What is a hotspot and how do you know it's there?
Most volcanic eruptions occur near the boundaries of tectonic plates, but there are some exceptions. In the interior of some tectonic plates, magma has been erupting from a relatively fixed spot below the plate for millions of years. As the plate continuously moves across that spot, a trail of progressively older volcanic deposits is left at the surface. The Hawaiian Islands are a good example of this. The island of Hawai‘i currently sits above the active hotspot, while a chain of older (and no longer active) island volcanoes extend to the northwest, in the direction of plate movement. A few hotspots (like the one in Iceland) have also been found at diverging plate boundaries.
Scientists don’t fully understand how and why hotspots occur, and there is vigorous scientific debate about their origins. A frequently-used hypothesis suggests that hotspots form over exceptionally hot regions in the mantle, which is the hot, flowing layer of the Earth beneath the crust. Mantle rock in those extra-hot regions is more buoyant than the surrounding rocks, so it rises through the mantle and crust to erupt at the surface.
Hotspots and their trails on the earth’s surface do not develop suddenly (within the span of a human lifetime, for example). Scientists are only able to identify hotspots because of their relatively fixed locations beneath the tectonic plates, which produce tracks of surface volcanism spanning millions of years.
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Related
How fast is the hotspot moving under Yellowstone? How fast is the hotspot moving under Yellowstone?
Actually, the source of the hotspot is more or less stationary at depth within the Earth, and the North America plate moves southwest across it. The average rate of movement of the plate in the Yellowstone area for the last 16.5 million years has been about 4.6 centimeters (1.8 inches) per year. However, if shorter time intervals are analyzed, the plate can be inferred to have moved about 6.1...
How fast is the hotspot moving under Yellowstone?
Actually, the source of the hotspot is more or less stationary at depth within the Earth, and the North America plate moves southwest across it. The average rate of movement of the plate in the Yellowstone area for the last 16.5 million years has been about 4.6 centimeters (1.8 inches) per year. However, if shorter time intervals are analyzed, the plate can be inferred to have moved about 6.1...
What is the difference between "magma" and "lava"? What is the difference between "magma" and "lava"?
Scientists use the term magma for molten rock that is underground and lava for molten rock that breaks through the Earth's surface.
What is the difference between "magma" and "lava"?
Scientists use the term magma for molten rock that is underground and lava for molten rock that breaks through the Earth's surface.
What is the "Ring of Fire"? What is the "Ring of Fire"?
Most earthquakes and volcanic eruptions do not strike randomly but occur in specific areas, such as along plate boundaries. One such area is the circum-Pacific Ring of Fire, where the Pacific Plate meets many surrounding tectonic plates. The Ring of Fire is the most seismically and volcanically active zone in the world. Learn more: USGS Volcano Hazards Program
What is the "Ring of Fire"?
Most earthquakes and volcanic eruptions do not strike randomly but occur in specific areas, such as along plate boundaries. One such area is the circum-Pacific Ring of Fire, where the Pacific Plate meets many surrounding tectonic plates. The Ring of Fire is the most seismically and volcanically active zone in the world. Learn more: USGS Volcano Hazards Program
What are some benefits of volcanic eruptions? What are some benefits of volcanic eruptions?
Over geologic time, volcanic eruptions and related processes have directly and indirectly benefited mankind: Volcanic materials ultimately break down and weather to form some of the most fertile soils on Earth, cultivation of which has produced abundant food and fostered civilizations. The internal heat associated with young volcanic systems has been harnessed to produce geothermal energy. Most of...
What are some benefits of volcanic eruptions?
Over geologic time, volcanic eruptions and related processes have directly and indirectly benefited mankind: Volcanic materials ultimately break down and weather to form some of the most fertile soils on Earth, cultivation of which has produced abundant food and fostered civilizations. The internal heat associated with young volcanic systems has been harnessed to produce geothermal energy. Most of...
How Do Volcanoes Erupt? How Do Volcanoes Erupt?
Deep within the Earth it is so hot that some rocks slowly melt and become a thick flowing substance called magma. Since it is lighter than the solid rock around it, magma rises and collects in magma chambers. Eventually, some of the magma pushes through vents and fissures to the Earth's surface. Magma that has erupted is called lava. Some volcanic eruptions are explosive and others are not. The...
How Do Volcanoes Erupt?
Deep within the Earth it is so hot that some rocks slowly melt and become a thick flowing substance called magma. Since it is lighter than the solid rock around it, magma rises and collects in magma chambers. Eventually, some of the magma pushes through vents and fissures to the Earth's surface. Magma that has erupted is called lava. Some volcanic eruptions are explosive and others are not. The...
The Yellowstone hotspot, Greater Yellowstone ecosystem, and human geography The Yellowstone hotspot, Greater Yellowstone ecosystem, and human geography
The San Francisco volcanic field, Arizona The San Francisco volcanic field, Arizona
This dynamic earth: the story of plate tectonics This dynamic earth: the story of plate tectonics
Yellowstone and Hawaiʻi—how similar are they?
The US hosts two of the world’s most famous volcanic systems: Yellowstone and Hawaiʻi. These systems a well known for producing large volumes of magma...
Buried calderas on the track of the Yellowstone hotspot
The track of the Yellowstone hotspot is defined by a series of old caldera systems that get older the farther to the southwest you get from...
Just how long has the Yellowstone Hotspot been around?
The Yellowstone hotspot—the source of heat that powers Yellowstone’s vast volcanic system—has long been thought to have initiated about 17 million...
The Blackfoot Volcanic Field of southeast Idaho—a result of interaction between the Yellowstone hotspot and tectonic activity
The Blackfoot Volcanic Field in southeast Idaho is a unique product of Yellowstone hotspot volcanism. While it is chemically similar to other volcanic...
Discovery of Ancient Super-eruptions Suggests the Yellowstone Hotspot May Be Waning
Explosive super eruptions are among the most extreme events to affect the Earth’s surface. Thankfully, humans have not experienced such an event in...
The Yellowstone Hotspot and Columbia River Basalts
The arrival of volcanoes in that area is geologically recent, however—volcanism associated with Yellowstone has migrated over 400 miles across...
Volcano Watch — On the Trail of Hotspots: the Galapagos and Hawaiian Islands
The Galapagos Islands are perhaps best known for their unique species of plants and animals and their role in influencing Charles Darwin and others in...
Volcano Watch — Hotspots
Many of the islands that dot the center of the Pacific Ocean are made up of active, dormant, or extinct volcanoes, whose geologic histories are...
Related
How fast is the hotspot moving under Yellowstone? How fast is the hotspot moving under Yellowstone?
Actually, the source of the hotspot is more or less stationary at depth within the Earth, and the North America plate moves southwest across it. The average rate of movement of the plate in the Yellowstone area for the last 16.5 million years has been about 4.6 centimeters (1.8 inches) per year. However, if shorter time intervals are analyzed, the plate can be inferred to have moved about 6.1...
How fast is the hotspot moving under Yellowstone?
Actually, the source of the hotspot is more or less stationary at depth within the Earth, and the North America plate moves southwest across it. The average rate of movement of the plate in the Yellowstone area for the last 16.5 million years has been about 4.6 centimeters (1.8 inches) per year. However, if shorter time intervals are analyzed, the plate can be inferred to have moved about 6.1...
What is the difference between "magma" and "lava"? What is the difference between "magma" and "lava"?
Scientists use the term magma for molten rock that is underground and lava for molten rock that breaks through the Earth's surface.
What is the difference between "magma" and "lava"?
Scientists use the term magma for molten rock that is underground and lava for molten rock that breaks through the Earth's surface.
What is the "Ring of Fire"? What is the "Ring of Fire"?
Most earthquakes and volcanic eruptions do not strike randomly but occur in specific areas, such as along plate boundaries. One such area is the circum-Pacific Ring of Fire, where the Pacific Plate meets many surrounding tectonic plates. The Ring of Fire is the most seismically and volcanically active zone in the world. Learn more: USGS Volcano Hazards Program
What is the "Ring of Fire"?
Most earthquakes and volcanic eruptions do not strike randomly but occur in specific areas, such as along plate boundaries. One such area is the circum-Pacific Ring of Fire, where the Pacific Plate meets many surrounding tectonic plates. The Ring of Fire is the most seismically and volcanically active zone in the world. Learn more: USGS Volcano Hazards Program
What are some benefits of volcanic eruptions? What are some benefits of volcanic eruptions?
Over geologic time, volcanic eruptions and related processes have directly and indirectly benefited mankind: Volcanic materials ultimately break down and weather to form some of the most fertile soils on Earth, cultivation of which has produced abundant food and fostered civilizations. The internal heat associated with young volcanic systems has been harnessed to produce geothermal energy. Most of...
What are some benefits of volcanic eruptions?
Over geologic time, volcanic eruptions and related processes have directly and indirectly benefited mankind: Volcanic materials ultimately break down and weather to form some of the most fertile soils on Earth, cultivation of which has produced abundant food and fostered civilizations. The internal heat associated with young volcanic systems has been harnessed to produce geothermal energy. Most of...
How Do Volcanoes Erupt? How Do Volcanoes Erupt?
Deep within the Earth it is so hot that some rocks slowly melt and become a thick flowing substance called magma. Since it is lighter than the solid rock around it, magma rises and collects in magma chambers. Eventually, some of the magma pushes through vents and fissures to the Earth's surface. Magma that has erupted is called lava. Some volcanic eruptions are explosive and others are not. The...
How Do Volcanoes Erupt?
Deep within the Earth it is so hot that some rocks slowly melt and become a thick flowing substance called magma. Since it is lighter than the solid rock around it, magma rises and collects in magma chambers. Eventually, some of the magma pushes through vents and fissures to the Earth's surface. Magma that has erupted is called lava. Some volcanic eruptions are explosive and others are not. The...
The Yellowstone hotspot, Greater Yellowstone ecosystem, and human geography The Yellowstone hotspot, Greater Yellowstone ecosystem, and human geography
The San Francisco volcanic field, Arizona The San Francisco volcanic field, Arizona
This dynamic earth: the story of plate tectonics This dynamic earth: the story of plate tectonics
Yellowstone and Hawaiʻi—how similar are they?
The US hosts two of the world’s most famous volcanic systems: Yellowstone and Hawaiʻi. These systems a well known for producing large volumes of magma...
Buried calderas on the track of the Yellowstone hotspot
The track of the Yellowstone hotspot is defined by a series of old caldera systems that get older the farther to the southwest you get from...
Just how long has the Yellowstone Hotspot been around?
The Yellowstone hotspot—the source of heat that powers Yellowstone’s vast volcanic system—has long been thought to have initiated about 17 million...
The Blackfoot Volcanic Field of southeast Idaho—a result of interaction between the Yellowstone hotspot and tectonic activity
The Blackfoot Volcanic Field in southeast Idaho is a unique product of Yellowstone hotspot volcanism. While it is chemically similar to other volcanic...
Discovery of Ancient Super-eruptions Suggests the Yellowstone Hotspot May Be Waning
Explosive super eruptions are among the most extreme events to affect the Earth’s surface. Thankfully, humans have not experienced such an event in...
The Yellowstone Hotspot and Columbia River Basalts
The arrival of volcanoes in that area is geologically recent, however—volcanism associated with Yellowstone has migrated over 400 miles across...
Volcano Watch — On the Trail of Hotspots: the Galapagos and Hawaiian Islands
The Galapagos Islands are perhaps best known for their unique species of plants and animals and their role in influencing Charles Darwin and others in...
Volcano Watch — Hotspots
Many of the islands that dot the center of the Pacific Ocean are made up of active, dormant, or extinct volcanoes, whose geologic histories are...