Catalog of Long Period seismic events recorded at Mt. Etna during the time interval 2019-2020 (LPSEC2019_2020)

The dataset consists of Long Period (LP) seismic events recorded on Etna volcano in the time interval 1/January/2019 – 30/June/2020. The catalog includes 62052 events, each identified by the picking time to the triggering station. Beside the picking time, peak-to –peak amplitude and peak frequency parameters are also reported. The detection of the event is obtained by means of an automated system operating in near real-time that implements an energy detector. In particular, the processing system applies an STA/LTA trigger algorithm (Short-Time Average/ Long-Time Average; e.g., Trnkoczy, 2012; Sciotto et al., 2022) to the continuous seismic signal filtered in the frequency band 0.5 – 5 Hz. Seismic stations used for the detection are installed at altitudes between 2.85 – 3.04 km a.s.l. and at distance that ranges between 1 and 2.5 km from central craters of Mt. Etna. To reduce false detections and make more robust the catalog, only located LP events are included. It is noteworthy to say that amplitude variations of the volcanic tremor can mask amplitude transients and affect the LP occurrence rate. From a volcanological point of view, during the time interval January –August 2019, Etna experienced a period of intermittent intra-crateric Strombolian activity, weak ash emission or isolated explosions from the summit craters. From September 2019 and until the end of the time interval, together with an increase of volcanic tremor amplitude, this eruptive activity became almost continuous at Voragine crater and South-East crater area (see Sciotto et al., 2022 for details). LP events at Mt. Etna volcano are frequently recorded and their occurrence rate, spectral and amplitude time variation are likely to be associated with the plumbing system shallowest portion conditions (e.g., Patanè et al., 2008; Cannata et al., 2015; 2018).