Geological process where hot molten rock from underneath the earth reaches the surface through an opening in the ground.
Volcanism
There are three main ways magma can rise to form volcanoes:
Convergent Boundaries
Divergent Boundaries
Hotspots and Mantle Plumes
Are areas where the mantle rises towards the surface, originating deep within the mantle.
Mantle plumes
The surface manifestation of a mantle plume.
Hotspot
As plates move above a hotspot, the increase in temperature induces partial melting and generates hotspot volcanism.
Smaller parasitic volcanoes that feed on the same magma chamber as the main volcano through secondary vents; usually emit volcanic gas called fumarole.
Secondary cone
Pyroclastic materials
Bombs
Blocks
Ashes
Others
Bowl-shaped depression located at the summit of the volcano that serves as the opening of the volcano to the Earth’s surface.
Crater
The reservoir of molten material in the Earth's crust, replenished with magma from a deeper reservoir in the mantle.
Magma chamber
The pathway for magma to come to the surface.
Main vent
Types of Volcano:
Shield Volcanoes
Cinder Cones
Composite Volcanoes or Stratovolcanoes
Are large dome-shaped volcanoes with broad gentle slopes and large craters.
Shield volcanoes
The largest volcano on Earth, Mauna Loa in Hawaii, is a shield volcano.
Shield volcanoes get their broad form due to the accumulation of layers of runny, fast-moving.
Basaltic lava flows
Are steeper and have smaller craters than shield volcanoes. They are usually made up of loose pyroclastic material called scoria.
Cinder cones
A dark-colored igneous rock that is highly vesicular (has lots of vesicles or cavities) and made from extruded basaltic magma.
Scoria
Cinder cone eruptions are moderately explosive, with lava coming from inside the vent or at the volcano’s base. Cinder cones usually have a short lifespan and are the most common type of volcanoes.
Is probably the most recognizable form of the volcano, with its symmetrical steep-sided cone-shaped morphology.
Composite volcano or stratovolcanoes
Composite volcano alternating layers of viscous volcanic ash, and cinders are responsible for their shape.
Andesitic lava flows
When a particularly explosive eruption occurs, the stratovolcano could collapse, forming a large depression called?
Caldera
Our very own Taal Volcano is an excellent example of a caldera filled in by water.
Rapidly-moving current of hot gases and tephra (volcanic material) driven by gravity.
Pyroclastic flow
Pyroclastic flow are also known as a French term meaning “glowing cloud" called?
Nuée ardentes
Occur when volcanic material becomes saturated with water, possibly from rainfall or melted ice, and rapidly descends steep volcano slopes.
Lahar flows
There are three main types of lava flows:
aa flows (pronounced as “ah-ah”) and is characterized by spiky and rough surfaces.
pahoehoe flows (pronounced as “pa-hoy-hoy”) and is described as having a “ropey” appearance with smooth surfaces.
occurs when lava is extruded along the oceanic ridge, producing smooth rounded shapes called pillow lavas.