Decoding a complex record of anthropogenic and natural impacts in the Lake of Cavazzo sediments, NE Italy

Polonia A, Albertazzi S, Bellucci LG, Bonetti C, Bonetti J, Giorgetti G, Giuliani S, Correa ML, Mayr C, Peruzza L, Stanghellini G, Gasperini L (2021)

Publication Language: English

Publication Type: Journal article

Publication year: 2021

Journal

Science of the Total Environment Elsevier

Book Volume: 787

Article Number: 147659

URI: https://www.sciencedirect.com/science/article/pii/S0048969721027303

DOI: 10.1016/j.scitotenv.2021.147659

Open Access Link: https://www.sciencedirect.com/science/article/pii/S0048969721027303

Abstract

The Lake of Cavazzo is a natural, lacustrine basin in the Friuli-Venezia Giulia region (NE Italy), which occupies a fluvio-glacial suspended valley of the Tagliamento river, at the southern front of the Alpine chain. The lake formed after the melting of major glacial tongues at the end of the Last Glacial Maximum, and has been affected in recent years by natural and anthropogenic events, with economic, cultural and environmental consequences. According to local witnesses, the lake environment has changed dramatically after the 1950s, when the basin was connected to a hydroelectric power plant collecting waters from a wider catchment area, as it served as its final discharge basin. In this work, based on a densely-spaced grid of high-resolution seismic reflection profiles complemented by sediment cores, we analysed the uppermost lake stratigraphy, highlighting major changes occurring at a decadal scale. Our main purpose is to verify whether and how the lake sediments record the transition from pristine/natural to artificial conditions, as well as the effects of multiple natural impacts including the 1976–77 Friuli earthquake sequence. The results of our analysis suggest varying environmental conditions of the lake after the 1950s indicated by changing sediment mineralogy, increased deposition of allochthonous clastic sediments, and recurrent episodes of anoxic conditions at the lake's floor, likely triggered by hyperpycnal flows derived from the hydroelectric power plant discharges. We also observe that the effects of the 1976–77 seismic sequence are recorded in the lake as resedimented levels, likely due to shaking, in situ deformation, landslides, and turbidity currents. Our results stress the importance of lacustrine environments as efficient recorders of anthropogenic and natural events.

Authors with CRIS profile

Christoph Mayr Institut für Geographie

Involved external institutions

Consiglio Nazionale delle Ricerche (CNR) / National Research Council of Italy IT Italy (IT) National Institute of Oceanography and Experimental Geophysics (OGS) IT Italy (IT)

How to cite

APA:

Polonia, A., Albertazzi, S., Bellucci, L.G., Bonetti, C., Bonetti, J., Giorgetti, G.,... Gasperini, L. (2021). Decoding a complex record of anthropogenic and natural impacts in the Lake of Cavazzo sediments, NE Italy. Science of the Total Environment, 787. https://dx.doi.org/10.1016/j.scitotenv.2021.147659

MLA:

Polonia, Alina, et al. "Decoding a complex record of anthropogenic and natural impacts in the Lake of Cavazzo sediments, NE Italy." Science of the Total Environment 787 (2021).

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