Alternative technologies

Here, we briefly describe some alternative methodologies to forecast earthquakes:

The Gutenberg–Richter law. In seismology, the Gutenberg–Richter law expresses the relationship between the energy and the total number of earthquakes in any given region and period. Applying this law, one can analyze earthquake statistics anomalies before the quake, find seismic gaps, and analyze seismic noise.

Seismic Gap Theory: This method is based on the observation that earthquakes are more likely to occur along portions of active faults that have had relatively few earthquakes in the recent past, known as seismic gaps. The theory suggests that these gaps are areas where stress is building up, potentially leading to an earthquake.

Statistical Analysis: This involves analyzing historical earthquake data to identify patterns and trends. By examining past earthquakes, scientists can estimate the likelihood of future events. This includes calculating recurrence intervals (the average time between earthquakes on a particular fault) and using probabilistic seismic hazard assessments to provide probabilities of certain magnitudes occurring within a specific timeframe.

Earthquake Clustering: Earthquakes often cluster in time and space, meaning that after a significant earthquake, the likelihood of aftershocks or related earthquakes is higher. Forecasting models can use this pattern to predict aftershock sequences and, in some cases, the likelihood of a larger earthquake following smaller events.

Earth’s surface deformations caused by seismic activity occur in three phases: pre-seismic or inter-seismic, co-seismic, or post-seismic. Co-seismic deformations can be evaluated up to meters and tens of meters, while pre-seismic movements are typically limited to centimeters. There are several traditional and modern methods used to detect deformation on the Earth’s surface, including leveling, water level measurements, GPS, satellite interferometry, and gravimetry.

GPS and Satellite Technology: Modern technology allows for the precise measurement of Earth’s surface movements. GPS data can show the build-up of tectonic strain along faults. By monitoring these changes, scientists can identify areas of increasing stress where earthquakes are more likely to occur.

Water and gas chemistry. In the past few decades, research on earthquake precursory phenomena has uncovered significant geochemical shifts that precede earthquakes. These shifts manifest as alterations in the concentrations of dissolved ions and gases in groundwaters, as well as variations in the concentrations of crustal and mantle volatiles in ground gases. Notably, radon, a gas produced by the radioactive decay of uranium in rock, has emerged as a potential earthquake predictor due to its detectability and short half-life (3.8 days).

Electromagnetic anomalies. Various electromagnetic phenomena are believed to be generated by tectonic forces acting on the Earth’s crust, which are associated with seismic activity. The study of these phenomena has been prompted by the prospect that they might be generated by the increased stress leading up to an earthquake and could provide a basis for short-term earthquake prediction. Several electromagnetic methods are applied for earthquake prediction, including ionosphere characteristics, total electron content by GPS, ultra-low frequency observations, and more. 

Thermal phenomena. Throughout human history, various thermal phenomena have been observed in connection with earthquakes. Many of these are linked to changes in water chemistry and water level. Satellite thermal observations, a particularly valuable tool, can detect shifts in the Earth’s surface temperature and near-surface atmosphere layers. Notably, significant thermal anomalies have been reported prior to earthquakes in high seismic areas. To ensure accuracy, the evaluation process involves removing the background of daily variation and noise from atmospheric disturbances and human activities before visualizing trends in the wider area of fault zones. This method has been in experimental use since the 1990s.