Recurring slope lineae (RSL) are seasonal flows on steep slopes on Mars. Their formation mechanism is unknown, but dry granular flows are a likely explanation. Any proposed trigger for these flows must be consistent with the observed temperature dependence of RSL: more active in warmer months or when sun‐facing. Here, we use atmospheric modeling and laboratory experiments to explore a potential mechanism that involves both wet and dry processes at Hale Crater, a known RSL location. We propose that dry flows are triggered by changes in soil cohesion due to the loss of water. When surface temperature and humidity were experimentally simulated, salts likely found in the soil only completely dehydrated during the active season for RSL. We propose that the loss of water from soil in warmer months (or when illuminated) lowers soil cohesion and maximum stability angle. Slope failure may occur, exposing darker underlying material and creating RSL.

中文翻译：

---

水蒸气交换引起的土壤内聚力的变化：火星上反复发生的斜坡线的干流触发机制

循环坡度线（RSL）是火星陡坡上的季节性流量。它们的形成机理是未知的，但是干燥的颗粒流是一个可能的解释。对于这些流量，任何建议的触发条件都必须与观察到的RSL对温度的依赖性相一致：在温暖的月份或朝阳时更活跃。在这里，我们使用大气建模和实验室实验来探索潜在的机理，该机理涉及Hale Crater（一个已知的RSL地点）的干湿过程。我们建议，由于水的流失而引起的土壤内聚力的变化触发了干流。当通过表面温度和湿度进行模拟实验时，在RSL的活动季节中，土壤中可能发现的盐仅完全脱水。我们建议在温暖的月份（或光照时）从土壤中流失水分会降低土壤的内聚力和最大稳定角。可能会发生边坡破坏，暴露出较暗的底层材料并形成RSL。