Morphological signature of the March 2008 swell event on Caribbean beaches

极端波浪往往对沉积海岸线产生最剧烈的影响，因为它们超过了正常的沉积阈值，到达的地区往往在波浪的影响范围之外，并输送了在其他情况下稳定的物质。极端波浪很少发生，但往往在几十年甚至几个世纪内对海岸行为产生主导影响。它们可以由不同的过程产生。与飓风和海啸有关的波浪和涌浪对加勒比和墨西哥湾海岸线的巨大影响是众所周知的。该地区每年都会发生几次飓风，每年都有一些岛屿受到影响。然而，它们在任何地点的影响取决于它们相对于特定海岸的路径。虽然它们可能是毁灭性的，但它们的影响往往是相当局部的。因此，在任何一个特定的岛屿上，它们都是相对罕见的。加勒比海海啸也有相当局部的影响;它们没有印度洋或太平洋海啸的大规模影响。相比之下，大型涌浪是由遥远的风暴产生的，当它们从起源点辐射时，会在很大的区域内传播。因此，在许多加勒比岛屿的海岸线上，它们比飓风和海啸更经常发生，传闻证据表明，它们对海滩的侵蚀和加积有重要影响。从圭亚那到波多黎各的整个西加勒比地区的观察员都注意到了2008年3月一次大涌浪事件的影响。在英属维尔京群岛，珊瑚从珊瑚礁上被扯下来，扔到内陆或沉积在海滩上;在裸露的海岸，海滩后退了30米以上，而在有遮蔽的海岸，海浪似乎把沙子推到岸上。该研究项目旨在调查和记录英属维尔京群岛周围这一事件的影响，从而直接评估加勒比岛屿上涌浪事件的形态影响。

Extreme waves often produce the most dramatic impacts on depositional shorelines because they exceed normal sedimentary thresholds, reaching areas that are often above the influence of waves and transporting material that is otherwise stable. Extreme waves occur infrequently but often have the dominant influenec on coastal behaviour over several decades or even centuries. They can be generated by different processes. Waves and surges associated with hurricanes and tsunami are well known for their dramatic impact on coastlines of the Caribbean and Gulf of Mexico. Several hurricanes occur in the region annually and every year some islands are affected. However, their impact at any location depends on their path relative to a particular coast. While they can be devastating, their impacts are often quite localised. Thus on any given island they are a relatively infrequent occurrence. Caribbean tsunami too, have a quite localised influence; they do not have the large scale influence of those in the indian Ocean or Pacific. Large swell waves, in contrast, are generated by distant storms and spread over a large area as they radiate from their point of origin. They are consequently a more frequent occurrence on many Caribbean island shorelines than hurricanes and tsunamis and anecdotal evidence suggests them to have an important influence on beach erosion and accretion. The impact of a large swell event in March 2008 was noted by observers throughout the western Caribbean from Guyana to Puerto Rico. In the British Virgin Islands coral was ripped from reefs and thrown inland or deposited on beaches; on exposed coasts beaches retreated by over 30m while on sheltered coasts the waves appeared to push sand onshore. This research project aims to investigate and record the impacts of this event around the British Virgin Islands and to thereby assess directly, the morphological effect of a swell wave event on Caribbean islands.