Observing a century of volcanic morphodynamics using photogrammetric analysis of recent and archive data

Volcanoes are the most dynamic landforms, capable of changing their shape and environment in a matter of minutes, posing a significant threat to the environment and populations. While modern monitoring approaches can detect short-term changes, the long-term evolution is not well understood. Through the collection and photogrammetric processing of optical data, we can now reconstruct the precise topographies of volcanic edifices during the last decades to study different stages of volcanic development. By comparing the obtained topographies, we calculate volume flows, including eruptive and eroded materials, and evaluate the resulting geomorphic changes. Recent advances in technology and algorithms have opened unique opportunities for the collection and processing of photogrammetric data, allowing quantitative analysis of aerial photographs from the mid-last century to modern satellite and drone data. Here, we present ultra-high-resolution point clouds and digital elevation models to study long-term morphological and structural changes at volcanoes. In particular, the availability of archive ground and aerial stereo imagery from the last century allows us to look into the past and reconstruct volcanic activity in glaciated regions, and explore the complex interactions and geomorphic changes these regions undergo. We illustrate volcano-cryosphere interactions in Kamchatka and Iceland, highlighting the use of the method by pioneers since the beginning of the last century. We describe the main features of the use of photogrammetry in volcanological research and discuss possible further developments in terms of improved visualization and virtual reality application for educational purposes.