| Free convection is an important process that has applications in many disciplines of earth science and is a factor in a variety of environmental issues. Although the study of free convection has been historically limited to theory, laboratory experiments, numerical modeling, and secondary field evidence, recent studies have used electrical resistivity geophysical methods to capture direct evidence of this phenomenon in a natural field setting. However, there is still very little known about the transient characteristics of free convection in a field setting.;This thesis uses geophysics and hydrological modeling to investigate the occurrence, initiating mechanisms, and transient nature of free convection in a coastal sabkha in the United Arab Emirates. The electrical resistivity data shows that free convection in the sabkha is an episodic process that is likely caused by the dissolution of the halite crust by precipitation and its subsequent infiltration to the aquifer. Hydrological modeling of the system supports precipitation as the initiating mechanism and allows for the characterization of the growth and decay of the convective fingers. |
