# Predicting Maximum Sea Levels

Predicting Maximum Sea Levels

Extreme value distributions are used to model the occurrence of extrema (i.e. extreme deviations from the median of a probability distribution). The parameters for GEV Distribution 1 are taken from a model fitted to annual maximum sea level data in Port Pirie, Australia from 1923–1987. GEV Distribution 2 has the same parameters as GEV Distribution 1, only the scale parameter has been increased to create more variability. The return level curves shown in the bottom-left give the expected maximum sea level that will occur once every years. For example, the Port Pirie return curve (blue) indicates that one may expect the sea level to reach 4.3 meters once every ten years, or 4.6 meters once every 100 years.

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The purpose of this Demonstration is to show how to interpret PDFs and return level curves for a GEV distribution with a real-world example. Move the sliders to adjust the various parameters and notice how each parameter affects both the PDF and the respective return level curve.