Action 2.4 : Magnitude and focal depth of historical earthquakes

Improve methods to estimate magnitude and hypocentral depth of historical earthquakes, especially for very incomplete sets of data


Update the French metropolitan FCAT17 seismic catalog (output product of the preceding SIGMA project) by refining magnitude and focal depth estimates of earthquakes.

Program of research

  • Complete the azimuthal-coverage of macroseismic observations
  • Update inversion scheme taking into account realistic uncertainties on historical epicentral locations
  • Account for the discrete character of macroseismic intensity values in the likelihood function
  • Incorporate a weighting function on (M, h) pairs using a Bayesian framework
  • Investigate the clustering of events based on g parameter value (Mayor et al., 2017)


  • Type: Research study
  • Collaboration: EDF
  • Status: In progress (started in 2017)

FCAT17: French catalogue of seismicity

Map of earthquake epicenters for the AD463 to 2009 period in the French metropolitan area (Manchuel et al., 2017; Traversa et al.2017; Beaumont et al., 2018)