The viscosity of the magma, however, is also an important factor in determining whether an eruption will be explosive or nonexplosive. A low-viscosity magma, like basalt, will allow
the escaping gases to migrate rapidly through the magma and escape
to the surface.
How does magma viscosity influence the explosive potential?
A more viscous (thick) magma will produce a more violent eruption This is controlled in part by
the concentration of silica in the magma
. A magma with low silica (<45%) will be runny and so the eruption will not be explosive. A magma with high silica (>60%) will be quite viscous and so the eruption will be violent.
How does the viscosity of lava in a volcano determine its volcanic type?
Magmas with a higher SiO2 content have a higher viscosity. Ultimately, the viscosity of a magma
will determine the shape a volcano takes over continued eruptions
. A magma’s silica content will not only control the rock type that forms, it also controls the relative viscosity of the magma.
How does the viscosity of lava affect the shape of a volcano?
Differences in a magma’s viscosity will determine the shape a volcano takes. High-silica (basalt) magma has a much lower viscosity. It flows much easier and over longer distances. As low-silica magma cools, it hardens to rock, adding a new thin layer of rock to the volcano.
What type of volcano has low viscosity?
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.
Which component of magma is the highest and lowest in value?
Felsic magma
has the highest silica content of all magma types, between 65-70%. As a result, felsic magma also has the highest gas content and viscosity, and lowest mean temperatures, between 650
o
and 800
o
Celsius (1202
o
and 1472
o
Fahrenheit).
What type of volcano has the highest viscosity?
Lavas and pyroclastics are usually andesitic to rhyolitic in composition. Due to the higher viscosity of magmas erupted from these volcanoes, they are usually more explosive than shield volcanoes
Which lava has the highest viscosity?
The magma that has the highest viscosity is
rhyolitic magma
.
Which type of volcano is the most common?
Cinder cone volcanoes (also called scoria cones)
are the most common type of volcano, according to San Diego State University, and are the symmetrical cone-shaped volcanoes we typically think of.
What type of magma has the lowest viscosity?
Thus,
basaltic magmas
tend to be fairly fluid (low viscosity), but their viscosity is still 10,000 to 100,0000 times more viscous than water.
What are the 7 types of volcano?
The result is the classic cone shape of composite volcanoes. A cross section of a composite volcano reveals alternating layers of rock and ash: (1) magma chamber, (2) bedrock, (3) pipe, (4) ash layers, (5) lava layers, (6) lava flow,
(7) vent, (8) lava, (9) ash cloud
.
What is the 22 active volcanoes in the Philippines?
| Item No. Name of Volcano Province | 19 Musuan (Calayo) Bukidnon in Mindanao | 20 Parker South Cotobato/General Santos/ North Cotabato/Sarangani Provinces in Mindanao | 21 Pinatubo Boundaries of Pampanga, Tarlac and Zambales in Luzon | 22 Ragang Lanao del Sur and Cotobato in Mindanao |
|---|
What are the three main components of magma?
Magma and lava contain three components:
melt, solids, and volatiles
. The melt is made of ions from minerals that have liquefied. The solids are made of crystallized minerals floating in the liquid melt.
What 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.
What are the three major types of magma?
It also contains small amounts of dissolved gases such as water vapor, carbon dioxide, and sulfur. The high temperatures and pressure under Earth’s crust keep magma in its fluid state. There are three basic types of magma:
basaltic, andesitic, and rhyolitic
, each of which has a different mineral composition.
Does lava have high viscosity?
Even though lava is 100,000 times more viscous than water, it can still flow great distances. When lava has low viscosity, it can flow very easily over long distances. … But most importantly,
highly viscous lava
is associated with explosive eruptions
