(Q3) SCIENCE - Types of Volcanoes and Eruptions

Volcanic Eruption

A phenomenon where lava and ashes are released by a volcano.

Explosive eruption

Large amounts of gas and a high viscosity (sticky) magma will form an _______

Effusive eruption

Small amounts of gas and (or) low viscosity (runny) magma will form....

Explosive

-catastrophic
-have severe environmental and climatic effects
-erupt 10-1000km^3 of magma
-sends ash clouds >25 km into the stratosphere
-occur where cooler, more viscous magmas (such as andesite) reach the surface

Ash fall, pyroclastic flow, pyroclastic surge

Explosive eruptions produce?

Mt. Pinatubo Eruption

Which explosive eruption occurred on 1991

Mayon Volcano eruption

Which explosive eruption occurred on 1984

Taal Volcano Eruption

Which explosive eruption occurred on 2020

Effusive eruption

-Characterized by outpourings of lava on to the ground
-There is little or no gas. The lava is thin and fluid so that it flows over the ground like a river.

Mauna Loa and Kilauea

Effusive Hawaiian volcanoes

Philippine Institute of Volcanology and Seismology

Meaning of PHIVOLCS

Phreatic

Explosion driven by steam produced when groundwater is heated due to an underlying heat source.

Vulcanian

Eruption resulting from the release of large quantities of magmatic gas forming voluminous cauliflower clouds.

Strombolian

Weak to violent eruption characterized by lava fountains and outbursts of molten lava

Pelean

Eruption that occurs when gas-rich, pasty lava accumulates to form a dome on the volcano, the dome bursts with explosive violence.

Phreatomagmatic

Eruption that results from an ejection of magmatic gases and steam.

Plinian

Violent explosion characterized by voluminous ejections of pumice and by ash flows.

Preparation Phase

The magma chamber is being filled with magma. An increase in seismic activity and steam or smoke coming out from a volcano can be observed.

Eruption Phase

Pressure will start to build up inside the magma chamber and the energy starts to increase for eruption. The magma flows out of the volcano and cools to become Lava

Ending Phase

After the eruption, the magma chambers now empty, which may trigger the walls of the conduit to weaken and to collapse into a Crater or a Caldera.