Assessing recharge mechanisms of the Pampa del Tamarugal Aquifer in northern Chile's Atacama Desert

Northern Chile's Atacama Desert is one of the driest inhabited regions on the planet. The Pampa del Tamarugal Basin is located within the Atacama Desert and is home to ~300,000 people, yet this region receives little to no rain (<5 mm/yr). However, despite the lack of rain, there is a large source of fresh water in the Pampa del Tamarugal Aquifer (PTA). The PTA is heavily relied upon for municipal, agriculture, and industrial uses. The source of water for the PTA is widely accepted to originate in the high Andes to the east, but the magnitude and mechanism for this recharge remains poorly understood. This study utilizes a 2-D numerical model that takes into account the complex geology and geothermal gradient in this region to further understand regional scale fluid flow within the Pampa del Tamarugal Basin. The results indicate that shallow fluid flow only recharges Salar de Huasco on the eastern edge of the model domain while deep, hydrothermal fluid circulation recharges the PTA and is also responsible for salar formation in the western portion of the basin.