viscous
A'a can occur at composite volcanoes, but block lava flows, which are far more viscous, are more common.
Galeras is a Strato/Composite volcano because of it's gently sloping sides.
A composite volcano, also known as a stratovolcano, typically has a thick and viscous lava flow due to its high silica content. This type of volcano tends to erupt explosively, producing a mixture of lava, ash, and volcanic rocks.
Lava high in silica (granitic lava) tends to be thick and viscous, so the volcano is likely to be composite rather than shield.
Viscous lava is very sticky and thick and is more felsic (ie it contains more silica) than non-viscous lava. This type of lava makes for a very explosive volcano, because it's so sticky that it sticks to itself and can't exit the volcano until it explodes violently. Non-viscous lava is more runny and is more mafic (has more iron, less silica). Volcanoes with non-viscous lava are less explosive because the lava just runs out slowly and no pressure builds. The Hawaiian islands are formed from volcanoes with non-viscous lava.
A'a can occur at composite volcanoes, but block lava flows, which are far more viscous, are more common.
Galeras is a Strato/Composite volcano because of it's gently sloping sides.
A composite volcano, also known as a stratovolcano, typically has a thick and viscous lava flow due to its high silica content. This type of volcano tends to erupt explosively, producing a mixture of lava, ash, and volcanic rocks.
Lava high in silica (granitic lava) tends to be thick and viscous, so the volcano is likely to be composite rather than shield.
Viscous lava is very sticky and thick and is more felsic (ie it contains more silica) than non-viscous lava. This type of lava makes for a very explosive volcano, because it's so sticky that it sticks to itself and can't exit the volcano until it explodes violently. Non-viscous lava is more runny and is more mafic (has more iron, less silica). Volcanoes with non-viscous lava are less explosive because the lava just runs out slowly and no pressure builds. The Hawaiian islands are formed from volcanoes with non-viscous lava.
Composite volcanoes are highly variable in what they erupt. Most often, eruptions will release clouds of ash, pumice, and rock fragments. In some cases they fountain or extrude lava.
A volcano that is fairly symmetrical and has both layers of lava and pyroclastic deposits is a stratovolcano, also known as a composite volcano. These volcanoes are characterized by their steep-sided conical shape and alternating layers of lava flows, volcanic ash, and pyroclastic debris. They are capable of explosive eruptions due to their viscous magma composition.
No. The term compostie volcano describes a kind of volcano, not a kind of volcanic eruption. The Soufrière Hills on Montserrat is indeed a composite volcano, however, whether it is erupting or not.
No. If a'a is present it will usually be only a minor portion of the volcano. A'a and pahoehoe are low-viscosity lavas with a low silica content They are usually found in shield volcanoes. A composite volcano is usually primarily composed of composed of tepha (loose ash, pumice, and lapilli), tuff (welded ash), and block lava (very viscous lava flows). This material is usually more viscous with more silica than what goes into a'a and pahoehoe.
The temperature varies widely, ranging from high temperatures of 1,800 to 2,200 degrees Fahrenheit for basaltic lava to as low as 1200 degrees of Rhyolitic lava. Ol Doinyo Lengai, a composite volcano in Africa, erupts unique carbonatite lava with temperatures between 950 and 1100 degrees.
Composite volcanoes, also known as stratovolcanoes, typically have more viscous lava compared to shield volcanoes. This lava is comprised of a mixture of gas-rich, acidic magma and silica, which makes it thicker and more prone to explosive eruptions.
Viscous lava ( such as in the caribbean