The Earth in Space Chapter 2 Section 1

2.1 Earth: A Unique Planet 70% of the earth is Salt Water. 70% of the earth is Salt Water. The earth is surrounded by a blanket of gases called the atmosphere The earth is surrounded by a blanket of gases called the atmosphere The atmosphere is made up of 78% nitrogen, 21% oxygen, 1% other gases. The atmosphere is made up of 78% nitrogen, 21% oxygen, 1% other gases.

2.1 Earth: A Unique Planet The solid outermost zone of the earth is called the crust. The solid outermost zone of the earth is called the crust. Beneath the oceans, the crust is called oceanic crust. Beneath the oceans, the crust is called oceanic crust. The part of the crust that makes up the continents is called continental crust. The part of the crust that makes up the continents is called continental crust.

2.1 Earth: A Unique Planet Below the crust is the mantle. Below the crust is the mantle. The uppermost part of the mantle is cool and brittle. The uppermost part of the mantle is cool and brittle. This part and the crust make up the lithosphere. This part and the crust make up the lithosphere.

2.1 Earth: A Unique Planet The bottom portion of the mantle is called the asthenosphere. The bottom portion of the mantle is called the asthenosphere. Because of the enormous heat and pressure, the solid rock of the asthenosphere has the ability to flow Because of the enormous heat and pressure, the solid rock of the asthenosphere has the ability to flow

2.1 Earth: A Unique Planet Below the mantle is the core. Below the mantle is the core. It is mostly made of iron. It is mostly made of iron. Scientists think the outer core is a dense liquid layer. Scientists think the outer core is a dense liquid layer. The inner core is a dense solid layer The inner core is a dense solid layer

2.1 Earth: A Unique Planet There are 2 types of seismic waves. There are 2 types of seismic waves. Primary waves or P waves Primary waves or P waves Secondary waves or S waves Secondary waves or S waves P waves travel through solids, liquids, and gases P waves travel through solids, liquids, and gases S waves only travel through solids S waves only travel through solids

2.1 Earth: A Unique Planet P waves travel faster than S waves P waves travel faster than S waves Both P and S travel faster when they are going through more rigid material. Both P and S travel faster when they are going through more rigid material. S waves cannot travel through the core, only the P waves can. S waves cannot travel through the core, only the P waves can.

2.1 Earth: A Unique Planet The speed of seismic waves increases abruptly from 32km to 70km beneath the surface. The speed of seismic waves increases abruptly from 32km to 70km beneath the surface. This is the boundary between the crust and the mantle. This is the boundary between the crust and the mantle. This is called the Moho. This is called the Moho.

2.1 Earth: A Unique Planet The earth’s magnetic field affects an area that extends beyond the atmosphere. The earth’s magnetic field affects an area that extends beyond the atmosphere. This region is called the magnetosphere. This region is called the magnetosphere.

2.1 Earth: A Unique Planet Gravity is the force of attraction that exists between all matter in the universe. Gravity is the force of attraction that exists between all matter in the universe. The larger the masses of the 2 objects and the closer together they are, the greater the force of gravity will be between them. The larger the masses of the 2 objects and the closer together they are, the greater the force of gravity will be between them.

2.1 Earth: A Unique Planet Weight is a measure of the strength of the pull of gravity on an object. Weight is a measure of the strength of the pull of gravity on an object. Weight and mass are not the same Weight and mass are not the same Mass is the amount of matter in an object. Mass is the amount of matter in an object. Weight is the force of gravity on that matter. Weight is the force of gravity on that matter. You weigh more at the North Pole than at the equator. You weigh more at the North Pole than at the equator.