• terrestrial laser scanning;
  • lava flow;
  • Mount Etna

[1] Regular topographic surveys of active lava flows could provide significant insight into the development of flow fields, but data of sufficient accuracy, spatial extent and repeat frequency to quantify the processes involved have yet to be acquired. Here, we report results from the use of a new very-long-range terrestrial laser scanner (TLS) on active lavas at Mount Etna, Sicily. The scanner proved capable of providing useful topographic data from volcanic terrain at ranges up to ∼3500 m, with laser returns from ash-covered slopes as well as from lava. Despite very low effusion rates (<1 m3s−1), topographic changes associated with the emplacement and inflation of new flows and the inflation of a tumulus were detected. Irregular data spacing resulting from oblique views makes the interpretation of laser-derived digital elevation models alone difficult, but fusing topographic data with thermal images allows active flow features to be clearly visualized.