Towards a crustal structure investigation in the area of Mefite d’Ansanto (Italy) by using equalised teleseismic waveforms

We propose and test a procedure in the time domain to directly compare the waveforms of teleseismic events recorded by seismic stations located a few kilometres from each other and equipped with different instrumentations. The method is based on the deconvolution of the signals at each seismic station for its sensor own frequency response and data sampling to equalise the waveforms, making them directly comparable. The horizontal components of the events are rotated versus back-azimuth, considering that P-to-S converted phases along a crustal discontinuity are generally more evident in the radial and transverse components. Finally, we apply the cross-correlation technique to the resulting signals to quantify the similarities among the waveforms. The method has been tested on teleseismic events recorded by the seismic stations located in and close to the Mefite d’Ansanto area (southern Apennines), which represents the largest non-volcanic low temperature CO2 emission area on Earth.