What Is A Volcanic HOTSPOT?
Summary
TLDRThis video explores tectonic hot spots and mantle plumes, which are stationary sources of magma deep within Earth's mantle. It explains how these plumes create volcanism, distinct from plate boundary activity, by rising through the mantle and decompressing to form magma. The video discusses famous hotspots like Hawaii and Yellowstone, describing how they form volcanic islands and domes over millions of years, illustrating Earth's dynamic geological processes.
Takeaways
- 🌋 Tectonic hot spots are areas with magma material under the lithospheric plate that is either hotter or less dense, causing it to rise.
- 🔥 A mantle plume, also known as a diapir, is a large volume of magma material that originates from the core-mantle boundary and rises through the mantle due to thermal or compositional differences.
- 📍 Mantle plumes are generally fixed in one geographic location under the plate and can feed magma to the surface for millions of years.
- 🌊 Mantle plumes are more common in oceanic locations due to the thinner crust, which ranges from 7 to 10 miles thick compared to the continental crust that can reach up to 50 miles thick.
- 🏞️ Famous locations of mantle plumes include Hawaii, the Galapagos Islands, Easter Island, Reunion Islands, and Yellowstone in the continental United States.
- 🌏 Mantle plumes can create both oceanic and continental volcanism, with the former being more common due to plate thickness.
- 🌄 Volcanoes formed by mantle plumes can grow into islands, such as the Hawaiian Islands, if they remain over the plume and receive a constant supply of magma.
- 🏔️ As volcanic islands move away from the plume with plate tectonics, they stop being active and eventually erode, becoming seamounts or extinct volcanoes under the sea level.
- 🔄 Mantle plumes are different from plate boundary volcanism, where the latter occurs along the edges of tectonic plates and is associated with three types of plate boundaries: divergent, convergent, and transform.
- ⛰️ Intraplate volcanism, such as that caused by mantle plumes, occurs in the middle of a tectonic plate and is distinct from the volcanism found at plate boundaries.
- 🌐 The study of volcanic island chains and seamounts can provide insights into the history and activity of mantle plumes and the geological processes involved.
Q & A
What is a mantle plume and how is it related to tectonic hotspots?
-A mantle plume is a large volume of magma that originates from the core-mantle boundary and rises through the mantle due to differences in thermal properties or composition, causing it to be less dense. It is related to tectonic hotspots as it creates areas of increased volcanic activity where it reaches the lithosphere, forming volcanoes on the surface.
How does a mantle plume create volcanism?
-A mantle plume creates volcanism by rising through the mantle and spreading out beneath the lithospheric plate. This process leads to decompression melting, causing more rock to melt due to the decrease in pressure. The magma from the plume then intrudes into the plate, creating volcanoes on the surface.
What is the difference between hotspot volcanism and plate boundary volcanism?
-Hotspot volcanism, or intraplate volcanism, occurs in the middle of a tectonic plate and is driven by stationary mantle plumes. Plate boundary volcanism occurs where tectonic plates interact, such as at divergent boundaries where new crust is formed or at convergent boundaries where one plate is subducted beneath another, leading to volcanic activity.
Why are mantle plumes typically fixed in one geographic location?
-Mantle plumes are typically fixed in one geographic location because they are anchored at the core-mantle boundary. As tectonic plates move over these stationary plumes, the volcanic activity remains in the same spot relative to the plume, but the location of the volcanic activity on the Earth's surface can change over time.
What is the role of the oceanic plate in the formation of mantle plumes?
-The oceanic plate plays a significant role in the formation of mantle plumes because it is generally thinner than the continental crust, ranging from 7 to 10 miles thick. This thinness allows for more occurrences of mantle plumes and the associated volcanic activity in oceanic locations.
How does the thickness of the tectonic plate affect the occurrence of mantle plumes?
-The thickness of the tectonic plate affects the occurrence of mantle plumes because thinner plates, like the oceanic plate, offer less resistance to the upward movement of magma from the mantle plume, making it easier for volcanic activity to occur.
What are some examples of locations with mantle plumes?
-Examples of locations with mantle plumes include Hawaii, the Galapagos Islands, Easter Island, French Polynesia, Reunion Islands in the Indian Ocean, the Azores in the Atlantic, and Yellowstone in the United States.
How do mantle plumes contribute to the formation of volcanic islands?
-Mantle plumes contribute to the formation of volcanic islands by providing a constant flow of magma from deep within the Earth. Over time, this magma accumulates on the ocean floor, forming volcanic seamounts that can eventually rise above sea level to become volcanic islands.
What happens to a volcanic island once it moves away from the mantle plume?
-Once a volcanic island moves away from the mantle plume, it no longer receives the constant supply of magma. The volcanic activity ceases, and the island becomes extinct. Over time, it will be eroded by natural forces such as weather, wave action, and exposure to elements, potentially becoming a seamount or subducting if it reaches a plate boundary.
How can the movement of tectonic plates over a mantle plume create a chain of volcanic islands?
-As tectonic plates move over a stationary mantle plume, a series of volcanic islands can form in a chain. The islands closest to the plume are active, while those that have moved away become extinct. This creates a sequence of islands of varying ages, reflecting the history of the mantle plume's activity.
What is the significance of the Emperor Seamounts in understanding mantle plumes?
-The Emperor Seamounts are a chain of volcanic islands and seamounts in the Pacific Ocean that date back 80 to 100 million years. They provide a geological record of the movement of the Pacific Plate over a mantle plume, illustrating the progression and history of volcanic activity associated with the plume.
Outlines
🌋 Mantle Plumes and Volcanism
This paragraph introduces the concept of mantle plumes, which are columns of hotter, less dense magma that rise from the core-mantle boundary into the lithosphere, causing decompression melting and creating volcanoes. Mantle plumes are distinct from plate boundary volcanism, as they are fixed in one geographic location and can persist for millions of years, feeding magma to the surface. Examples of locations with mantle plumes include Hawaii, the Galapagos Islands, and Yellowstone. The paragraph also explains the difference between mantle plumes and diapir, emphasizing the thermal and compositional characteristics of mantle plumes.
🌿 Formation of Volcanic Islands
Paragraph 2 discusses the process by which mantle plumes lead to the formation of volcanic islands. It explains how a fixed mantle plume can feed magma into the crust, creating a volcano on the ocean floor. Over time, this volcano grows as more lava is erupted and solidifies into basaltic rock. Eventually, the island may break the ocean surface, forming a volcanic island. The paragraph also describes how these islands can grow into island chains, such as the Hawaiian Islands, and how they can move away from the plume over time, becoming extinct volcanoes or seamounts. The concept of intraplate volcanism is introduced, contrasting it with the more common plate boundary volcanism.
🏞️ Plate Tectonics and Volcanism
The final paragraph contrasts interplate volcanism, which is associated with mantle plumes, with the volcanism that occurs at plate boundaries. It explains that while mantle plumes are stationary and create specific volcanic features like domes or islands, plate boundary volcanism is characterized by chains of volcanoes along divergent and convergent boundaries. The paragraph highlights the differences in the location and movement of volcanic activity between these two types of volcanism, emphasizing the unique characteristics of mantle plumes and their role in creating distinct geological features.
Mindmap
Keywords
💡Mantle Plume
💡Volcanism
💡Lithospheric Plate
💡Decompression Melting
💡Mesosphere
💡Convection Currents
💡Oceanic Plate
💡Continental Crust
💡Afar Triple Junction
💡Seamount
💡Intraplate Volcanism
Highlights
Tectonic hot spots are locations with hotter magma material beneath the lithospheric plate.
A mantle plume is a large volume of magma that rises from the core-mantle boundary due to thermal and compositional differences.
Mantle plumes create decompression melting as they rise, causing surrounding rock to melt.
Mantle plumes have a tail and a connected pipe of magma that extends from the core-mantle boundary to the surface.
Mantle plumes are generally fixed in one geographic location under the plate.
Mantle plumes can feed volcanism for millions of years in specific locations.
Mantle plumes are found in both oceanic and continental locations, with a higher occurrence in thinner oceanic plates.
Examples of mantle plume locations include Hawaii, the Galapagos Islands, and Yellowstone.
Mantle plumes can create volcanic islands as they feed magma to the crust.
Volcanic islands grow over time as more lava forms into igneous rock.
As tectonic plates move, volcanic islands can become inactive and erode into seamounts.
The Hawaiian Islands and Emperor Seamounts showcase a chain of islands formed by a mantle plume.
Mantle plumes are stationary and different from plate boundary volcanism, which occurs along plate edges.
Intraplate volcanism, caused by mantle plumes, occurs in the middle of a plate, unlike plate boundary volcanism.
Mantle plumes can create domes or calderas, as seen in Africa and Yellowstone.
Key terms related to mantle plumes include magma, decompression melting, and lithospheric plate interaction.
Transcripts
foreign
this is the earth science classroom
welcome back to the channel so this
video is in the playlist for both
tectonics and volcanoes and looking at
tectonic hot spots which is some
locations around the world that have
hotter magma material right under the
lithospheric plate and this video is
going to discuss what is a mantle plume
where do these metal plumes occur on the
earth and how a mantle plume creates
volcanism and finally how this hot spot
volcanism or interplate volcanism is
different to volcanoes that form on a
plate boundary whether you have a
convergent plate boundary and one plate
is subducting
so geologically a mantle plume oil magma
plumer is occasionally known as is a
form of diaper now diaper is a large
amount or large volume of magnetic
material that is either
different to the Australian rock through
thermal properties being hotter or
through the composition where it's just
less dense and can rise based on density
so this large amount of generally magma
this large volume of magma is under the
surface generally at the core mantle
boundary heated by the insane heat from
the core the outer core and send in
large volumes of magnetic material
to rise up through the lower mantle or
mesosphere into the acetosphere or the
upper mantle and go through the
convection currents and on its way
towards the lithospheric plate which is
the lithosphere and the crust towards
the surface and that also create
decompression melting which would cause
more of the rock around it to melt as it
goes into an area of less pressure so
the liquid has an area to move now this
diaper or plume has a tail and a
connected pipe or continued volume of
magma that is coming from the core
mantle boundary up through the mantle
and the layers out towards the surface
and it's connected and at the head or
top of the deer Pier or plume you're
going to have this spreading out effect
of the magma right underneath the
lithospheric plate and send in magma
into the plate and creating volcanoes on
the surface
now these mantle plumes are special
because they are generally fixed in one
geographic location under the plate
around the world and these may stay for
an extended period of time so this
mantle plume could be feeding hot fluid
magma basaltic magma and mafic magma
from deep down in the lower mantle up
towards the surface in a certain
location around the world for in excess
of hundreds of thousands if not hundreds
of millions of years and feeding this
volcanism on the surface from this
mantle plume just below the plate so
locations around the world are both
found in Oceanic locations and on
continents and mostly Oceanic because
the oceanic plate is generally thinner
even though it's dense made up of salt
it's generally thinner between 7 and 10
miles thick compared to the continental
crust which could be in some areas of
rogeny belts or Mountain belts could be
as as 50 miles
So based on the plate thickness the
oceanic plate and the oceans around the
world have more occurrence of these
mantle plumes and the volcanism
occurring so areas like the Southern
Pacific South Pacific Northern Pacific
areas like Hawaii the Galapagos Islands
Easter Island and various areas around
French Polynesia they look at the Indian
Ocean and reunion islands and the
Atlantic with the Azores or Azores or on
the continents you have areas like
Yellowstone which is a classic National
Park in the US but also is a location of
a massive mantle plume that has moved
great distances since its formation or
Discovery millions of years ago and the
other locations famous is in Africa on
the African continental plate with the
afar Junction triple Junction caused by
two large domes where the Magna plume is
pushing up under the crust pushing
across higher elevation and causing
these two domes the Ethiopian Dome and
the king and Dome you can check more
about those domes on my East African
Rift videos
[Music]
at some points around the world as I
discussed like Hawaii and the Galapagos
you have this fixed mantle plume feeding
hot magmac material which is mafic in
composition that is basaltic magma and
it's feeding into the play into the
crust and flowing onto the ocean floor
and providing the ocean floor with this
constant flow of of magma and lava turn
into basaltic igneous rock and forming a
volcano on the ocean floor now over time
that volcano is going to grow and
develop as more and more lava comes out
and forms into igneous rock and it grows
eventually it's going to reach the top
of the ocean surface and go above the
ocean's surface and become a volcanic
island this island is going to grow as
long as it's on top of the mantle plume
being fed this constant magma and over
the course of thousands of years the
volcano Island's going to grow and grow
into a large island series like the
Hawaiian Islands or the Galapagos
Islands or the Azores in Atlantic and
the island that's on top of the plume is
going to grow and develop and as it
moves with the tectonic plate in the
direction of the convection currents by
the Pacific Oceans moving certain
direction according to the oceanic crust
then that island that volcanic island
will no longer be active and just become
an island and it'll move off the plume
and it will just start to exist as an
island but slowly break down due to the
forces of weather and erosion out in the
exposure to the elements over a long
period of time and the wave action and
that Island's going to start to break
down and that solid
saltic rock is going to break down and
that Island's going to get smaller and
smaller and smaller until it eventually
gets under the sea level under the ocean
and become what we call a seamount so an
extinct volcano a seamount and it's you
get small and small and smaller and you
can see it through sonar and radar and
satellites but you see this long chain a
long sequence of
currently active volcanoes over the
plume and then a long sequence of chain
of increasingly older islands and
extinct volcanoes that have been moved
by the plate motion and a long sequence
of these Island chains that you can see
now the classic one is the Hawaiian
islands and the emperor sea mounts here
is thousands of miles long chain of
islands dating back 80 to 100 million
years and you see where some of the
islands have actually been subducted at
the edge of the Pacific Ocean where it's
going to descend underneath the carnival
crust of the Eurasian plate or the the
North American plates but in particular
the Eurasian plate and be partially
melted back into magma that's going to
erupt through a continental volcanic
chain or volcanic Arc and the cycle of
the rock cycle is going to continue but
these amazing Islands in this long chain
of sequence
based on age and how fast it's moving
off the plume and the current active
volcanoes on the plume are a fantastic
way to see the progression and the
history of this area and of the mantle
plume how long it's been there how
active it is and how much it produces to
create these large volcanic islands
so a mantle plume an intraplate
volcanism intra means in the middle or
inside so in the middle of this massive
Atomic plate you have volcanism and it's
different to the volcanism that occurs
on the plate boundary now plates
boundaries come in three types we know
Divergent where you have the mid-ocean
ridge or Rift Valley and you have
convergent plate boundaries where you
have two plates converging towards each
other and you have subduction based on
density differences of each plate and
you also have transform where they slide
past each other now volcanism generally
occurs with divergent plate boundary
where you have the lava coming out the
ridge the ocean ridge that has found in
63 and you also have volcanism that
happens where one plate the denser plate
is going to subduct under the subduction
or subducting slab will partially melt
due to friction and temperature
increases back down towards the
asthenosphere and you'd have partial
melting of this starting to subduct him
play but mostly the melting of the plate
that's going to float on top generally
is going to be that lighter Dent lighter
less dense
plate which is going to be Continental
or sometimes Oceanic and that's going to
create magma it's going to rise up on
the edge or
coastlines of these plates and form
either volcanic island chains on the
boundary of the two plates a certain
distance away from the subduction zone
or more commonly like the ring of fire
on the edge of continental plates where
you have this long chain or Arc of
volcanoes that are actually a certain
distance and parallel to the coastline
which is showing you where the
subduction zones are located and the
trenches so it's different because this
mantle plume is a certain location and
it's fixed whereas the plate boundaries
and subduction you have this long chain
that is the volcanoes are usually fixed
in location whereas the mantle plume the
volcanoes can move with the plate but
the actual magma is in the same location
so there's some differences between the
interplate volcanism and the volcanism
you get with plate boundaries
so in conclusion a interplate volcanism
or a mantle plume is a stationary plume
of magma rising up from the core mantle
boundary rising up through the mantle
into the upper mantle and reaches the
plate spreads out and pours Mythic
basaltic magma into that lithospheric
plate creating volcanoes on the surface
with this ocean floor or vacant Islands
or pushing up the
ground the surface of the Earth into a
dome where the magma pushes up and it's
going to increase the elevation of the
above crust and cause domes like in
Africa or volcanism like you see in
Yellowstone with the geysers and the
flow of magma
under the National Park to create a
Caldera volcano so there are certain key
terms we know with plumes it is that
long tailed magmatic material rising up
and creating volcanism on the surface
[Music]
thank you
تصفح المزيد من مقاطع الفيديو ذات الصلة
5.0 / 5 (0 votes)