Excluding steam eruptions, these volcanoes have shown activity:
- Mount St. Helens, Washington - Eruptions and/or lava dome growth occurred in the late 1700s, 1800-1857, 1980-1986, and 2004-2007.
- Lassen Peak, California - A series of steam blasts began on May 30, 1914. An eruption occurred 12 months later on May 21, 1915. Minor activity continued through the middle of 1917.
- Mount Hood, Oregon - After being dormant for over 1,000 years, Mount Hood had an eruptive period beginning in 1781 that lasted for about a decade. In the mid-1800s, local residents reported minor explosive activity.
Related Content
What was the largest volcanic eruption in the 20th century?
The world's largest eruption of the 20th century occurred in 1912 at Novarupta on the Alaska Peninsula. An estimated 15 cubic kilometers of magma was explosively erupted during 60 hours beginning on June 6th. This volume is equivalent to 230 years of eruption at Kilauea (Hawaii) or about 30 times the volume erupted by Mount St. Helens (Washington) in 1980!Due to the remote location of the eruption...
Will extinct volcanoes on the east coast of the U.S. erupt again?
No. The geologic forces that generated volcanoes in the eastern United States millions of years ago no longer exist. Through plate tectonics, the eastern U.S. has been isolated from the global tectonic features (tectonic plate boundaries and hot spots in the mantle), that cause volcanic activity. So new volcanic activity is not possible now or in the near future. If you wait around several hundred...
Which volcanic eruptions were the deadliest?
Deadliest Volcanic Eruptions Since 1500 A.D.EruptionYearCasualtiesMajor CauseNevado del Ruiz, Colombia198525,0001,3Mudflows3Mont Pelée, Martinique190230,0001 (29,025)2Pyroclastic flows2Krakatau, Indonesia188336,0001 (36,417)2Tsunami2Tambora, Indonesia181592,0001,2Starvation2Unzendake, Japan179215,0001 (14,030)2Volcano collapse, Tsunami2Lakagigar (Laki), Iceland17839,0001 (9,350)2Starvation2Kelut...
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 many active volcanoes are there on Earth?
There are about 1,350 potentially active volcanoes worldwide, aside from the continuous belts of volcanoes on the ocean floor at spreading centers like the Mid-Atlantic Ridge. About 500 of those 1,350 volcanoes have erupted in historical time. Many of those are located along the Pacific Rim in what is known as the "Ring of Fire." In the United States, volcanoes in the Cascade Range and Alaska...
What was the most destructive volcanic eruption in the history of the United States?
The May 18, 1980 eruption of Mount St. Helens (Washington) was the most destructive in the history of the United States. Novarupta (Katmai) Volcano in Alaska erupted considerably more material in 1912, but owing to the isolation and sparse population of the region, there were no human deaths and little property damage. In contrast, the eruption of Mount St. Helens caused loss of lives and...
Where does the United States rank in the number of volcanoes?
The United States ranks third, behind Indonesia and Japan, in the number of historically active volcanoes (that is, those for which we have written accounts of eruptions). In addition, about 10 percent of the more than 1,500 volcanoes that have erupted in the past 10,000 years are located in the United States. Most of these volcanoes are found in the Aleutian Islands, the Alaska Peninsula, the...
Where is the largest active volcano in the world?
Rising gradually to more than 4 km (2.5 mi) above sea level, Hawaii’s Mauna Loa is the largest active volcano on our planet. Its submarine flanks descend to the sea floor an additional 5 km (3 mi), and the sea floor in turn is depressed by Mauna Loa's great mass another 8 km (5 mi). This makes the volcano's summit about 17 km (10.5 mi) above its base!Learn more: USGS Hawaiian Volcano Observatory
Are there earthquakes associated with Mount Hood?
Felt earthquakes on Mount Hood (Oregon) occur every two years on average. Seismic monitoring, in effect since 1977, indicates a generalized concentration of earthquakes just south of the summit area and 2-7 kilometers below sea level. A seismic swarm in July 1980, during which nearly 60 earthquakes (mostly 5-6 kilometers deep with a maximum bodywave magnitude of 2.8) recorded in a 5-day period...
When did Lassen Peak last erupt?
The most recent eruptive activity at Lassen Peak (California) took place in 1914-1917. This eruptive episode began on May 30, 1914, when a small phreatic eruption occurred at a new vent near the summit of the peak. More than 150 explosions of various sizes occurred during the following year.By mid-May 1915, the eruption changed in character; lava appeared in the summit crater and subsequently...
How would an eruption of Mount Rainier compare to the 1980 eruption of Mount St. Helens?
Eruptions of Mount Rainier usually produce much less volcanic ash than do eruptions at Mount St. Helens. However, owing to the volcano's great height and widespread cover of snow and glacier ice, eruption-triggered debris flows (lahars) at Mount Rainier are likely to be much larger--and will travel a greater distance--than those at Mount St. Helens in 1980. Furthermore, areas at risk from debris...
How many eruptions have there been in the Cascades during the last 4,000 years?
Eruptions in the Cascades have occurred at an average rate of one to two per century during the last 4,000 years. Future eruptions are certain.Learn more:Eruptions in the Cascade Range During the Past 4,000 YearsUSGS Cascades Volcano Observatory
Related Content
- FAQ
What was the largest volcanic eruption in the 20th century?
The world's largest eruption of the 20th century occurred in 1912 at Novarupta on the Alaska Peninsula. An estimated 15 cubic kilometers of magma was explosively erupted during 60 hours beginning on June 6th. This volume is equivalent to 230 years of eruption at Kilauea (Hawaii) or about 30 times the volume erupted by Mount St. Helens (Washington) in 1980!Due to the remote location of the eruption...
Will extinct volcanoes on the east coast of the U.S. erupt again?
No. The geologic forces that generated volcanoes in the eastern United States millions of years ago no longer exist. Through plate tectonics, the eastern U.S. has been isolated from the global tectonic features (tectonic plate boundaries and hot spots in the mantle), that cause volcanic activity. So new volcanic activity is not possible now or in the near future. If you wait around several hundred...
Which volcanic eruptions were the deadliest?
Deadliest Volcanic Eruptions Since 1500 A.D.EruptionYearCasualtiesMajor CauseNevado del Ruiz, Colombia198525,0001,3Mudflows3Mont Pelée, Martinique190230,0001 (29,025)2Pyroclastic flows2Krakatau, Indonesia188336,0001 (36,417)2Tsunami2Tambora, Indonesia181592,0001,2Starvation2Unzendake, Japan179215,0001 (14,030)2Volcano collapse, Tsunami2Lakagigar (Laki), Iceland17839,0001 (9,350)2Starvation2Kelut...
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 many active volcanoes are there on Earth?
There are about 1,350 potentially active volcanoes worldwide, aside from the continuous belts of volcanoes on the ocean floor at spreading centers like the Mid-Atlantic Ridge. About 500 of those 1,350 volcanoes have erupted in historical time. Many of those are located along the Pacific Rim in what is known as the "Ring of Fire." In the United States, volcanoes in the Cascade Range and Alaska...
What was the most destructive volcanic eruption in the history of the United States?
The May 18, 1980 eruption of Mount St. Helens (Washington) was the most destructive in the history of the United States. Novarupta (Katmai) Volcano in Alaska erupted considerably more material in 1912, but owing to the isolation and sparse population of the region, there were no human deaths and little property damage. In contrast, the eruption of Mount St. Helens caused loss of lives and...
Where does the United States rank in the number of volcanoes?
The United States ranks third, behind Indonesia and Japan, in the number of historically active volcanoes (that is, those for which we have written accounts of eruptions). In addition, about 10 percent of the more than 1,500 volcanoes that have erupted in the past 10,000 years are located in the United States. Most of these volcanoes are found in the Aleutian Islands, the Alaska Peninsula, the...
Where is the largest active volcano in the world?
Rising gradually to more than 4 km (2.5 mi) above sea level, Hawaii’s Mauna Loa is the largest active volcano on our planet. Its submarine flanks descend to the sea floor an additional 5 km (3 mi), and the sea floor in turn is depressed by Mauna Loa's great mass another 8 km (5 mi). This makes the volcano's summit about 17 km (10.5 mi) above its base!Learn more: USGS Hawaiian Volcano Observatory
Are there earthquakes associated with Mount Hood?
Felt earthquakes on Mount Hood (Oregon) occur every two years on average. Seismic monitoring, in effect since 1977, indicates a generalized concentration of earthquakes just south of the summit area and 2-7 kilometers below sea level. A seismic swarm in July 1980, during which nearly 60 earthquakes (mostly 5-6 kilometers deep with a maximum bodywave magnitude of 2.8) recorded in a 5-day period...
When did Lassen Peak last erupt?
The most recent eruptive activity at Lassen Peak (California) took place in 1914-1917. This eruptive episode began on May 30, 1914, when a small phreatic eruption occurred at a new vent near the summit of the peak. More than 150 explosions of various sizes occurred during the following year.By mid-May 1915, the eruption changed in character; lava appeared in the summit crater and subsequently...
How would an eruption of Mount Rainier compare to the 1980 eruption of Mount St. Helens?
Eruptions of Mount Rainier usually produce much less volcanic ash than do eruptions at Mount St. Helens. However, owing to the volcano's great height and widespread cover of snow and glacier ice, eruption-triggered debris flows (lahars) at Mount Rainier are likely to be much larger--and will travel a greater distance--than those at Mount St. Helens in 1980. Furthermore, areas at risk from debris...
How many eruptions have there been in the Cascades during the last 4,000 years?
Eruptions in the Cascades have occurred at an average rate of one to two per century during the last 4,000 years. Future eruptions are certain.Learn more:Eruptions in the Cascade Range During the Past 4,000 YearsUSGS Cascades Volcano Observatory
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