Originally published in 1993, Active Lavas looks at the practical aspects of monitoring uncontrolled streams of molten rock and how field data can be applied for theoretical modelling and forecasting the growth of lava flows. It describes the basic features of common subaerial lava flows and domes - both on Earth and on other bodies in the Solar System - before discussing the logistics of measuring lava properties during eruption and how these measurements are used to develop simple theoretical models for forecasting flow behaviour.