The Gulf of Honduras

Abstract

The Gulf of Honduras is a 10,000 km2 tri-national body of coastal and marine waters in the extreme western Caribbean Sea, including portions of the exclusive economic zones of Belize, Guatemala, and Honduras. For purposes of this paper, the Gulf extends from Gladden Spit (16.5° N, 88° W) on the Belize barrier reef to Punta Sal (15.9° N, 87.6° W) on the north coast of Honduras, including Bahia de Amatique and the entire Caribbean coast of Guatemala and the southern portion of the Belize barrier reef lagoon until Placentia (16.5° N, 88.4° W; Fig. 1.1). During the complex geologic history of the Gulf, volcanic and Paleozoic marine sedimentary rocks experienced successive periods of uplift and inundation resulting in metamorphism and karstification (Lara 1994). Volcanic activity is still evident from volcanic eruptions in Guatemala City, hot springs in Rio Dulce and southern Belize, and a recent earthquake (6.6 on the Richter scale). The tectonic plate boundary between North and South American lithospheric plates is marked by the Cayman Trench, which bisects the Gulf from northeast to southwest and stretches landward into the Motagua watershed at the Guatemala-Honduras border. As a result, water depths exceeding 2,000 m extend deeply into the Gulf of Honduras. The 1,000 m isobath parallels the Belize barrier reef for 50 km starting less than 3 km seaward of the reef crest at Gladden Spit and extending towards the southwest. At the Sapodilla Cays in the southern extreme of the barrier reef, the 200 m isobath continues 40 km south towards the Central American land mass. The northwestern edge of the trench in Belize exhibits an extremely steep wall adjacent to the reef and coastal lagoon, while the southeastern edge of the trench rises more gently but without interruption such that the Honduran coast is oceanic to the shore (Fig. 1.1).