EGU2020-12116
https://doi.org/10.5194/egusphere-egu2020-12116
EGU General Assembly 2020
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Field analysis Vs boat-based photogrammetry derived data in volcanotectonics: an example from the Santorini dyke swarm

Kyriaki Drymoni1, Fabio Luca Bonali2,3, John Browning4,5, Agust Gudmundsson1, Luca Fallati2, Varvara Antoniou6, and Paraskevi Nomikou6
Kyriaki Drymoni et al.
  • 1Department of Earth Sciences, Queen's Building, Royal Holloway University of London Egham, Surrey TW20 0EX, UK
  • 2Department of Earth and Environmental Science, University of Milan-Bicocca, Milano, Italy
  • 3CRUST- Interuniversity Center for 3D Seismotectonics with Territorial Applications, Italy
  • 4Department of Mining Engineering and Department of Structural and Geotechnical Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile
  • 5Centro de Excelencia en Geotermia de los Andes (CEGA), Chile
  • 6Department of Geology and Geoenvironment, National and Kapodistrian University of Athens, Greece

Field studies are vital for mapping and understanding active geological processes on Earth. Such studies commonly inform analogue and numerical modelling setups and provide insights over a variety of scales. However, geological field studies have several limitations as they are sensitive both to field-based conditions (e.g. weather conditions, geomorphology, weathering, erosion and access) and the experience of the researchers conducting the work. All of these limitations can add significant error or uncertainty to geological measurements. At the same time, new geological measurement techniques (e.g. photogrammetry) are easy to access, fast and friendly to use, but also often depend on ground truthing parameters.

In this study, we compared two different methods for mapping and surveying volcanotectonic processes related to dyking events: classical field analysis and boat-based photogrammetry. We tested the two approaches on dykes located within a section of a steep cliff face that makes up part of the Santorini caldera. The caldera wall is accessible by land only in the upper most parts and so most measurements require access by boat or by abseiling down the cliff faces. The latter is very dangerous and not recommended.

The core of the work is to carefully compare field data with the equivalents collected on photogrammetry-derived 3D model, focusing on the sea level area in order to compare reliable dataset. Data comparison is focused on dyke attitudes, thicknesses, petrological descriptions, along the 4-km length profile of the northern caldera wall of Santorini volcano.

We collected a series of high-resolution images, around 800 pictures in total, aimed at 3D modelling the dyke swarm using photogrammetry methods. They have been collected using a 20 MPX hand-held camera equipped with commercial GPS from a boat, moving parallel and to a constant distance from to the caldera wall.

Comparison of both datasets allowed insights into 1) the completeness and, 2) the limitations of each technique. Here we assess the various advantages to design a novel multidimensional methodology that allows fast, accurate and low-cost data generation in difficult working conditions, such as at steep cliff faces and flooded terrains.

How to cite: Drymoni, K., Bonali, F. L., Browning, J., Gudmundsson, A., Fallati, L., Antoniou, V., and Nomikou, P.: Field analysis Vs boat-based photogrammetry derived data in volcanotectonics: an example from the Santorini dyke swarm, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-12116, https://doi.org/10.5194/egusphere-egu2020-12116, 2020.

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