## 4 Results and Discussions
### Discussion and Benchmark against Recent Studies  
Among others, [PERSON] et al. [7] estimated ice velocity in two cross sections of PMG's front during 2009, using Cosmo-Skymed images at 1 m resolution, processed with the maximum correlation approach. They found flow velocity very similar to our values here, i.e., about 2 m day\({}^{-1}\) (main flow line) at flow peak season (austral summer, December-January-February). Moreover, they reported seasonal dependence as we found here, i.e., the warmer the faster (see Figure 8 therein). More recently, [PERSON] et al. [22] provided a benchmark for analysis of PMG flow features. They used normalized cross correlation of spatial variations in image intensity (e.g., [38]), also validated using GPS positioning of an ice drilled pole (upstream section TA1 in Figure 3b here) during some periods in 2010-2014. They provide surface flow velocity mapping (Figure 5 in [22]) somewhat consistent during the (austral) winter and summer. Figure 8: Transect B in [PERSON] et al. [27], here TB62. Seasonal variability of flow velocity, summer JFM (average of 9 couples of images), fall AMJ (average of 9 couples of images), winter JAS (average of 5 couples of images) from 2000 to 2017. Spring OND, only 1 couple available. Moreover, we report the surface profile of the glacier along the transect, as from ASTER Global Digital Elevation Model (Version 2), and an interpolated bedrock profile, according to [PERSON] et al. [27] and [PERSON] [29]. Their estimated velocities vary from about \(Vs\) = 4 m day\({}^{-1}\) in the upper (Southern) part of the glacier (winter accumulation zone, about 120 m a.s.l. ), to about Vs = 2 m day\({}^{-1}\) at the front, along the main (central) flow line. Lower flow velocity is mapped in the ablation tongue along the borders (\(V_{S}\) = 0-1 m day\({}^{-1}\)). Such estimates are well consistent with those from our values here (see Figure 3b, covering the same areas of Figure 5 in [22]). We found \(Vs\) = 4 m day\({}^{-1}\) in the South (accumulation) area of the PMG, with about 2 m day\({}^{-1}\) in the calving front instead. Moreover, here along the edges of the calving front, lower velocities are found. In Figure 8, we report seasonal variability of surface flow velocity. We report averaged velocity \(Vs\) along transect TB62 (North to South) during the summer (December-January-February, average of 9 couples of images from SENTINEL2), fall (March-April-May, average of 9 couples of images), and winter (June-July-August, average of 5 couples of images). Spring (September-October-November) is also reported, but it is likely less accurate because we had only a couple of images available. In general, higher velocities occur in the summer/fall with warmer temperature, and lower velocities occur in the winter/spring with colder weather. This is in agreement with presently available literature on the PMG and especially [22], where surface velocity at the front fluctuates by \(\pm\)25% or so (about 1.5-2.5 m day\({}^{-1}\)\(Vs\) about 2 m day\({}^{-1}\) on average), between summer and winter (see Figure 8 therein). Moreover, from benchmarking of the estimated velocity profiles against approximate estimation of glaciers depth (altitude of surface profile minus altitude of bedrock profile, see Figures 4-8) the largest (surface) velocity occurs mostly in the deepest areas, as expected. Figure 9 demonstrates flow velocity change along the glaciers from 2015 to 2017 using SENTINEL2 images. We calculated mean velocity across the glacier on transects starting from the front and moving backward with steps of 230 m, until 7.5 km upstream, at about the TA3 section in Figure 3b. We report the mean flow velocity in each transect (16 sections), together with the local deviation in each section for each acquisition date, colored seasonally. The largest \(Vs\) is seen at the front, and it fluctuates largely between different images (overall \(\mu_{VS}\) = 1.10 m s\({}^{-1}\), with \(\sigma_{VS}\) = 0.44 m s\({}^{-1}\)).