Last updated August 21, 2025

Overview of North American Volcanoes: From Mount Saint Helens to Popocatépetl

Historical Volcanic Eruptions in North America

Mount St. Helens, 1980

The eruption of Mount St. Helens in Washington State is one of the most devastating in U.S. history. On May 18, 1980, a lateral blast destroyed the volcano's summit, releasing an ash column over 24 km high. The eruption killed 57 people, destroyed hundreds of square kilometers of forest, and caused devastating pyroclastic flows and lahars. This event marked a turning point in volcanic monitoring in the United States.

Mount Pelée, 1902

Although located in the French Antilles, Mount Pelée is often associated with North America due to its historical impact. Its eruption on May 8, 1902 wiped the city of Saint-Pierre, Martinique, off the map, killing nearly 30,000 people in minutes. This Peléan-type eruption is famous for its pyroclastic flow that destroyed everything in its path.

Lassen Peak, 1914-1917

Lassen Peak in California erupted between 1914 and 1917, producing lava flows, steam explosions, and lahars. Although less deadly than others, this series of eruptions marked the region and led to the creation of Lassen Volcanic National Park, a major site for the study of volcanoes in the United States.

Mount Mazama (Crater Lake), around 5700 B.C.

The cataclysmic eruption of Mount Mazama in Oregon, about 7,700 years ago, was one of the most powerful in North American history. It caused the volcano to collapse, forming the caldera that now holds Crater Lake, one of the deepest in the United States. This eruption had a regional climatic impact and left ash deposits visible as far as Canada.

Novarupta, 1912

The eruption of Novarupta in Alaska in 1912 was the most powerful of the 20th century. It emitted a colossal volume of ash and magma, forming the Valley of Ten Thousand Smokes. Although located in a sparsely populated area, this eruption had global climatic repercussions and was studied to understand volcanic super-eruptions.

Mount Redoubt, 1989-1990 and 2009

Mount Redoubt in Alaska is one of the most active volcanoes in the region. Its eruptions, particularly in 1989-1990 and 2009, disrupted air traffic and threatened local communities. In 1989, an eruption caused a commercial airplane to crash due to volcanic ash, highlighting the dangers of ash clouds to aviation.

Dynamics and Danger of North American Volcanoes

Volcanoes of the Pacific Ring of Fire

The Pacific Ring of Fire runs along the west coast of the United States and Canada. The volcanoes in this area, such as Mount Saint Helens, Mount Rainier, and Mount Baker, are mostly explosive gray volcanoes. Their eruptions can be sudden and violent, with pyroclastic flows and ash clouds threatening nearby cities and infrastructure.

Mexican Volcanoes

Mexico has a high density of stratovolcanoes, including Popocatépetl, Colima, and Paricutin. The high viscosity of the magma and its silica richness favor explosive eruptions with ash plumes that can affect millions of inhabitants.

Basaltic Volcanoes of the Northwest and Hawaii

Some volcanoes in the American Northwest, as well as those in Hawaii like Mauna Loa and Mauna Kea, produce effusive red volcanoes. The fluid basaltic lava spreads over vast areas and generates rapid but less explosive flows, creating iconic landscapes.

Secondary Risks and Human Impacts

North American volcanoes can cause earthquakes, lahars, and ashfall that disrupt agriculture, air transport, and health. The 1980 eruption of Mount Saint Helens illustrates the destructive power of an explosive gray volcano.

Table of Main North American Volcanoes

Main Active and Dormant Volcanoes of North America
Volcano	Color	Location	Altitude (m)	Type	Last Eruption	Comment	Status
Mount Saint Helens	Gray	Washington, USA	2549	Stratovolcano	2008	Major eruption in 1980, continuous monitoring.	Active
Mount Rainier	Gray	Washington, USA	4392	Stratovolcano	~1890	Potentially explosive volcano, glaciers, and lahars.	Active
Mount Baker	Gray	Washington, USA	3285	Stratovolcano	1880	Historical minor eruptions, active monitoring.	Active
Mount Hood	Gray	Oregon, USA	3426	Stratovolcano	1865	Potentially explosive, lahar risk for valleys.	Active
Popocatépetl	Gray	Mexico, Puebla	5426	Stratovolcano	2025	Frequent eruptions, threats to Mexico City and Puebla.	Active
Colima	Gray	Mexico, Colima	3850	Stratovolcano	2023	Very active volcano, recurrent pyroclastic flows.	Active
Paricutin	Red	Mexico, Michoacán	2800	Shield volcano	1952–1954	Historical eruption, volcano formed in just 9 years.	Active
Mauna Loa	Red	Hawaii, USA	4169	Shield volcano	2023	World's largest volcano, frequent effusive eruptions.	Active
Mount Shasta	Gray	California, USA	4322	Stratovolcano	1786	Dormant volcano, glaciers, and lahar risks.	Dormant
Mauna Kea	Red	Hawaii, USA	4207	Shield volcano	~4000 years ago	Dormant volcano, summit covered with snow in winter.	Dormant
Tres Hermanos Volcano	Gray	Mexico, Oaxaca	2100	Stratovolcano	~1900	Dormant but with potential for future eruption.	Dormant
Mount Garibaldi	Gray	British Columbia, Canada	2678	Stratovolcano	~1850	Dormant volcano, glaciers, and ancient lava flows.	Dormant
Mount Edziza	Red	British Columbia, Canada	2786	Shield volcano	~1250	Dormant, extensive volcanic field with recent basalts.	Dormant

Red and Gray Volcanoes: Two Eruptive Dynamics

Red volcanoes correspond to effusive volcanoes with fluid basaltic lava, such as Paricutin or Mauna Loa. Their activity is spectacular but less explosive, with extensive lava flows.

Gray volcanoes correspond to explosive volcanoes, rich in silica and gas, such as Mount Saint Helens, Mount Rainier, or Popocatépetl. Eruptions are violent and produce pyroclastic flows and ash plumes.

Comparison Between Red and Gray Volcanoes
Characteristic	Red Volcanoes	Gray Volcanoes
Magma Type	Basaltic, low in silica (< 52% SiO₂)	Andesitic to rhyolitic, rich in silica (> 55% SiO₂)
Viscosity	Low \(\eta \sim 10^{1-3}\, \text{Pa·s}\)	High \(\eta \sim 10^{5-9}\, \text{Pa·s}\)
Eruptive Style	Effusive: fluid lava flows	Explosive: ash plumes, pyroclastic flows
Visible Manifestations	Incandescent red lava, extensive lava fields	Gray ash, steep stratovolcanoes
Main Risks	Slow but destructive lava flows	Pyroclastic flows, sudden explosions, ashfall
North American Examples	Paricutin (Mexico), Mauna Loa (Hawaii)	Mount Saint Helens (USA), Popocatépetl (Mexico)