The Dynamic Earth

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Questions and Answers

What are some features of the Earth that can be observed underwater and on land?

Volcanoes and earthquakes

Why is Hawai'i a great place to observe changes in the Earth's crust?

Because all types of changes can occur there

What causes earthquakes?

Stress building up in the Earth's crust and causing it to break in a fault

What is a fault?

A crack in the Earth's crust caused by stress in the surrounding rocks Signup and view all the answers

How does stress build up in the Earth's crust?

Pieces of the Earth pushing and grinding past each other, and getting stuck on each other Signup and view all the answers

What happens when stress in the Earth's crust reaches its breaking point?

The rock breaks and an earthquake occurs Signup and view all the answers

What is the main cause of tsunamis?

Earthquakes. Signup and view all the answers

How do seismologists use earthquake waves to study the Earth's interior?

They deduce the structure of the Earth's interior based on the arrival and behavior of earthquake waves. Signup and view all the answers

What are the five layers of the Earth's interior?

Solid inner core, liquid outer core, liquid mantle, taffy-like upper layer, and outer crust. Signup and view all the answers

How are tsunamis formed?

Tsunamis can be triggered by earthquakes, underwater landslides, or volcanic eruptions. Signup and view all the answers

What causes the shoreline water to recede before a tsunami?

The water gets pulled into the wave itself. Signup and view all the answers

How are volcanoes formed by hot spots?

Hot magma moves toward the surface of the Earth through mantle plumes, and when it reaches the crust, it breaks through in one spot, forming an area of volcanism. Signup and view all the answers

What is the oldest island in the Hawaiian archipelago?

The furthest northwest island is the oldest. Signup and view all the answers

Where is the hot spot in the Hawaiian archipelago located?

The hot spot is directly under the Big Island of Hawai'i. Signup and view all the answers

What is the name of the active volcano on the Big Island?

The active volcano on the Big Island is called Kilauea. Signup and view all the answers

What is the process by which a new island is forming off the southeast coast of the Big Island?

A new island is forming through volcanic activity deep under water. Signup and view all the answers

What is the name of the new island that is forming off the southeast coast of the Big Island?

The new island is called Lo'ihi. Signup and view all the answers

What does the study of lava from volcanoes reveal about the Earth's interior?

The study of lava from volcanoes gives scientists clues about the Earth's interior. Signup and view all the answers

What are the two processes that are evident on the surface of Hawai'i?

The two processes that are evident on the surface of Hawai'i are weathering and deposition. Signup and view all the answers

Define weathering and deposition.

Weathering is the wearing away of rock by natural agents, while deposition is the accumulation of sediment and broken-down parts of rocks to create landforms. Signup and view all the answers

Study Notes

Earth's Features

Underwater features include ocean trenches, ridges, and coral reefs; land features include mountains, valleys, and rivers.
Both environments show geological formations that provide insights into Earth's structure and processes.

Hawai'i and Earth's Crust

Hawai'i serves as a natural laboratory for observing tectonic activity due to its volcanic islands formed by the Pacific Plate moving over a hot spot.
Research into volcanic processes and geological changes offers a unique perspective on crustal activity.

Earthquake Fundamentals

Earthquakes are caused by the sudden release of energy in the Earth's crust, resulting in seismic waves.
A fault is a fracture or zone of fractures between two blocks of rock; movements along faults can trigger earthquakes.

Stress in Earth's Crust

Stress builds up in the crust due to tectonic forces as plates interact, which can deform rocks over time.
When stress exceeds the strength of rocks, it results in a sudden rupture along the fault, creating an earthquake.

Tsunamis

The main cause of tsunamis is underwater earthquakes, volcanic eruptions, or landslides displacing large volumes of water.
Before a tsunami arrives, shoreline water may recede sharply as the sea floor is drawn down, allowing water to pull back.

Seismology and Earth's Interior

Seismologists analyze earthquake waves to infer the composition and behavior of the Earth's layers, as different materials affect wave propagation.
The Earth's interior consists of five layers: the crust, mantle, outer core, inner core, and the lithosphere includes the crust and upper mantle.

Volcano Formation and Hot Spots

Volcanoes are formed at hot spots where magma from the mantle breaks through the crust, creating new land.
The oldest island in the Hawaiian archipelago is Kauai, which is approximately 5.1 million years old.

Hot Spot Location

The hot spot in the Hawaiian archipelago is located beneath the Pacific Plate, responsible for the volcanic activity observed in the islands.

Active Volcano Activity

The active volcano on the Big Island is Kilauea, known for its frequent eruptions and lava flows.

New Island Formation

A new island is forming off the southeast coast of the Big Island due to ongoing volcanic activity, which is the result of lava from Kilauea accumulating underwater.
This island is known as Lo'ihi, which is rising above sea level as lava builds its structure.

Geological Insights

The study of volcanic lava provides data about the mantle's composition and conditions, offering insights into the Earth's evolution.

Surface Processes in Hawai'i

Two key geological processes observed on the surface of Hawai'i are volcanic activity (creation of new land through eruptions) and erosion (shaping of landscapes).

Weathering and Deposition

Weathering is the process that breaks down rocks and minerals into smaller particles through physical, chemical, or biological means.
Deposition involves the accumulation of sediments transported by water, wind, or ice, leading to the formation of new geological features.

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Description

Test your knowledge about the dynamic Earth and its ever-changing lithosphere with this quiz. Dive into the fascinating features that shape our planet, both underwater and on land. Explore the mysteries of the Earth's crust and uncover clues about its transformations.