by:Abang Njoh

The Three Types Of Volcanoes

Composite Volcanoes

A composite volcanco is built by hard layers of hard lava. They are taller then the sheild and cinder cone volcanoes. Composite volcanoes also shoot out ashes and flows out lava. Composite volcanoes can erupt quietly or vioolently. Both sides of the volcano are exactly alike.It is approximately one hundred to three thousand five hundred meters tall. Composite volcanoes are one of the most common types found.For example people living in langleg can see this type of volcano know as Mount Baker located in the south. There are three types of volcanoes Composite,Shiled.and Cinder Cone.

Shield Volcanoes

Shield Volcanoes are made of thousand of thin basalt lava flows. Because the lava has a relatively low viscosity ( low resistance to flow ) the lava can traval far from the vent, the location where the lava reaches the surface. The resulting volcanic landfrom has a broad base and very gentle slopes, much like a warrior's inverted shield.

Cinder Cone

Cinder Cones are mounds of basaltic scoria that are fromed by streaming gases, which carry lava into the atmosphere to from lava fountain's. The lava blobes commonly soildify during flight through the air before landing on the ground. If gas pressure drops, the final stage of building a Cinder Cone may be a lava flow that breaks though the base of the cone. Cinder Cones can occur alone but commonly occur in groups or fields.

aa lava

Aa lava flows form when basalt lava flows down the side of a volcano and is cooler than pahoehoe lava flows. The lava flow has a rough or rubbly surface with sharp edges. The Hawaiians first used this term to describe these type of lava flows on their islands. The rocks in the lava flow where unstable and had sharp edges that could easily cut a foot when walked on with bare feet.

Ropy pahoehoe


Ropy pahoehoe

Ropy pahoehoe is the most common surface texture of pahoehoe flows. The numerous folds and wrinkles ("ropes") that are characteristic of ropy pahoehoe form when the thin, partially solidified crust of a flow is slowed or halted (for example, if the crust encounters an obstruction or slower-moving crust). Because lava beneath the crust continues to move forward, it tends to drag the crust along. The crust then behaves like an accordian that is squeezed together--the crust is flexible enough to develop wrinkles or a series of small ridges and troughs as it is compressed and driven forward.