Physical geography at the entrance to
Madalena harbor, formed from a submerged crater The island is 17.5 km south of
São Jorge and just 7 km east of
Faial, in the Central Group of islands, an area that is colloquially known as
O Triângulo (The Triangle). Pico is 46.3 kilometers long, and at its maximum extent about 16 kilometers wide; making it the second largest of the Azores islands. The 151.8 km coastline is slightly indented with
inlets and
coves. Accessibility to the sea poses no difficulties, except in sections with plunging, unstable cliffs, subject to frequent
landslides (as seen in the northeast and southeast). Seabirds find favorable conditions for nesting in these habitats, in particular the species of Tern (
Sterna hirundo and
Sterna dougallii) and Shearwater (
Calonectris borealis). The rocky substrates prevail throughout the coast (slabs that alternate with rolled
pebbles), there are no sandy beaches, but there are numerous
tide pools and natural inlets used for bathing. Along the central plain of volcano cones to the eastern coast, the landscape is pitted with the remnants of craters and lake-filled cones, and dominated by the ancient volcano of Topo. Geomorphologically, the island is composed of three units: •
Topo Volcano - Located on the southernmost side of the island, it corresponds to an ancient
shield volcano created by the overlap of various lava flows and destroyed by erosion and landslides; •
Achada Plateau - Extending from the east side of the island to the stratovolcano, the Achada Plateau is an axial zone comprising spatter and lava cones along a mountainous ridge filled with lake-filled craters, dense scrub and forests.
Cones in this region are oriented along a west-northwest and south-southeast axis along a path east to west between the other volcanic structures; •
Pico Volcano - It occupies the western portion of the island, and corresponds to a central volcano with in altitude, created by numerous
Hawaiian and
Strombolian eruptions. Along its flanks are diverse lava and spatter cones that are formed along radial fractures and faults. Pico Island's tectonic structures are generally oriented along a west-northwest to east-southeast and a northeast to southwest axis. The main axis controls the main structures, especially the main mountain of Pico, while the secondary axises affect the radial fractures and faults along the central plain and eastern volcano. Similar to the geomorphological structures described above, the volcanic landforms have been identified by Madeira (1998) in the following units: •
Volcanic Complex of Lajes - pertains to the oldest volcanic structures, comprising volcanoes, lavas and debris that are between 35 and 300,000 thousand years old; it makes up the structures of the eastern part of the island, including the ancient volcano of Topo. •
Volcanic Complex of Calheta de Nesquim - dating to about 230,000 thousand years ago, this is a fissural zone of cones and basaltic lavas, associated with the Achada Plain, and the many faults along the central plateau of the island. •
Volcanic Complex of Madalena - the most recent volcanic complex, with both geological and historical eruptions; it includes the
basaltic
stratovolcano of Pico, but also many of the cones, faults and lava fields that circle the 2,351 meter summit. The last volcanic eruption (which is debatable) occurred in 1963, in a small submarine eruption off the northwest coast (north of Cachorro in
Santa Luzia). Prior to this, major volcanic activity was evident in lava fields generated in only the areas of
Prainha (1562–64),
Santa Luzia (1718), São João (1718) and Silveira (1720). The paths of the lava flows are still visible; those in the 16th century and 1718 were particularly substantial, extending for over 10 km. Today, the only visible evidence of active volcanism appears on the summit of Pico, in the base and interior of the Piqueninho (the mini-peak on the summit); there are irregular emissions from cracks in this zone. Additionally, there are emissions on the eastern flanks between 1500 and 2000 meters altitude. There have also been found areas of de-gasification along the fault associated with the Lagoa do Capitão and another in the Topo Volcano, as well as a spring rich in in the area of Silveira.
Earthquakes Pico, much like the other islands, is susceptible to seismic events, although their epicenters have primarily been localized in the
Faial-Pico or Pico-São Jorge Channels. Only three significant tectonic earthquakes have hit the island of Pico since the beginning of settlement: The
1757 earthquake, which caused significant damage in the eastern region of the island including the death of 11 people and the collapse of a church and a few houses; the 1973 seismic crisis (October 1973 – May 1974) in which the main earthquake (with magnitude 5.5) did considerable damage to 604 houses in Faial and 2,000 in Pico, which left nearly 5,000 people homeless; Like the remaining islands of the Azores, Pico suffered extensive deforestation following its occupation. While some land, especially at the coast, was used for housing, the majority was and is still used for farming, livestock and the wood industry (of
Cryptomeria). Additionally, several introductions of exotic species in the 19th century, like
Hydrangea macrophylla,
Pittosporum undulatum,
Hedychium gardnerianum and
Psidium cattleyanum, resulted in invasion and destruction of the remaining native habitats.
Gaspar Frutuoso gave a brief description of the island's flora only a century after being occupied: Over a third of the
Natura 2000 protected areas of the Azores are located on Pico. It has also the largest number of volcanic cavities (
lava caves) of anywhere in the archipelago, 86 out of 225.
Climate s that remain near the shores of Lagoa do Capitão Pico, like the other islands in the archipelago, has a mild maritime climate with high precipitation and high humidity for most of the year. However, due to its distinctive topographic variation, temperature and precipitation levels vary significantly depending on altitude and location, with rainfall generally more concentrated in the east. Temperatures fluctuate by approximately 8°C (14.4°F) between the coolest month, February, and the warmest month, August. At lower elevations, where most of the population resides, Pico has a
humid subtropical climate (
Köppen:
Cfa;
Thornthwaite:
B) with mild, rainy winters (mean around ) and warm, noticeably drier summers, (mean around ) although generally not dry enough to be classified as
Mediterranean. Because of its high
relative humidity (around 80%), summers can feel slightly warmer than they really are. At higher elevations, like the
Achada Plateau, temperatures are cooler and precipitation increases, it therefore transitions into a wet
oceanic climate (
Köppen:
Cfb;
Thornthwaite:
A), average relative humidity stays around 90% and although there are no climatic stations at Mount Pico, it is likely that the island has also experienced the lowest temperatures in the archipelago at the top of the mountain.
Human geography Geological, geomorphological and climatic constraints played (and still have) a determining role in economic activity, in the distribution of urban agglomerations and in demographic evolution. The settlement pattern is a good example of adaptation to the specific physical geography of this island, developing mainly along the coast and along the roads of communication. The main urban centers, municipality seats, are located by the sea:
Madalena,
São Roque do Pico and
Lajes do Pico. Regarding demographic behavior, the population has continued to decline since the middle of the last century, a trend that continues to the present day. However, the 1960s and 1970s were the decades that showed a more negative population variation rate, due to the intense
emigration surge that was generated at this time and that was generalized to the entire archipelago. Unlike other islands in the Azores, in the 1990s the situation did not change, continuing to register a negative population variation (-2.6%), even higher than that registered in the 1980s. According to the XIV General Census of Population (INE, 2002), the population totaled 14,806 inhabitants, which represents a decrease of 396 inhabitants compared to 1991. In 2001, the municipality of Madalena had the largest population (6,136 inhabitants), followed by Lajes do Pico (5,041 inhabitants) and São Roque (3,629 inhabitants). The population density (33.3 inhabitants/km2) was among the lowest in the archipelago and the age structure showed signs of aging, with more than 50% of the population aged between 25 and 64 years, against 30% of young people and about 20% of seniors. As of 2021, the total population is estimated to be around 13,895 inhabitants. Pico100.jpg|The village of
Madalena at the western base of Mount Pico, as seen from the Faial-Pico Channel PIC LAJ Lajes do Pico.JPG|
Lajes do Pico, along the south-central coast, with Mount Pico in the distance PIC SRQ São Roque do Pico.JPG|The port and historic centre of the civil parish of
São Roque, showing the whaling museum, and former rendering factory along the coast Ilha do Pico - Açores.jpg|East side of the island, viewed from Mount Pico ==Economy==