Body tides and elastic stresses in the Earth’s crust

Solid tides, predominantly diurnal and semi-diurnal, are commonly observed on Earth's surface through horizontal and vertical movements (a few tens of centimeters), along with gravity measurements (~100 microgal). This study focuses specifically on tidal effects within the elastic stress field at the surface, which is approximately 1000 Pascals. We initially established a correlation between tidal elastic pressure and natural hydrogen emission. Hydrogen, in its gaseous form, escaping from Proterozoic basins, represents a potential source of carbon-free energy, leading to extensive research on vents. A notable characteristic of these emissions is the consistent daily cycle observed in specific regions. While atmospheric pressure effects have been shown to account for this cycle, solid tides could serve as an alternative explanation. Considering that tidal waves do not have a uniform spatial distribution on the Earth's surface, we computed time series of elastic pressure at two locations where natural hydrogen emissions are observed: one near the equator in the Sao Francisco basin (Brazil) and another near the North Pole in the Lovozero deposits (Kola Peninsula). We then explored the maximum shear stress generated by tidal potential in areas experiencing tectonic stresses. We demonstrated that in expansive regions, the maximum shear stress correlates with the peak of the tidal potential, while in compressive regions, it is associated with the minimum tidal peak.