Linear dunes occur on planetary surfaces, including Earth, Mars, and Titan, yet their dynamics are poorly understood. Recent studies of terrestrial linear dunes suggest they migrate by elongation only in supply limited environments. Here, we investigate elongating linear dunes in the Hellespontus Montes region of Mars which are morphologically similar to terrestrial systems. Multi-temporal, high-resolution orbital images show these linear dunes migrate by elongation only and that the fixed sediment source of the dunes probably restricts any lateral migration. Some linear dunes maintain their along length volume and elongate at rates comparable to adjacent barchans, whereas those which decrease in volume show no elongation, suggesting they are near steady state, matching morphometric predictions. Limited sediment supply may restrict Martian linear dunes to several kilometres, significantly shorter than many terrestrial linear dunes. Our results demonstrate the close similarities in dune dynamics across the two planetary surfaces.

中文翻译：

---

火星上拉长线性沙丘的形态、发育和沉积动力学

线性沙丘出现在行星表面，包括地球、火星和泰坦，但它们的动力学知之甚少。最近对陆地线性沙丘的研究表明，它们仅在供应有限的环境中通过伸长迁移。在这里，我们调查了火星 Hellespontus Montes 地区在形态上与陆地系统相似的拉长线性沙丘。多时相、高分辨率轨道图像显示这些线性沙丘仅通过伸长迁移，并且沙丘的固定沉积物源可能限制了任何横向迁移。一些线性沙丘保持其沿长度方向的体积并以与相邻新月形沙丘相当的速度伸长，而体积减小的沙丘则没有伸长，表明它们接近稳定状态，与形态学预测相符。有限的沉积物供应可能会将火星线性沙丘限制在几公里以内，明显短于许多陆地线性沙丘。我们的结果证明了两个行星表面沙丘动力学的密切相似性。