Volcanoes Case

Volcanoes

Volcanoes are openings in the Earth's crust. Volcanoes are geological like earthquakes and landslides. There are many volcanoes along the plate boundaries where the oceanic plates sink beneath other plates or where the plates pull apart. But volcanoes can also form on hot spots which are not near the plate boundaries, for example, Hawaii is a hot spot which is far from the plate boundaries. There are also many types of volcanoes in the world, but actually they are all based on three main types of volcanoes. Volcanic eruptions can cause tremendous destructions and bring advantages for people.

There are many ways for volcanoes to form. Volcanoes form near plate boundaries because plate boundaries crash against each other. As one of the plates sinks, when crashing against another plate, the plate heats and begins to melt when it reaches a subduction zone and then becomes magma. Next, the magma reaches the surface, creating a volcano after cooling down, and as plates pull apart, the magma inside the mantle will rise to the surface, forming volcanoes. Volcanoes can also form over a hot spot far from the plate boundaries, where volcanoes often form above the thin column that rises from the mantle because the heat from the column can partly melts some of the rock in the tectonic plate above it. For example, the Hawaiian Islands are formed as the Pacific plate moves slowly over the hot spot.

Volcanoes have many shapes and sizes. Most of them can be grouped into three main types based on their patterns of eruption. The first type of volcano is called a shield volcano. A shield volcano is built up of many thin layers of lava that has erupted. It's broad and flat. The famous Mauna Loa volcano is an example of a shield volcano. The second type of volcano is a composite volcano. It's cone-shaped and is built up by many layers of rock fragments and lava. It's steep at the top and becomes flatter and flatter as it reaches the bottom. The third type of volcano is the cinder cone. A cinder cone has steep sides and is formed by the eruption of cinders and other rock fragments that pile up around a crater.

The effects of volcanic eruptions are huge. There are two types of effects, immediate effects and long-term effects. Immediate effects are effects that happen depending on how much and what type of materials the volcano erupts. For example, lava flows and pyroclastic flows that knocks down and burns everything in its path, heavy volcanic ashes that cause roofs of buildings to collapse, suffocate living things, and landslides that might cause tsunamis if the place where the volcano erupts is next to the ocean. Long-term effects are far more destructive than immediate effects because they can make damage to the place where the volcano erupted for a long period of time. Mudflows and acid rain are two cases of long-term effects after a volcano erupts. Although volcanic eruptions