Geology '' that united the island of São Miguel. 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. From west to east these zones are: the trachyte stratovolcano of the Sete Cidades Massif; a field of alkali-basalt cinder cones and lava flows with minor trachyte; the trachyte stratovolcano of the
Água de Pau Massif; a field of alkali-basalt cinder cones and lava flows with minor trachyte and tristanite; the trachyte stratovolcano of Furnas; and the Nordeste shield, which includes the Povoação caldera and consists of alkali basalt, tristanite and trachyte. Dormancy ages for these regions include: 400 year for Sete Cidades, 145 for zone 2, 1150 for Água de Pau, and 370 for Furnas, while eruptions in the Nordeste have not occurred in the past 3000 years. The highest elevation on São Miguel is the
Pico da Vara at . Lying at the eastern end of the island, it is the focus of a
Special Protection Area containing the largest remnant of
laurisilva forest on the island, which is home to the
endemic and
vulnerable bird, the
Azores bullfinch.
Whale watching tours, starting from
Ponta Delgada and
Vila Franca do Campo are available. One may see
sea turtles,
dolphins and
humpback whales.
Climate São Miguel has a mild maritime climate, which is drier in the summer and wetter in the winter, though according to the
Köppen climate classification, four different climatic classifications can be found throughout the island. At lower elevations, the hot-summer
Mediterranean climate (
Csa) dominates over the
Humid subtropical climate (
Cfa) typical of the more westerly islands and truly only found around
Capelas. Above altitude, the Mediterranean climate transitions into its warm-summer variant (
Csb), and past the climate is strictly
oceanic (
Cfb). The western half of the island is generally drier, due to the lower topography. Precipitation varies from less than in the Northwest coastline between
Mosteiros and
Ajuda da Bretanha, to over around
Pico da Vara in the east. Similar to other islands in the archipelago, São Miguel is influenced by ocean currents and winds, and, in particular, the cyclonic
Gulf Stream. This stream functions as a moderating force in the islands, keeping temperatures hovering between and throughout the year. The island's location also makes it susceptible to some Atlantic storms, and precipitation tends to be elevated during the winter periods. Winters are mild by European standards and summers are warm (sometimes very warm due to the high humidity) and relatively dry. Temperatures above or below have never been recorded at the coast.
Human geography Owing to the predominance of volcanic cones and craters in the interior, human settlement has developed primarily along coastal and interior plains. In addition, there are several communities that have developed within ancient craters (such as
Sete Cidades,
Furnas or
Povoação), river-valleys (such as
Ribeira Chã,
Pilar da Bretanha) or coastal deltas (
Mosteiros). Regardless, these settlements were largely agrarian and concentrated around the parish churches and the many fertile parcels of land. The communities were largely isolated throughout the year, owing to the great distances and rough landscape of the island, and only became integrated with the development of the many road networks that circle and bisect the island. Two cities have developed, largely because the island was divided by mountainous volcanic cones in the interior:
Ponta Delgada and
Ribeira Grande. Administratively, the island is governed by five municipalities, with Ponta Delgada and Ribeira Grande having more administrative functions associated with their larger populations:
Lagoa, the youngest of the municipalities of São Miguel, has a population of about 14,126 inhabitants (2008 census), incorporating the south-central parishes east of Ponta Delgada;
Nordeste, literally the north-eastern municipality, well known for an abundance of natural vegetation and the highest point on the island, Pico da Vara;
Ponta Delgada, includes not only the industrial/commercial city of Ponta Delgada, but also many rural parishes, as well as the large crater of Sete Cidades;
Povoação, home to the first colony on the island, Povoação is located in the south-east corner of the island, and includes active and dormant volcanic features, including
Furnas and the crater of
Povoação;
Ribeira Grande, the second largest municipality, with approximately 30,852 inhabitants, received its charter in 1981, and incorporates an extensive area of the northern coast (including the parish of
Rabo de Peixe, the largest parish by population); and
Vila Franca do Campo, once the seat of the historical capital of São Miguel (until it was almost destroyed by earthquake and landslides in 1522), it is located along the southern coast between Lagoa and Povoação. 's main plant is the most popular devotion in São Miguel island. Government is administered at the local level by the civil parish (), which are responsible for the provision of services and implementation of municipal initiatives. Based on the historical ecclesiastical limits established after settlement, the civil parishes are run by a president, treasurer and secretary (at the head of a parish council). These presidents have municipal council standing and represent their constituencies in the assemblies of the
Câmara Municipal. On the island of São Miguel there are 64 local area authorities, that include: •
Achada •
Achadinha •
Água de Alto •
Água de Pau •
Água Retorta •
Algarvia •
Ajuda da Bretanha •
Arrifes •
Cabouco •
Calhetas •
Candelária •
Capelas •
Conceição •
Covoada •
Faial da Terra •
Fajã de Baixo •
Fajã de Cima •
Fenais da Ajuda •
Fenais da Luz •
Feteiras •
Furnas •
Ginetes •
Livramento •
Lomba da Fazenda •
Lomba da Maia •
Lomba de São Pedro •
Maia •
Matriz •
Mosteiros •
Nordeste •
Nossa Senhora dos Remédios •
Nossa Senhora do Rósario •
Pico da Pedra •
Pilar da Bretanha •
Ponta Garça •
Porto Formoso •
Povoação •
Rabo de Peixe •
Relva •
Remédios •
Ribeira Chã •
Ribeira das Tainhas •
Ribeira Quente •
Ribeira Seca (Ribeira Grande) •
Ribeira Seca (Vila Franca do Campo) •
Ribeirinha •
Salga •
Santa Bárbara (Ribeira Grande) •
Santa Bárbara (Ponta Delgada) •
Santa Clara •
Santa Cruz •
Santana •
Santo António •
Santo António de Nordestinho •
São Brás •
São José •
São Miguel •
São Pedro (Ponta Delgada) •
São Pedro (Vila Franca do Campo) •
São Pedro de Nordestinho •
São Roque •
São Sebastião •
São Vicente Ferreira •
Sete Cidades ==Transport==