Seismic microzoning in the Basel area

For the city of Basel, a qualitative microzonation was performed in 2007. The zonation was mainly based mainly on the properties of the quaternary sediments. This triggered a study that provided a quantitative assessment of ground motion amplification in order to determine which levels of amplifications have to be taken into account a site-specific hazard assessment in the Basel area. It is the result of two large projects, the ETH project “Earthquake scenarios for Switzerland” (1997-2002) and the INTERREG project “Seismic Microzonation in the upper Rhine Graben area” (2003-3006) (Fäh end Huggenberger, 2006). Earthquakes in the Basel region triggered the strong motion network in Basel and provided a data set for comparison. Spectral ratios from recordings confirm the results of the microzonation study.

Finally uniform hazard spectra were derived for each zone by combining the hazard on rock with the amplification functions. The microzonation is published on the Internet.

Specific publications can be requested from the authors:

  • Fäh, D. and P. Huggenberger, 2006. INTERREG III, Erdbebenmikrozonierung am südlichen Oberrhein. Zusammenfassung für das Projektgebiet Gebiet in der Schweiz. CD and Report (in german; available from the authors).
  • Fäh, D. and T. Wenk, 2009. Mikrozonierung für die Kantone Basel Stadt und Basel Landschaft: Optimierung der Form der Antwortspektren und der Anzahl der Mikrozonen. Abschlussbericht: Teilbericht B Projekt "Umsetzung der Mikrozonierung in den Kantonen Basel Stadt und Basel Landschaft". Schweizerischer Erdbebendienst ETH Zürich.