## 3 Results  
### Beach Ridge Patterns  
Satellite images and lidar data show beach ridge topography at Dungeness. Along the section studied, we found that the number of beach ridges decreased from south to north (Figure 4).  
Figure 3: Google Earth image of the east-facing beach at Dungeness showing the location of the GPR profiles Beach 1–7 and locations of mapped shorelines from 1940 (green), 1960 (orange), 1990 (red), 2006 (purple), and 2019 (Blue).  
Figure 4: The number of beach ridges depicted in dark green, yellow, and orange decreases from south to north along the coast. Elevation maps compiled from 25 cm Lidar data with the location of the GPR survey lines Beach 1–7, see Figures 1 and 3 for locations.  
We note three patterns of beach ridge truncation and termination. Terminations are found at both the landward and seaward ends of beach ridges where they onlya against earlier (older) beach ridges. Truncations are formed at the seaward end of beach ridges where they are truncated (eroded) before the deposition of younger ridges that overlap the beach-ridge terminations. Towards the apex of the ness, there are short sections of beach ridge arranged in echelons, parallel rows with successive ridges overlapping, and each ridge terminating against a former shoreline and truncated by a later shoreline (Figure 5a,b). Similar patterns can be found within the salients to the north of the ness and are attributed to accretion from shingle bedforms migrating along and accreting onto the shoreline. At the southern end of the studied section, larger, wider, and higher elevation beach ridges can be traced around 3 km along the coast, but packages of smaller, narrower, and lower elevation beach ridges thin and pinch out towards the north. The higher and wider ridges extend further along the coast than the lower narrower ridges and appear to truncate the smaller lower ridges (Figure 5e,f). This pinch out and truncation of smaller ridges appears to be the main reason for the northward decrease in the number of beach ridges preserved. A third pattern of beach ridges is apparent at the northern end of the studied section, where low-angle sigmoid shaped beach ridges overlap and pinch out towards the north with successive ridges over lapping and extending further along the coast (Figure 5c,d). The sigmoid pattern appears to be due to the movement of sediment along the coast by longshore drift, possibly remnants of the kilometer-scale bedforms observed near the ness, although the accumulation appears to be a on a longer, decadal time scale.  
Figure 5: Three patterns of beach ridges that record changes in beach ridge preservation along the coast. Panels (**a,b,e,f**) are lidar images, and panel (**c,d**) is a satellite image from GoogleEarth(tm). Panels (**b,d,f**) are the same as (**a,c,e**), respectively, with added lines showing interpretation. (**a,b**) Short echelon ridges that overlap and terminate against earlier shorelines at the landward end and are truncated by younger shorelines on their seaward ends; (**c,d**) low-angle sigmoid oblique beach ridges that thin and overlap towards the north in the direction of longshore drift; (**e,f**) truncation of lower elevation and narrower beach ridges by wider, higher elevation beach ridges that extend further along the coast.  
Measurements of beach degradation between the shorelines picked from historic images on Google Earth \(\text{Pro}^{\text{TM}}\) are shown graphically in Figure 6, with the data in Table 1. Overall, beach degradation is greater in the south (Beach 1) than it is in the north (Beach 7), Figure 6 and Table 1. The average rate of progradation is 1.85 m/year at Beach 7 to 0.86 m/year at Beach 7 (Table 1). This is a consistent pattern that persists between all of the mapped shorelines between 1940 and 2019. It is worth noting that between 1960 and 1990 the shoreline at profile Beach 7 retreated by 5 m (Figure 6 and Table 1).