Abstract

Mars' slope streaks are dark albedo features created by the avalanching of surface dust. Recent work provided geostatistical evidence for the dry nature of streaks and their drivers, but presented no direct, quantitative measure of streak formation rates and seasonality. Here, I associate the global, spatiotemporal occurrence of more than 2.1 million slope streaks, identified between 2006 and 2024, with their hypothesized dry, (non)seasonal drivers: meteoroid impacts, marsquakes, and wind action. Streak formation rates vary across Mars and time, with an average of ~0.05 newly-formed streaks per existing streak per Mars Year. Only ~0.1 % of the annually formed streak population can be directly attributed to non-seasonal processes like meteoroid impacts and quakes. The bulk of streak formation coincides with the seasonal delivery of atmospheric dust and peaks in the southern summer and autumn, when wind stress systematically exceeds the threshold required for the initiation of sand saltation and dust mobilization. The conditions most conducive to seasonal streak formation appear to occur at sunrise and sunset, explaining the lack of direct observations of streak forming events to date. This work underscores the dry nature of slope streaks and enumerates their potentially important role in the Martian dust cycle.