stratovolcanoes.
Subduction-zone stratovolcanoes, such as Mount St. Helens, Mount Etna and Mount Pinatubo, typically erupt with explosive force: the magma is too stiff to allow easy escape of volcanic gases.
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.
What type of volcano is Mount Pompeii?
complex stratovolcano
The volcano is classed as a complex stratovolcano because its eruptions typically involve explosive eruptions as well as pyroclastic flows. A pyroclastic flow is a high-density mix of hot lava blocks, pumice, ash and volcanic gas, according to the U.S. Geological Survey.
Is Mt St Helens a cinder cone volcano?
The result is a cone that has a gentler slope than a cinder cone but is steeper than a shield volcano. Washington state’s Mt. St. Helens is an example of a composite cone volcano.
Is Mt St Helens Plinian?
The May 18, 1980 eruption of Mount St. Helens was Plinian. The 1912 eruption of Novarupta in Katmai National Park and Preserve also was Plinian. It produced an eruption column that rose to a height of more than 100,000 feet (30 km) and spread over most of southern Alaska and the Yukon Territory.
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.
Is Mount Vesuvius a shield or composite volcano?
composite stratovolcano
Vesuvius is a composite stratovolcano, made up of pyroclastic flows, lava flows, and debris from lahars that accumulated to form the volcanic cone.
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.
Was the Pompeii volcano a supervolcano?
A “supervolcano” might sound like something out of a sci-fi fantasy film, but one supervolcano lies hidden near Pompeii, Italy, where thousands were killed in 79 A.D., and it could potentially kill millions.
What are 2 examples of a cinder cone volcano?
Mauna Kea, a volcano on the American island of Hawaii, and Mount Etna, a volcano on the Italian island of Sicily, are both covered with hundreds of cinder cones.
What is a cinder cone type volcano?
Cinder cones are the simplest type of volcano. They are built from particles and blobs of congealed lava ejected from a single vent. As the gas-charged lava is blown violently into the air, it breaks into small fragments that solidify and fall as cinders around the vent to form a circular or oval cone.
What volcano has a cinder cone?
Wizard Island in Crater Lake National Park is a cinder cone that formed after the caldera-forming eruption. Craters of the Moon National Monument contains 25 cinder cones. Cinder Cone in Lassen Volcanic National Park erupted about 1650 CE.
Was Pompeii a Plinian eruption?
The 79 AD eruption of Mount Vesuvius in Pompeii, Italy. It was the prototypical Plinian eruption.
Was St Helens a Plinian eruption?
A wave of decreasing pressure down the volcanic conduit to the subsurface magma reservoir, which then began to rise, form bubbles (degas), and erupt explosively, driving a 9-hour long Plinian eruption. Steam-blast eruption from summit crater of Mount St. Helens.
What type of volcano is Plinian?
characteristics. The Plinian type is an intensely violent kind of volcanic eruption exemplified by the outburst of Mount Vesuvius in Italy in 79 ce that killed the famous Roman scholar Pliny the Elder and was described in an eyewitness account by his nephew, the historian Pliny the…
What type of volcano is Mount St. Helens and what caused the explosion quizlet?
What type of volcano is Mount St. Helens and what caused the explosion? It is a strato-volcano that exploded when trapped gasses were quickly released. The most violent volcanic eruptions occur when gasses cannot easily escape from the magma.
What type of fault is Mt St Helens?
The 2004–2008 eruption of Mount St. Helens produced seven dacite spines mantled by cataclastic fault rocks, comprising an outer fault core and an inner damage zone.
Is Mt St Helens a hot spot volcano?
It is responsible for the island of St. Helena and the St. Helena Seamount chain. It is one of the oldest known hotspots on Earth, which began to produce basaltic lava about 145 million years ago.
What type of volcano is Mount St. Helens cinder cone shield or composite?
stratovolcano
Geologists call Mount St. Helens a composite volcano (or stratovolcano), a term for steepsided, 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.
What is a shield and composite volcano?
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 are 3 differences between shield and composite volcanoes?
Composite volcanoes have a low magma supply rate, resulting in infrequent eruptions. Shield volcanoes feature basaltic lava. This type of lava is hot, fluid and low in gas content. Shield volcanoes are characterized by a high magma supply rate, lending itself to frequent eruptions.