Salt lake deformation detected from space

Abstract

To investigate the spatiotemporal evolution of salars in the Atacama Desert in Chile (24–26°S), we use a deformation time series retrieved by applying satellite radar interferometry techniques for the period from 2003 to 2008. We find that all 12 salars surveyed are actively deforming, with displacement rates from −1.4 to 1.5cm/yr in the satellite line-of-sight direction. Displacement rates are mostly confined to the salars themselves, and are generally constant in time and space. To understand the reason for this displacement signal, we further compare these observations with LANDSAT imagery and field observations. Relationships between these observations suggest that the most rapid uplift regions indicate subsurface material accretion. A variety of saline sedimentary processes related to the salar hydrology can explain this accretion, the most likely being capillary halite precipitation within and below surficial salt crusts. We further propose that salars, whose dynamics are dependent on the presence of brine and resurging saline groundwater, may be used as potential indicators of water resource evolution in the central Andes, and in similar water-limited regions elsewhere on earth.