Citation

Sayre, R., S. Noble, S. Hamann, R. Smith, D. Wright, S. Breyer, K. Butler, K. Van Graafeiland, C. Frye, D. Karagulle, D. Hopkins, D. Stephens, K. Kelly, Z, basher, D. Burton, J. Cress, K. Atkins, D. van Sistine, B. Friesen, B. Allee, T. Allen, P. Aniello, I Asaad, M. Costello, K. Goodin, P. Harris, M. Kavanaugh, H. Lillis, E. Manca, F. Muller-Karger, B. Nyberg, R. Parsons, J. Saarinen, J. Steiner, and A. Reed. 2018. A new 30 meter resolution global shoreline vector and associated global islands database for the development of standardized global ecological coastal units. Journal of Operational Oceanography – A Special Blue Planet Edition. https://doi.org/10.1080/1755876X.2018.1529714

Although ocean islands are ubiquitous on the planet, and are homes to a stunning variety of people, plants, and animals, there have been surprisingly few attempts to accurately delineate all the islands on Earth. Every landmass, no matter how big, is surrounded by ocean waters. Island sizes range from continental (e.g. Africa), to very large (e.g. Madagascar) to large (e.g. Tasmania) to medium (e.g. Maui), to small (e.g. Key West) to very small islands and tiny rock outcrops. Size is relative, however, and there is no accepted standard for what separates big islands from small islands.
The global island data are grouped into four size classes: continental mainlands, big islands (larger than 1 square kilometre), small islands (between 0.0036km2 and 1 square kilometre), and very small islands (smaller than 0.0036 square kilometre). This dataset builds on a USGS Esri product produced in 2018 through global classification of composite 2015 Landsat imagery as water or land with a minimum mapping unit of 3600 square meters (the area of four contiguous Landsat pixels) (Sayer et al. 2018). The USGS Esri data was compared and merged with a global islands dataset created and maintained by UNEP-WCMC and Island Conservation. Islands that were missing from the original USGS Esri dataset were gathered and included from the UNEP-WCMC and Island Conservation data and further polygon attribute information was collected as well.