Hotspot volcanoes

10 of the biggest “super volcanoes” – HeritageDaily

A supervolcano is classified as a volcano with an eruption magnitude of 8, the largest Volcanic Explosivity Index (VEI) value where the volume of deposits for that eruption is greater than 1,000 cubic kilometers (240 cubic miles) .

Supervolcanoes occur when mantle magma rises in the crust and is unable to break through a fissure or vent. Over time, immense pressure begins to build in a growing pool of magma until it violently explodes through the crust.

This can occur in hotspots (eg Yellowstone Caldera) or in subduction zones (eg Toba). Large-volume supervolcanic eruptions are also often associated with large igneous provinces, which can cover large areas of volcanic lava and ash. These can cause lasting climate change (such as the onset of a Little Ice Age) and threaten species with extinction.


1 – Garita Caldera

Garita Caldera is a large supervolcanic caldera located in the San Juan Volcanic Field in the San Juan Mountains near the town of Creede in southwestern Colorado, United States. The eruption that created the La Garita caldera is one of the largest known volcanic eruptions in Earth’s history.

La Garita Caldera is one of several calderas that formed during a massive ignimbrite outbreak in Colorado, Utah, and Nevada 40 to 18 million years ago, and was the site of massive eruptions about 28.01 ± 0.04 million years ago, during the Oligocene Epoch.

The La Garita volcanism scale was the second largest of the Cenozoic era. The resulting ash flows created by the volcano, notably the “Fish Canyon Tuff”, have a volume of about 1,200 cubic miles (5,000 km3), giving it a Volcanic Explosivity Rating of 8. In comparison, the eruption of Mount St. Helens on May 18, 1980 had a volume of 0.25 cubic miles (1.0 km3).

Caldera de la Garita – Image credit: Google Earth

2 – Lake Toba

Lake Toba is a large caldera remnant of a supervolcano in the Toba Caldera complex in North Sumatra. The complex comprises four superimposed volcanic craters which adjoin the “volcanic front” of Sumatra. Covering an area of ​​100 km by 30 km, it is the largest quaternary caldera in the world and the fourth and youngest caldera.

This last major eruption occurred approximately 75,000 ± 900 years ago and had an estimated VEI = 8, making it the largest known explosive volcanic eruption in the past 25 million years.

About 2,800 km3 of dense rock-equivalent pyroclastic material, known as the younger Toba tuff, was released. Following the eruption, a resurgent dome formed in the new caldera which filled with water to create Lake Toba.

Lake Toba – Image credit – Google Maps

3 – Cerro Guacha

Cerro Guacha is a Miocene caldera located in the province of Sur Lípez, in southwestern Bolivia. Part of the Andes Volcanic System, it is considered part of the Central Volcanic Zone (CVZ), one of the three volcanic arcs of the Andes, and its associated Altiplano-Puna Volcanic Complex (APVC).

Cerro Guacha and the other volcanoes in this region are formed from the subduction of the Nazca Plate under the South American Plate. Above the subduction zone, the crust is chemically modified and generates large volumes of melt that form the local caldera systems of the APVC.

Two major ignimbrites, the 5.6-5.8 mya Guacha ignimbrite with a volume of 1,300 cubic kilometers (310 cu mi) and the 3.5-3.6 mya Tara ignimbrite with a volume of 800 cubic kilometers (190 cu mi) erupted from Cerro Guacha. More recent activity occurred at 1.7 mya and formed a smaller ignimbrite with a volume of 10 cubic kilometers (2.4 cu mi).

The larger caldera has dimensions of 60 by 40 kilometers (37 mi × 25 mi) with a rim elevation of 5,250 meters (17,220 ft). Prolonged volcanic activity has generated two interlocking calderas, a number of lava domes and lava flows, and a resurgent central dome.

Cerro Guacha – Image credit: Google Maps

4 – Yellowstone Caldera

The Yellowstone Caldera is a volcanic caldera and supervolcano in Yellowstone National Park in the western United States, sometimes referred to as the Yellowstone Supervolcano. The caldera and most of the park are located in the northwest corner of Wyoming.

Volcanism in Yellowstone is relatively recent, with calderas that were created in large eruptions that sit on a hotspot beneath the Yellowstone Plateau.

The three super eruptions occurred 2.1 million, 1.3 million, and about 630,000 years ago, forming the Island Park Caldera, Henry’s Fork Caldera, and Yellowstone Caldera, respectively.

The Island Park Caldera super-eruption (2.1 million years ago), which produced the Huckleberry Ridge Tuff, was the largest and produced 2,500 times more ash than the Mount St. Helens in 1980.

The next largest supereruption formed the Yellowstone Caldera (about 630,000 years ago) and produced the Lava Creek Tuff. The Henry’s Fork caldera (1.2 million years ago) produced the smallest Mesa Falls tuff, but it is the only Snake River Plain-Yellowstone hotspot caldera that is clearly visible today .

Yellowstone – Image credit: Google Maps

5 – Lake Taupo

Lake Taupo located on the North Island of New Zealand is the caldera of a large rhyolitic supervolcano called Taupo Volcano. Taupo Volcano is part of the Taupo Volcanic Zone, an area of ​​volcanic activity that stretches from Ruapehu in the south, through the Taupo and Rotorua regions, to White Island in the Bay of Plenty.

The most notable event was the Oruanui eruption around 26,500 years ago during the Late Pleistocene with VE=8. It is one of the largest eruptions in New Zealand history and generated approximately 430 km3 (100 cu mi) of pyroclastic drop deposits, 320 km3 (77 cu mi) of pyroclastic density current (PDC) deposits (mainly ignimbrite) and 420 km3 (100 cu mi) of intracaldera primary material, equivalent to 530 km3 (130 cu mi) of magma, totaling 1,170 km3 (280 cu mi) of total deposits.

Lake Taupo – Image credit: NASA

6 – Cerro Galan

Cerro Galán is a caldera in the province of Catamarca in Argentina. It is one of the largest exposed calderas in the world and is part of the Central Andes Volcanic Zone.

The volcanic activity at Galán is the indirect consequence of the subduction of the Nazca plate under the South American plate.

The caldera was active between 5.6 and 4.51 million years ago, with the largest eruption occurring 2.08 ± 0.02 million years ago, producing 1,050 km3 of deposits.

Cerro Galán – Image credit: Google Maps

7 – Island Park Caldera

The Island Park Caldera crosses the borders of Idaho and Wyoming in the United States and is one of the largest calderas in the world, with dimensions of approximately 80 by 65 km.

Ashfall from eruptions is the origin of the Huckleberry Ridge Tuff found from Southern California to the Mississippi River near St. Louis. This approximately 2,500 km3 (600 cubic mile) super-eruption occurred 2.1 Ma ago (millions of years ago) and produced 2,500 times more ash than the eruption of 1980 from Mount St. Helens.

The island park caldera is sometimes referred to as the first phase of the Yellowstone Caldera or the Huckleberry Ridge Caldera.

Island Park Caldera – Image credit: Google Maps

8 – Villama

Vilama is a Miocene caldera in Bolivia and Argentina. Straddling the border between the two countries, it is part of the Central Volcanic Zone, one of the four volcanic belts of the Andes. Vilama is remote and part of the Altiplano-Puna volcanic complex, a province of large calderas and associated ignimbrites that had been active for about 8 million years, sometimes in the form of supervolcanoes.

Vilama is the source of the massive Vilama Ignimbrite, which was emplaced in an eruption with a Volcanic Explosiveness Rating of 8 about 8.4 to 8.5 million years ago. A large amount of Vilama ignimbrite occurs inside the caldera depression, while the part outside the caldera covers an area exceeding 4,000 square kilometers (1,500 sq mi). The total volume of ignimbrite is about 1,200–1,800 cubic kilometers (290–430 cu mi), possibly up to 2,100 cubic kilometers (500 cu mi). Another large ignimbrite, the Sifon ignimbrite, may also have erupted by Vilama, while the Granada ignimbrite was later attributed to a separate volcano.

Vilama – Image credit: Google Maps

9 – The Pecan

La Pacana is a Miocene caldera located in the Antofagasta region of northern Chile. Part of the central volcanic zone of the Andes, it is part of the Altiplano-Puna volcanic complex, a major volcanic field of caldera and silicic ignimbrite. J

La Pacana as well as other regional volcanoes were formed by the subduction of the Nazca Plate under the South American Plate in the Peru-Chile Trench. La Pacana is responsible for the eruption of the giant Atana Ignimbrite, which reaches a volume of 2,451 to 3,500 cubic kilometers (588 to 840 cu mi) and is the fifth largest known explosive eruption. The Atana ignimbrite erupted 3.8 ± 0.1 and 4.2 ± 0.1 million years ago, almost simultaneously with the much smaller Toconao ignimbrite (volume of 180 cubic kilometers ( 43 cubic miles)).

Pecan

10 – Pastos Grandes

Pastos Grandes is the name of an interlocking caldera and crater lake in Bolivia that measures approximately 35 by 40 kilometers (22 mi × 25 mi) wide and has a maximum depth of 400 meters (1,300 ft).

The caldera is part of the Altiplano-Puna volcanic complex, a large ignimbrite province that is part of the central volcanic zone of the Andes.

Pastos Grandes has erupted a number of ignimbrites during its history, some of which exceeded a volume of 1,000 cubic kilometers (240 cu mi). After the ignimbrite phase, the lava domes of the Cerro Chascon-Runtu Jarita complex erupted near the caldera and along the faults.

Pastos Grandes – Image credit: Google Maps