Corvo Island (Portuguese: Ilha do Corvo, pronounced [ˈiʎɐ du ˈkoɾvu]), literally the Island of the Crow, is the smallest and the northernmost island of theAzores archipelago and the northernmost in Macaronesia, with a population of approximately 468 inhabitants (in 2006) constituting the smallest singlemunicipality in Azores and in Portugal.
The island is located on the North American Plate, west of the Mid-Atlantic Ridge on a sea-mount of approximately 1.5-1.0 million years. The islands of Corvo and Flores emerged from a submarine mount oriented along a north-northeast to south-southwest, while Corvo is controlled by a faults oriented north to south, parallel to the mid-Atlantic Ridge, and transform faults oriented west to east which crosscut secondary cones on outer slopes. The island formed from a 5 km diameter central volcano (Monte Gorde) that emerged around 730,000 years ago, whose central cone was approximately 1000 meters in altitude. The crater collapsed 430,000 years ago during a Plinian eruption, forming a subsidence caldera (2000 meters in diameter and 300 metres depth), referred to as the Caldeirão. Within the caldera are several cinder and spatter cones (20–30 m in height) giving rise to small lakes, peat bogs, and islets (two long and five rounded). The highest point on the island, the Morro dos Homens, crowns the southern rim of the Caldeirão at 718 meters above sea level.
Two main volcanic complexes are usually recognized:
- The Basal Complex - the oldest formative structures, that includes pyroclastic submarine tuff cones, around the southwest and northern sea cliffs. In some areas, specifically along the western, northern and north-east, the island is cut by faults extending from the Upper Complexes;
- The Upper Complex (Complex Superior 1 and 2) - divided into two volcanic units of pre- and post-caldera episodes; theComplex 1 (or pre-caldera) is represented by sub-aerial volcanism, characterized by both explosive and effusive volcanism. This phase is characterized by a succession of basaltic lavas in the base, and developing into mixture of basaltic and Hawaiian lavas in later phases. The secondary (Complex 2) formations occupy 90% of the island, and pertain to the central caldera, including pumice and explosive particulars that are a mixture of escoria lava of a basaltic and Hawaiian in nature. The most recent of the deposits correspond to pyroclastic and phreatomagmatic pyroclastic material associated with secondary cones.
While the initial phases were dominated by basaltic lava flows and pyroclastic deposits, the final phase was characterized by pumice, surges, lahars, and pyroclastic flows characteristic of Plinian and sub-Plinian eruptions.
Shear cliffs dominate the coastal areas, the exception being along the southern margin which is composed of ancient lava flows. The western cliffs, with an almost vertical slope rises 700 meters above sea level; one of the major coastal elevations in the Atlantic. Remnants of the ancient volcano are partially preserved in the southern and eastern flanks of the island (which retain altitudes between 500 and 700 meters above seas level). In addition to marine erosion, the island is constantly eroded by strong northeast and western winds. In the south, secondary cinder cones, such as Coroínha, Morro da Fonte, Grotão da Castelhana and Coroa do Pico, are visibly preserved with little erosion, and responsible for many basaltic flows that formed the southern lava fajã (10 to 60 meters above sea level). The last eruption took place about 80-100,000 ago in the vicinity of Vila Nova do Corvo.
In the extreme northeast, along the Ponta Torrais there are two small islets, Ilhéu dos Torrais and the Ilhéu do Torrão, in addition to several submarine reefs, that are dangerous to navigation.
Like many of the other Azorean islands, the climate is humid, with 915.7 mm of precipitation annually, comfortable although generally windy. Temperatures are 17.6°C in Vila do Porto, with a variance between 14°C in February to 20°C in August. In the higher elevations fog is common and almost permanent. Due to maritime agitation, particular in the western coast, there is elevated erosion along the coast. The relative humidity is between 74% in October and 85% in June, when fog is more frequent (referred to as the Fogs of São João).
There is one urban center on the island: Vila do Corvo. Principally, it is a collection of many residential homes, interspersed with commercial businesses located on the southern one-third of the island. Functionally, by law, Vila do Porto is the only Portuguese top-level municipality without a civil parish. The urbanized area is divided between the village, the Corvo Aerodrome, and the island's ports (being the primary links to the other islands in the archipelago). The lands immediately around the settlement are small zones along the eastern coast (Quintas and Fojo) that can sustain cultivation of some crops and fruit trees, and where some older trees have survived settlement; the best pasture-lands are located in the north in the zone of Terras Altas.The southern coast, referred to as Enseada de Nossa Senhora do Rosário, is the location of three ports, constructed at various times for diverse needs: Porto Novo (currently not utilized), the Porto do Boqueirão and Porto da Casa (the largest and the island's commercial port). Portinho da Areia, on the extreme west of the southern coast (at the end of the airport's runway) is the only beach and principal swimming area on the island.
Subsistence agriculture has predominated on the island since it was first settled. It currently occupies 17.5% of the area of the municipality, and concentrated on small parcels in the eastern half of the island and along the northern parts of Vila do Corvo. In this patchwork of volcanic hedge-rows, farmers concentrate on semi-permanent crops (potatoes, some cereals, including wheat and citrus orchards).
Dairy production is the primary activity, although the raising of pigs and poultry is also common, and cheese one of the primary commercialized products. Until the 1960s, the raising of sheep and the commercialization of wool was also important on the island. This was until a change in forestry policy forced many farmers to vacate uncultivated lands, lands that were routinely used to graze sheep. It was quickly the end of the wool industry on the island, an industry that been integral to the islands small export industry.
