Abstract Knowledge of the spatial pattern of erosion on shore platforms is needed to better understand their evolution. The long-term spatial and temporal variation of downwearing remains difficult to interpret from erosion data commonly collected over 1–3 years of monitoring. We report erosion data recorded with a micro-erosion meter (MEM) over 40 years (1979–2019) on sandstone shore platforms in a micro-tidal environment along the Otway coast, Victoria, Australia. This well-preserved monitoring network (43 out of 44 original MEM sites) allowed a detailed investigation over a multidecadal timescale not previously considered. Over 40 years the mean erosion rate was 0.25 mm/yr. This value was statistically similar to erosion rates calculated over 2-year (0.32 mm/yr) and 32-year (0.26 mm/yr) periods. In the vertical plane, two significant but opposite relationships between elevation and erosion rates were displayed in the central intertidal zone. There was also a peak in the erosion rate near mean higher high water level. This spatial pattern was strongly associated with wetting and drying controlled by tides and waves. At elevations lower than mean higher low water, downwearing rates were one or two orders of magnitude lower than the average rate of the entire platform. The low erosion rates may be caused by the longer wetting condition of surfaces at lower elevation. Fast erosion rates were recorded in the upper intertidal zone where the bedrock was only inundated by spring high tides or storm waves. Salt weathering may be the primary mechanism but the effect of thermal weathering cannot be neglected at higher elevation. Based on the experience from the near complete MEM network in the study area, suggestions were provided to extend the longevity of monitoring network for future long-term erosion records on shore platforms.

中文翻译：

---

澳大利亚东南部砂岩岸台侵蚀的年代际空间格局

摘要 需要了解岸上平台侵蚀的空间格局才能更好地了解其演变。从通常在 1-3 年的监测中收集的侵蚀数据，仍然难以解释羽绒服的长期空间和时间变化。我们报告了在澳大利亚维多利亚州奥特韦海岸微潮环境中的砂岩海岸平台上使用微侵蚀计 (MEM) 记录的侵蚀数据超过 40 年（1979-2019 年）。这个保存完好的监测网络（44 个原始 MEM 站点中的 43 个）允许对以前未考虑的数十年时间尺度进行详细调查。40 多年来，平均侵蚀率为 0.25 毫米/年。该值与 2 年 (0.32 毫米/年) 和 32 年 (0.26 毫米/年) 期间计算的侵蚀率在统计上相似。在垂直平面上，中央潮间带显示了海拔和侵蚀率之间的两种重要但相反的关系。在平均较高的高水位附近，侵蚀率也有一个峰值。这种空间格局与潮汐和波浪控制的湿润和干燥密切相关。在低于平均较高低水位的海拔处，磨损率比整个平台的平均率低一到两个数量级。低侵蚀率可能是由于低海拔表面较长的润湿条件造成的。在上潮间带记录了快速侵蚀率，那里的基岩仅被春季高潮或风暴浪淹没。盐风化可能是主要机制，但在高海拔地区不能忽视热风化的影响。