Science 3rd Quarter lesson

Philippine seaplate and Eurasia plate

Philippines is situated between two tectonic plates called

Vulcano “Burning mountain”

Word volcano come from the Italian word ____ which means ____

Volcano

Is a vent hill or mountain that erupts releasing molten rocks, rock fragment & gaseous materials onto earths

Magma rise to the surface of the earth

Volcanoes forms when

Cone shaped volcano

Lava builds up & form from the

Outside

Lava

Inside

Magma

1.Ashcloud 2.Ash 3.Lava flow 4.Crater

5.Main vent 6.Secondary vent

7.Magma chamber 8.secondary cone

Label the parts of the volcano 1-8

Main vent

It is where magma passes through from the magma chamber to reach earth's

Magma chamber

Large reservoir that stores molten rock(magma)

Crater

Bowl-shaped depression

Lava flow

Stream of molten rock flowy out of the crater

Secondary vent

Alternative smaller outlet

Secondary core

Formed when lava & ashes escape from smaller vents: parasitic cones

Ash cloud

Thick volcanoes are discharged into the atmosphere

Ash

Mixture or rocks & minerals & glass particles

Cindercone

Formed from pyroclastic fragments & volcanic ashes

Composite

-Stratovolcanoes are typically symmetrical cones

-Usually dormant

Shield

-Formed from non-acidic basaltic lava

-Not very explosive & among the largest volcanoes into the world

Active

Have erupted during historical times within the last 600 years they have erupted once in the past 10,000 years

Dormant

Active but not erupting however they are expected to erupt anytime soon

Extinct

Have not have yet any eruption I threw past 10,00p years & are expected not to erupt anymore in the future

Main vent, Magma chamber, Crater, Lava flow, Secondary vent, Secondary cone, Ash cloud, Ash

The anatomy of an volcano

Cinder cone, Composite, Shield

Types of volcanoes according to their shape

Active, Dormant, Extinct

The three types of volcanoes

Preparation phase

Magma chamber is being filled with magma. Increase insemic activity.

Steam or smoke being out from the volcano can be observed

Eruption phase

Pressure will start to build up inside the magma chamber and the energy starts to increase for eruption

Ending phase

After the eruption, the chamber is now empty which may trigger the walls of the conduit to weaken and to collapse into a crater or a caldera

Effusive eruption

Involving the outpouring the basaltic magma

Explosive eruption

Involve magma of high viscosity and high gas content

Hawaiian type

Fluid basaltic lava is thrown into the air creating a lava fountain or lava flows

Strombolian type

There is a burst of glowing lava due to the bursting of gas bubbles at the vents to the volcano

Vulcanian type

Eruption is short, explosive and violent

Plinian type

Most violent among all types of volcanic eruptions

Phreatic eruption

A stream-driven explosion. When magma heats the surface or ground water, the water begins to boil or directly produce steam that causes the explosion

Phreatomagmatic eruption

It involves the eruption of magma that reacts to external water the interaction between magma and water results in explosion releases steam and pyroclastic fragments into earth's surface

Preparation phase, Eruption phase, Ending phase

Phases of an eruption

Effusive eruptions, Explosive eruptions, Hawaiian type, Strombolian type, Vulcanian type, Plinian type, Phreatic eruption, Phreatomagmatic eruption

Types of volcanic eruptions

Effusive eruptions and Explosive eruptions

General types of volcanic eruptions

Hawaiian type, Strombolian type, Vulcanian type, Plinian type, Phreatic eruption, Phreatomagmatic eruption

Specific types of volcanic eruptions

Lava

Refers to magma (molten rock) that has been expelled oo n earth's surface

Tephra

Pyroclastic materials and rock fragments that are being expelled during volcanic eruptions

Gases

Volcanic gases are also being released during eruptions

Volcanic bombs, Volcanic gases, Lapilli, Volcanic rocks

Different types of pyroclastic materials(TEPHRA)

Volcanic bombs

-Large dense pyroclastic rocks that cool in the air before they reach the ground

-Common found in older shield volcanoes

-Name according to shape: ribbon or cylindrical, spherical and spindle to name a few

-larger than 64mm (2.5 inches) in diameter

Volcanic ash

-A mixture of powder-sized (2mm or smaller) rocks minerals and gas particles

Lapilli

-Means “little stones” in Latin

-lapillus (singular)

-4 to 32 (0.16 to 1.26 inches) in a diameter

Volcanic rocks

-Are already solid when ejected during eruptions

-More angular because they are not shaped and cooled in air just like volcanic bombs

-Larger than 64mm in diameter

Good effects and Bad effects

Effects of volcanic eruptions

Good effects

-The high levels of heat and activity underneath earth's surface can provide an alternative

-Source of energy (geometrical energy)

-Fertile and good for agriculture

-Volcanic eruptions may cause long term effects on climate and may cause global cooling

Bad effects

-Volcanic ashes and gases ejected into the air may cause breathing problems when inhaled

-Volcanic eruptions can cause damage to crops and properties and may endanger the lives of humans and animals near the area

-If ash and mud mix with water a fast moving mudflow, also known as lahar may destroy properties and lives