Informational analysis of apparent Earth's resistivity time series to assess the reliability of magnetotelluric measurements

We used the informational methods of the Shannon entropy power and the Fisher Information Measure to analyze the time dynamics of one year of semi-daily values of apparent resistivity, calculated on the base of the magnetotelluric (MT) monitoring at Penghu Island, Taiwan. The performed statistics indicate that the day-time measurements present higher disorder and lower organization than the night-time measurements. Such difference is more evident for the high-frequency band of resistivity data, which suggests that possibly some source of the electromagnetic field could be of anthropic origin. Furthermore, we also note the characteristics of so-called MT dead-band with the periodicity of ∼10 s could be revealed in the high values of Shannon entropy power.