

Abstract

In the network-based on-site earthquake early warning system (EEWS), the “blind zone”, namely the zone where the issued warning arrives later than the destructive S and surface waves, is one of the challenges affecting its effectiveness. The blind zone is determined by the interstation distance, or equivalently the density of seismic stations, of the network. In this paper, we suggest a practical approach according to which, when in a region a temporary increase of seismic hazard is declared, additional stations are deployed in such a way that the blind zone is temporarily reduced. In the procedure, the time-dependent neo- deterministic seismic hazard assessment (TD-NDSHA) plays a vital role in the identification of the regions potentially exposed to high macroseismic intensities. As a showcase example, we consider the scenario of year 2014 at the Sichuan-Yunnan border of southwest China. The TD-NDSHA is based on the standard NDSHA procedure at regional scale (bedrock conditions), with the “controlling earthquakes” defined on the basis of the Annual Consultation. We show that the blind zone can be reduced in the identified areas of interest (e.g., MMI ≥ VI), by deploying a limited number of additional seismic stations. In the case where false alarms can be tolerated, significant reduction of the blind zone can be implemented by moving from a network-based EEWS to a single-sensor-based EEWS and skipping the process of location and magnitude-determination/prediction procedures.
2023
Pubblicato
https://onlinelibrary.wiley.com/doi/epdf/10.1111/ter.12647
File in questo prodotto:
File Dimensione Formato  
Terra Nova - 2023 - Zhang.pdf

accesso aperto

Descrizione: free access at link:https://onlinelibrary.wiley.com/doi/10.1111/ter.12647
Tipologia: Documento in Versione Editoriale
Licenza: Creative commons
Dimensione 13.02 MB
Formato Adobe PDF
13.02 MB Adobe PDF Visualizza/Apri
Terra+Nova+-+2023+-+Zhang-Post_print.pdf

Open Access dal 04/03/2023

Tipologia: Bozza finale post-referaggio (post-print)
Licenza: Digital Rights Management non definito
Dimensione 13.52 MB
Formato Adobe PDF
13.52 MB Adobe PDF Visualizza/Apri
Pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11368/3041982
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 0
  • ???jsp.display-item.citation.isi??? 0
social impact