Frequent surveys using modern remote sensing technology enable observations of subaerial beach morphology and surface sediment type (sand vs. gravel/cobble) with unprecedented spatial and temporal resolution. Here we show weekly terrestrial mobile light detection and ranging (LiDAR) observations of cusps on a mixed sediment beach, consisting of sand and gravel/cobble, spanning ∼2 km alongshore. Surface gravel/cobble coverage varied from almost complete to none (e.g., all sand), over times ranging from weekly to seasonal, and with location. Cusp morphologies also varied in space and time. Cusps with 11–20 m alongshore wavelengths (L) primarily developed in winter and were composite with gravel‐cobble horns and sandy bays. Cusps with L between 21 and 40 m developed throughout the year and were either composite or entirely sandy. Previously not reported, composite mega cusps (L between 200 and 400 m) occurred in winter. Composite cusps, with L between 11 and 40 m, were clustered in gravel/cobble‐rich mega cusp bays and absent on the sandier mega cusp horns.

中文翻译：

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混合沉积海滩上的尖峰和巨型尖峰观测

使用现代遥感技术进行的频繁调查能够以空前的时空分辨率观察海底海滩的形态和地表沉积物类型（沙与砾石/卵石）。在这里，我们显示了每周一次陆地移动光检测和测距（LiDAR）观测，该观测值位于混合沉积物海滩（由沙子和砾石/卵石组成）沿岸约2 km处。砾石/鹅卵石的表面覆盖范围从几乎完整到没有（例如，所有沙子），其变化范围从每周到季节性，并随位置而变化。尖头形态在空间和时间上也不同。沿岸波长（L）为11–20 m的尖峰主要形成于冬季，并且由砾石角和沙质海湾组成。带L的小块全年发育21至40 m，范围为复合或完全为沙质。以前没有报道过，复合巨型尖峰（L在200至400 m之间）发生在冬季。L在11至40 m之间的复合风口聚集在砾石/卵石丰富的大型风口海湾中，而沙质的大型风口角上则没有。