Surface expressions of morphostructural features at Hasandağ stratovolcano on DEM datasets

Abstract

Although the young pyroclastic cover tends to hide the structural features, derivatives of Digital Elevation Models (DEM) help reveal the morphological elements exposing the structure of the volcanoes. While the shaded relief maps improve the visuality of the DEM data, they are not the best derivatives to express the detailed morphological characteristics of the terrain. Advanced morphometric DEM derivatives, such as Red Relief Image Maps and Openness images, provide improved terrain legibility especially on volcanic landforms. Satellite-derived mid-resolution DEM and very-high-resolution aerial stereo-photogrammetric summit model of Hasandag was used to investigate the structural features of the volcano. The mid-resolution topographic derivatives evidently mapped structural features which have had important role in the evolution of the volcano. Effect of fault systems on the development of the volcano, evident and probable topographic rims of collapse structures, avalanche and lava flow surface morphologies and characteristics revealed by the advanced derivatives of DEMs were evaluated. Summit of Greater Hasandag volcano was modeled using Structure-from-Motion/Multiview stereo-photogrammetry using acquired drone imagery; the model presents the summit geology in high-resolution and precision.