The UMAP projections in Fig. are reconstructed back into images in Fig. to visualize the initial pit area. A comparison of the images at t = 0.4 s in Fig. and Fig. underscores the importance of this procedure, as not all dark pixels in the original image correspond to the pit area. This indicates that the intensity in these pixels does not exceed the standard deviation of normalized intensities across the image. This strict formalism allowed us to define pit initiation times and initial pit areas for the entire dataset in 5-100 mM NaCl solutions, as shown in Fig. . While a similar result could be achieved by defining a threshold in normalized intensity variation, doing so in an unsupervised manner eliminates the need to set this threshold a priori, making the approach more objective and data-driven.