Philippines volcano alert raised after ash and lava spill out
The Philippines ordered the forced evacuation of people from two more municipalities near a restive volcano on Monday as the chief volcanologist warned of a possible hazardous eruption “within weeks or even within days”.
The lava flow has reached some areas around three kilometers away from the volcano.
is the phenomenon of eruption of molten rock (magma) onto the surface of the Earth or a solid-surface planet or moon, where lava, pyroclastic and volcanic gases erupt through a break in the surface called a vent.
Types of Volcano
Interior: The magma that does not erupt outside the surface of earth
Exterior: The magma that erupts outside the earth surface
A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface.
Earth’s volcanoes occur because its crust is broken into 17 major, rigid tectonic plates that float on a hotter, softer layer in its mantle. Therefore, on Earth, volcanoes are generally found where tectonic plates are diverging or converging, and most are found underwater. For example, a mid-oceanic ridge, such as the Mid-Atlantic Ridge, has volcanoes caused by divergent tectonic plates whereas the Pacific Ring of Fire has volcanoes caused by convergent tectonic plates.
Volcanoes can also form where there is stretching and thinning of the crust’s plates, e.g., in the East African Rift and the Wells Gray-Clearwater volcanic field and Rio Grande Rift in North America. This type of volcanism falls under the umbrella of “plate hypothesis” volcanism. Volcanism away from plate boundaries has also been explained as mantle plumes. These so-called “hotspots”, for example Hawaii, are postulated to arise from upwelling diapirs with magma from the core–mantle boundary, 3,000 km deep in the Earth. Volcanoes are usually not created where two tectonic plates slide past one another.
Erupting volcanoes can pose many hazards, not only in the immediate vicinity of the eruption. One such hazard is that volcanic ash can be a threat to aircraft, in particular those with jet engines where ash particles can be melted by the high operating temperature; the melted particles then adhere to the turbine blades and alter their shape, disrupting the operation of the turbine.
Large eruptions can affect temperature as ash and droplets of sulfuric acid obscure the sun and cool the Earth’s lower atmosphere (or troposphere); however, they also absorb heat radiated from the Earth, thereby warming the upper atmosphere (or stratosphere).