Where is the greatest volume of magma produced?
The greatest volume of magma is produced along the oceanic ridge system in association with seafloor spreading.
What magma is the most abundant type of magma erupted on Earth?
geo quiz 6
| Question | Answer |
|---|---|
| ________ is a major dissolved volatile constituent in both magmas and volcanic gases. | Water |
| Volcanic bombs originate ________. | as erupted magma blobs that partly congeal before falling to the ground |
| ________ magma is the most abundant type erupted at oceanic spreading centers. | Basaltic |
What type of magma is the most abundant at oceanic spreading centers?
Basalt is the most common magma erupted along oceanic rift systems.
Why does newly formed magma at divergent plate boundaries rise to the surface?
This reduction in overlying pressure, or decompression, enables the mantle rock to melt and form magma. Decompression melting often occurs at divergent boundaries, where tectonic plates separate. The rifting movement causes the buoyant magma below to rise and fill the space of lower pressure.
Which tectonic setting does magma formed?
As summarized in Chapter 3, magma is formed at three main plate-tectonic settings: divergent boundaries (decompression melting), convergent boundaries (flux melting), and mantle plumes (decompression melting). The mantle and crustal processes that take place in areas of volcanism are illustrated in Figure 4.4.
Which plate boundary produces the most magma?
Most volcanoes are associated with convergent plate boundaries (at subduction zones), and there is also a great deal of volcanic activity at divergent boundaries and areas of continental rifting.
Which type of magma would you expect to produce the most explosive volcanic eruption?
Explosive eruptions are favored by high gas content & high viscosity magmas (andesitic to rhyolitic magmas). The explosive bursting of bubbles fragments the magma into clots of liquid that cool as they fall through the air.
Where are most volcanoes located?
the Pacific Ocean Sixty percent of all active volcanoes occur at the boundaries between tectonic plates. Most volcanoes are found along a belt, called the “Ring of Fire” that encircles the Pacific Ocean. Some volcanoes, like those that form the Hawaiian Islands, occur in the interior of plates at areas called “hot spots.”
Which of the following magma types has the highest gas content?
The amount of gas in a magma is also related to the chemical composition of the magma. Rhyolitic magmas usually have higher gas contents than basaltic magmas.
What are the tectonic settings where magma is formed?
As summarized in Chapter 3, magma is formed at three main plate-tectonic settings: divergent boundaries (decompression melting), convergent boundaries (flux melting), and mantle plumes (decompression melting).
How does magma form at divergent boundaries?
At divergent boundaries magma forms because of decompression melting. Decompression melting also takes place within a mantle plume.
Which plate boundary produces magma?
When two plates are moving away from each other, we call this a divergent plate boundary. Along these boundaries, magma rises from deep within the Earth and erupts to form new crust on the lithosphere. Most divergent plate boundaries are underwater and form submarine mountain ranges called oceanic spreading ridges.
How is magma formed in continental rift zones?
These landscapes are a result of continental rifting, or places where the continental crust is extending and thinning. As the crust thins, the hot, buoyant upper mantle (the asthenosphere) rises. Eventually the asthenosphere upwells so close to the surface that magma that erupts onto the surface.
In which tectonic setting is magma formed?
As summarized in Chapter 3, magma is formed at three main plate-tectonic settings: divergent boundaries (decompression melting), convergent boundaries (flux melting), and mantle plumes (decompression melting). The mantle and crustal processes that take place in areas of volcanism are illustrated in Figure 4.4.
How is magma generated at convergent plate boundaries?
At convergent boundaries magma is formed where water from a subducting plate acts as a flux to lower the melting temperature of the adjacent mantle rock. At divergent boundaries magma forms because of decompression melting. Decompression melting also takes place within a mantle plume.
What type of plate boundary do most volcanoes occur along?
Sometimes, the plates collide with one another or move apart. Volcanoes are most common in these geologically active boundaries. The two types of plate boundaries that are most likely to produce volcanic activity are divergent plate boundaries and convergent plate boundaries.
What do plate tectonics have to do with the type and or explosiveness of the volcanoes?
Most of the world's volcanoes are found around the edges of tectonic plates, both on land and in the oceans. On land, volcanoes form when one tectonic plate moves under another. Usually a thin, heavy oceanic plate subducts, or moves under, a thicker continental plate.
Where are volcanoes located on plate boundaries?
Destructive, or convergent, plate boundaries are where the tectonic plates are moving towards each other. Volcanoes form here in two settings where either oceanic plate descends below another oceanic plate or an oceanic plate descends below a continental plate.
Which type of volcano the magma content is high?
Viscosity of Magmas
| Summary Table | ||
|---|---|---|
| Magma Type | Solidified Rock | Gas Content |
| Basaltic | Basalt | Low |
| Andesitic | Andesite | Intermediate |
| Rhyolitic | Rhyolite | High |
Sep 14, 2015
What type of magma has the highest temperature?
Basaltic magma is high in iron, magnesium, and calcium but low in potassium and sodium. It ranges in temperature from about 1000oC to 1200oC (1832oF to 2192oF). Andesitic magma has moderate amounts of these minerals, with a temperature range from about 800oC to 1000oC (1472oF to 1832oF).
What type of plate tectonic setting is responsible for the vast majority of the Earth’s eruptions?
Volcanoes are most common in these geologically active boundaries. The two types of plate boundaries that are most likely to produce volcanic activity are divergent plate boundaries and convergent plate boundaries.
How is magma generated at divergent boundaries?
At divergent boundaries magma forms because of decompression melting. Decompression melting also takes place within a mantle plume.
Where do volcanoes occur the most?
the Pacific Ocean Sixty percent of all active volcanoes occur at the boundaries between tectonic plates. Most volcanoes are found along a belt, called the “Ring of Fire” that encircles the Pacific Ocean. Some volcanoes, like those that form the Hawaiian Islands, occur in the interior of plates at areas called “hot spots.”
In which of the following tectonic settings do most of the Earth’s active volcanoes occur?
Volcanoes are most common in these geologically active boundaries. The two types of plate boundaries that are most likely to produce volcanic activity are divergent plate boundaries and convergent plate boundaries.
How is magma generated along convergent plate boundaries?
Magma is produced at convergent boundaries when water from a subducting plate acts as a flux lowering the melting temperature of the nearby mantle rock. Magma forms at divergent boundaries due to decompression melting. Inside a mantle plume decompression melting also occurs.
What type of plate boundary has the most volcanoes?
Volcanoes are most common in these geologically active boundaries. The two types of plate boundaries that are most likely to produce volcanic activity are divergent plate boundaries and convergent plate boundaries.
Where are most volcanoes formed?
the Pacific Ocean Sixty percent of all active volcanoes occur at the boundaries between tectonic plates. Most volcanoes are found along a belt, called the “Ring of Fire” that encircles the Pacific Ocean. Some volcanoes, like those that form the Hawaiian Islands, occur in the interior of plates at areas called “hot spots.”
Which of the following elements has the highest amount in the magma?
Oxygen, the most abundant element in magma, comprises a little less than half the total, followed by silicon at just over one-quarter. The remaining elements make up the other one-quarter. Magmas derived from crustal material are dominated by oxygen, silicon, aluminum, sodium, and potassium.
How is magma formed at the subduction zone?
As a tectonic plate slides into the mantle, the hotter layer beneath Earth's crust, the heating releases fluids trapped in the plate. These fluids, such as seawater and carbon dioxide, rise into the upper plate and can partially melt the overlying crust, forming magma.
Which tectonic plate boundary has the most volcanoes?
The majority of volcanic arcs can be found in the Ring of Fire, a horseshoe-shaped string of about 425 volcanoes that edges the Pacific Ocean.