姶良カルデラにおける長期連続反射法第2回目基礎実験

Abstract

The second experiment for the Time-lapse Seismic Volcano Monitoring is reported. The experiment was performed on December 2022 after two years gap from the previous experiment in 2020 in order to inspect reproducibility of seismic source. The source device has identical specifications with that of the previous experiment. Two shooting parameter sets, same tow depth and same clearance were done with same operating pressure and same chamber size with those of the previous experiment because there was different water level in the experiment 2022 by 0.5 m higher than that of the experiment 2020. The observed seismogram showed some difference which smaller air wave, rich high frequency component, and some earlier arrivals in the later part. Temperature difference around the shot point can affect air wave amplitude and high frequency rich source waveform can cause earlier arrival. Such source effect can be reduced with using deconvolution processing which uses NFH seismogram.