(Table 1) Moisture content of buried snowpack deposit samples from Pearse Valley, McMurdo Dry Valleys

Buried snowpack deposits are found within the McMurdo Dry Valleys of Antarctica, which offers the opportunity to study these layered structures of sand and ice within a polar desert environment. Four discrete buried snowpacks are studied within Pearse Valley, Antarctica, through in situ observations, sample analyses, O-H isotope measurements and numerical modelling of snowpack stability and evolution. The buried snowpack deposits evolve throughout the year and undergo deposition, melt, refreeze, and sublimation. We demonstrate how the deposition and subsequent burial of snow can preserve the snowpacks in the Dry Valleys. The modelled lifetimes of the buried snowpacks are dependent upon subsurface stratigraphy but are typically less than one year if the lag thickness is less than c. 7 cm and snow thickness is less than c. 10 cm, indicating that some of the Antarctic buried snowpacks form annually. Buried snowpacks in the Antarctic polar desert may serve as analogues for similar deposits on Mars and may be applicable to observations of the north polar erg, buried ice at the Mars Phoenix landing site, and observations of buried ice throughout the martian Arctic. Numerical modelling suggests that seasonal snows and subsequent burial are not required to preserve the snow and ice on Mars.

在南极洲麦克默多干谷（McMurdo Dry Valleys）中发现了埋藏积雪沉积体，该区域为研究极地荒漠环境下的砂冰层状结构提供了研究契机。研究团队在南极洲皮尔斯谷（Pearse Valley）内针对四处独立的埋藏积雪沉积体开展研究，采用的研究手段包括原位观测、样品分析、氧氢同位素（O-H isotope）测量以及积雪沉积体稳定性与演化的数值模拟。该类埋藏积雪沉积体全年持续演化，依次经历沉积、融化、再冻结与升华过程。本研究阐明了积雪沉积与后续埋藏过程如何使干谷内的积雪沉积体得以保存。埋藏积雪沉积体的模拟寿命取决于地下地层结构，当覆盖层厚度小于约7厘米、积雪厚度小于约10厘米时，其模拟寿命通常不足一年，这表明部分南极洲埋藏积雪沉积体为年度形成的沉积体。南极洲极地荒漠中的埋藏积雪沉积体可作为火星同类沉积体的类比研究对象，相关结论可应用于火星北部极地沙海（erg）、火星凤凰号（Mars Phoenix）着陆点埋藏冰以及整个火星北极地区埋藏冰的观测研究。数值模拟结果表明，火星上的冰雪保存并不需要季节性积雪沉积与后续埋藏过程。