Inscribing in the bulk of transparent materials with UV femtosecond lasers has recently shown its advantages compared to standard IR laser machining. Amongst the other things, faster waveguide writing and higher etching rate were achieved. Here, we further explore the potential of UV lasers on modifying fused silica. In particular, we show the capability of inscribing self-organized nanoscale periodic patterns that we characterize and classify. We suggest a link between these features and the etching rate and we expose a phenomenological explanation for the formation of the self-organisation. Finally, we develop a model to assess the importance of stress-induced cumulative effects on the generation of these structures. Apart of the technological relevance, exploring such regimes allows us to shed light on the phenomenon of self-organizsation.