Volcanic Eruption | Types Of Eruption: Explosive And Effusive | Theory Explained.

Sci Fi

16 Jul 202003:57

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

🌋 Volcanic activity involves magma being ejected to the Earth's surface through volcanoes, which form at tectonic plate boundaries.
🗺️ Volcanoes are not randomly distributed but often form long chains at the edges of tectonic plates.
⛰️ Volcanic activity plays a key role in the formation of mountains as magma reaches the Earth's surface and solidifies.
🔥 Magma beneath the Earth's surface is called lava once it flows to the surface and helps form volcanoes.
💥 Explosive eruptions, typical of cinder cone volcanoes, involve steam, gases, and pyroclastic flow, causing widespread destruction.
🌪️ Pyroclastic flows are fast-moving and extremely dangerous, as seen in eruptions like Krakatoa and Mount Saint Helens.
🌋 Effusive eruptions, found in shield volcanoes like Mauna Kea and Mauna Loa, are characterized by lava flows without explosions.
🌋 Stratovolcanoes exhibit mixed eruptions with both explosive events and lava flows, creating layered volcanic cones.
🧪 Post-volcanic activity includes the release of gases such as sulfur and carbon dioxide through vents like fumaroles and moffettas.
🌍 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

00:00

🌋 The Formation of Volcanoes and Their Importance

Volcanic activity involves magma being pushed to the Earth's surface through its crust. Volcanoes don’t 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.

💥 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 Pelée, and Mount St. Helens.

🌊 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.

🌋 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.

💨 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.

🌋 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 history’s most powerful eruptions. Such events have far-reaching global impacts on the atmosphere, climate, and ecosystems.

Mindmap

Keywords

💡Volcanic Activity

Volcanic activity refers to the process where magma is ejected from beneath the Earth's surface through cracks in the crust. It plays a critical role in shaping the Earth's surface, including mountain formation. The video explains that volcanic activity forms in chains along tectonic plate boundaries.

💡Magma

Magma is molten rock located beneath the Earth's surface. When it is expelled during volcanic activity and reaches the surface, it is called lava. The video emphasizes that magma is central to the formation of volcanoes.

💡Tectonic Plates

Tectonic plates are large sections of the Earth's crust that move and interact at their boundaries, where volcanic activity often occurs. The video explains that volcanoes are not random but form in chains along these plate boundaries.

💡Explosive Eruption

An explosive eruption is a violent type of volcanic activity characterized by massive explosions, the release of steam and gases, and pyroclastic flows. The video highlights that this type of eruption is found in cinder cone volcanoes, with examples such as Krakatoa and Mount Saint Helens.

💡Effusive Eruption

Effusive eruptions are non-explosive volcanic events where lava flows gently to the surface, creating broad, shield-shaped cones. The video notes that Mauna Kea and Mauna Loa in Hawaii are prime examples of volcanoes with effusive eruptions.

💡Stratovolcano

A stratovolcano is a type of volcano with layers of solidified lava and volcanic fragments, formed through mixed eruptions. These eruptions involve both explosive activity and lava flows. The video mentions Mount Etna and Stromboli as examples of stratovolcanoes.

💡Pyroclastic Flow

A pyroclastic flow is a fast-moving current of hot gas and volcanic matter that flows down the sides of a volcano during explosive eruptions. The video describes this as the most devastating aspect of volcanic eruptions, as seen in events like the eruption of Krakatoa.

💡Fumarole

A fumarole is an opening in the Earth's crust where steam and gases, often containing sulfur, are released following volcanic activity. The video describes fumaroles as post-volcanic features that emit chemicals from vents, contributing to the after-effects of an eruption.

💡Tephra

Tephra refers to fragments of volcanic rock and ash ejected during an eruption. The video highlights that large amounts of tephra are scattered during powerful eruptions, such as the 1883 eruption of Krakatoa, which spread 18 cubic kilometers of tephra.

💡Geyser

A geyser is a spring that periodically ejects hot water and steam due to underground heating from volcanic activity. The video explains that geysers form when water accumulates in hollows beneath the ground and eventually boils and erupts.

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.