Earthquake Rupture Forecasts for the MPS19 Seismic Hazard Model of Italy

In recent years, new approaches for developing earthquake rupture forecasts (ERFs) have been proposed to be used as an input for probabilistic seismic hazard assessment (PSHA). Zone- based approaches with seismicity rates derived from earthquake catalogs are commonly used in many countries as the standard for national seismic hazard models. In Italy, a single zone- based ERF is currently the basis for the official seismic hazard model. In this contribution, we present eleven new ERFs, including five zone-based, two smoothed seismicity-based, two fault- based, and two geodetic-based, used for a new PSH model in Italy. The ERFs were tested against observed seismicity and were subject to an elicitation procedure by a panel of PSHA experts to verify the scientific robustness and consistency of the forecasts with respect to the observations. Tests and elicitation were finalized to weight the ERFs. The results show a good response to the new inputs to observed seismicity in the last few centuries. The entire approach was a first attempt to build a community-based set of ERFs for an Italian PSHA model. The project involved a large number of seismic hazard practitioners, with their knowledge and experience, and the development of different models to capture and explore a large range of epistemic uncertainties in building ERFs, and represents an important step forward for the new national seismic hazard model.

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Planar Seismic Source Characterization Models Developed for Probabilistic Seismic Hazard Assessment of Istanbul

10.5194/nhess-2017-113 ◽

2017 ◽

Author(s):

Zeynep Gülerce ◽

Kadir Buğra Soyman ◽

Barış Güner ◽

Nuretdin Kaymakci

Keyword(s):

Seismic Hazard ◽

Hazard Assessment ◽

Seismic Hazard Assessment ◽

Seismic Source ◽

Probabilistic Seismic Hazard Assessment ◽

Model Parameters ◽

Probabilistic Seismic Hazard ◽

Maximum Magnitude ◽

Source Characterization ◽

Seismicity Rates

Abstract. This contribution provides an updated planar seismic source characterization (SSC) model to be used in the probabilistic seismic hazard assessment (PSHA) for Istanbul. It defines planar rupture systems for the four main segments of North Anatolian Fault Zone (NAFZ) that are critical for the PSHA of Istanbul: segments covering the rupture zones of 1999 Kocaeli and Düzce earthquakes, Central Marmara, and Ganos/Saros segments. In each rupture system, the source geometry is defined in terms of fault length, fault width, fault plane attitude, and segmentation points. Activity rates and the magnitude recurrence models for each rupture system are established by considering geological and geodetic constraints and are tested based on the observed seismicity that associated with the rupture system. Uncertainty in the SSC model parameters (e.g. b-value, maximum magnitude, weights of the rupture scenarios) is considered in the logic tree. To acknowledge the effect of earthquakes that are not associated with the defined rupture systems on the hazard, a background zone is introduced and the seismicity rates in the background zone are calculated using smoothed-seismicity approach. The state-of-the-art SSC model presented here is the first fully-documented and ready-to-use fault-based SSC model developed for the PSHA of Istanbul.

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Planar seismic source characterization models developed for probabilistic seismic hazard assessment of Istanbul

Natural Hazards and Earth System Science ◽

10.5194/nhess-17-2365-2017 ◽

2017 ◽

Vol 17 (12) ◽

pp. 2365-2381 ◽

Cited By ~ 2

Author(s):

Zeynep Gülerce ◽

Kadir Buğra Soyman ◽

Barış Güner ◽

Nuretdin Kaymakci

Keyword(s):

Seismic Hazard ◽

Hazard Assessment ◽

Seismic Hazard Assessment ◽

Seismic Source ◽

Probabilistic Seismic Hazard Assessment ◽

Model Parameters ◽

Probabilistic Seismic Hazard ◽

Maximum Magnitude ◽

Source Characterization ◽

Seismicity Rates

Abstract. This contribution provides an updated planar seismic source characterization (SSC) model to be used in the probabilistic seismic hazard assessment (PSHA) for Istanbul. It defines planar rupture systems for the four main segments of the North Anatolian fault zone (NAFZ) that are critical for the PSHA of Istanbul: segments covering the rupture zones of the 1999 Kocaeli and Düzce earthquakes, central Marmara, and Ganos/Saros segments. In each rupture system, the source geometry is defined in terms of fault length, fault width, fault plane attitude, and segmentation points. Activity rates and the magnitude recurrence models for each rupture system are established by considering geological and geodetic constraints and are tested based on the observed seismicity that is associated with the rupture system. Uncertainty in the SSC model parameters (e.g., b value, maximum magnitude, slip rate, weights of the rupture scenarios) is considered, whereas the uncertainty in the fault geometry is not included in the logic tree. To acknowledge the effect of earthquakes that are not associated with the defined rupture systems on the hazard, a background zone is introduced and the seismicity rates in the background zone are calculated using smoothed-seismicity approach. The state-of-the-art SSC model presented here is the first fully documented and ready-to-use fault-based SSC model developed for the PSHA of Istanbul.

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Seismic hazard map of Austria

10.5194/egusphere-egu2020-4820 ◽

2020 ◽

Author(s):

Stefan Weginger ◽

Papí Isaba María del Puy ◽

Yan Jia ◽

Wolfgang Lenhardt

Keyword(s):

Seismic Hazard ◽

Seismic Hazard Assessment ◽

Least Square ◽

Probabilistic Seismic Hazard Assessment ◽

Hazard Map ◽

Uniform Hazard Spectra ◽

Statistical Parameters ◽

Smoothed Seismicity ◽

Local Measurements ◽

Seismic Hazard Map

<p>After 25 years, a new seismic hazard map for Austria was created. The improvements in the Probabilistic Seismic Hazard Assessment (PSHA) are based on expanded and updated catalog data with improved depth, source-mechanism and moment magnitudes. Locally adapted ground motion prediction equations (GMPE) were calculated by applying a least square adjustment to the local measurements. A neuronal networks approach was successfully tested. The final selection is carried out by using statistical parameters, like Log-Likelihood and Euclidean Distance Range. Verified calculation methods, like Bayesian Penalized Maximum Likelihood and modified Gutenberg Richter, were used. The uncertainties have been considered by using the covariance matrix according to Stromeyer (2015). The PSHA approach combines a model of seismic zones (area sources), which is composed of zones and superzones, a zone-free model (smoothed seismicity) and a model with geological fault zones. A logic tree function was used to merge the models, the maximum magnitudes (by EPRI-Approach) and the GMPE. The calculations were carried out with the Openquake software framework. The results were compared with the current norm and the results of neighboring countries. Furthermore, the uniform hazard spectra were compared with the new Eurocode draft.</p>

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