El Misti is one of the most famous landmarks in Peru. Because it sits only 17 km from the city of Arequipa (the second-largest city in Peru), it is considered one of the most dangerous volcanoes in the Andes. Many of Arequipa's historic buildings are constructed from "sillar," a white volcanic stoneRead more
El Misti is one of the most famous landmarks in Peru. Because it sits only 17 km from the city of Arequipa (the second-largest city in Peru), it is considered one of the most dangerous volcanoes in the Andes. Many of Arequipa’s historic buildings are constructed from “sillar,” a white volcanic stone (tuff) produced by ancient eruptions in the region. The volcano is part of the Central Volcanic Zone of the Andes, created by the subduction of the Nazca Plate beneath the South American Plate.
Located on the island of Luzon, Pinatubo's 1991 eruption was a classic example of a dormant volcano "waking up" with catastrophic force. It ejected roughly 10 billion tons of magma and created a massive caldera. The eruption coincided with a typhoon, leading to deadly "lahars" (mudflows) of volcanicRead more
Located on the island of Luzon, Pinatubo’s 1991 eruption was a classic example of a dormant volcano “waking up” with catastrophic force. It ejected roughly 10 billion tons of magma and created a massive caldera. The eruption coincided with a typhoon, leading to deadly “lahars” (mudflows) of volcanic ash and rainwater that devastated the surrounding plains. The event led to the permanent closure of the U.S. Clark Air Base. It remains a primary case study for how long-dormant volcanoes can still pose a massive risk to modern civilization.
The "funnel" is the path through which magma, gases and ash are channeled during an eruption. While a standard crater is usually less than 1 km in diameter, its shape is defined by the balance between the upward force of the eruption and the downward pull of gravity on the loose volcanic debris (tepRead more
The “funnel” is the path through which magma, gases and ash are channeled during an eruption. While a standard crater is usually less than 1 km in diameter, its shape is defined by the balance between the upward force of the eruption and the downward pull of gravity on the loose volcanic debris (tephra). If the eruption is extremely large and the summit collapses entirely, the funnel-shaped crater is replaced by a much larger, basin-like caldera. The funnel shape is the most common feature of “Cinder Cones” and “Stratovolcanoes” worldwide.
Magma is a "reducing" environment, meaning it lacks free oxygen. The gases released are those that were trapped in the Earth's interior since its formation or recycled through subduction. While nitrogen, hydrogen and carbon-based gases are common, oxygen only exists in the volcano as part of chemicaRead more
Magma is a “reducing” environment, meaning it lacks free oxygen. The gases released are those that were trapped in the Earth’s interior since its formation or recycled through subduction. While nitrogen, hydrogen and carbon-based gases are common, oxygen only exists in the volcano as part of chemical compounds like CO2 or SO2. This is an important distinction in planetary science, as it shows that the early Earth’s atmosphere (formed by volcanic outgassing) was “anoxic” (lacked oxygen) until the evolution of cyanobacteria.
This high percentage of water vapor is what drives the explosiveness of many volcanoes. As magma rises toward the surface, the dissolved water turns into steam. This steam expands rapidly, shattering the magma into ash and powering the eruption column. This process is similar to opening a shaken botRead more
This high percentage of water vapor is what drives the explosiveness of many volcanoes. As magma rises toward the surface, the dissolved water turns into steam. This steam expands rapidly, shattering the magma into ash and powering the eruption column. This process is similar to opening a shaken bottle of soda. Besides water vapor, the remaining 10-20% of gases include carbon dioxide and sulfur dioxide. The release of this water vapor over billions of years is one of the primary theories for how the Earth’s oceans were originally formed.
In which country is the El Misti volcano located?
El Misti is one of the most famous landmarks in Peru. Because it sits only 17 km from the city of Arequipa (the second-largest city in Peru), it is considered one of the most dangerous volcanoes in the Andes. Many of Arequipa's historic buildings are constructed from "sillar," a white volcanic stoneRead more
El Misti is one of the most famous landmarks in Peru. Because it sits only 17 km from the city of Arequipa (the second-largest city in Peru), it is considered one of the most dangerous volcanoes in the Andes. Many of Arequipa’s historic buildings are constructed from “sillar,” a white volcanic stone (tuff) produced by ancient eruptions in the region. The volcano is part of the Central Volcanic Zone of the Andes, created by the subduction of the Nazca Plate beneath the South American Plate.
See lessWhich volcano in the Philippines erupted after remaining dormant for approximately six centuries?
Located on the island of Luzon, Pinatubo's 1991 eruption was a classic example of a dormant volcano "waking up" with catastrophic force. It ejected roughly 10 billion tons of magma and created a massive caldera. The eruption coincided with a typhoon, leading to deadly "lahars" (mudflows) of volcanicRead more
Located on the island of Luzon, Pinatubo’s 1991 eruption was a classic example of a dormant volcano “waking up” with catastrophic force. It ejected roughly 10 billion tons of magma and created a massive caldera. The eruption coincided with a typhoon, leading to deadly “lahars” (mudflows) of volcanic ash and rainwater that devastated the surrounding plains. The event led to the permanent closure of the U.S. Clark Air Base. It remains a primary case study for how long-dormant volcanoes can still pose a massive risk to modern civilization.
See lessWhat is the main shape of a crater (volcanic vent)? (A) Conical (B) Vertical (C) Circular (D) Funnel-shaped
The "funnel" is the path through which magma, gases and ash are channeled during an eruption. While a standard crater is usually less than 1 km in diameter, its shape is defined by the balance between the upward force of the eruption and the downward pull of gravity on the loose volcanic debris (tepRead more
The “funnel” is the path through which magma, gases and ash are channeled during an eruption. While a standard crater is usually less than 1 km in diameter, its shape is defined by the balance between the upward force of the eruption and the downward pull of gravity on the loose volcanic debris (tephra). If the eruption is extremely large and the summit collapses entirely, the funnel-shaped crater is replaced by a much larger, basin-like caldera. The funnel shape is the most common feature of “Cinder Cones” and “Stratovolcanoes” worldwide.
See lessWhich of the following gases is not released during a volcanic eruption?
Magma is a "reducing" environment, meaning it lacks free oxygen. The gases released are those that were trapped in the Earth's interior since its formation or recycled through subduction. While nitrogen, hydrogen and carbon-based gases are common, oxygen only exists in the volcano as part of chemicaRead more
Magma is a “reducing” environment, meaning it lacks free oxygen. The gases released are those that were trapped in the Earth’s interior since its formation or recycled through subduction. While nitrogen, hydrogen and carbon-based gases are common, oxygen only exists in the volcano as part of chemical compounds like CO2 or SO2. This is an important distinction in planetary science, as it shows that the early Earth’s atmosphere (formed by volcanic outgassing) was “anoxic” (lacked oxygen) until the evolution of cyanobacteria.
See lessWhat is the percentage of water vapor in the gases released during a volcanic eruption?
This high percentage of water vapor is what drives the explosiveness of many volcanoes. As magma rises toward the surface, the dissolved water turns into steam. This steam expands rapidly, shattering the magma into ash and powering the eruption column. This process is similar to opening a shaken botRead more
This high percentage of water vapor is what drives the explosiveness of many volcanoes. As magma rises toward the surface, the dissolved water turns into steam. This steam expands rapidly, shattering the magma into ash and powering the eruption column. This process is similar to opening a shaken bottle of soda. Besides water vapor, the remaining 10-20% of gases include carbon dioxide and sulfur dioxide. The release of this water vapor over billions of years is one of the primary theories for how the Earth’s oceans were originally formed.
See less