The difference between Magma and Lava has been a thing of debate among a number of people, while some say they are the same, others argue that they are in fact very distinct. Both Magma and Lava are residue from a volcanic eruption. What then is a volcano?
What Is A Volcano?
A Volcano is a rupture in the crust of a planetary-mass object (in this case, EARTH) that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates are diverging or converging, and most are found underwater. Volcanoes can also form where there is stretching and thinning of the crust’s plates, such as in the East African Rift and the Wells Gray-Clear water volcanic field and Rio Grande rift in North America. Large eruptions can affect atmospheric temperature as ash and droplets of sulfuric acid obscure the Sun and cool the Earth’s troposphere. Historically, large volcanic eruptions have been followed by volcanic winters which have caused catastrophic famines. Asides planet Earth, other planets also have Volcanoes. A good example is Mercury, it has pyroclastic deposits formed by explosive volcanic activities.
The Difference Between Magma And Lava.
From the explanation of what a Volcano is, you would notice that Magma and Lava were mentioned. The difference between Magma and Lava is not much, they are both molten rock. Magma is Molten rock stored under the earth’s surface While Lava is Molten rock that has reached the earth’s surface through Volcanic eruptions.
Magma
Magma is the molten or partially molten rock from under the earth’s surface. It cools to form igneous rocks. Magma forms due to high temperature and pressure. It usually consists of silicate liquid, although carbonate and sulfide melt occur as well. Rocks which forms due to solidification of magma beneath Earth’s surface are intrusive igneous. Magma is generated within Earth’s mantle, the thick layer between the crust and outer core. On its way up toward the surface, magma can melt adjacent rock and forms metamorphic rocks. Silicon dioxide (SiO2) is mainly found in magma. Along with its small proportions of aluminum oxide, iron, magnesium, calcium, sodium, potassium, titanium, manganese, phosphorus, and water is also there.
Types of Magma
There are three basic types of magma,
1) Basaltic originating in the lower crust/upper mantle. It contains molten rock enriched in iron and magnesium and depleted in silica.
2) Rhyolitic originates in the oceanic crust. It erupts explosively, forming a frothy solidified magma called pumice along with ash.
3) Andesitic originates is the continental crust. It has fine-grained rocks that form when magma erupts and crystallized quickly on the surface.
Lava
Lava is actually the molten magma (molten rocks) released by a volcano during a Volcanic eruption. Lava reaches the surface through a volcano vent. When first exuded from a volcanic vent, the hot lava is at temperatures ranging from 700 °C to 1,200 °C. When lava solidifies it is called “lava flow,” whereas the material that still contains molten rock is called an “active lava flow.” The major component of almost all types of lava has silicate minerals, mostly feldspars, olivine, pyroxenes, amphiboles, micas, and quartz.
Types Of Lava
Basically, there are four (4) types of Lava:
1) Pahoehoe lava flows are smooth, gently undulating, or broadly hummocky surfaces.
2) Aa lava flow resembles a very rough surface, covered with clinkers.
3) Block lava flow resembles as in having tops consisting largely of loose rubble, but the fragments are more regular in shape.
4) Pillow lava flow is a form of volcanic rock that results when low-viscosity magma such as basalt erupts underwater.