It is now known unambiguously that wind-driven bedform activity is occurring on the surface of Mars today, including early detections of active sand dunes in Meridiani Planum’s Endeavour crater. Many of these reports are only based on a few sets of observations of relatively isolated bedforms and lack regional context. Here, we investigate aeolian activity across central Meridiani Planum and test the hypothesis that dune sites surrounding Endeavour crater are also active and part of region-wide sediment migration driven by northwesterly winds. All 13 dune fields investigated clearly showed evidence for activity and the majority exhibited dune migration (average rates of 0.6 m/Earth-year). Observations indicate substantial geographic and temporal heterogeneity of dune crest fluxes across the area and per site. Locations with multiple time steps indicate dune sand fluxes can vary by a factor of five, providing evidence for short periods of rapid migration followed by near-stagnation. In contrast, measurements at other sites are nearly identical, indicating that some dunes are in a steady-state as they migrate. The observed sediment transport direction was consistent with a regional northeasterly-to-northwesterly wind regime, revealing more variations than were appreciated from earlier, more localized studies. Craters containing shallow, degraded, flat-floored interiors tended to have dunes with high sediment fluxes/activity, whereas local kilometer-scale topographic obstructions (e.g., central peaks, yardangs) were found to be inversely correlated with dune mobility. Finally, the previous, more limited detections of dune activity in Endeavour crater have been shown to be representative of a broader, region-wide pattern of dune motion.

现在明确地知道，今天在火星表面正在发生风成岩床活动，包括在Meridiani Planum的Endeavor火山口中早期发现了活跃的沙丘。这些报告中的许多报告仅基于相对孤立的床形的一些观测结果，并且缺乏区域背景。在这里，我们调查了整个Meridiani Planum中部的风沙活动，并检验了Endeavor火山口周围的沙丘站点也很活跃，以及西北风推动部分区域性泥沙迁移的假说。所有被调查的13个沙丘场都清楚地显示了活动的证据，并且大多数都显示出沙丘迁移（平均速率为0.6 m /地球年）。观测结果表明，整个区域和每个站点的沙丘顶通量在地理和时间上都存在很大的异质性。具有多个时间步长的位置表明，沙丘的沙子通量可能相差五倍，为短期快速迁移随后接近停滞提供了证据。相反，其他地点的测量值几乎相同，表明某些沙丘在迁移时处于稳态。观测到的泥沙运移方向与区域性东北向西北风向一致，揭示了比早期，更局限的研究更多的变化。内含浅层，退化的，平坦地板的火山口倾向于沙丘具有较高的泥沙通量/活动度，而当地千米规模的地形障碍物（例如中心峰，比扬邦）则与沙丘的流动性成反比。最后，上一个