Santorini, officially Thira and Classical Greek Thera, is an island in the southern Aegean Sea, about 200 km (120 mi) southeast from the Greek mainland. It is the largest island of a small, circular archipelago formed by the Santorini caldera. It is the southernmost member of the Cyclades group of islands, with an area of approximately 73 km2 (28 sq mi) and a 2021 census population of 15,480. The municipality of Santorini includes the inhabited islands of Santorini and Therasia, as well as the uninhabited islands of Nea Kameni, Palaia Kameni, Aspronisi and Christiana. The total land area is 90.623 km2 (34.990 sq mi). Santorini is part of the Thira regional unit.
Pumice, called pumicite in its powdered or dust form, is a volcanic rock that consists of extremely vesicular rough-textured volcanic glass, which may or may not contain crystals. It is typically light-colored. Scoria is another vesicular volcanic rock that differs from pumice in having larger vesicles, thicker vesicle walls, and being dark colored and denser.
Newberry Volcano is a large, active, shield-shaped stratovolcano located about 20 miles (32 km) south of Bend, Oregon, United States, 35 miles (56 km) east of the major crest of the Cascade Range, within the Newberry National Volcanic Monument. Its highest point is Paulina Peak. Newberry is the largest volcano in the Cascade Volcanic Arc, with an area of 1,200 square miles (3,100 km2) when its lava flows are taken into account. From north to south, the volcano has a length of 75 miles (121 km), with a width of 27 miles (43 km) and a total volume of approximately 120 cubic miles (500 km3). It was named for the geologist and surgeon John Strong Newberry, who explored central Oregon for the Pacific Railroad Surveys in 1855.
Mount Mazama is a complex volcano in the western U.S. state of Oregon, in a segment of the Cascade Volcanic Arc and Cascade Range. A volcanic peak once existed, but it collapsed following a major eruption approximately 7,700 years ago. The volcano is in Klamath County, in the southern Cascades, 60 miles (97 km) north of the Oregon–California border. Its collapse, due to the eruption of magma emptying the underlying magma chamber, formed a caldera that holds Crater Lake. Mount Mazama originally had an elevation of 12,000 feet (3,700 m), but following its climactic eruption this was reduced to 8,157 feet (2,486 m). Crater Lake is 1,943 feet (592 m) deep, the deepest freshwater body in the U.S. and the second deepest in North America after Great Slave Lake in Canada.
Sakurajima is an active stratovolcano, formerly an island and now a peninsula, in Kagoshima Prefecture in Kyushu, Japan. The lava flows of the 1914 eruption connected it with the Ōsumi Peninsula. It is the most active volcano in Japan.
Kikai Caldera is a massive, mostly submerged caldera up to 19 kilometres (12 mi) in diameter in the Ōsumi Islands of Kagoshima Prefecture, Japan.
Plinian eruptions or Vesuvian eruptions are volcanic eruptions marked by their similarity to the eruption of Mount Vesuvius in 79 AD, which destroyed the ancient Roman cities of Herculaneum and Pompeii. The eruption was described in a letter written by Pliny the Younger, after the death of his uncle Pliny the Elder.
Therasia, also known as Thirasía, is an island in the volcanic island group of Santorini in the Greek Cyclades. It lies north-west of Nea Kameni, a small island formed in recent centuries by volcanic activity and thus marking the centre of the island group. Therasia is the second largest island of the group, the largest by far being Thera.
A somma volcano, also known as a sommian, is a volcanic caldera that has been partially filled by a new central cone. The type is named after Mount Somma ("Summit"), a stratovolcano in southern Italy with a summit caldera in which the upper cone of Mount Vesuvius has grown. Other examples of somma volcanoes can be found on Russia's Kamchatka Peninsula and the Kuril Islands, stretching south from Kamchatka to Hokkaidō, Japan.
The Methana volcano peninsula is situated approximately 50 kilometres (31 mi) southwest of Athens in Greece.
The Minoan eruption was a catastrophic volcanic eruption that devastated the Aegean island of Thera circa 1600 BCE. It destroyed the Minoan settlement at Akrotiri, as well as communities and agricultural areas on nearby islands and the coast of Crete with subsequent earthquakes and paleotsunamis. With a Volcanic Explosivity Index (VEI) of between 6 and 7, it resulted in the ejection of approximately 28–41 km3 (6.7–9.8 cu mi) of dense-rock equivalent (DRE), the eruption was one of the largest volcanic events in human history. Since tephra from the Minoan eruption serves as a marker horizon in nearly all archaeological sites in the Eastern Mediterranean, its precise date is of high importance and has been fiercely debated among archaeologists and volcanologists for decades, without coming to a definite conclusion.
Nea Kameni is a small, uninhabited Greek island of volcanic origin located in the Aegean Sea, within the flooded Santorini caldera. Nea Kameni and the neighbouring small island Palea Kameni have formed over the past two millennia through repeated eruptions of dacite lava and ash. The Roman historian Cassius Dio records in the year 47 CE "This year a small islet, hitherto unknown, made an appearance close to the island of Thera." Cassius' report may refer to Palaia Kameni. Pliny the Elder reports a new island emerging on July 8, in the year of the consulship of M. Junius Silanus and L. Balbus, thus 19 CE.
Dense-rock equivalent (DRE) is a volcanologic calculation used to estimate volcanic eruption volume. One of the widely accepted measures of the size of a historic or prehistoric eruption is the volume of magma ejected as pumice and volcanic ash, known as tephra during an explosive phase of the eruption, or the volume of lava extruded during an effusive phase of a volcanic eruption. Eruption volumes are commonly expressed in cubic kilometers (km3).
Phreatomagmatic eruptions are volcanic eruptions resulting from interaction between magma and water. They differ from exclusively magmatic eruptions and phreatic eruptions. Unlike phreatic eruptions, the products of phreatomagmatic eruptions contain juvenile (magmatic) clasts. It is common for a large explosive eruption to have magmatic and phreatomagmatic components.
Kolumbo is an active submarine volcano in the Aegean Sea in Greece, about 8 km northeast of Cape Kolumbo, Santorini island. The largest of a line of about twenty submarine volcanic cones extending to the northeast from Santorini, it is about 3 km in diameter with a crater 1.5 km across. It first noticed by humans when it breached the sea surface in 1649-50. The Smithsonian Institution's Global Volcanism Program treats it as part of the Santorini volcano, though at least one source maintains that it is a separate magmatic system.
Submarine eruptions are volcano eruptions which take place beneath the surface of water. These occur at constructive margins, subduction zones and within tectonic plates due to hotspots. This eruption style is far more prevalent than subaerial activity. For example, it is believed that 70 to 80% of the Earth's magma output takes place at mid-ocean ridges.
The volcanoes of east-central Baja California are located on the Baja California Peninsula near the Gulf of California, in the state of Baja California Sur, in Mexico.
Santorini caldera is a large, mostly submerged caldera, located in the southern Aegean Sea, 120 kilometers north of Crete in Greece. Visible above water is the circular Santorini island group, consisting of Santorini, the main island, Therasia and Aspronisi at the periphery, and the Kameni islands at the center. It has been designated a Decade Volcano.
Kurile Lake is a caldera and crater lake in Kamchatka, Russia. It is also known as Kurilskoye Lake or Kuril Lake. It is part of the Eastern Volcanic Zone of Kamchatka which, together with the Sredinny Range, forms one of the volcanic belts of Kamchatka. These volcanoes form from the subduction of the Pacific Plate beneath the Okhotsk Plate and the Asian Plate.
Aspronisi is an uninhabited island lying within the Santorini caldera. The island was originally formed by the massive Minoan eruption in the 2nd millennium BC, after which it was gradually built up by successive volcanic activity. The name Aspronisi, which means 'White Island' in Greek, is derived from the island being partially composed of white pumice.
