Volcanic Eruption | Types Of Eruption: Explosive And Effusive | Theory Explained.
Summary
TLDRThis video explains volcanic activity, detailing the formation of volcanoes, types of eruptions, and their effects. Volcanoes form along tectonic plate boundaries and can be explosive, effusive, or mixed in nature. Explosive eruptions, like those from Krakatoa and Mount St. Helens, release pyroclastic flows, while effusive eruptions, such as those from Mauna Loa, produce liquid lava. Mixed eruptions combine both elements. The video also covers post-volcanic phenomena like fumaroles, geysers, and mud volcanoes, and highlights how major eruptions can impact the global atmosphere and climate.
Takeaways
- π Volcanic activity involves magma being ejected to the Earth's surface through volcanoes, which form at tectonic plate boundaries.
- πΊοΈ Volcanoes are not randomly distributed but often form long chains at the edges of tectonic plates.
- β°οΈ Volcanic activity plays a key role in the formation of mountains as magma reaches the Earth's surface and solidifies.
- π₯ Magma beneath the Earth's surface is called lava once it flows to the surface and helps form volcanoes.
- π₯ Explosive eruptions, typical of cinder cone volcanoes, involve steam, gases, and pyroclastic flow, causing widespread destruction.
- πͺοΈ Pyroclastic flows are fast-moving and extremely dangerous, as seen in eruptions like Krakatoa and Mount Saint Helens.
- π Effusive eruptions, found in shield volcanoes like Mauna Kea and Mauna Loa, are characterized by lava flows without explosions.
- π Stratovolcanoes exhibit mixed eruptions with both explosive events and lava flows, creating layered volcanic cones.
- π§ͺ Post-volcanic activity includes the release of gases such as sulfur and carbon dioxide through vents like fumaroles and moffettas.
- π Large volcanic eruptions can have a global impact, affecting the Earth's atmosphere, climate, and ecosystems, as demonstrated by Krakatoa and Mount Tambora.
Q & A
What is volcanic activity?
-Volcanic activity refers to the process of magma being ejected to the surface of the Earth from beneath its crust.
How do volcanoes form?
-Volcanoes form in long chains, which are essentially the boundaries of tectonic plates.
What role does volcanic activity play in mountain formation?
-Volcanic activity contributes to mountain formation by ejecting magma, which solidifies and builds up over time.
What is the difference between magma and lava?
-Magma is red-hot molten rock beneath the Earth's surface, while lava is magma that flows to the surface.
What are the three types of volcanic eruptions?
-The three types of volcanic eruptions are explosive, effusive, and mixed.
Which type of volcano is associated with explosive eruptions?
-Explosive eruptions are characteristic of cinder cone volcanoes, which release steam, gases, and pyroclastic flows.
What are examples of volcanoes that experience effusive eruptions?
-Mauna Kea and Mauna Loa on the Hawaiian Islands are examples of volcanoes that experience effusive eruptions.
What is a stratovolcano and how does it erupt?
-Stratovolcanoes are characterized by mixed eruptions, involving both explosive activity and lava flows, forming alternating layers of tephra and solidified lava.
What is a fumarole and what gases does it emit?
-A fumarole is an opening in the Earth's crust that emits steam and various gases, including sulfurous gases in the case of a sulfatara.
What global impacts can powerful volcanic eruptions have?
-Powerful volcanic eruptions can have significant impacts on the Earth's atmosphere, climate, and wildlife by dispersing large amounts of tephra and gases.
Outlines
π The Formation of Volcanoes and Their Importance
Volcanic activity involves magma being pushed to the Earth's surface through its crust. Volcanoes donβt form randomly but align along tectonic plate boundaries. These formations play a crucial role in mountain building. Magma, a red-hot molten rock beneath the surface, becomes lava when it reaches the surface, forming a volcano. Volcanoes are classified based on their eruptions: explosive, effusive, and mixed.
π₯ Explosive Eruptions and Their Impact
Explosive eruptions, seen in cinder cone volcanoes, involve violent steam and gas explosions, creating a tall eruption column and pyroclastic flows. These devastating eruptions can cover vast areas with ash. The pyroclastic flow, traveling at high speed, is highly destructive. Well-known examples of such eruptions are Krakatoa, Mount PelΓ©e, and Mount St. Helens.
π Effusive Eruptions: Calm Lava Flows
Effusive eruptions, typical of shield volcanoes, occur without explosive activity or pyroclastic flows. Instead, liquid lava rises and solidifies, creating a volcanic cone. These eruptions are relatively calm and often occur in volcanoes like Mauna Kea and Mauna Loa in Hawaii.
π Mixed Eruptions and Stratovolcanoes
Mixed eruptions, characteristic of stratovolcanoes, involve both explosions and lava flows. The resulting volcanic cones have alternating layers of tephra (volcanic fragments) and solidified lava. Famous stratovolcanoes include Stromboli, Mount Etna, and Cotopaxi.
π¨ Post-Volcanic Activity: Fumaroles, Geysers, and More
After volcanic eruptions, post-volcanic activity includes the release of steam and gases from vents called fumaroles. Sulfataras emit sulfurous gases, while mofettas discharge carbon dioxide, either dry or wet. Geysers periodically shoot hot water, heated by magma, into the air. Mud volcanoes release gas through liquid mud bubbles.
π The Scale of Devastating Eruptions
The most destructive eruptions scatter vast amounts of tephra. The 1883 Krakatoa eruption dispersed 18 cubic kilometers of tephra, while the 1815 Mount Tambora eruption released 80 cubic kilometers, one of historyβs most powerful eruptions. Such events have far-reaching global impacts on the atmosphere, climate, and ecosystems.
Mindmap
Keywords
π‘Volcanic Activity
π‘Magma
π‘Tectonic Plates
π‘Explosive Eruption
π‘Effusive Eruption
π‘Stratovolcano
π‘Pyroclastic Flow
π‘Fumarole
π‘Tephra
π‘Geyser
Highlights
Volcanic activity involves magma being ejected to the surface of the Earth through the crust.
Volcanoes form in long chains, often at the boundaries of tectonic plates.
Volcanic activity plays an important role in mountain formation.
Magma beneath the Earth's surface is called lava when it reaches the surface.
Volcanoes are differentiated by types of eruptions: explosive, effusive, and mixed.
Explosive eruptions, characterized by steam, gases, and massive explosions, occur in cinder cone volcanoes.
Pyroclastic flow, a devastating high-speed flow of volcanic material, is a key feature of explosive eruptions.
Examples of explosive eruptions include Krakatoa, Mount Pelee, and Mount St. Helens.
Effusive eruptions occur in shield volcanoes and are characterized by the non-explosive release of liquid lava.
Mauna Kea and Mauna Loa in Hawaii are well-known examples of volcanoes with effusive eruptions.
Mixed eruptions occur in stratovolcanoes and include both explosions and lava flows.
Stromboli, Mount Etna, and Cotopaxi are examples of volcanoes that experience mixed eruptions.
Post-volcanic activity includes the release of steam and gases from fumaroles, such as sulfurous gases from sulfatara.
Mud volcanoes occur in clay areas, where gases are released through liquid mud as bubbles.
The 1815 eruption of Mount Tambora spread 80 cubic kilometers of tephra and had global impacts on the atmosphere, climate, and wildlife.
Transcripts
volcanic activity
is a process of magma being ejected to
the surface of the earth
out of its crust volcanoes do not occur
at random
they form long chains which are
essentially the boundaries of tectonic
plates
volcanic activity has an important role
in mountain formation
magma is red-hot molten rock beneath the
earth's surface
magma that flows to the surface is
called lava
and a volcano is formed where it reaches
the surface
volcanoes can be differentiated
according to types of eruption
which are explosive effusive and mixed
explosive eruptions are characteristic
of cinder cone volcanoes
this type of eruption is accompanied by
steam and gases
that escape to the surface through the
crater with massive explosions
and it results in a tall eruption column
and pyroclastic flow
wind can spread the ash cloud over a
large area
the pyroclastic flow rolls down the
volcanic cone at a high speed
it is the most devastating type of
volcanic eruption
krakatoa mount pillai and mount saint
helens
are the best known examples of volcanoes
where this type of eruption occurs
effusive eruptions are characteristic of
shield volcanoes
this type of eruption is not accompanied
by explosions or a pyroclastic flow
the only substance that rises to the
surface is liquid lava
once the lava solidifies it creates a
volcanic cone
examples of volcanoes where effusive
eruptions occur
are mauna kea and mauna loa both
on the hawaiian islands mixed eruptions
are characteristic of stratovolcanoes
this type of eruption is accompanied by
explosions and
lava flows as well the volcanic cone
consists of alternating layers of tephra
or fragments
and solidified lava the best known
examples of stratovolcanoes
are stromboli mount etna and catopaxy
after volcanic eruptions post-volcanic
activity can also be observed
which essentially consists of steam and
gases made up of various chemicals
emitted from vents called fumaroles
a sulfatara is a type of fumarole it is
an opening in the earth's crust that
emits sulfurous gases
a moffetta is a discharge of carbon
dioxide
a mofetta can be called dry if it
contains carbon dioxide
or wet if it contains carbonated water
a geyser is a spring that periodically
discharges hot water
this happens because water seeps into
and accumulates in small hollows beneath
the ground
and then starts to boil due to the heat
of the magma and eventually
erupts volcanic activity
in clay areas are accompanied by mud
volcanoes
where gases are released by liquid mud
as bubbles
the most devastating volcanic eruptions
scatter large amounts of tephra
during the 1883 eruption of krakatoa
18 cubic kilometers of tefra were
dispersed
while during the 1815 eruption of mount
tambora
which was one of the most powerful
eruptions in history
a total of 80 cubic kilometers of these
fragments were spread
over a large area such powerful
eruptions have global impacts on the
earth's atmosphere
climate and wildlife as well
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