Volcano Flashcards
Italian word vulcano, which means
burning mountain
Latin word Vulcan
Roman God of fire
It is where magma passes through from the magma chamber to reach earth’s surface
Main Vent
This is a large reservoir that stores molten rocks (magma) prior year to eruption
Magma chamber
It is a bowl-shaped depression produced by volcanic activity and explosion
Crater
Is a vent hill or mountain that erupts releasing molten rocks rock fragments and gaseous materials onto earth’s surface
Volcano
This is the stream of molten rock flowing out of the crater
Lava flow
This is an alternative smaller outlet where magma escapes to reach earth’s surface
Secondary vent
This is formed when lava and ashes escape from smaller vents it is also known as a parasitic cones
Secondary cone
It is formed when thick volcanic ashes are discharged into the atmosphere caused by violent explosion or eruption of the volcano
Ash cloud
It is a mixture of rocks minerals and glass particles expelled during a volcanic eruption
Ash
Are formed from pyroclastic fragments and volcanic ashes that form and solidify around the main vent to form a cone which can be either circular or oval
Cinder cone volcano
Also known as stratovolcanoes are typically symmetrical cones that are steep and may rise as high as 2 400 meters from the ground
Composite volcanoes
Are formed from non-acidic basaltic lava flows of high viscosity producing broad sloping sides and shield like structures
Shield volcanoes
This volcanoes have erupted during historical times within the last 600 years in addition they have erupted at least once in the past 10,000 years
Active
This volcanoes are active but not erupting however they are expected to erupt anytime soon
Dormant
This volcanoes have not had any eruption in the past 10,000 years and are expected not to erupt anymore in the future. This volcanoes have been intensively weathered and eroded
Extinct
Types of volcano according to shape
Cinder cone volcanoe, composite volcanoes or stratovolcanoes and shield volcanoes
Types of volcanoes according to eruptive history
Active, dormant and extinct
3 Phases of a volcanic eruption
Preparation phase, eruption phase and ending phase
The magma chamber is being filled with magma an increase in seismic activity and steam or smoke coming from the volcano can be observed
Preparation phase
The pressure will start to build up inside the magma chamber and the energy starts to increase for eruption
Eruption phase
The magma flows up from the volcano and cools to became
Lava
After the eruption the magma chamber is now empty
Ending phase
Types of volcanic eruptions
Effusive eruptions, explosive eruptions, hawaiian type, strombolian type, volcanian type, plinian eruption, phreatic eruption and phreatomagmatic eruption
In general volcanic eruptions may be classified as
Effusive and explosive eruptions
It involve the outpouring of basaltic magma that is relatively low in viscosity and low in gas content
Effusive eruption
It Involves magma of high viscosity and high gas content
Explosive eruptions
Fluid basaltic lava is thrown into the air creating a lava fountain or lava flows
Hawaiian type
There is a burst of glowing lava due to the bursting of gas bubbles at the vents of the volcano this eruption creates eruptive products such as scoria ( hardened chunks of bubbly lava) and lava bombs
Strombolian type
The eruption is short explosive and violent. this happens when the pressure is enough to blow off the overlaying layer of solidified lava over the entrapped gases in magma
Volcanian type
The most violent among all types of volcanic eruptions it releases huge amounts of gases and ashes at great speed
Plinian eruption
Is a steam-driven explosion. when magma heats the surface or groundwater the water begins to boil or directly produce steam that causes the explosion.
Phreatic eruption
Involve the eruption of magma that reacts to external water the interaction between magma and water results in explosion that releases steam and pyroclastic fragments into earth’s surface
phreatomagmatic eruption
Refers to magma that has been expelled onto earth’s surface
Lava
Refers to the pyroclastic materials and rock fragments that are being expelled during volcanic eruptions
Tephra
A mass of molten rock that is larger than 64 mm in diameter large dense cyroclastic rocks that cool in the air before they reach the ground
Volcanic bombs
A mixture of powder sized rocks minerals and gas particles
Volcanic ash
Means little stones in latin pyroclastic materials that are range from 4 to 32 mm in diameter
Lapilli
Pyroclastic materials that are already solid when ejected during eruptions more angular because they are not shape and cool in the air just like volcanic bombs
Volcanic blocks
Good effects
Geothermal energy, nutrients in the soil, global cooling
Bad effects
Breathing problems, damage to crops and propertied, lahar
