Islas Desventuradas
The Islas Desventuradas are a small group of rugged oceanic islands located in an isolated position in the eastern Pacific, 917 km directly west from the northern coast of Chile. The nearest island neighbours to the Islas Desventuradas are the islands of the Juan Fernández Archipelago, 810 km to the south. Their only permanent population are the personnel stationed at the Chilean naval facility on the island of San Félix.
The group consists of two main islands: Isla San Félix (2.5 km²) and the slightly smaller Isla San Ambrosio (2.4 km²), located 19 km southeast from San Félix. The two largest of the minor islets that complete the group both lie off Isla San Félix: Isla González (just off the southeastern corner) and the Roca Catedral (2 km to the northwest). The islands are extinct/dormant volcanoes located upon the eastern Pacific's Nazca Plate and are part of a broad group of seamounts that extend eastwards from the East Pacific Rise (the Nazca Plate's divergent boundary with the Pacific Plate); other emergent features in this band of seamounts include Isla de Pascua (Easter Island) and Sala y Gomez.
At 2.5 km² in area San Félix is the largest island of the Islas Desventuradas group. The island is roughly triangular in outline, consisting of a flat series of layered basalt lavas that drop to the sea via low cliffs. The northwestern corner of the island is marked by the eroded dome of Cerro Amaraillo, reaching 193 m above sea level. The landscape is largely arid and barren, consisting of bare lava flows and rock. Vegetation cover is scant, comprising low-lying shrubs and herbs — a type often described as matorral scrub; there are also introduced tree species. Just visible in the San Félix image is the 2,000 m long runway that runs along the western side of the island.
Located 19 km southeast from San Félix is the 2.4 km² Isla San Ambrosio. The island presents a stark contrast with its arid neighbour, rising from the sea via tall, near vertical cliffs of layered lavas to a flat-topped plateau. The plateau slopes from the south (around 250 m above sea level) to the lower northern end of the island (100 m above sea level) giving the island a distinct wedge-shaped profile, 4 km in length and 850 m in width. The plateau contains many erosional features such as ravines and drainage channels. Its has a moister climate than San Félix and thus supports are a thicker and taller vegetation cover.
The warm, dry oceanic climate supports a flora with a high degree of endemism and provides nesting and breeding habitat to many species of subtropical seabird.
