A simple lateral-flow model adequately explains many of the features associated with the Salton Sea Geothermal Field. Earthquake swarms, a magnetic anomaly, and aspects of the gravity anomaly are all indirect evidence for the igneous activity that is the ultimate source of heat for the system. Heat is transferred from this area of intrusion by lateral spreading of hot water in a reservoir beneath an impermeable cap rock.
A two-dimensional analytic model encompassing this transport mechanism matches general features of the thermal anomaly and has been used to estimate the age of the currently observed thermal system. The age is calculated by minimizing the variance between the observed surface heat-flow data and the model. Estimates of the system age for this model range from 3,000 to 20,000 yr.