São Miguel Island

São Miguel Island (; ), nicknamed "The Green Island" (), is the largest and most populous island in the Portuguese archipelago of the Azores. The island covers and has around 140,000 inhabitants, with 45,000 people residing in Ponta Delgada, the archipelago's largest city.

History

In 1427, São Miguel became the second of the islands discovered by Gonçalo Velho Cabral to be settled by colonists from continental Portugal. This date is uncertain, as it is believed that the island was discovered between 1426 and 1437 and inscribed in portolans from the middle of the 15th century. Its discovery was later recorded by Father Gaspar Frutuoso in the seminal history of the Azores, ''Saudades da Terra'', as he began: "This island of São Miguel where...we are, is mountainous and covered in ravines, and it was, when we discovered it, covered in trees...due to its humidity, with its water showers and ravines warm with sun..."

It was sometime after the initial settlement of Povoação Velha (on the southeastern coast) that (between 1439 and 1444) a volcanic eruption occurred in the crater of Sete Cidades (then uninhabited). There are no records of the precise date, but Gaspar Frutuoso noted that navigators returning to São Miguel (soon after its discovery) encountered the western part of the island completely changed and tree trunks and pumice stone floating in the waters around the island. After docking in Povoação, the settlers reported feeling tremors and aftershocks; "...those settlers living in their earthen holes of straw and hay, heard almost within a year a great loud noise, roars and snorts that came from the earth with large tremors still proceeded the subversion and fire from the peak that had disappeared."

In the early 15th century, Prince Henry the Navigator first authorized the settlement of the Azores, and many settlers from the historical provinces of Estremadura, Alto Alentejo, Algarve and Madeira travelled to São Miguel, under the ''Carta Régia'' (a decree of the regency). The fertile soils and temperate climate attracted settlers from other countries, notably French and Flemish people. Cultural minorities such as Sephardic Jewish New Christians are believed to have comprised as much as 30% of the island's population. (i.e., many had surnames such as Pereira, Pimentel, Dias, Menezes, Oliveira, Nunes, Castro, Pinheiro, Rosa, Furtado, Ferreira, Lima, Fonseca, Machado, Franco, Elias, Teixeira, Duarte, Souza, Pacheco, Almeida, Cardoso, Mendes, Gouveia, Estrela, Carneiro, Melo, Morreira, Cruz, Figueira Mesquita, Josué, Salvador, Teles, Meira, Silva, Amorim, Alvarez, Brandão, Miranda, Mota, Ribeiro, Aguiar, Soares, Coelho, Carvalho, Gomes, Mascarenhas, Henriques, Rodrigues, Costa, Pinto etc.), Some Moors were also exiled to the island during the inquisition. Its geographic position and fertile soils permitted rapid economic development. The establishment of a military garrison made the island an obligatory port-of-call in the African and Asian commercial trade, while the export of sugar, and later orchil (a dye exported to Flanders for the making of cloth) stabilized the island's export trade.

The first capital of the island was Vila Franca do Campo, which was devastated by the 1522 Vila Franca earthquake and landslides. The tragedy helped to elevate Ponta Delgada to the administrative and economic status of capital and business centre from 1546.

During the Portuguese succession crisis of 1580, the people from São Miguel won the naval Battle of Vila Franca against a French squadron that supported the claims of the pretender António, Prior of Crato.

With the Portuguese Restoration War (1640), the island regained its position as a commercial centre, establishing new contacts in Brazil, which was heavily colonized during this period. Some of the island's historic buildings, including mansions and churches, date from this period; the island's architectural expansion and developed came from revenues from the export of oranges, mainly to Great Britain.

In 1831, during the Liberal Wars, following the landing of troops loyal to Queen Maria II in Nordeste (sent by future Duke of Terceira), a resistance to the Absolutist regime on the Island was organized. In 1832, this militia declared allegiance to the Charter (constitutional monarchy) and Queen Maria, forming a contingent that sailed to the continent where they were involved in the liberation of Porto.

Following the Liberal Wars, the period of Devourism allowed the economy to flourish, and the port of Ponta Delgada expanded, through the export of new crops such as tea, pineapple, and tobacco. The development of the fishing industry, cultivation of food staples and expansion of the dairy industry permitted the growth of many of the population centres on the island.

Following the Carnation Revolution, the island received the seat of the Presidency of the Autonomous Region of the Azores, located in Ponta Delgada, while its economic, social and political importance continued to grow within the archipelago.

Geography

Geology

São Miguel is bisected by many faults from the northwest to southeast in the direction of the Terceira Rift, a triple junction of the African, Eurasian, and North American tectonic plates. This system is best expressed in the western part of the island with extensive geological formations, such as the Mosteiros Graben (along the western flank of the Sete Cidades Massif), the Ribeira Grande Graben (along the northern flank of the Água de Pau Massif), and the many cones and fissural structures along the interior of the island. In the ancient crater of Furnas the faults are aligned west-northwest to east-southeast. Zbysewsky (1959), among others (note references) identifies eight geomorphological structures on São Miguel that correspond to the formative features that built the island, including:

* The Sete Cidades Massif – an area that occupies the extreme western part of the island, and corresponds to a central volcanic crater and lake-filled caldera, with various cones, deposits of pumice, lava domes and maars. In the northeastern flank of this volcano the Mosteiros Graben, a tectonic structure created from the collapse of lands and located along a northwest to southeast orientation. Along other regional fractures and radial faults there are ancient spatter cones and lava domes;
* The Picos Volcanic System or Picos Region – is situated along a northwest–southeast alignment, and defines a range of spatter cones and relatively level ground between the Sete Cidades and the Água de Pau Massifs;
* The Água de Pau Massif – this central feature corresponds to the central volcano on the island, and includes the ''Lagoa do Fogo'' (Lake of Fire), many lava domes and pumice cones. On the northeastern flank of the Massif the Ribeira Grande Graben is visible, representing a tectonic depression oriented northwest to southeast;
* The Achada das Furnas Plateau – a region with a central plain marked by cones and maars, with deposits along a west-northwest to east-southeast and northwest to southeast;
* Furnas Volcano – located in the eastern part of the island, along the southern coast, and comprising two ancient calderas, occupied by a lake (''Lagoa das Furnas''). Within the system one can find many pumice cones, maars and lava domes;
* Povoação Volcano – comprising a central caldera, generally well-eroded and whose southern rim has disappeared to the southern coast. Within its interior, marked by several river-valleys and cliffs, are several spatter cones;
* The Tronqueira Region – it occupies the extreme easterly portion of the island and corresponds to a mountainous region, divided by many river-valleys that are usually delineated by tectonic fractures;
* The Northern Coastal Platform – located along the northeastern portion of the island, and marks a zone of relatively moderate topography, limited by the coast to the north and the northern crater rims of Furnas and Povoação volcanoes to the south.

São Miguel comprises six volcanic zones; all are Quaternary in age except the last, which is partly Pliocene