Unstable Earth

What are the three layers of the Earth identified in the lecture?

Crust, mantle, and core.

How are the three layers of the Earth arranged?

According to their chemical compositions and density.

What is the thickness range of the Earth's crust?

6 to 70 km.

What are the two types of crust mentioned in the notes?

Continental crust and oceanic crust.

What type of rock is primarily found in the continental crust?

Granite.

What is the main difference between continental and oceanic crust?

Continental crust is thicker and lighter, while oceanic crust is thinner and denser.

What layer of the Earth lies between the core and the crust?

The mantle.

What is the thickness of the mantle?

2900 km.

What is the asthenosphere?

A layer below the lithosphere consisting of magma in a plastic state.

What materials primarily compose the core?

Iron and nickel.

What is the estimated temperature of the Earth's core?

About 7000°C.

How many layers can the core be divided into?

Two layers: outer core and inner core.

What state is the outer core in, and why?

Liquid form due to high temperatures causing materials to melt.

What state is the inner core in, and why?

Solid form due to extreme pressure.

What are tectonic plates?

Pieces of lithosphere broken by internal forces of the Earth.

What characterizes oceanic plates?

Contain more oceanic crust than continental crust.

What characterizes continental plates?

Carries a continent.

What forces create plate movement?

Convection currents in the asthenosphere.

What are the three different types of plate boundaries?

Destructive, constructive, and conservative.

What happens at constructive plate boundaries?

Plates diverge and new crustal materials are formed.

What occurs at destructive plate boundaries?

Plates collide, and the denser one subducts into the asthenosphere.

What is the major internal force at conservative plate boundaries?

Lateral force.

What is the example given for a constructive plate boundary?

The boundaries between the Pacific Plate and the Nazca Plate.

What is an example of a destructive plate boundary?

The boundaries between the Pacific Plate and the Eurasian Plate.

What major landform represents a conservative plate boundary in the lecture?

San Andreas Fault.