Do French macroseismic intensity observations agree with expectations from the European Seismic Hazard Model 2013?

TY - JOUR

T1 - Do French macroseismic intensity observations agree with expectations from the European Seismic Hazard Model 2013?

AU - Rey, Julien

AU - Beauval, Céline

AU - Douglas, John

PY - 2018/5/9

Y1 - 2018/5/9

N2 - Probabilistic seismic hazard assessments are the basis of modern seismic design codes. To test fully a seismic hazard curve at the return periods of interest for engineering would require many thousands of years’ worth of ground-motion recordings. Because strong-motion networks are often only a few decades old (e.g. in mainland France the first accelerometric network dates from the mid-1990s), data from such sensors can be used to test hazard estimates only at very short return periods. In this article several hundreds of years of macroseismic intensity observations for mainland France are interpolated using a robust kriging-with-a-trend technique to establish the earthquake history of every French mainland municipality. At twenty-four selected cities representative of the French seismic context, the number of exceedances of intensity IV, V and VI are determined over time windows considered complete. After converting these intensities to peak ground accelerations using the global conversion equation of Caprio et al. (2015), these exceedances are compared with those predicted by the European Seismic Hazard Model 2013 (ESHM13). In half of the cities, the number of observed exceedances for low intensities (IV and V) is within the range of predictions of ESHM13. In the other half of the cities, the number of observed exceedances is higher than the predictions of ESHM13. For intensity VI, the match is closer, but the comparison is less meaningful due to a scarcity of data. According to this study, the ESHM13 underestimates hazard in roughly half of France, even when taking into account the uncertainty on the conversion from intensity to acceleration. However, these results are valid only for the acceleration range tested in this study (0.01 to 0.09 g).

AB - Probabilistic seismic hazard assessments are the basis of modern seismic design codes. To test fully a seismic hazard curve at the return periods of interest for engineering would require many thousands of years’ worth of ground-motion recordings. Because strong-motion networks are often only a few decades old (e.g. in mainland France the first accelerometric network dates from the mid-1990s), data from such sensors can be used to test hazard estimates only at very short return periods. In this article several hundreds of years of macroseismic intensity observations for mainland France are interpolated using a robust kriging-with-a-trend technique to establish the earthquake history of every French mainland municipality. At twenty-four selected cities representative of the French seismic context, the number of exceedances of intensity IV, V and VI are determined over time windows considered complete. After converting these intensities to peak ground accelerations using the global conversion equation of Caprio et al. (2015), these exceedances are compared with those predicted by the European Seismic Hazard Model 2013 (ESHM13). In half of the cities, the number of observed exceedances for low intensities (IV and V) is within the range of predictions of ESHM13. In the other half of the cities, the number of observed exceedances is higher than the predictions of ESHM13. For intensity VI, the match is closer, but the comparison is less meaningful due to a scarcity of data. According to this study, the ESHM13 underestimates hazard in roughly half of France, even when taking into account the uncertainty on the conversion from intensity to acceleration. However, these results are valid only for the acceleration range tested in this study (0.01 to 0.09 g).

KW - earthquake

KW - macroseismic intensity

KW - seismic hazard

KW - probabilistic seismic hazard assessment

KW - kriging

KW - France

UR - https://link.springer.com/journal/10950

U2 - 10.1007/s10950-017-9724-7

DO - 10.1007/s10950-017-9724-7

M3 - Article

VL - 22

SP - 589

EP - 604

JO - Journal of Seismology

JF - Journal of Seismology

SN - 1383-4649

IS - 3

ER -