Mount Shasta is inside the western end of the North American continental plate, west of it under the Pacific Ocean the Pacific oceanic plate is subducting under the North American continental plate. Deep under the North American continental plate friction with the descending Pacific oceanic plate, melts rock in the contact zone which feeds the magma supply of Mount Shasta. As the magma surfaces trapped ocean water flashes to steam producing explosive lava.
mount shasta is a stratovolcano
Mount Shasta is a composite volcano, (also called a stratovolcano).
Mount Shasta is a stratovolcano, which is a type of volcano characterized by a steep-sided cone shape and explosive eruptions due to volatile-rich magma.
Mount Shasta primarily produces andesitic lava, which is a type of intermediate lava characterized by a medium viscosity and silica content. This type of lava typically results in eruptions that produce a combination of lava flows and explosive eruptions.
Mount Shasta typically has andesitic magma, which is a type of intermediate magma that is common in subduction zone environments. This type of magma is rich in silica and forms from the partial melting of both oceanic and continental crust.
Shasta is a dormant volcano in Northern CA. In the area there is also hot springs and mud pots. The last eruption was in the early 1920's.
The Antarctic Plate.
mount etna is on asubduction plate boundary under the african and eurasian plate
Mount Merapi is near a convergent plate boundary where the Indo-Australian Plate subducts beneath the Eurasian Plate.
Divergent plate boundary.
subduction
Mount Adatara is associated with a convergent plate boundary, as are all of Japan's volcanoes.