My Own Kind of Space

                                                 VOLCANO

Volcanoes are vents or openings that expel molten rocks or magma from Earth's Interior. The interior of Earth has very high temperature and pressure that can cause rocks to melt as well as dissolve other substances. 

How is a volcano formed?

Volcanoes are formed by the plates colliding and one of them goes under the other, the heat coming from the mantle will cause these rocks to melt. Melted rocks may be added with differenrt substances such as water and silicon. The fluid that forms from this process is called magma. Because magma is very hot and the pressure in this layer is high, magma tends to melt other rocks above it as it tries to break into the surface. When this happens, magma released into the surface is now called lava. The lava eventually solidifies into different types of rocks. Upon constant eruption over time, layers of lava will pile up, which will give rise to a volcano.

This mechanism is evident in the Pacific Ring of Fire, due to the collision of the Pacific plate with several surrounding plates. The Philippines is one country with several volcanoes because the pacific plate collides with the philippine plate. And also the Pacific Ring of Fire is the region of the Earth where most volcanoes have formed. (just like the illustration above).

Parts Of Volcano

A volcano has many parts. On the outside, you have the base (bottom), the flank (the sloped portion), and the summit (the top). On the in the inside, the first part is called magma reservoir, located beneath the surface of the crust. The second part, the conduit of the volcano, is where the magma reservoir will flow. This conduit often leads to the volcano crater located at the summit, where magma is released. In some  instances, magma can also find different paths to reach the surface. The paths are called dikes, which lead to the vent located at the flank. Magma ejected from these vents often forms parasitic cones. The formation of different types of volcanoes is caused by a variety of factors. The size of the volcano depends on the frequency of the eruption and how much magma is ejected into the surface.

   There are two types of volcanoes according to their activity or how often they erupt.

ACTIVE VOLCANOES - are those that have erupted over the last 10,000 years and still continue to erupt. The Philippines has 21 active volcanoes, including the famous Mt. Mayon, which is probably the most active.

INACTIVE VOLCANOES - are those do not erupt as of today but have a potential to do so. Mt. Pinatubo in Pampanga, for example, was considered an inactive volcano until 1991, when it erupted. It's eruption is now recorded as the second largest eruption in the 20th century. Mt. Makiling, Mt. Mariveles, and Mt. Apo are examples of inactive volcano.

Scientist who are experts in studying volcanoes are called volcanologist. The agency that monitors the volcanic activities in the Philippines is the Philippine Institute of Volcanology and Seismology (PHIVOLCS). They use the following devices that will help them collect any data on volcanoes. 

•Tiltmeter - measure any slight vertical changes on the inclination on Earth's surface. Such changes may indicate an incoming volcaning eruption or an interesting volcanic acticity.

•Spectrometer - is used to determine the volcanic gases using the light emission in the volcanic plumes.

•Thermal imagers - are special cameras that can take pictures of heat emitted by volcanoes.

•Radar mapping instruments - carried by aircraft or satelittes help volcanologist get three-dimensional maps of Earth's surface. Such mapping may help predict the path of lava flow.

        TYPES OF VOLCANOES

Composite volcanoes are constructed from multiple eruptions, sometimes recurring over hundreds of thousands of years, sometimes over a few hundred. Andesite magma, the most common but not the only magma type forming composite cones, produces lava more brittle thanbasaltic lava because of its higher viscosity. Although andesitic composite cones are constructed dominantly of fragmental debris, some of the magma intrudes the cones as dike or sills. In this way, multiple intrusive events build a structural framework that knits together the voluminous accumulation of volcanic rubble, which can stand higher than cones composed solely of fragmental material. Composite cones can grow to such heights that their slopes become unstable and susceptible to collapse from the pull of gravity.

Shield volcanoes are the largest volcanoes in terms of volume, and in diameter can be tens to hundreds of kilometers across, or more. A shield volcano gets its name from its appearance. It is large in terms of area, but much flatter than the other two types of volcanoes. Viewed from above, it looks like a warrior's shield: slightly raised in the center, with long, gently-sloping sides.

Cinder cones are simple volcanoes which have a bowl-shaped crater at the summit and only grow to about a thousand feet, the size of a hill. They usually are created of eruptions from a single opening, unlike a strato-volcano or shield volcano which can erupt from many different openings.

They are usually made of piles of lava, not ash. During the eruption, blobs ("cinders") of lava, blown into the air, break into small fragments that fall around the opening to the volcano. 

                                                          VOLCANIC ERUPTION

An eruption occurs when magma, along with several materials, is ejected into the volcano's vent. Genrally, some of the effects observed during an eruption include earthquakes, release of ash clouds that results in the darkening of the sky, lahar (mudflows created when lava mixes wirth water) and flash floods, acid rain, and tsunamis, especially if the volcano is located near the coastline. 

How a volcano erupts? 
However, may depend on -composition of the volcano, especially the materials that were present in the magma.

Do you still remember what magma is?
 It is the molten rock material inside Earth's crust Magma can be classified based on the dissolve materials in it, its temperature, and its viscosity or the resistence to flow.

REFLECTIONS:

A. Which concept on the topic did you find easy to understand? What made them interesting?

-  I find it interesting because i can barely imagine what they look like and I find the types of volcanoes are easy to understand due to its fully explanations and definations.

B. What were your personal discoveries or learnings while studying the topic?

- The Types of Volcanoes

C. Which area or concept do you like to expound more?

- The Volcanic Eruption