http://www.depedbukidnon.net.ph/resources/grade-10-lms-and-tgs/es of volcanic eruption grade 9

2. There are three different metatypes of
eruptions. The most well-observed are
magmatic eruptions, which involve the
decompression of gas within magma that
propels it forward. Phreatomagmatic eruptions
are another type of volcanic eruption, driven
by the compression of gas within magma, the
direct opposite of the process powering
magmatic activity. The last eruptive metatype
is the phreatic eruption, which is driven by the
superheating of steam via contact with
magma; these eruptive types often exhibit no
magmatic release, instead causing the
granulation of existing rock.

3. In a Hawaiian eruption, fluid basaltic lava is
thrown into the air in jets from a vent or line of
vents (a fissure) at the summit or on the flank
of a volcano. The jets can last for hours or
even days, a phenomenon known as fire
fountaining. The spatter created by bits of hot
lava falling out of the fountain can melt
together and form lava flows, or build hills
called spatter cones. Lava flows may also
come from vents at the same time as
fountaining occurs, or during periods where
fountaining has paused. Because these flows
are very fluid, they can travel miles from their
source before they cool and harden.

5. Strombolian eruptions are often associated
with small lava lakes, which can build up in
the conduits of volcanoes. They are one of
the least violent of the explosive eruptions,
although they can still be very dangerous if
bombs or lava flows reach inhabited areas.
Strombolian eruptions are named for the
volcano that makes up the Italian island of
Stromboli, which has several erupting
summit vents. These eruptions are
particularly spectacular at night, when the
lava glows brightly.

6. Strombolian Eruption

7.  A Vulcanian eruption is a short, violent,
relatively small explosion of viscous magma
(usually andesite, dacite, or rhyolite). This type
of eruption results from the fragmentation and
explosion of a plug of lava in a volcanic
conduit, or from the rupture of a lava dome
(viscous lava that piles up over a vent).
Vulcanian eruptions create powerful explosions
in which material can travel faster than 350
meters per second (800 mph) and rise several
kilometers into the air. They produce tephra,
ash clouds, and pyroclastic density currents
(clouds of hot ash, gas and rock that flow
almost like fluids).

8. Vulcanian Eruption

9.  Peléan eruptions (or nuée ardente) are a type of volcanic eruption,
named after the volcano Mount Pelée in Martinique, the site of a
massive Peléan eruption in 1902 that is one of the worst natural disasters
in history. In Peléan eruptions, a large amount of gas, dust, ash, and
lava fragments are blown out the volcano's central crater, driven by
the collapse of rhyolite, dacite, and andesite lava dome that often
create large eruptive columns. An early sign of a coming eruption is the
growth of a so-called Peléan or lava spine, a bulge in the volcano's
summit preempting its total collapse.The material collapses upon itself,
forming a fast-moving pyroclastic flow (known as a block-and-ash flow)
that moves down the side of the mountain at tremendous speeds,
often over 150 km (93 mi) per hour. These massive landslides make
Peléan eruptions one of the most dangerous in the world, capable of
tearing through populated areas and causing massive loss of life. The
1902 eruption of Mount Pelée caused tremendous destruction, killing
more than 30,000 people and competely destroying the town of St.
Pierre, the worst volcanic event in the 20th century.
 Peléan eruptions are characterized most prominently by the
incandescent pyroclastic flows that they drive. The mechanics of a
Peléan eruption are very similar to that of a Vulcanian eruption, except
that in Peléan eruptions the volcano's structure is able to withstand
more pressure, hence the eruption occurs as one large explosion rather
than several smaller ones.

10. Pyroclastic flows at Mayon
Volcano,Philippines, 1984.
The lava spine that
developed after the 1902
eruption of Mount Pelée
Mount Lamington following the
devastating 1951 eruption

11. Plinian eruptions are extremely destructive,
and can even obliterate the entire top of a
mountain, as occurred at Mount St. Helens
in 1980. They can produce falls of ash,
scoria and lava bombs miles from the
volcano, and pyroclastic density currents
that raze forests, strip soil from bedrock and
obliterate anything in their paths. These
eruptions are often climactic, and a
volcano with a magma chamber emptied
by a large Plinian eruption may
subsequently enter a period of inactivity.

12. April 1990 eruptive
column fromRedoubt
Volcano, as viewed to
the west from the Kenai
Peninsula.
Plinian eruption

14. Surtseyan eruption (or hydrovolcanic) is a
type of volcanic eruption caused by
shallow-water interactions between water
and lava, named so after its most famous
example, the eruption and formation of
the island of Surtsey off the coast of
Iceland in 1963.

15. Surtseyan
Eruption
Surtsey, erupting 13
days after breaching
the water. A tuff
ringsurrounds the vent

16. Submarine eruptions are a type of volcanic
eruption that occurs underwater. An
estimated 75% of the total volcanic
eruptive volume is generated by
submarine eruptions near mid ocean
ridges.

17. Subglacial eruptions are a type of volcanic
eruption characterized by interactions
between lava and ice, often under a
glacier.

18. Phreatic eruptions (or steam-blast
eruptions) are a type of eruption driven by
the expansion of steam. When cold ground
or surface water come into contact with
hot rock or magma it superheats and
explodes, fracturing the surrounding
rock[47] and thrusting out a mixture of
steam, water, ash, volcanic bombs, and
volcanic blocks.[48] The distinguishing
feature of phreatic explosions is that they
only blast out fragments of pre-existing solid
rock from the volcanic conduit; no new
magma is erupted

19.  The crystal and gas content and temperature of a
magma help determine a volcano's eruption
style.
 Crystals in magma make it more viscous, so
magma with a high crystal content is more likely
to explode than flow.
 Gases create explosions if they cannot easily
escape from viscous magma, but they can also
be released without explosions (or with only minor
ones) from fluid magma.
 High-temperature magmas usually erupt
effusively, while low-temperature magmas cannot
flow easily and are more likely to erupt explosively.