Evolution natural (terrestrial) solutions

Specific tasks: Evolution of groundwater from volcanic areas (Ethiopia/Hessia/Azores)

Groundwater from volcanic aquifer is the main source of water supply for Axum town in semi-arid region of northern Ethiopia. Poor quality of groundwater from bore holes in the study area has been a major problem for the water supply.

The study aims to examine the effects of hydrochemical processes on the composition of groundwater using hydrochemical and isotopic tools. Stable isotopic (δ²H and δ¹⁸O) data suggest that the analyzed groundwaters are of meteoric origin. δ¹³C_DIC values and solution composition indicate that the chemistry of shallow groundwater is controlled by the uptake of soil CO₂ and silicates weathering. Abundant weathering of silicates in the deeper parts of aquifer is caused by the uptake of magmatic CO₂ at high pCO₂.

Figure (left): Relationships between δ²H and δ¹⁸O values for sampled solutions.

Figure (right): δ¹³C_DIC values versus the reciprocal of HCO₃⁻ concentrations.

Contact: Martin Dietzel