Geological heritage sites assessment in the northern flank of the Calbuco volcano (Southern Andes, Chile)

Abstract

Calbuco volcano (41.3°S, Southern Andes) ranks second in the Chilean volcanic risk ranking. The products of Calbuco’s last eruption (April 22-23, 2015) severely affected the surroundings of the volcano, particularly the Ensenada village (~1,500 inhab.), evidencing a growing need for effective volcanic risk management and mitigation. The geological study of volcanic deposits and landforms is a key step in reconstructing past volcanic eruptions and for the evaluation of volcanic hazards and associated risks. Additionally, well-preserved and easily accessible volcanic deposits can be considered as geological heritage sites (geosites) that could be used to educate communities and visitors about geological hazards and volcanic risk through different outreach, educational, and touristic activities. In the northern flank of the Calbuco volcano, a series of protected public and private areas (Llanquihue National Reserve, Valle Los Ulmos Park, and Volcanes Park) foster the conservation of natural heritage and facilitate the accessibility to volcanic deposits. Our contribution therefore assesses the geological heritage potential of the northern flank of the Calbuco volcano, through a literature review, geological mapping, and stratigraphic and petrographic studies of recent eruptive deposits. The identified geosites were scored and ranked through a quantitative procedure. The top three-ranked geosites hold high scientific value and good accessibility conditions. These sites may sustain a geoconservation strategy based on scientific, educational, and touristic activities and contribute to volcanic risk reduction in the area.