Open AccessGround motion and macroseismic intensities of a seismic event related to geothermal reservoir stimulation below the city of Basel—observations and modelling
Author(s) -
Ripperger Johannes,
Kästli Philipp,
Fäh Donat,
Giardini Domenico
Publication year - 2009
Publication title -
geophysical journal international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0956-540X
DOI - 10.1111/j.1365-246x.2009.04374.x
Subject(s) - geothermal gradient , induced seismicity , geology , seismology , borehole , intensity (physics) , event (particle physics) , population , ground motion , magnitude (astronomy) , geophysics , geotechnical engineering , quantum mechanics , astronomy , physics , demography , sociology
SUMMARY To stimulate a geothermal reservoir below the city of Basel, Switzerland, fluid was injected in December 2006 at high pressure into a 5 km deep borehole. This stimulation led to an increase in local seismicity with the largest seismic event ( M L = 3.4) occurring on 2006 December 8. The event was widely felt by the local population, slight non‐structural damage to buildings was reported and ultimately this event was the cause to put the geothermal project on hold. In this study, we present recorded ground motion and determinations of macroseismic intensity of the M L 3.4 event as well as simulations of seismic wave propagation and a model to predict macroseismic intensities. As the two models are based on different simplifying assumptions and different underlying physical processes, the predicted intensity distributions exhibit differences in their details. However, the first‐order characteristics of the observed macroseismic intensity distribution are well matched. Based on this result, we compute intensities also for hypothetical scenarios of earthquakes with larger magnitudes.