Activity: Academic Talks or Presentations › Seminar › Research
This seminar will report on research into techniques, developed and adapted from techniques more familiar in the field of signal analysis, for investigating paired geophysical – and other – time-series for simultaneous similar anomalous features. Analysis of a paired radon time-series dataset is used to illuminate these techniques in the context of earthquake precursory phenomena but potential applications extend beyond this. Changes in radon and other soil-gas concentrations, and other parameters, before and after earthquakes have been widely reported. However, in the majority of such radon cases, changes in magnitude in single time-series have been reported, often large changes recorded using integrating detectors, and the majority of the analysis is reported for single time-series. With a single time-series, recorded at a single location, there is no measure of the spatial extent of any anomaly and, to a great extent, only anomalies in magnitude can be investigated. With two, or more, time-series from different locations as will be focused on in this seminar, it is possible to investigate the spatial extent of anomalies and also investigate anomalies in time, i.e. frequency and phase components, as well as anomalies in magnitude.