| Abstrakt: |
A new global compilation of barrier islands is presented. A total of 1,500 barrier islands, 15,100 kilometers in total length have been recognized constituting 6.5% of the world's open ocean shoreline. Roughly 73% of all barrier islands are on trailing edge coasts while 9% are on collision coasts and 18% along the shorelines of marginal seas. A disproportionate number (86% by island length) are in the Northern Hemisphere, possibly a reflection of regional variation of sea level history during the last 5,000 years. Thirty percent of the world's barrier islands are along the shores of the United States. About 30% of all barrier islands are found on deltas, many not recognized in previous surveys, that are most abundant at low latitudes. Deltaic barrier islands account for 60% of all barrier islands in the Southern Hemisphere, but less than 30% in the Northern Hemisphere. Over 12% of the world's barrier islands (25% by number of individual islands) are found in the Arctic Ocean. At least half of these characteristically short Arctic islands (average length of 3 kilometers) are composed of gravel or mixed sand and gravel, and virtually all are transgressive. [ABSTRACT FROM AUTHOR] |
