Fig. 2From: Mapping and measuring lava volumes from 2002 to 2009 at El Reventador Volcano, Ecuador, from field measurements and satellite remote sensing a Field photograph of an EDM measurement under optimal conditions (limited cloud, good visibility, point 3 on Fig. 1). b Schematic drawing showing the geometry of the rangefinder used to measure lava thicknesses. Lava thicknesses were estimated as a vertical distance from the horizontal distance to the base of the flow and the direct distance to its top, using trigonometryBack to article page