# Applied Engineering Using Schumann Resonance for Earthquakes Monitoring
## 3 Results and Discussion
In spite of this, there is evidence that a continuous study of the patterns of ELF band signals (such as RS signal) can be a powerful methodology that allows for the possible early detection of important seismic phenomena. A seismograph is capable of collecting seismograms from any earthquake (M \(\approx\) 7) at any point on the earth. The filtering effect of the high seismic frequencies allows us to determine the remoteness of the earthquake and to center our study of correlation with the earthquakes located within a radius of between 500 km and 1000 km, if it is located within range of a the ELF station. These are the estimated distances for the detection and correlation of the previous phenomena, as well as a possible explanation for the ELF stations performance ranges that are proposed in this paper. \begin{table}
\begin{tabular}{l l l} \hline
**Precursor Phenomenon** & **Earthquake (Year)** & **Reference** \\ \hline Increase of Very Low Frequency/Extremely Low Frequency (VLF/ELF) electromagnetic noise before and after an earthquake. & Hyogo-Ken Nanbu earthquake (1995) & [88] \\ \hline Anomalous increases up to 10 Hz in Ultra Low Frequency (ULF) signals were detected at Shigaraki, 90 km of the epicentre and at Kokubunji, 500 km east of the epicentre. & Hyogoken-Nanbu earthquake (1995) & [89] \\ \hline Strong ELF noise from lightning strikes 2 days before a major earthquake. & Hyogoken-Nanbu earthquake (1995) & [90] \\ \hline The anomalous and sporadic ionization of Earth’s electric field before major earthquakes. & Hyogoken-Nanbu earthquake (1995) & [91] \\ \hline Observation of ULF anomalies prior to the development of an earthquake. & Loma Prieta earthquake (1989) & [6,7] \\ \hline A geomagnetic field variation of 7.2 nT was detected approximately 7 min before an earthquake. & Tohoku earthquake (2011) & [8, 9, 10] \\ \hline Detection of a series of pre-earthquakes magnetic anomalies. & Nepal earthquake (2015) & [11] \\ \hline Abnormal variations in the amplitude and phase of these ELF signals when crossing regions of certain seismic activity. & earthquakes in Taiwan (1999–2004) & [48] \\ \hline An atypical amplitude increase of all its modes, highlighting the variation in the fourth mode of resonance. & Chi-chi earthquake (1999) & [49] \\ \hline The existence of depressions in the frequency of the fourth mode resonance occurring between 2 and 6 days before one of earthquakes. & The Kamchatka region (during the last 30 years) & [50] \\ \hline ELF Signals anomalies before an earthquake. & Sichuan earthquake (2008) & [52] \\ \hline ELF Signals anomalies before an earthquake. & Kobe earthquake (2013) & [53] \\ \hline Interference Signals in the ELF band. & Japan Earthquake (2011) & [64] \\ \hline \end{tabular}
\end{table} 
Table 4: Earthquake precursor phenomena. Correlation studies of the ELF signals captured at the Calar Alto station with data from the Alboran earthquake (M = 6.3) [92], which occurred in January 2016, are being carried out. The results of this study may be adequate to extract quantitative conclusions of this methodology and to further strengthen its potential for the early detection of possible seismic events.