Figure 5. Jetties on the old river course at Arecibo
Figure 6. Shoreline changes at Arecibo.
Studies of the beach sediments showed a shift from mixed terrigenous and biogenic beach sand to terrigenous sand in the 1990’s (Barreto, pers. obs.). After the passage of Hurricane George in 1998, the beach showed an extreme change in sediment composition from the back beach to the swash zone.