## 3 Results
### SAR Observations
Furthermore, the regular spacing between craters is notable on 29 September 2021 (Figure 4a) and varies slightly on the following dates. The second phase (Phase 2), from 27 October 2021 (day 39 from the eruption), is characterized by the migration of craters to the SE, maintaining its linearity in the NW and disaggregated to the SE (Figure 4h-l). Again, we can see the equal spacing of craters, especially in the NW-aligned craters. Finally, in the third phase (Phase 3) from 28 November (day 71 of the eruption), we see an outbreak and migration of the craters to the NE and SE of the main cone (Figure 4m). In this phase, the new crater positions suggest the formation of a broader zone or even development of a second row of craters oblique to the main row, striking roughly N-S (Figure 4m-p). Figure 4: Crater evolution according to the SAR amplitude images acquired in descending orbit. In the panels, we see the chronological emergence of the craters during the eruption of the new Tajogaite cone. The image date and corresponding number of days from the beginning of the eruption are denoted on the upper right side of each image. The colored dots represent each of the visible craters, color coded by the date of the first crater appearance in the SAR image (cold colors are older, warmer colors are later crater ages). Three phases can be distinguished: (**a–g**) a linear crater row defines Phase 1; (**h–l**) a southeastwardly propagating and broadening crater cluster defines Phase 2; (**m–p**) a strongly nested and dispersed crater appearance and formation of a N–S trend define Phase 3. While the descending data provide very good insight into the evolving crater row, the ascending radar data (Figure S2) add temporal details and allow for independent confirmation of the three-phase crater evolution. Due to the higher geometric distortion of the ascending data and the combination of two orbits, the linearity of the craters is not as clear as in the descending data. This is because the ascending data LOS direction is orthogonal with respect to the crater row, which forms across the evolving cone, resulting in a rather curved crater row arrangement. In addition, other geometric distortions prevail. For instance, in the ascending data (Figure S2), the SW flank looks brighter and tilted, especially in the more central craters. Furthermore, the SE craters show stronger distortion and are barely recognizable. The craters are close to each other but do not show an alignment; instead, they can be traced along a curve. Despite this, these data complement the results of the first dataset. We see that Phase 1 did not end on 27 October (day 38 of the eruption) but earlier, around 16 October (day 27 of the eruption) (Figure S2). Here, we can also observe the beginning of the migration and disaggregation of the craters toward the southeastern part of the cone. Moreover, it also supports the results of the descending data about Phase 2 ending around November 25 (day 68 of the eruption) (Figure S2). Finally, at the beginning of Phase 3 (Figure S2), the appearance of the second row of craters in the northeastern flank of the cone, oblique to the first, is detected more clearly. Here, we see how the NE craters that emerge on this flank on 28 November (Figure S2) align with the craters that emerge on 31 October and connect the linear to the disaggregated group (Figure S2). We note that the number of craters identified in the ascending data is lower (14 craters) than the descending data (18 to 20 craters) by 6 December. However, it shows similar disaggregation characteristics concentrated in the cone's NW and SE parts. Likewise, we validated the SAR data analysis results by comparing and identifying the craters in an orthophoto and the DEM generated from the drone survey realized on 15 January 2022. Here, we observed the same structure of the volcanic edifice and found a similar number of craters, which maintain the same structure and distribution (Figure S6).