How do you measure the coastline of Rosguill peninsula in County Donegal, Ireland? Flanked with fjords and inlets, Alaska has the most coastline in the United States. But what is the exact length of its oceanic coast? It depends on who you ask. The Congressional Research Service says it’s 6,640 miles, while the National Oceanic and Atmospheric Administration (NOAA) claims it’s 33,904 miles. So, why the discrepancy?
Ryan Stoa, a law professor at Louisiana State University, stumbled upon this issue while researching coastline changes and landowner rights. This led him to the coastline paradox, a mathematical conundrum that experts have been debating for decades. The paradox arises because coastlines are not straight lines; they have many features like bays, inlets, rocks, and islands. The closer you look, the more intricate they become.
Geographer Katherine Sammler explains that the length of a coastline depends on the size of the ruler you use. A longer ruler gives a simpler measurement, while a smaller one captures more complexity, resulting in a longer measurement. This paradox has fascinated mathematicians since the 1960s when Lewis Fry Richardson and Benoit Mandelbrot explored the concept of fractals, leading to the discovery of shapes with infinite complexity.
Coastline measurements have real-world implications, especially in international laws like the U.N. Convention on the Law of the Sea. Different datasets with varying resolutions can lead to different coastline lengths, impacting resource rights for coastal nations. Additionally, coastlines are constantly changing due to tides, erosion, and sea level rise, making accurate measurements even more challenging.
In conclusion, the exact length of coastlines remains elusive due to the coastline paradox and the dynamic nature of coastal environments. While we may never know the precise number, understanding the complexities of coastline measurement is crucial for environmental conservation and resource management.
Alice Sun, a science journalist based in Brooklyn, explores a wide range of topics, including ecology, neuroscience, social science, and technology. With a background in environmental biology and science reporting, she provides insightful perspectives on complex scientific issues.