Correction: Marchese et al. Mt. Etna Paroxysms of February–April 2021 Monitored and Quantified through a Multi-Platform Satellite Observing System. Remote Sens. 2021, 13, 3074

In the original article [1], there were some mistakes in Figure 4 and Figure 8, and Sections ‘Abstract’, ‘Discussion’, and ‘Conclusions’. The correct contents appears below. The authors apologize for any inconvenience caused and state that the scientific conclusions are unaffected. The original article has been updated.

1. Error in Figures

In Figure 4, the label ‘1st’ erroneously referred to 18 February 2021. The correct Figure 4 appears below.

Figure 4. Temporal trend of the total hotspot area (m²) retrieved using NHI tool, by integrating L8-OLI and S2-MSI observations over the period 1 February−4 April 2021, with the indication of the relative paroxysm.

Figure 4. Temporal trend of the total hotspot area (m²) retrieved using NHI tool, by integrating L8-OLI and S2-MSI observations over the period 1 February−4 April 2021, with the indication of the relative paroxysm.

In Figure 8 as published. Three labels of the plot were wrong. The correct Figure 8 appears below.

Figure 8. Plot of hotspot area generated through the NHI tool, integrating L8-OLI (from April 2013 onwards) and S2-MSI observations (from June 2015 onwards).

Figure 8. Plot of hotspot area generated through the NHI tool, integrating L8-OLI (from April 2013 onwards) and S2-MSI observations (from June 2015 onwards).

2. Text Correction

2.1. Correction in Section ‘Abstract’

In the original article, estimates of volcanic radiative power (VRP) up to 14 GW did not refer to the Spinning Enhanced Visible and Infrared Imager (SEVIRI) data. And the largest thermal anomaly affecting Mt. Etna according to the Normalized Hotspot Indices (NHI) tool, on 18 and 28 February 2021, was not related to the 1st and 3rd paroxysm. A correction has been made to the Abstract:

“…Results retrieved from Advanced Very High Resolution Radiometer (AVHRR), Moderate Resolution Imaging Spectroradiometer (MODIS), starting from outputs of the Robust Satellite Techniques for Volcanoes (RST_VOLC), indicate that the 17th paroxysm (31 March–1 April) was the most intense in terms of radiative power, with values estimated around 14 GW…”

“…according to the Normalized Hotspot Indices (NHI) tool, the 2nd (17–18 February) and 7th (28 February) paroxysm generated the largest thermal anomaly at Mt. Etna after April 2013, when Landsat-8 OLI data became available…”

2.2. Correction in Section ‘Discussion’

The sentence reporting the 17th paroxysm as the most powerful is incorrect. A correction has been made to the Discussion, paragraph 6:

“…Therefore, by combining information from MODIS (Figure 5) and SEVIRI (Figure 9) data, we can assert that the 17th paroxysm was among the most significant events and probably radiated the largest amount of energy…”

2.3. Correction in Section ‘Conclusions’

The sentence reporting the 17th paroxysm as the most powerful is partially correct. And the largest thermal anomaly affecting Mt. Etna according to the Normalized Hotspot Indices (NHI) tool, on 18 and 28 February 2021, erroneously referred to the 1st and 3rd paroxysm. A correction has been made to the Conclusions, paragraph 2:

“…The latter indicates that the 17th paroxysm, leading to values of radiative power up to about 14 GW from MODIS data (e.g., we retrieved VRP values up to 4 GW during the paroxysms of May 2016 [17]), was probably the most energetic of the time series as indicated by SEVIRI…”

“…Additionally, based on the information retrieved from L8-OLI and S2-MSI data, the 2nd and 7th paroxysm generated the largest thermal anomaly at Mt. Etna after 26 October 2013…”