A numerical model was used to determine whether the landward migration of shore platforms at the low tidal level, due to downwearing and possibly other mechanisms, can match the recession caused by wave erosion at the high tidal level. The hybrid model calculated the time required to undercut a cliff face and to remove the debris, and the amount of recession accomplished at the low tidal level during that time. These iterations were repeated over the equivalent of a 40,000 year period. The rates of high tidal erosion calculated during model runs were representative of cliff recession rates recorded in the field, and downwearing rates, specified for each run, were based on data recorded on shore platforms with micro-erosion meters. Almost all runs demonstrated that platform gradients decline asymptotically to a state of dynamic equilibrium that is strongly related to tidal range and rock resistance, although its relationship to wave height varies according to attenuation rates in the surf zone. Periodic changes in rock resistance and continuous changes in cliff height can introduce perturbations that delay equilibrium or, depending on their severity, prevent its occurrence. The conclusion that platforms trend towards dynamic, as opposed to static, equilibrium is contrary to other models which have considered only the effect of wave erosion. The results of this work have important implications for coastal modelling and the estimation of platform lowering for cosmogenic dating.

使用数值模型来确定低潮时沿岸平台的陆上迁移是否由于磨损和其他可能的机制而与高潮时沿波侵蚀引起的衰退相匹配。混合模型计算了对悬崖面进行底切和清除碎屑所需的时间，以及在这段时间内在低潮位完成的后退量。这些迭代重复了相当于40,000年的时间。在模型运行期间计算出的高潮汐侵蚀速率代表了现场记录的悬崖衰退率，而每次运行所指定的磨损率则是基于在岸上平台上使用微侵蚀计记录的数据。几乎所有运行都表明，平台坡度渐近地下降到动态平衡状态，该状态与潮汐范围和岩石阻力密切相关，尽管其与波高的关系根据冲浪区的衰减率而变化。岩石阻力的周期性变化和悬崖高度的连续变化会引入扰动，从而延迟平衡，或者根据平衡的严重程度阻止平衡的发生。平台趋向于动态平衡而不是静态平衡的结论与其他仅考虑波浪侵蚀影响的模型相反。这项工作的结果对海岸建模和宇宙成因测年平台降低的估计具有重要意义。尽管其与波高的关系根据冲浪区的衰减率而变化。岩石阻力的周期性变化和悬崖高度的连续变化会引入扰动，从而延迟平衡，或者根据平衡的严重程度阻止平衡的发生。平台趋向于动态平衡而不是静态平衡的结论与其他仅考虑波浪侵蚀影响的模型相反。这项工作的结果对海岸建模和宇宙成因测年平台降低的估计具有重要意义。尽管其与波高的关系根据冲浪区的衰减率而变化。岩石阻力的周期性变化和悬崖高度的连续变化会引入扰动，从而延迟平衡，或者根据平衡的严重程度阻止平衡的发生。平台趋向于动态平衡而不是静态平衡的结论与其他仅考虑波浪侵蚀影响的模型相反。这项工作的结果对海岸建模和宇宙成因测年平台降低的估计具有重要意义。平台趋向于动态平衡而不是静态平衡的结论与其他仅考虑波浪侵蚀影响的模型相反。这项工作的结果对海岸建模和宇宙成因测年平台降低的估计具有重要意义。平台趋向于动态平衡而不是静态平衡的结论与其他仅考虑波浪侵蚀影响的模型相反。这项工作的结果对海岸建模和宇宙成因测年平台降低的估计具有重要意义。