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What is the molten material beneath the solid rocks of the Earth’s crust, which sometimes comes to the surface during a volcanic eruption, called?
The molten material located beneath the solid rocks of the Earth’s crust is known as magma. It is formed due to extremely high temperatures and pressure inside the Earth, causing rocks to melt. Magma is composed of molten rock, dissolved gases, and mineral crystals. When pressure builds up, magma moRead more
The molten material located beneath the solid rocks of the Earth’s crust is known as magma. It is formed due to extremely high temperatures and pressure inside the Earth, causing rocks to melt. Magma is composed of molten rock, dissolved gases, and mineral crystals. When pressure builds up, magma moves upward through cracks and weak zones in the Earth’s crust. During a volcanic eruption, magma reaches the surface and flows out as lava. This process plays an important role in shaping the Earth’s surface by forming volcanic mountains, plateaus, and new landforms.
See lessBesides water vapor, what are the main gases in a volcano?
Volcanic gas composition is vital for predicting eruptions. Water vapor is the most abundant, but CO2 is the second most common; since it is heavier than air, it can collect in low-lying areas and pose a suffocation risk. SO2 is responsible for the "rotten egg" smell and reacts with atmosphere to caRead more
Volcanic gas composition is vital for predicting eruptions. Water vapor is the most abundant, but CO2 is the second most common; since it is heavier than air, it can collect in low-lying areas and pose a suffocation risk. SO2 is responsible for the “rotten egg” smell and reacts with atmosphere to cause acid rain or “volcanic smog” (Vog). Nitrogen is also released in significant quantities, contributing to the Earth’s atmospheric composition over billions of years. Monitoring the ratio of these gases helps scientists determine if fresh magma is rising toward the surface.
See lessWhat is the collective term for the lava and fragments of surface rocks obtained as a result of a volcanic eruption? (A) Lapilli (B) Scoria (C) Pyroclast (D) Breccia
When a volcano erupts explosively, it shatters magma and surrounding rock into millions of fragments. These are collectively called pyroclastic materials or Tephra. They are classified by size: ash is less than 2mm, lapilli are 2-64mm and bombs are larger than 64mm. These materials can travel at higRead more
When a volcano erupts explosively, it shatters magma and surrounding rock into millions of fragments. These are collectively called pyroclastic materials or Tephra. They are classified by size: ash is less than 2mm, lapilli are 2-64mm and bombs are larger than 64mm. These materials can travel at high speeds as “pyroclastic flows,” which are gravity-driven clouds of hot gas and debris that destroy everything in their path. The study of pyroclastic deposits allows geologists to reconstruct the history and intensity of ancient eruptions.
See lessWhich landform is not formed by volcanic activity? (A) Sill and dike (B) Meander (C) Lava plateau (D) Lava plain
Meanders are surface features formed by the kinetic energy of flowing water in mature river systems. In contrast, sills and dikes are intrusive volcanic features where magma solidifies within crustal cracks. Lava plateaus and plains are extrusive features formed by "fissure eruptions," where highlyRead more
Meanders are surface features formed by the kinetic energy of flowing water in mature river systems. In contrast, sills and dikes are intrusive volcanic features where magma solidifies within crustal cracks. Lava plateaus and plains are extrusive features formed by “fissure eruptions,” where highly fluid basaltic lava spreads over vast areas, such as the Deccan Traps in India. Because meanders rely on external atmospheric and hydraulic processes, they belong to the category of exogenic landforms, whereas the other options are products of magmatic or volcanic processes.
See lessWhich of the following landforms is not related to volcanic activity? (A) Geyser (B) Fjord (C) Crater (D) Caldera
While craters and calderas are topographic depressions formed by eruptions and geysers are hydrothermal vents heated by magma, a fjord is purely a product of ice. During the ice ages, massive glaciers carved "U-shaped" valleys deep into the Earth's crust. When the glaciers melted and sea levels roseRead more
While craters and calderas are topographic depressions formed by eruptions and geysers are hydrothermal vents heated by magma, a fjord is purely a product of ice. During the ice ages, massive glaciers carved “U-shaped” valleys deep into the Earth’s crust. When the glaciers melted and sea levels rose, these valleys were flooded by the ocean. Fjords are characteristic of coastlines like Norway, Chile and New Zealand. They represent the power of erosional glaciation, distinguishing them fundamentally from the endogenic (internal) forces that create volcanic landforms.
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