Moment Tensor Resolvability: Application to Southwest Iberia

• DOI: 10.1785/0120110216
• Publication Date: 2012-06-05T15:57:03Z
• Authors: J. Zahradnik; S. Custodio
• Keywords: Moment tensor

Abstract We present a method to assess the uncertainty of earthquake focal mechanisms based on standard theory linear inverse problems. compute moment tensor, M , then map it into uncertainties strike, dip, and rake. The inputs are: source station locations, crustal model, frequency band interest, an estimate data error. output is six‐dimensional (6D) error ellipsoid, which shows individual parameters . focus double‐couple (DC) part applicable both with without waveforms. latter particularly useful for network design. As example we maps DC resolvability earthquakes in southwest Europe, computed find that depends critically range depth. Shallow sources (10 km) are theoretically better resolved than deeper (40 km 60 km). 40‐km‐deep event improves considerably when Portuguese supplemented by stations Spain Morocco. can be further improved using few ocean bottom seismometer (OBS) or dense land network. A able resolve well spite large azimuthal gap, spans ∼200°. theoretical resolution analysis also explains success single‐station inversions broad range, as exemplified application waveforms w 6 offshore Iberia.