Upper Florida Keys-Seafloor elevation change in Maui, St. Croix, St. Thomas, and the Florida Keys

Coral reefs serve as natural barriers that protect adjacent shorelines from coastal hazards such as storms, waves and erosion but projections indicate global degradation of coral reefs due to anthropogenic impacts and climate change will cause a transition to net erosion by mid-century. The U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center conducted research to quantify the combined effect of all constructive and destructive processes on modern coral reef ecosystems by measuring regional-scale changes in seafloor elevation. USGS staff assessed five coral reef ecosystems in the Atlantic Ocean (Upper and Lower Florida Keys), Caribbean Sea (U.S. Virgin Islands: St. Thomas and Buck Island, St. Croix), and Pacific Ocean (Maui, Hawaii), including both coral-dominated and adjacent, non-coral dominated habitats. Scientists used historical bathymetric data from the 1930s to 1980s and contemporary light detection and ranging (lidar) digital elevation models (DEMs) from the late 1990s to 2000s to calculate changes in seafloor elevation for each study site over time periods reflecting low to high anthropogenic impacts. UFK_ElevationChange.zip contains the location, elevation, and elevation change data for the Upper Florida Keys. Using these changes in elevation, further analysis was done to calculate corresponding changes in seafloor volume for all study areas and habitat types within each site.

珊瑚礁是抵御风暴、海浪与侵蚀等海岸灾害、保护邻近岸线的天然屏障。然而相关预测表明，受人为活动影响与气候变化的共同作用，全球珊瑚礁正持续退化，预计至本世纪中叶将转为净侵蚀状态。美国地质调查局（U.S. Geological Survey, USGS）圣彼得堡海岸与海洋科学中心开展了此项研究，通过测量区域尺度的海底高程变化，量化各类建设性与破坏性过程对现代珊瑚礁生态系统的综合影响。该中心研究人员评估了大西洋（佛罗里达礁岛群上、下海域）、加勒比海（美属维尔京群岛：圣托马斯岛与巴克岛、圣克罗伊岛）以及太平洋（夏威夷毛伊岛）共5处珊瑚礁生态系统，涵盖以珊瑚为主导的栖息地及其邻近的非珊瑚主导生境。科学家采用1930年代至1980年代的历史水深测量数据，与1990年代末至2000年代的当代激光雷达（light detection and ranging, lidar）数字高程模型（digital elevation models, DEMs），针对各研究站点在低到高人为影响强度的不同时段，计算得到海底高程变化情况。UFK_ElevationChange.zip 包含了佛罗里达北部礁岛群的位置、高程及高程变化数据。基于上述高程变化数据，研究人员进一步开展分析，计算得到所有研究区域及各站点内不同生境类型对应的海底体积变化。