Continuous monitoring of instrumental clock errors at 50 volcanoes in Japan based on seismic interferometry

Abstract The correct absolute time of a seismogram is an important prerequisite for many seismological processing methods. Recently, seismic interferometry has been applied to continuously estimate instrumental clock errors in certain regions. However, previous studies have focused on estimating only one target region each study, and data methods that provide more stable results different regions not explored. This study presents new method are various based with windowed cross-correlation least deviation regression. applicability this was validated by its application 50 active volcanoes Japan. We found at 23 stations 13 between January 2017 December 2021. maximum amplitude the ranged 0.24 18.27 s. value range significantly larger than background fluctuation estimated values errors, which less 0.05 s most volcanoes. A comparison approaches estimation error shows our proposed uses regression can reduce effect waveform changes ambient noise functions, probably because source fluctuations. Managing stamps using will contribute quality assurance ensure reliability analysis information Graphical