Monitoring and Correction Methods for Geomagnetic Data Influenced by Artificial Disturbances

Abstract

ABSTRACT

Cross-validation of independent ultra-low-frequency magnetic recording systems for active fault studies

“…Alternatively, because the signal was recorded at a wide range of sites, the source of the signal could be deduced by inverse-modeling of current source shape and location (cf. Minamoto et al 2011; Nagamachi et al 2013). The sensor-spacing of such an array would need to be compatible with the nature of the sources.…”

“…Most recently, the QuakeFinder network of magnetometers (see below) has been used to catalo and categorize thousands of transient magnetic pulses of duration 1–30 s, some prior to moderate earthquakes (Bleier et al 2009; Dunson et al 2011) and others apparently unassociated with earthquake activity (Kappler et al 2017). Given the broad range of possible electromagnetic signatures available to study, some magnetic observatories deliberately work to remove pulses that are likely related to cultural noise (Minamoto et al 2011; Nagamachi et al 2013). By contrast, we have chosen to focus on transient pulses, not only as these have been recently and extensively studied (Bleier et al 2009; Dunson et al 2011; Kappler et al 2017), but also as they are crucial to some of the most controversial claims of ULF electromagnetic precursors (e.g., Varotsos et al 1999, 2006 and references cited therein).…”