An Update of Coastal Erosion in Puerto Rico
Jack Morelock and Maritza Barreto
Department of Marine Sciences, University of Puerto Rico at Mayagüez and Geography Department, University of Puerto Rico at Río Piedras
This is an update of a 1978 survey of coastal erosion in Puerto Rico (Morelock, 1984). Since the time of the 1977 photographs, several storms and hurricanes have passed close enough to Puerto Rico to cause higher than normal wave impingement on the shoreline of Puerto Rico. This has left large areas of the north coast a beachrock shoreline instead of sand (Figure 1). Sites from the original study were surveyed for changes in shoreline position between 1977 and 1999, using the same photographic techniques described in the first study.
Figure 1. Beachrock on the north coast of Puerto Rico exposed after Hurricane Georges
Continued research confirms that the rate of erosion in these beaches is not constant with time; there are accelerations, decelerations and even reversals from erosion to accretion. The effects of winter storms and occasional hurricane wave events exert a strong influence on erosion rates compared to the normal wave regime. Aerial photographs taken several years apart will not provide information on episodic changes in erosion rates, but will allow a determination of net shoreline change.