Detecting the development of active lava flow fields with a very‐long‐range terrestrial laser scanner and thermal imagery

Abstract

[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 m 3 s À1 ), 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. Citation: James, M. R., H. Pinkerton, and L. J. Applegarth (2009), Detecting the development of active lava flow fields with a very-long-range terrestrial laser scanner and thermal imagery, Geophys. Res. Lett., 36, L22305,

Lava flow hazard at Fogo Volcano, Cabo Verde, before and after the 2014–2015 eruption

“…However, previous studies have shown that, particularly in volcanic areas, useful point cloud densities could only be achieved at a maximum distance of ∼ 3500 m (James et al, 2009). Therefore, the technique is usually applied to study smaller areas of ∼ 1-5 km 2 in very high spatial (centimetre scale) and temporal resolutions (up to 1 scan every 10 min) (e.g.…”

“…Therefore, the technique is usually applied to study smaller areas of ∼ 1-5 km 2 in very high spatial (centimetre scale) and temporal resolutions (up to 1 scan every 10 min) (e.g. James et al, 2009;Jones et al, 2015;Slatcher et al, 2015).…”

“…Ground-based techniques are especially effective for effusive volcanic eruptions, where only the directly affected areas need to be updated. The potential of very long-range terrestrial laser scanner (TLS) instruments to survey the dynamics of active lava flow fields and to map the topographic changes associated with the emplacement of new flows was shown at Mount Etna, Italy (James et al, 2009). We produced the first posteruptive topographic map of the 2014-2015 Fogo lava flow using TLS and ground-based photogrammetric data in order to update a pre-eruptive photogrammetric DEM of Fogo Island, both featuring a 5 m spatial resolution.…”

Rapid Updating and Improvement of Airborne LIDAR DEMs Through Ground-Based SfM 3-D Modeling of Volcanic Features

“…LIDAR-based DEMs are commonly derived from airborne acquisition platforms (e.g., airplanes or helicopters) because they offer an optimal vantage point and a flexible geometry, and make it possible to rapidly cover large areas [13]- [16]. However, LIDAR technology is also frequently used as a ground-based method, where it enables high temporal and spatial resolution surface modeling [17], [18]. Airborne LIDAR surveys permit the generation of DEMs for large areas and the recovery of detailed and comprehensive elevation maps.…”

“…The most challenging application of SfM is the reconstruction of highly dynamic geologic features such as active lava flows [17], [18], [31], [39], [40]. Low-cost airborne applications of SfM photogrammetry are also beginning to play a role in geosciences [37], [41]- [43].…”