The four types of volcanoes
Summary
TLDRThis script explores the diverse world of volcanoes, distinguishing between Shield, Cinder Cone, and Stratovolcanoes, and introducing the lesser-known deep-sea volcanoes. It highlights the unique characteristics of these underwater formations, such as pillow lava, and invites viewers to ponder their classification, emphasizing the vastness of volcanic knowledge yet to be uncovered.
Takeaways
- 🌋 A volcano is a fissure in Earth's crust where magma moves towards the surface.
- 🛡️ Volcanoes are classified into three main types: Shield, Cinder Cone, and Stratovolcanoes.
- 🏔️ Shield volcanoes are broad, domed structures formed by layers of lava flows, like Mauna Loa in Hawaii.
- ⛰️ Cinder Cones are smaller and steeper, made of scoria from ejected lava bits that solidify in midair.
- 🗻 Stratovolcanoes are large, steep composite volcanoes with alternating layers of scoria and lava, like Mount Fuji in Japan.
- 🌊 Most volcanoes actually erupt underwater, creating a different kind of lava known as pillow lava.
- 🌍 There is a global ocean ridge system spanning over 70,000 kilometers, which is a nearly continuous range of underwater volcanic mountains.
- 🌐 The mid-Atlantic ridge is a famous example of a spreading ocean ridge, essentially one long underwater volcano.
- 🔥 Volcanic eruptions underwater are not explosive and create pillow lava, which is tube-shaped and indicative of submarine volcanic activity.
- 🧠 There is a lot more to learn about volcanoes, especially those hidden deep in the ocean.
Q & A
What is a volcano?
-A volcano is a fissure in the Earth's crust that develops as magma moves forcefully towards the surface, often forming a structure as magma accumulates around the opening.
What are the three main types of volcanoes mentioned in the script?
-The three main types of volcanoes mentioned are Shield volcanoes, Cinder Cones, and Stratovolcanoes.
Can you describe Shield volcanoes and give an example?
-Shield volcanoes are large, broad, domed structures formed by layers of lava that flow quietly out of the vent and accumulate over time. An example is Mauna Loa in Hawaii.
What materials are Cinder Cones made of and how are they formed?
-Cinder Cones are made of scoria, which are small bits of lava ejected by volcanic gases that harden in midair. They are steep because scoria is not thrown far from the vent.
Why are Stratovolcanoes considered the most beautiful type of volcano?
-Stratovolcanoes are considered the most beautiful because they are large, steep, and composite volcanoes formed from alternating layers of scoria and lava, reaching great heights.
What is a deep-sea volcano and how does it differ from the three types mentioned?
-Deep-sea volcanoes are those that erupt under the sea and cannot be easily classified as Shield, Cinder Cones, or Stratovolcanoes. They are part of the world's ocean ridge system and are different in formation and eruption style.
What is the mid-Atlantic ridge and how is it related to deep-sea volcanoes?
-The mid-Atlantic ridge is a spreading ocean ridge and is considered one long underwater volcanic mountain range. It is related to deep-sea volcanoes as it is a site of volcanic activity that forms part of the Earth's tectonic plates.
What type of lava is typically formed during underwater volcanic eruptions?
-Pillow lava is typically formed during underwater volcanic eruptions. It is distinctly tube-shaped and is indicative of a submarine volcanic eruption.
How does the volcanic process at mid-ocean ridges differ from traditional volcano types?
-Volcanic processes at mid-ocean ridges differ as they are not explosive and generally create pillow lava, which is different from the lava formed in traditional volcano types.
What should we call submarine volcanoes according to the script?
-The script suggests that we need to consider what to call submarine volcanoes since they do not fit into the traditional categories of Shield, Cinder Cone, or Stratovolcanoes.
What is the significance of the ocean ridge system in the context of volcanoes?
-The ocean ridge system, spanning more than 70,000 kilometers, is significant as it represents a nearly continuous range of underwater volcanic mountains that are part of the Earth's tectonic activity.
Outlines
🌋 Volcanoes: Formation and Types
The paragraph introduces the concept of volcanoes as fissures in the Earth's crust through which magma forcefully moves towards the surface. It explains that volcanoes are formed by the accumulation of magma around these openings. The text categorizes volcanoes into three main types: Shield volcanoes, which are large and broad with gently sloping sides formed by layers of lava flows; Cinder Cones, which are smaller and steeper, made of scoria, a type of volcanic rock formed by solidified lava fragments ejected by volcanic gases; and Stratovolcanoes, which are large, steep, and composite volcanoes formed by alternating layers of scoria and lava. The paragraph also mentions that most volcanoes are found under the sea, and they do not fit into the three traditional types. These submarine volcanoes produce a different kind of lava known as pillow lava, which is indicative of underwater volcanic eruptions.
Mindmap
Keywords
💡Volcano
💡Magma
💡Shield Volcano
💡Cinder Cone
💡Stratovolcano
💡Scoria
💡Deep-sea Volcanoes
💡Ocean Ridge System
💡Pillow Lava
💡Divergent Margins
💡Mid-ocean Ridge
Highlights
A volcano is defined as a fissure in the Earth's crust where magma moves forcefully towards the surface.
Volcanoes are classified into Shields, Cinder Cones, and Stratovolcanoes.
Shield volcanoes are large, broad, domed structures formed by layers of lava.
Mauna Loa in Hawaii is an example of a Shield volcano.
Cinder Cones are smaller volcanoes made of scoria, a volcanic rock.
Scoria is formed by bits of lava ejected by volcanic gases that harden in midair.
Stratovolcanoes are large, steep composite volcanoes formed from alternating layers of scoria and lava.
Fujiyama in Japan is a famous example of a Stratovolcano.
Most volcanoes erupt deep under the sea and are not easily classified into the three types.
Deep-sea volcanoes are part of the world's ocean ridge system spanning over 70,000 kilometers.
The mid-Atlantic ridge is a famous example of a spreading ocean ridge.
Submarine volcanic eruptions generally create a different kind of lava known as pillow lava.
Pillow lavas are distinctly tube-shaped and indicative of a submarine volcanic eruption.
Volcanic processes at mid-ocean ridges differ from traditional types of volcanoes.
Submarine volcanoes are an area of study with much to learn, especially those hidden deep in the ocean.
Transcripts
What do you think about when you think about volcanoes? Do you think about
explosive eruptions or slow lava flows? There is a lot more to know about
volcanoes and volcanic eruptions. First, let's talk about what a volcano is. A
volcano is defined as a fissure that develops in the Earth's crust as magma
moves forcefully towards the Earth's surface. Volcanoes are constructed as
magma accumulates around the fissure opening. Volcanoes are normally
classified into Shields, Cinder Cones and Stratovolcanoes. Shield volcanoes are
large, broad, domed structures formed by layers of lava that quietly flow out of
the vent and accumulate over time. Mauna Loa in Hawaii is a good example. A second
type is smaller and called a Cinder Cone. These are made of a volcanic rock called
scoria which are small bits of lava ejected by volcanic gases that hardened
in midair. Because scoria is never thrown very far
from the vent, cinder cones are steep. The most beautiful volcanoes are large, steep
stratovolcanoes. These are composite volcanoes that are formed out of
alternating layers of scoria, like pyroclastic material and lava. These
constructions are steep and strong and reach great heights.
Fujiyama in Japan is a famous example. These are the three types of volcanoes
that you may be familiar with, but did you know that most volcanoes erupt
deep under the sea? These deep-sea volcanoes can't easily be classified as
Shield, Cinder Cones, or Stratovolcanoes. So what are they? This is a map of the
world's ocean ridge system that spans more than 70,000 kilometers in total.
These spreading ridges are located at divergent margins and are defined as a
nearly continuous range of underwater volcanic mountains. The mid-atlantic
ridge is arguably the most famous example of a spreading ocean ridge. These
ridges are essentially one long volcano that is neither Shield, Composite, or
Cinder Cone. Because volcanic eruptions underwater are not explosive they
generally create a different kind of lava known as pillow lava. Pillow lavas
are distinctly tube shaped and are indicative of a submarine volcanic
eruption. The volcanic processes found at mid-ocean ridges
and the way that these volcanoes form are different than any of the three
traditional types of volcanoes. What do you think we should call these submarine
volcanoes? As you can see there is so much to learn about them especially
those hidden deep in the ocean.
5.0 / 5 (0 votes)