## 5 Conclusions  
Our study of the 2021 Tajogate crater alignment suggests that profound changes of the location and arrangement of eruption craters and lava fountains occur, which is important to understand, as they also strongly affect the direction of lava flows. The  
Figure 7: Conceptual model of the 2021 Cumbre Vieja Eruption. (**a**) Phase 1 of the eruption shows craters aligned on the NW flank with a single crater on the SE side. (**b**) Phase 2 shows a new intrusion on the SE side with several new craters opening, producing two separate groups of craters. (**c**) Phase 3 shows disaggregation of new open craters in the NE and SE flanks, possibly associated with a new dike intrusion oblique to the main one. The post-eruption UAS DEM was used for the cone visualization, which is why the position of some craters does not coincide with the vent locations. 2021 Tajogaite eruption was distinguished by the opening of vents, which developed in an aligned direction NW-SE. We studied a large 48-image dataset of synthetic aperture radar (SAR) amplitude data acquired by the CSK satellite. We found an increase in the number of craters and a decrease in the level of linear arrangement thereof. We compared profound changes occurring at the crater distribution and identified three main phases of activity consisting of (1) an initial linear of craters above the erupting dike in NW-SE orientation, (2) renewed intrusion forming separate craters along the same lineament, and (3) disaggregation of craters due to a new dike intrusion in N-S orientation. Notably, the transition of these phases is marked or preceded by pronounced seismic activity increases. We speculated about the occurrence of possible pressure surges explaining these observations and developed a conceptual model summarizing the surface expression of the craters. Specifically, we conjectured that changes in the crater row are linked to changes in the underlying feeder dike, which may propagate, open or close, or newly orient to form an oblique dike during the late stages of the eruption. Our study has relevance for other volcanoes as well, as through the analysis of seismic data in relation to the activity of lava fountains, the opening of erupting fissures and emergence of lava flows at the surface can be foreseen in seismic data days to hours prior to occurrence. We did not attempt to forecast locations and expressions of these changes, which appeared rather complex and rapidly evolving during the transition between the phases identified. Importantly, understanding of such a deep to shallow communication may in the future lead to the development of tools where seismic data can be used as an indicator of changes at the surface, and where SAR data rapidly depict crater arrangements and lava flow direction in near real time. The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/rs14236168/s1](https://www.mdpi.com/article/10.3390/rs14236168/s1)]([https://www.mdpi.com/article/10.3390/rs14236168/s1](https://www.mdpi.com/article/10.3390/rs14236168/s1)), Figure S1: Composite maps between pairs of SAR amplitude images from two consecutive dates; Figure S2: SAR amplitudes ascending images from September 29 to December 9, 2021; Figure S3: Kymograph Camera 1. Day and Night data; Figure S4: Kymograph Camera 2. Day and Night data; Figure S5: Kymograph Camera 3. Day and Night data; Figure S6: Comparison of craters between SAR and a shaded relief map from drone data and UAS orthophoto; Figure S7: Comparison between 6 December SAR images corrected with two different DEMs. Table S1: Descending data orbit 08 specifications; Table S2: Ascending data orbit 06 specifications; Table S3: Ascending data orbit 12 specifications. [PERSON] performed the SAR and crater analysis and the kymograph study and led the writing of the manuscript. [PERSON] supervised the data collection, analysis and writing of the manuscript. [PERSON] and [PERSON] collected and processed UAS data. [PERSON] together with [PERSON] processed the SAR ascending data.