The 2003-2007 Seismic Hazard Model for Cuba and Surrounding Areas
In the last years a PSHA has been performed in response to a revision and update of the Cuban building standards (NC-46-99) for earthquake-resistant building design. The seismic zonation presented here is part of these elaborations, and summarizes the implementation of the PSHA input model proposed in Garcia et al. (2003), which was improved in 2007 (Garcia, 2007) and recently proposed by Garcia and Llanes, 2013. The model and the results obtained are valid only for the Cuban territories. Here we present a short description of how this model was implemented in the OpenQuake-engine.
The Seismic source model
The north-eastern Caribbean plate is characterised by complex tectonics, with a transform plate boundary in the vicinity of Cuba, which governed the interaction of the Caribbean plate with the north American plate. The seismicity in the vicinity of Cuba clearly indicates the capability of the major transform system faults: the Oriente and the Septentrional transform faults where very large transpressive and strike-slip earthquakes occur.
In addition, to the west we have the Cayman Spreading Centre, which generates normal faulting earthquakes typically and “intraplate” seismicity related to tectonic structures of minor relevance. For Cuba, two source models reflecting this complexity were considered:
- The source model proposed in Garcia et al. (2003)
- The source zone proposed in Chuy and Alvarez (1995), with some modifications proposed by Despaigne et al. (2002)
In both models, the tectonic figures are defined as area sources at a fixed depth. In the OpenQuake-engine implementation, we use the same typology defined in the original models, then the source zones are modelled as NRML areaSource objects.
The map below depicts the annual occurrence rate per source (between minimum and maximum magnitudes) for the first source model cited above, the only one considered in the OpenQuake-engine implementation.
operating instructions
Various functions are available as part of the map.
mouse/touch operation
- moving by grabbing the map with a mouse-click you can move the map around
- overview map using the + button in the bottom right of the map you can expand an overview map
- zooming in and out using the + and - buttons in the top left of the map you can obtain more or less detail in the map
- switching themes or maps clicking on the ≡ icon on the right-hand side of the map you can view and select available maps and themes
- retrieving information the map may contain elements that contain more information, by clicking these a popup will show this information
- fullscreen display using the ✈ button the map can be maximized to fullscreen display, use the ✕ button to return to page display.
keyboard operation
Keyboard operation becomes available after activating the map using the tab key (the map will show a focus indicator ring).
- moving using the arrow keys you can move the map
- overview map using the + button in the bottom right of the map you can expand an overview map
- zooming in and out using the + and - buttons in the top left of the map or by using the + and - keys you can obtain more or less detail in the map
- switching themes or maps clicking on the ≡ icon on the right-hand side of the map you can view and select available maps and themes
- retrieving information the map may contain elements that contain more information, using the i key you can activate a cursor that may be moved using the arrow keys, pressing the enter will execute an information retrieval. press the i or the escape key to return to navigation mode
- fullscreen display using the ✈ button the map can be maximized to fullscreen display, use the ✕ button to return to page display.
It's possible that some of the functions or buttons describe above have been disabled by the page author or the administrator
(number of events / year)
- < 1e-6
- 1e-6 - 1e-5
- 1e-5 - 1e-4
- 1e-4 - 1e-3
- 1e-3 - 1e-2
- 1e-2 - 1e-1
- 1e-1 - 1
- 1 - 10
- >= 10
The Ground motion model
As there are no ground motion prediction equations (GMPEs) for the Cuban/Caribbean region, GMPE's from literature have been used. In the original model, two GMPEs for active shallow crust regimes were used and combined using a logic tree.
| Active Shallow Crust | Weight |
| Ambraseys et al. (1996) | 0.5 |
| Boore and Atkinson (2008) | 0.5 |
In our OpenQuake-engine implementation we decided to use only one GMPE (Boore and Atkinson, 2008).
| Active Shallow Crust | Weight |
| Boore and Atkinson (2008) | 1.0 |
Reference site condition
A rock condition is assumed in the OpenQuake-engine implementation. The site condition is defined using a Vs30 = 760 m/s.
Hazard results
In the original model the calculation was made using the Cornel (1968) approach, first using SEISRISK III and then CRISIS (v.2013) codes. In both cases a logic tree was used to take into account epistemic uncertainties.
The figure below represent hazard maps for peak ground acceleration, for 10% probabilities of exceedance in 50 years, using the OpenQuake-engine and CRISIS and the Boore and Atkinson (2008) as GMPE.
References
- Chuy, T., and Alvarez, L. (1995): Zonación sísmica de Cuba con fines de la norma sismorresistente cubana, Internal Report, National Centre for Seismological Research, Ministry of Science, Technology and Environment, Cuba, pp. 23, (in Spanish).
- Garcia, J. (2007): Estimados de peligrosidad sísmica con el error asociado para Cuba, y cálculo de pérdidas para la ciudad de Santiago de Cuba usando técnicas SIG, Tesis en opción al Grado de Doctor en Ciencias Geofísicas. Fondos del Centro Nacional de Investigaciones Sismológicas (CENAIS),CITMA, Cuba, 188 pp. (in Spanish)
- Garcia, J. and Llanes-Buron, C. (2013): Probabilistic seismic hazard zonation for the Cuban building code, American Geophysical Union, Spring Meeting 2013, abstract-poster: S43B-18, Cancun, Mexico, 14-17 May 2013. Abstract
- Garcia, J., Slejko, D., Alvarez L., Peruzza L., Rebez, A. (2003): Seismic hazard maps for Cuba and surrounding area, Bull. Seism. Soc. Am. Vol.93; Num. 6, pp. 2563-2590. Journal website
- Kijko, A. and Graham, G. (1998). Parametric-historic procedure for probabilistic seismic hazard analysis. Part i: Estimation of maximum regional magnitude Mmax. Pure Appl. Geophys., 52, pp. 413-442. Journal Website
- NC-46 (1999). Construcciones sismorresistentes. requisitos básicos para el diseño y construcción, la Habana, Cuba, Comité Estatal de Normalización.
- Wells, D.L., and Coppersmith, K.J., 1994, New empirical relationships among magnitude, rupture length, rupture width, and surface displacements: Bulletin of the Seismological Society of America, v. 84, p. 974–1002. Journal Website
Model summary table
This table summarises the main characteristics of the original implementation of this model
| 1 | Datasets availability | |
|---|---|---|
| 1.1 | Earthquake catalogue | Not available |
| 1.2 | Geological database | Not available |
| 1.3 | Strong-motion database | Not used |
| 1.4 | Site characterization database | Not used |
| Notes | ||
| 2 | Methodology for model development | |
| 2.1 | Scientific participation (SSHAC levels) and review process | |
| 2.2 | Documentation describing model preparation | Not available |
| 2.3 | Codes used for model preparation | Not available |
| Notes | ||
| 3 | PSHA input model | |
| 3.1 | Seismic Source Model | |
| 3.1.1 | Area sources | YES |
| 3.1.2 | Grid sources | NO |
| 3.1.3 | Crustal faults | NO |
| 3.1.4 | Subduction faults | NO |
| 3.1.5 | Non-parametric ruptures | NO |
| 3.1.6 | Magnitude-area scaling relationships | Wells and Coppersmith (1994) |
| 3.2 | Ground Motion Model | |
| 3.2.0 | Tectonic regionalisation | NO |
| 3.2.1 | Models for active shallow seismicity | YES |
| 3.2.2 | Models for subduction interface | NO |
| 3.2.3 | Models for subduction intraslab | NO |
| 3.2.4 | Models for stable continental regions | NO |
| 3.2.5 | Models for deep non-subduction sources | NO |
| 3.2.6 | Models for volcanic areas | NO |
| 3.3 | Site Response Model | |
| 3.3.1 | Based on GMPEs | YES |
| 3.3.2 | Based on site-response analysis | NO |
| 3.4 | Epistemic uncertainties | |
| 3.4.1 | Seismic Source Model | Included |
| 3.4.2 | Ground Motion Model | Included using a logic tree (see the ground motion model section) |
| 3.4.3 | Site Response Model | Not included |
| Notes | ||
| 4 | Hazard Input Description | |
| 4.1 | Hazard input document | Partially available |
| 4.2 | Input files | Partially available |
| Notes | ||
| 5 | Calculation | |
| 5.1 | Software | Available upon request- CRISIS-2012 |
| 5.2 | Results | |
| 5.2.1 | Hazard curves | Not available |
| 5.2.2 | Hazard maps | Not available |
| 5.2.3 | Uniform hazard spectra | Not available |
| 5.2.4 | Disaggregation | Not available |
| 5.2.5 | Stochastic event sets | Not available |
| 5.2.6 | Ground motion fields | Not available |
| Notes | The results will be available soon (paper in preparation) | |
Download The OpenQuake-engine Input Model
The OpenQuake-engine input model (NRML format) can be downloaded at the link provided below - Please read the license and disclaimer attached to the model.
N.B. This is a model adapted by GEM to the OpenQuake-engine from the original model developed by Garcia eta l. (2003). This explains minor differences you might encounter between the results presented in the OpenQuake platform and those disseminated by the original Organisation.