Geology in general. Plate tectonics drives the system by which the Pacific Plate subducts below the North American Plate and this evolves molten rock, which eventually appears as a Volcano.
Mount St. Helens was formed along a subduction zone, where the Juan de Fuca Plate plate dives under (subducts) the North American plate.
Geography
The cause of Mt. St. Helens' volcanism is due to the subduction melting of the Pacific Plate as it subducts under the North American Plate, located along a convergent plate boundary or fault. No, Mount Saint Helens is not on a hot spot, nor is it on a fault. Mount Saint Helens is part island arc volcanic chain (the Casade Mountaind) due to the subduction of the Pacific Plate under the North American Craton. NOTE: The Farallon Plate is no longer here; it ceased to exist with the end of the Laramide Orogeny some 30 million years ago. The remnants of the Farallon Plate are the Juan de Fuca Plate of British Columbia and northwestern Washington State, and the Cocos Plate of southwestern Mexico. Neither of these microplates has any effect on Mount Saint Helens, which is in southwestern Washington. I found this answer on answers.yahoo.com
On a continental plate. Mount Saint Helens is on a convergent plate boundary. The Juan de Fuca plate is being pushed under the North American Plate.
Mount St. Helens was formed as a result of the Juan de Fuca plate's subduction under the North American plate.
Mount Saint Helens is a product of the Juan de Fuca Plate subducting under the North American Plate.
Under Mount St. Helens.
The study of rocks belongs under the geology branch of science.
Mount St. Helens was formed along a subduction zone, where the Juan de Fuca Plate plate dives under (subducts) the North American plate.
Mount St. Helens is located near a subduction zone. Here, the oceanic Juan de Fuca PLate is colliding with and sliding under the continental North American Plate.
gas
This is not a branch of agriculture but a branch of medial science.
The cause of Mt. St. Helens' volcanism is due to the subduction melting of the Pacific Plate as it subducts under the North American Plate, located along a convergent plate boundary or fault. No, Mount Saint Helens is not on a hot spot, nor is it on a fault. Mount Saint Helens is part island arc volcanic chain (the Casade Mountaind) due to the subduction of the Pacific Plate under the North American Craton. NOTE: The Farallon Plate is no longer here; it ceased to exist with the end of the Laramide Orogeny some 30 million years ago. The remnants of the Farallon Plate are the Juan de Fuca Plate of British Columbia and northwestern Washington State, and the Cocos Plate of southwestern Mexico. Neither of these microplates has any effect on Mount Saint Helens, which is in southwestern Washington. I found this answer on answers.yahoo.com
Geography
Earth science
Rheumatology.
It falls under Marine Science since ichthyology is the study of fish.