Temperature and conductivity fluctuations due to the hydrothermal emissions released during the degasification stage of the Tagoro submarine volcano, off El Hierro Island in the Canary Archipelago, may provide robust indicators for characterising and predicting the activity of the system. 21 CTD time series along a regular high-resolution grid were gathered in the VULCANO1016 cruise with the rosette sampler directly over the main seafloor crater (Santana-Casiano et al., 2016; Fraile-Nuezet al., 2018). Temperature and conductivity data compiledare analysed as manifestations of stochastic processes in terms of the Generalized Moments Method (GMM) (Bakaliset al., 2017; Bakalis et al., 2018). GMM provides the statistical momentsof the underlying processes and delivers their structure functions being their shape an indicator of the stochastic mechanism/s governing such a stochastic process. Our findings pointto an active submarine volcano, which conveys energy to the surrounding ecosystem. Yet, both temperature and conductivity fluctuations present long tails depict to strong sub-normal processes, which change very slowly in the long time limit. Temperature and conductivity fluctuations are classified as multifractal processes whose structure functions show a crossover in two distinct regimes. Multifractality suggests the multiplicative action of at least two random processes, which can be attributed to the volcano and to the aquatic environment. From the physical viewpoint the Tagoro submarine volcano can be defined as an open system given the variations over time of temperature moments

This study has been supported by funds from FEDER and the Spanish Ministry of Economy and Competitiveness through VULCANA-II (IEO2018-2020) and VULCANO-II (CTM2014-51837-R) research projects

VII International Symposium on Marine Sciences (ISMS 2020), 1-3 July 2020 (Barcelona).-- 2 pages

Peer reviewed