Correlation of geomagnetic anomalies recorded at Muntele Rosu Seismic Observatory (Romania) with earthquake occurrence and solar magnetic storms

Abstract

The study presents a statistical cross-correlation between geomagnetic anomalies, earthquake occurrence and solar magnetic storms. The working data are from: (i) geomagnetic field records from Muntele Rosu (MLR) Observatory, and from Surlari (SUA) and/or Tihany (THY) INTERMAGNET Observatories; (ii) seismic data for the Vrancea source zone; and (iii) daily geomagnetic indices from the NOAA/Space Weather Prediction Center. All of the geomagnetic datasets were recorded from 1996 to the present, at MLR, SUA or THY, and they were automatically corrected using a LabVIEW program developed especially for this purpose, highlighting the missing or bad data. Missing data blocks were completed with the last good measured value. After correction of the data, there were a number of issues seen regarding previous interpretations of the geomagnetic anomalies. Some geomagnetic anomalies identified as precursory signals were found to be induced either by increased solar activity or by malfunction of the data acquisition system, which produced inconsistent data, with numerous gaps. The MLR geomagnetic data are compared with the data recorded at SUA/THY and correlated with seismicity and solar activity. These 15 years of investigations cover more than a complete solar cycle, during which time the solar-terrestrial perturbations have fluctuated from very low to very high values, providing the ideal medium to investigate the correlations between the geomagnetic field perturbations, the earthquakes and the solar activity. The largest intermediate depth earthquake produced in this interval had a moment magnitude Mw 6.0 (2004) and provided the opportunity to investigate possible connections between local geomagnetic field behavior and local intermediate seismicity.

Exploring the Relationship between Geomagnetic Variations and Seismic Energy Release in Proximity to the Vrancea Seismic Zone

“…The authors in [27] highlighted part of this anomaly through a graphical representation that spanned one month. The anomaly observed by the authors in [26] is also visible in Figure 6, representing the first part of an anomaly that lasted for 7 months. This anomaly has a different morphology, which is differentiated by a strong variation of the B y component (60 nT) encountered in the first part of it.…”

Prospective Neural Network Model for Seismic Precursory Signal Detection in Geomagnetic Field Records

“…The most prominent short-term variations are caused by ionospheric currents and solar storms [4], but some anomalous signals have been recognized as precursors to earthquakes. These include magnetic polarization variations [5,6], changes in the diurnal oscillation rates of the vertical components [7], and ultralow-frequency intensity anomalies [8].…”

Comment on "Non-inductive components of electromagnetic signals associated with L'Aquila earthquake sequences estimated by means of inter-station impulse response functions" by Di Lorenzo et al. (2011)

“…In recent years some researchers have reviewed many cases of observations of earthquake precursors (e.g. Campbell, 2009;Masci, 2010Masci, , 2012aMoldovan et al, 2012;Thomas et al, 2009aThomas et al, , b, 2012a showing that there is no strong relationship between the presumed precursors and the subsequent seismic events.…”