Global distribution of coastal cliffs

Abstract

Previous studies have estimated that coastal cliffs exist on about 80% of the global shoreline, but have not been validated on a global scale. This study uses two approaches to capture information on the worldwide existence and erosion of coastal cliffs: a detailed literature survey and imagery search, and a GIS‐based global mapping analysis. The literature and imagery review show coastal cliffs exist in 93% of the combined recognized independent coastal states and non‐independent coastal regions worldwide (total of 213 geographic units). Additionally, cliff retreat rates have been quantified in at least one location within 33% of independent coastal states and 15% of non‐independent regions. The GIS‐based mapping used the near‐global Shuttle Radar Topography Mission 3 arc second digital elevation model and Arctic Coastal Dynamics Database to obtain near‐global backshore coastal elevations at 1 km alongshore intervals comprising about 1,340,000 locations (81% of the world vector shoreline). Backshore coastal elevations were compared with the mapped distribution of European coastal cliffs to produce a model training set, and this relationship was extended globally to map the likelihood of coastal cliff locations. About 21% of the transects (17% of the world vector shoreline) were identified as mangroves and eliminated as potential cliff locations. The results were combined with estimates of cliff percentages for Greenland and Antarctica from the literature, extending the global coverage to estimate cliff occurrence across 89% of the world vector shoreline. The results suggest coastal cliffs likely exist on about 52% of the global shoreline. © 2018 The Authors. Earth Surface Processes and Landforms published by John Wiley & Sons Ltd.

Dynamics of Global Coastline: An Exposition of Erosional and Depositional Landforms Along The Komenda Coastline in The Central Coastal Plains of Ghana

“…This observation aligns with [20] assertion that the cliff is covered with vegetation. The observation of vegetation on the cliff confirms [15] assertion that the cliff serves as a habitat for plants. The cliff generally consists of a rocky substrate and appears to be very high.…”

“…They are mostly massive and dominate the coastline where it is found. One key importance of the cliff is that it provides habitat for plants and animals [15]. Further coastal processes lead to the formation of the Caves at the bottom of the cliff.…”

Variation in Population Structure and Standing Stocks of Kelp Along Multiple Environmental Gradients and Implications for Ecosystem Services

“…The estimates of the suitable area per depth interval was based on a digital depth model with 25 m horizontal resolution, provided by the Norwegian Hydrographic Service. To exclude the proportion of the area that is unsuitable due to inappropriate substrate, i.e., soft bottoms, a rough estimate of 56% coastal cliff (Young and Carilli, 2018) was used, assuming this is applicable in areas down to 20 m depth outside the Norwegian shoreline. To estimate total standing biomass for Norway, we also included wave sheltered areas dominated by Saccharina latissima.…”

Impact of Nested Moisture Cycles on Coastal Chalk Cliff Failure Revealed by Multiseasonal Seismic and Topographic Surveys

“…Coastal change can have a profound impact on these assets. Around half of the world's coasts consist of eroding cliffs (Young & Carilli, 2019). On these coasts, cliff failure occurs across a range of scales and by a multitude of processes acting on the different materials that form cliffs (e.g., Collins & Sitar, 2008;Duperret et al, 2005;Kogure et al, 2006;Rosser et al, 2013;Stephensen, 2014).…”