Science 10: Lesson 3 Volcanic Hot Spots (Part 3)

D’Marianne

10 Sept 202007:06

Summary

TLDRIn this science lesson, Marian Soriano introduces students to the concept of volcanic hot spots, explaining that not all volcanoes are near plate boundaries. Hot spots, like those in Hawaii, form due to intraplate activity and mantle plumes. The Hawaiian Islands serve as a prime example, showing how volcanic island chains are created and how plate movement affects their activity. Students are engaged in an activity to identify the oldest and youngest islands and the direction of plate movement, concluding with the understanding that hot spot volcanoes are distinct from those at plate boundaries.

Takeaways

🌋 Active volcanoes are not only found near plate boundaries but can also exist in the middle of a plate, like the Hawaiian Islands.
🔥 Volcanic hot spots are areas of geologic activity that occur within a plate, caused by a mantle plume which brings magma up to the surface.
🌍 The movement of tectonic plates carries islands away from a hot spot, creating a chain of volcanic islands and seamounts, as seen in the Pacific Ocean.
🏝️ The Hawaiian Islands are a prime example of a hotspot volcanic chain, with the direction of plate movement indicated by the progression of the islands.
📉 Older islands in a hotspot chain are farther from the hot spot and tend to be less active, while younger islands are more active and closer to the hot spot.
🚫 Hot spots are more common beneath oceanic crust because it is thinner than continental crust, allowing for easier penetration by magma plumes.
🌆 Yellowstone is an example of a volcanic hot spot within continental crust, responsible for significant volcanic activity in North America.
📝 Students are encouraged to engage with the material by studying the Hawaiian Islands and answering activity questions about the islands' age, activity, and plate movement.
📉 Kauai is identified as the oldest island in the Hawaiian chain, while Hawaii is the youngest and most active.
➡️ The direction of plate movement can be deduced from the arrangement of the Hawaiian Islands, moving from Hawaii to Kauai.
🔥 The molten material in a hot spot is called magma, which is responsible for the formation of volcanic islands.

Q & A

What is the main focus of the science lesson presented by Marian Soriano?
-The main focus of the lesson is to explain the concept of volcanic hot spots and how they are responsible for the formation of certain volcanic islands, particularly the Hawaiian Islands.
Why are most active volcanoes found near plate boundaries?
-Most active volcanoes are found near plate boundaries because of the tectonic activity that occurs there, which allows magma to rise to the surface and form volcanoes.
What is a volcanic hot spot and how does it differ from a typical volcano found at plate boundaries?
-A volcanic hot spot is an area within a tectonic plate where there is a source of molten material from the mantle, called a mantle plume, that forms volcanoes. Unlike typical volcanoes at plate boundaries, hot spots are not directly related to the movement of tectonic plates.
What is the term used to describe the geological activity that occurs within a plate rather than at its boundaries?
-The term used to describe this type of geological activity is 'intraplate activity'.
How do volcanic hot spots contribute to the formation of volcanic island chains?
-Volcanic hot spots contribute to the formation of volcanic island chains by remaining stationary while the tectonic plate moves over them, creating a line of volcanic islands as new islands form over the hot spot and older ones move away and become extinct.
Which island in the Hawaiian chain is considered the oldest based on the script?
-Kauai is considered the oldest island in the Hawaiian chain because it is the farthest from the hot spot.
Which island in the Hawaiian chain is the youngest and why?
-The youngest island is Hawaii because it is located directly above the hot spot, where the most recent volcanic activity is occurring.
What is the least active volcano among the Hawaiian islands according to the script?
-The least active volcano is on the island of Kauai, as it is the oldest and furthest from the hot spot.
What is the most active volcano among the Hawaiian islands?
-The most active volcano is on the island of Hawaii, as it is situated above the hot spot where magma is readily available.
How can the direction of plate movement be determined from the Hawaiian Islands?
-The direction of plate movement can be determined by observing the chain of islands, with the oldest at one end and the youngest at the other, indicating the direction from where the plate has moved over the hot spot.
What is the molten material found in a hot spot called?
-The molten material found in a hot spot is called magma.
Why are hot spots more common beneath oceanic crust than continental crust?
-Hot spots are more common beneath oceanic crust because it is thinner than continental crust, allowing the magma plume to more easily penetrate and create a hot spot.
What is a notable example of a volcanic hot spot found in continental crust?
-Yellowstone is a notable example of a volcanic hot spot found in the continental crust of the North American plate.

Outlines

00:00

🌋 Introduction to Volcanic Hot Spots

The first paragraph introduces the concept of volcanic hot spots, explaining that not all active volcanoes are located near plate boundaries. It highlights the Hawaiian Islands as an example of volcanic activity occurring in the middle of a tectonic plate. The paragraph discusses the formation of volcanic hot spots due to intraplate activity, which is tectonic activity within a plate rather than at its boundaries. The concept of a mantle plume is introduced as the source of molten material that forms hot spots. The paragraph also explains the process of volcanic island chain formation due to the movement of tectonic plates over a stationary hot spot, leading to the creation of a trail of volcanic islands and seamounts across the Pacific Ocean floor. The Hawaiian Islands serve as a prime example of this process, and the paragraph concludes with an activity prompting students to analyze the Hawaiian Islands' volcanic track to deduce the direction and rate of plate movement.

05:05

📚 Activity and Summary of Hot Spot Volcanoes

The second paragraph serves as both an activity guide and a summary of the lesson on hot spot volcanoes. It begins with an activity where students are asked to study a picture of the Hawaiian Islands and answer questions about the age, activity level, and direction of plate movement. The paragraph provides answers to these questions, revealing that Kauai is the oldest island due to its distance from the hot spot, while Hawaii is the youngest and most active. The direction of plate movement is indicated from Hawaii to Kauai. The paragraph also clarifies that the molten material in a hot spot is called magma. The summary explains that hot spot volcanoes occur far from plate boundaries and are formed over a mantle plume or an area of the crust where magma is hotter than the surrounding magma. As plates move, the stationary hot spot may create a chain of volcanoes on the Earth's surface. The magma plume associated with hot spots causes melting and thinning of the crust, leading to widespread volcanic activity. The lesson concludes with a recap of the key points and an introduction to Yellowstone as another example of a volcanic hot spot in continental crust.

Mindmap

Keywords

💡Active Volcanoes

Active volcanoes are those that are currently erupting or show signs of eruptive activity likely to resume. They are a central theme of the video, illustrating the dynamic nature of Earth's surface. For instance, the script mentions that most active volcanoes are found along plate boundaries, emphasizing the connection between tectonic activity and volcanic eruptions.

💡Plate Boundaries

Plate boundaries are the edges of tectonic plates, where the majority of the Earth's volcanic and seismic activity occurs due to the movement and interaction of these plates. The script explains that not all volcanoes are near plate boundaries, but the concept is crucial for understanding where most volcanic activity takes place.

💡Volcanic Hot Spot

A volcanic hot spot is an area of intense geologic activity that results in the formation of volcanoes, typically not located at plate boundaries. The video script describes hot spots as areas where a mantle plume brings magma to the surface, creating volcanic islands like those in Hawaii, which are formed above such a hot spot.

💡Intraplate Activity

Intraplate activity refers to geological events that occur within a tectonic plate, rather than at its boundaries. The script uses this term to explain how some volcanic activity, like that in Hawaii, is not associated with plate tectonics but is instead caused by a hot spot within a plate.

💡Mantle Plume

A mantle plume is a hypothetical column of abnormally hot rock rising from deep within the Earth's mantle. The script suggests that a mantle plume is the source of the magma for a hot spot, such as the one beneath the Hawaiian Islands, contributing to their formation and activity.

💡Volcanic Island Chains

Volcanic island chains are a series of islands formed by volcanic activity along a hot spot as a tectonic plate moves over it. The script uses the Hawaiian Islands as an example of such a chain, showing how the islands were formed as the Pacific Plate moved over a stationary hot spot.

💡Extinct Volcano

An extinct volcano is one that is not expected to erupt again because it has been cut off from its magma supply. The video script explains how, as the plate moves away from a hot spot, the volcanoes can become extinct, while new ones form over the hot spot.

💡Seamounts

Seamounts are underwater mountains formed by volcanic activity on the ocean floor. The script mentions seamounts as part of the trail left by the movement of tectonic plates over a hot spot, illustrating the long-term geological processes involved in the formation of volcanic features.

💡Direction of Plate Movement

The direction of plate movement is the path that a tectonic plate takes as it moves over the Earth's surface. The video script uses the Hawaiian Islands to demonstrate how the direction of plate movement can be inferred from the alignment of volcanic islands and seamounts.

💡Magma

Magma is molten rock found beneath the Earth's surface, which can rise to form volcanic features when it reaches the surface. The script identifies magma as the molten material in a hot spot, which is responsible for the formation of volcanic islands like those in Hawaii.

💡Yellowstone

Yellowstone is a volcanic hot spot located in the continental crust of the North American Plate, known for its large-scale volcanic history. The script mentions Yellowstone as an example of a hot spot within continental crust, highlighting the variety of geological settings where hot spots can occur.

Highlights

Introduction to the lesson on major active volcanoes of the world.

Not all active volcanoes are located near plate boundaries; some are in the middle of a plate, like the Hawaiian Islands.

Explanation of the formation of Hawaiian volcanic islands, different from plate boundary volcanoes.

Definition and explanation of volcanic hot spots and their occurrence in the middle of tectonic plates.

Intraplate activity as the cause of volcanic hot spots, distinct from activity at plate boundaries.

Mantle plume as the source of molten material forming hot spots.

Description of how hot spots form volcanic island chains as plates move over them.

Process of volcanic island growth and extinction as plates move away from the hot spot.

Hawaiian Islands as the best example of a hotspot volcanic chain and the volcanic track left by moving plates.

Direction of plate movement can be determined by the arrangement of islands in a hotspot chain.

Hot spots are more common beneath oceanic crust due to its thinness compared to continental crust.

Yellowstone as an example of a volcanic hot spot in continental crust.

Activity for students to study the Hawaiian Islands and answer questions about plate movement and volcano activity.

Identification of Kauai as the oldest island and Hawaii as the youngest in the Hawaiian hotspot chain.

Direction of plate movement from Hawaii to Kauai indicated by the arrangement of islands.

Magma as the molten material in hot spots responsible for volcanic activity.

Summary of the lesson on hot spot volcanoes, their formation, and the process of creating volcanic chains.

Conclusion of the lesson with a reminder of the key concepts learned about hot spot volcanoes.