GNGTS 2014 - Atti del 33° Convegno Nazionale

92 GNGTS 2014 S essione 1.1 Tab. 1 - Description of the configuration parameters for the detection procedure in Antelope system; in the last col- umns there are the best results we obtained for the events local, regional and teleseismic. BP refers to Butterworth bandpass filter. Parameter Description Local 1 Local 2 Regional Teleseismic S phase sta_twin short term average time window 1.0 1.0 1.0 2.0 3.0 sta_tmin short term average minimum time for average 1.0 1.0 1.0 2.0 1.0 sta_maxtgap short term average maximum time gap 0.5 0.5 0.5 0.5 0.5 lta_twin long term average time window 10.0 10.0 10.0 20.0 50.0 lta_tmin long term average minimum time for average 5.0 5.0 5.0 10.0 5.0 lta_maxtgap long term average maximum time gap 4.0 4.0 4.0 4.0 4.0 nodet_twin no detection if on time is less than this 2.0 2.0 5.0 10.0 2.0 thresh detection SNR threshold 5.0 3.0 5.0 5.0 5.0 threshoff detection-off SNR threshold 2.5 2.5 2.5 2.5 2.5 det_tmin detection minimum time 5.0 5.0 10.0 20.0 2.0 det_tmax detection maximum time 10.0 10.0 200.0 600.0 10.0 filter Butteworth filter applied to the signals BP 5.0-25.0 BP 5.0-25.0 BP 3.0-5.0 BP 0.8-3.0 BP 1.0-5.0 Tab. 2 - Description of the configuration parameters for the association procedure in Antelope system; in the last columns there are the best we obtained for the events local, regional and teleseismic. Parameter nsta_thresh cluster_twin try_S priority use_dwt dwt_dist_near - DN dwt_dist_max closest_stations - CS relocate travel_time_model arrival_residual Description minimum allowable number of stations to lo- cate an earthquake; in case of local events this parameter is expressed as a function of maximum source-receiver distance in degree clustering time window in seconds that is used to de- termine whether an observed arrival associates with a hypothetical event location also S travel-times are tried to locate the events priority to select the association in case of locations falling inside multiple grids use source receiver distance weighting factor if use_dwt=yes, the maximum source-receiver distan- ce with weight=1 if use_dwt=yes, the minimum source-receiver distan- ce with weight=0 use only a selected number of closest stations to a particular source node in the search for defining phases run the relocation script (inversion) to refine the final solution velocity model for inversion weights method Local 1 4 for d ≤ 1.2° 6 for d ≤ 1.5° 8 for d ≤ 2.0° 10 for d ≤ 180° 1.5 No 5 Yes (for P phases) 0.0 4.0 no Yes Friuli Huber Local 2 4 for d ≤ 0.5° 5 for d ≤ 1.0° 6 for d ≤ 1.5° 8 for d ≤ 2.0° 10 for d ≤ 180° 1.5 Yes 4 Yes (for S phases) 0.0 0.5 no Yes Friuli Huber Regional 10 2.0 No 2 No - - 30 No - - Teleseismic 14 5.0 No 1 No - - no No - -