LAVA
by:Abang Njoh
Ropy Pahoehoe
When lava is underground in its molten state it is called magma. As it reaches the ground, and air, it is called lava. Once lava begins to harden it can turn into a variety of shapes and colors. The color of lava depends on the temperature of the flow as well as what impurities are in the liquid rock. Colors can include black, red, gray, brown and tan, metallic sliver, pink, and green. Some lava has peridot (olivine) in it which are beautiful olive colored semi-precious crystals that, once they weather and break apart, are responsible for our famous green sand beaches
AA lava
Aa lava is a rough rubbly crust of a lava flow. It is a major lava flow type. Other important subaerial lava flow types are pahoehoe and blocky lava. Aa and pahoehoe are terms that were brought to geological terminology from the Hawaiian language. Aa is according to native Hawaiians a sound one makes if he or she tries to walk barefoot on such a lava flow. There are different spelling versions, ‘a’a, a’a, a-aa are used as well as simple aa. Pahoehoe means in Hawaiian “on which one can walk
AA lava
A'a' lava forms when the viscosity of the lava (e.g. because of high gas bubbles content and relatively low temperatures) and/or the strain rate of the flow (related mainly to eruption rate and steepness of the ground) are high. When these factors change, the same original lava can sometimes produce the other end-member known as pahoehoe lava, which has a smooth, often twisted surface. In addition, transitional types of lava between both a'a and pahoehoe lava can be found.