Stratovolcano facts for kids
.jpg)
A stratovolcano is a tall, conical volcano built up by many layers (strata) of hardened lava, tephra, pumice, and volcanic ash. Unlike shield volcanoes, stratovolcanoes have a steep slope and explosive eruptions every now and then.
Stratovolcanoes are common along plate tectonic boundaries where oceanic crust is drawn under continental crust.
Contents
Hazards
In addition to potentially affecting the climate, volcanic clouds from explosive eruptions pose a serious hazard to aviation.
Lava flows from stratovolcanoes are generally not a significant threat to humans or animals because the highly viscous lava moves slowly enough for everyone to flee away from the path of flow. The lava flows are more of a threat to property. However, not all stratovolcanoes erupt viscous and sticky lava. Nyiragongo, near Lake Kivu in central Africa, is very dangerous because its magma has an unusually low silica content, making it quite fluid.
Volcanic bombs are extrusive igneous rocks ranging from the size of books to small cars, that are explosively ejected from stratovolcanoes during their climactic eruptive phases. These "bombs" can travel over 20 km (12 mi) away from the volcano, and present a risk to buildings and living beings while shooting at very high speeds (hundreds of kilometers/miles per hour) through the air. Most bombs do not themselves explode on impact, but rather carry enough force to have destructive effects as if they exploded.
Lahars (from a Javanese term for volcanic mudflows) are mixtures of volcanic debris and water. Lahars usually come from two sources: rainfall or the melting of snow and ice by hot volcanic elements, such as lava. Depending on the proportion and temperature of water to volcanic material, lahars can range from thick, gooey flows that have the consistency of wet concrete to fast-flowing, soupy floods. As lahars flood down the steep sides of stratovolcanoes, they have the strength and speed to flatten or drown everything in their paths.
List of stratovolcanoes in North America
Canada
Northern British Columbia
Southern British Columbia
- Mount Boucherie
- Mount Cayley massif See also Mount Cayley volcanic field.
- Mount Garibaldi
- Mount Meager massif About 2,400 years ago, it produced the most recent major catastrophic eruption in Canada.
- Mount Price
- The Black Tusk
- Coquihalla Mountain
Mexico
- Popocatépetl, just 70 km (43 mi) southeast of Mexico City
- Colima, in the Free and Sovereign State of Jalisco; designated as a Decade Volcano
- Nevado de Toluca
- Pico de Orizaba
United States
Alaska
- Mount Bobrof
- Mount Akutan
- Augustine Volcano, Cook Inlet
- Mount Bona
- Mount Churchill
- Mount Cleveland
- Frosty Peak Volcano
- Mount Katmai, Katmai National Park and Preserve
- Korovin Volcano
- Mount Mageik
- Mount Pavlof
- Mount Redoubt
- Mount Shishaldin
- Mount Vsevidof
Washington
- Mount Baker
- Glacier Peak
- Mount Rainier; designated as a Decade Volcano
- Mount St. Helens. On May 18, 1980, it produced a large eruption preceded by a massive landslide which decimated the volcano's height.
- Mount Adams
- Mount Pugh
Oregon
- Mount Hood
- Mount Jefferson
- Black Butte
- The Three Sisters
- Broken Top
- Mount Bachelor
- Mount Scott (Klamath County, Oregon)
- Mount McLoughlin
California
Arizona
New Mexico
Related pages
Images for kids
-
Mount Vesuvius, near the city of Naples in Italy, violently erupted in 79 AD. The last eruption of this stratovolcano occurred in March 1944.
-
Paluweh eruption as seen from space
-
Northwest side of Mount Rainier seen from Tacoma
See also
In Spanish: Estratovolcán para niños
