Geologists call Mount St. Helens a composite volcano (or stratovolcano), a term for steep-sided, often symmetrical cones constructed of alternating layers of lava flows, ash, and other volcanic debris. Composite volcanoes tend to erupt explosively and pose considerable danger to nearby life and property.
Is Mt. St. Helens a shield volcano?
Mount St. Helens is an example of a composite or stratovolcano. These are explosive volcanoes that are generally steep-sided, symmetrical cones built up by the accumulation of debris from previous eruptions and consist of alternating layers of lava flows, volcanic ash and cinder.
What type of volcano is Mt. St. Helens?
stratovolcano
Mount St. Helens is a stratovolcano, a steep-sided volcano located in the Pacific Northwest region of the United States in the state of Washington.
Is Mt. St. Helens a shield cone?
Mount St. Helens is a composite volcano. These are often called ‘stratovolcanoes.
Is composite volcano a shield?
What is the main difference between a shield volcano and a composite volcano? The main difference between the two is that a shield volcano is composed of basaltic lava while a composite volcano is composed of andesitic magma.
What mountain is a shield volcano?
Examples of shield volcanoes are Kilauea and Mauna Loa (and their Hawaiian friends), Fernandina (and its Galápagos friends), Karthala, Erta Ale, Tolbachik, Masaya, and many others.
What are shield volcanoes?
Where a volcano produces low viscosity, runny lava, it spreads far from the source and forms a volcano with gentle slopes: a shield volcano. Most shield volcanoes are formed from fluid, basaltic lava flows. Mauna Kea and Mauna Loa are shield volcanoes.
What is St Helens classed as?
St Helens ( pronunciation (help·info)) is a town in Merseyside, England, with a population of 102,629. It is the administrative centre of the Metropolitan Borough of St Helens, which had a population of 176,843 at the 2001 Census.
What type of volcano is Mount St. Helens and what caused the explosion?
Mount St. Helens, a stratovolcano or composite volcano located in Washington State, USA (46.2º latitude north, 122.2º longitude west,) erupted violently on the Sunday morning of May 18th 1980 at precisely 8:32.
What type of volcano is Mt. St. Helens quizlet?
Mount St. Helens is an active stratovolcano located in Skamania County, Washington, in the Pacific Northwest region of the United States.
What is a composite cone volcano?
Composite cones are large volcanoes (many thousands of feet or meters tall) generally composed of lava flows, pyroclastic deposits, and mudflow (lahar) deposits, as well as lava domes. Composite volcanoes are active over long periods (tens to hundreds of thousands of years), and erupt periodically.
What type of plate is Mount St. Helens?
In Mount St. Helens’ case, an oceanic plate called Juan de Fuca slips under the North American plate, creating the Cascadia subduction zone. A continental arc brews adjacent to the subduction zone, where high pressures and hot temperatures force molten rock to the surface. The result is a chain of volcanoes.
Is Mount St. Helens constructive or destructive?
Destructive
Destructive; The lateral blast erupted lava from Mount St. Helens. This further destroyed the mountain and the surrounding forest. Both; Ash and pumice from the plume injured trees and buried plants and crops.
Which is a good example of a shield volcano?
Examples of shield volcanoes are Kilauea and Mauna Loa (and their Hawaiian friends), Fernandina (and its Galápagos friends), Karthala, Erta Ale, Tolbachik, Masaya, and many others.
What type of volcanoes are composite?
Composite volcanoes are tall, symetrically shaped, with steep sides, sometimes rising 10,000 feet high. They are built of alternating layers of lava flows, volcanic ash, and cinders. Famous composite volcanoes include Mount Fuji in Japan, Mount Shasta and Mount Lassen in California, Mount St.
How do you know if a volcano is composite?
Composite volcanoes have the following characteristics:
- Acidic lava, which is very viscous (sticky).
- Steep sides as the lava doesn’t flow very far before it solidifies.
- Alternate layers of ash and lava. For this reason, they’re also known as stratovolcanoes .
- Violent eruptions.
- Longer periods between eruptions.
Is Mount Everest a shield volcano?
The giant shield volcanoes on Mars are much larger than any feature on Earth. Shown here is a graphic comparison of Olympus Mons to the two largest mountains on Earth. (Note: Mount Everest is not a volcano.)
What is the largest shield volcano?
From sea floor to peak, Mauna Loa, on Hawaii’s Big Island, is the tallest shield volcano on Earth.
Where are shield volcanoes?
Shield volcanoes are found worldwide. They can form over hotspots (points where magma from below the surface wells up), such as the Hawaiian–Emperor seamount chain and the Galápagos Islands, or over more conventional rift zones, such as the Icelandic shields and the shield volcanoes of East Africa.
Is the Yellowstone volcano A shield volcano?
No, Yellowstone does not have a shield volcano. Instead, the supervolcano beneath Yellowstone is classified as a caldera at the moment, a volcano with a collapsed magma chamber.
What is the difference between a shield and a composite volcano?
Composite volcanoes have an upwardly concaved slope and a small summit crater. They are constructed of alternating layers of hardened lava and pyroclastic flows. Shield volcanoes have an upwardly convex slope, averaging less than 15 degrees and flatter on top.