Cenozoic volcanism II: the Canary Islands

[EN] The Canarian archipelago comprises seven main volcanic islands and several islets that form a chain extending for c. 500 km across the eastern Atlantic, with its eastern edge only 100 km from the NW African coast (Fig. 18.1). The islands have had a very long volcanic history, with formations over 20 million years old cropping out in the eastern Canaries. Thus all stages of the volcanic evolution of oceanic islands, including the submarine stage as well as the deep structure of the volcanoes, can be readily observed. Rainfall and vegetation cover are relatively low, with the exception of the island of La Palma, favouring both geological observation and rock preservation. Furthermore, the absence of surface water has promoted groundwater mining by means of up to 3000 km of subhorizontal tunnels (locally known as ‘galerías’).

The coast of Cape Verde hosts the third largest loggerhead nesting population in the world

[EN] Extensive sea turtle nesting monitoring has been conducted in several islands of the Archipelago of Cape Verde during the past years. The loggerhead turtle is the only species that nests in these islands though green and hawksbill turtle juveniles are very often found feeding around their coasts. Around 90% of loggerhead nests are deposited in the island of Boavista on approximately 50 km of white sandy beaches. This is one of the less populated islands with more inaccessible beaches, as all villages are far from the main nesting areas. Another 9% of nests are equally distributed among the islands of Sal, Maio and San Nicolau and the remaining 1% of nests are found among the other six major islands and several islets of the archipelago.

Incidental Capture of Loggerhead Turtles (Caretta caretta) on Boa Vista (Cape Verde Islands)

[EN] The sea is one of the major natural resources of the Cape Verde Islands, a small archipelago located 500 kilometers off the coast of Senegal (West Africa). This country consists of ten main islands and several islets, and possesses an Exclusive Economical Zone (EEZ) of about 734 square kilometers and a coastal perimeter of nearly 2000 kilometers. The marine shelf, whose limit is the 200 m isobath, is particularly extensive on the island of Boa Vista (Figure 1). lt is likely that most of the loggerhead turtles (Caretta caretta) that breed in this archipelago are concentrated on this island (López-Jurado et al., 1999).