Uplift of the shoreline in tectonically‐active areas can have a profound influence on geomorphology changing the entire process dynamics of the coast as the landforms are removed from the influence of the sea. Over decadal timescales it is possible for the landforms to return to their pre‐earthquake condition and this paper examines the re‐establishment of mixed sand and gravel beaches on the coast of Wellington, New Zealand, subsequent to an uplift event in 1855. Over 60 topographic profiles were surveyed, seven sets of aerial photographs from a 67 year period were mapped and sediment size analyses conducted in order to quantify the nature of beach change following uplift, and associated relative sea level fall. These data were supported by surveys using ground penetrating radar. It is found that uplift raised the gravel beaches out of the swash zone thereby removing them from the littoral zone. Intertidal rocky reefs which occur between each embayment were also uplifted during the same event and completely interrupted the longshore transport system. Continued input of gravel material to the littoral zone allowed beaches to re‐establish sequentially along the coast as each embayment was infilled with sediment. This reconnection of the embayments with the longshore drift system is associated with the beach planform being initially drift dominated during infill but then switching to swash alignment once the embayment becomes infilled. This has resulted in shoreline accretion of over 100 m in some places, at rates of up to 4 m/yr, covering shore protection works built in the past few decades. The ability of the shore to adjust back to its pre‐uplift condition appears to be a function of the accommodation space created during uplift and the rate of sediment supply. Copyright © 2012 John Wiley & Sons, Ltd.

<p>Mixed Sand and Gravel (MSG) Beach research in recent decades has overwhelmingly focussed on open-oceanic environments, however, those found in fetch limited settings remain poorly understood. This thesis has examined spatial and temporal morphological change through such a system in Eastbourne, Wellington Harbour, New Zealand. This site has only recently prograded following several decades of erosion. This accretion has been the result of a northward migrating gravel front, which is introducing gravel sized sediment into the previously sandy system resulting in significant changes in beach morphology and volume. The aim of this study is to quantify these spatial and temporal changes and to assess shoreline stability on a decadal timescale. Additionally it aims to ascertain whether the current progradation is a long term change to the system or the result of a short term sediment increase. This assessment has been conducted in the form of topographic surveying, grain size and aerial photograph analysis. The topographic surveying and grain size analysis provides an accurate description of beach morphology. This is compared to the established MSG beach morphology models for the open coast, but operating on a smaller scale because of the lower energy fetch-limited environment of the study area. Aerial photograph analysis is used to show the longer term changes in beach width and the northern migration of the gravel fraction of the sediment supply regime. The spatial analysis results show that the beach morphology is highly variable. In the embayments that are more exposed to oceanic swell waves beach profiles are broad and steep, and in the beaches in the northern sections of the coastline which are more sheltered from oceanic swell waves, profiles are flat and narrow. The temporal results show that the coastal accretion observed through the study area has been initially rapid, followed by sustained increased beach width. These results suggest that the morphological variation on this coastline is part of a long term adjustment to a change in sediment supply, initiated by tectonic uplift and subsequently driven by longshore sediment transport. The observed mechanism of longshore transport has been suggested to be a function of sediment properties, relative wave energy and bathymetry/topography. The findings of this research are used to develop a conceptual model of shoreline evolution for the study area in response to changes that have occurred over the last 154 years.</p>