ИСТИНА

In microseismic monitoring applications weak earthquakes are observed. Their magnitude assessments are used for the re- leased energy analysis and for their scaling in terms of this en- ergy. Different approaches are applied now in industry, but the assessed with borehole monitoring system magnitudes are sel- dom approved with conventional seismological observations. We here show the case study for downhole magnitudes calibra- tion with magnitudes assessed by on-land seismological equip- ment. Wave coda length based magnitude formula is used and calibrated in the paper. Calibration methodology and approach choice justification are presented in a paper.