Dear Colleagues,
This Special Issue of Geosciences aims to gather high-quality original research articles, reviews, and technical notes on the topic precursory phenomena prior to earthquakes.
Several types of emissions are detected prior to earthquakes which provide a potential data source for seismic prediction. Recent research suggests that specific pre-seismic activity can be directly related to specific earthquakes, although this is still an open issue. It is still unclear how pre-seismic emissions and the subsequent earthquake events can be linked with accuracy. Known precursors are the electromagnetic radiation of a wide frequency range from ultra-low frequencies (ULF) between 0.001 and 1 Hz, low frequencies (LF) between 1 and 10 kHz, high frequencies (HF) between 40 and 60 MHz to very high frequencies (VHF) up to 300 MHz. Significant precursors are also the enhanced radon gas emissions before earthquakes with an equally long history and debate in association with seismic activity. Pre-earthquake activity of radon gas and progeny has been observed in atmosphere, surface water, groundwater, and underground water, in soil gas, thermal spas, active faults, volcanic processes, and other seismotectonic environments. The related research also includes observations for several trace gases, e.g., CO2 in active faults, satellite measurements and remote sensing techniques, surface mapping, and other earthquake activity observations and studies. The research adopts diverging types of methodological approaches, such as those related to the stochastic and statistical behavior of earthquake-related systems, fractals, long memory, fractal dimension, Hurst exponent, entropy, symbolic dynamics, DFA and MFDFA, R/S analysis, spectral analysis, Fourier analysis and wavelets, signal analysis, and signal processing. All the above topics are indicative.
The problem of earthquake prediction is a significant challenge among the scientific community, with several reported attempts to resolve issues related to the discovery of credible and unambiguous pre-earthquake precursors, especially for strong and catastrophic earthquakes. The whole research is multifaceted and involves several types of measurements and analysis methods. For the above reasons, I would like to invite you to submit articles about your recent work, experimental research, and case studies with respect to the topics described above. Papers in the interconnection of the above topics are strongly encouraged.
I invite you to send me a short abstract outlining the purpose of the research and the principal results obtained, in order to verify at an early stage if the contribution you intend to submit fits with the objectives of the Special Issue.
Prof. Dr. Dimitrios Nikolopoulos
Guest Editor
