Chapter 6

Where is the radius of the Earth greater?

equator

A break in a rock mass where there is plate movement is called a

fault or fault line

What is the most abundant element in the Earth's core?

it is composed mostly of iron(32.1%), oxygen (30.1%), silicon (15.1%), magnesium (13.9%), sulfur (2.9%), nickel (1.8%),

Why does magma reach the Earth's surface?

less dense than the surrounding rocks and a structural zone in the Earth's crust enables movement. When it reaches the surface, magma is referred to as lava

Where does new ocean crust form?

mid-ocean

Which gas was not part of earth's early atmosphere?

oxygen

What is Procession and how does it affect the direction of the Earth's rotation axis.

the changing in direction of the spin of the axis

The heat in the earth causing convection in the mantle is from where?

the interior of the Earth to the surface. This hot added material cools down by conduction and convection of heat.

Stress in the Earth's crust is caused by

the plates moving

Is the polarity of the Earth changing?

yes

How much do the earth's plates move per year?

2.5 cm

What is the age of the Earth?

4.543 Billion years

What is the density of the Earth?

5.51 g/cm³

Who developed the continental drift hypothesis and why was it originally rejected?

Alfred Wegener, it was rejected because it challenged many established scientific theories at the time, and he lacked a compelling explanation for the cause of continental drift. He did not understand how the plates moved on the ocean floor or understand why/how they were moving.

What are Greenhouse gases made from?

CO2/Ozone

Where there is subduction, what occurs?

Convection currents drive one layer beneath another layer

How is density measured?

Density is calculated by the dividing the mass by the volume, so that density is measured as units of mass/volume, often g/mL.

What are the 3 types of plate boundaries and how do they move?

Divergent- move away from each other Convergent- two plates come together transform- Two plates sliding past each othe

Explain the Greenhouse Effect and how it is affecting global warming.

Greenhouse effect helps keep the warm gases close to the Earth. The greenhouse effect keeps the earth temperate. If the concentration of greenhouse gases is too high, the planet could warm too quickly. This is the greenhouse effect. Global warming is the process where Earth's temperature will rise and cause problems over time.

If the Earth is rotating more slowly, would you expect it to have as strong a magnetic field?

If the Earth rotated more slowly the magnetic field would be weaker due to rotational motion and convection. The Earth's magnetic field is driven by rotational motions in the liquid (and solid) core of the Earth, which in turn are related to the motion of the Earth as a whole. If the Earth rotated more slowly, we would expect the core to also rotate more slowly, and the field would not be as strong.

What are some of the most common elements composing the Earth's crust, mantle, and core?

Iron, oxygen, silicon, magnesium, aluminum

Is the crust less or more dense than the overall density?

Less dense

What are silicates?

Material composed of silicon and oxygen, and generally containing others substances as well ; ex: ordinary rocks

What is ozone? Where is it located and what is it made from?

Ozone is a gas made up of three oxygen atoms (O3). It occurs naturally in small (trace) amounts in the upper atmosphere (the stratosphere). Ozone protects life on Earth from the Sun's ultraviolet (UV) radiation.

What are the two different types of seismic waves and which ones travel through solids and which ones travel through liquids?

Primary and Secondary; P waves travel through both, while S waves can only travel through solids

The inner core of the Earth is solid/liquid? Why is it like this?

Solid The earth was once liquid and now the more dense materials are going to sink to the bottom. That is why we have an solid iron core.

Which of these layers are solid and which are liquid?

Solid: crust, mantle, and inner core ; liquid: outer core

What affects the jet streams?

The Coriolis force affects the jet streams

Think about a stone thrown from the pole to the Equator. If the Earth rotates faster, would the Corliolis Effect be larger?

The Corliolis Effect does make the object curve to the side, to the right. The effect is larger with faster rotation.

What is the composition of Earth's atmosphere?

The Earth's atmosphere is primarily nitrogen (78%) and oxygen (21%)

How does the eventual acceptance of the plate tectonic theory illustrate some aspects of the scientific method?

The acceptance of the plate tectonic theory demonstrates how scientists from different disciplines discover information, share the information and put the puzzle together. (Geographer, scientist studying fossils and a geologist.)

What are the layers of the Earth?

The crust, mantle, convection currents, outer core, inner core

How do we know this?

The denser materials (iron and nickel) are at the core, while the lighter materials (silicates) are more toward the surface or at the surface; differentiation explains this

What is the magnetosphere and where do they exist?

The region surrounding the earth or another astronomical body in which its magnetic field is the predominant effective magnetic field in the upper regions of the ionosphere where charged particles are strongly affected by the magnetic fields of Earth and the Sun.

What factors are thought to be responsible for the Earth's magnetic field?

The rotation of the Earth and the solid and liquid core.

Flicking your finger against your cheek makes a different sound from flicking it against your forehead. How is that similar to studying the interior of the Earth with seismic waves?

The speed of the seismic wave depends on the properties of the material that the wave is passing through. Your cheek is the flesh around your hollow mouth cavity. It is soft tissue. Your forehead is the bone of your skull containing your brain. They make different sounds because sound waves (and seismic waves) travel differently through material of different densities and states (solid, liquid). The vibration of a sound wave is very similar to the vibration of seismic waves.

How do Greenhouse gases affect the Earth?

The sun heats the earth during the day and then at night the clouds help keep the heat in so that the temperature doesn't drop a lot, it is like a blanket on the earth Greenhouses gases keep stuff from going to space and it a good thing but can raise the temperature.

How is age of rock determined?

They do through radioactive dating and decay. They can tell by how much % has decayed.

What does it mean that the Earth is differentiated?

This means that when the Earth's mixture of high and low density materials melted, the more dense materials sank and the lighter materials rose to the surface.

What will be the star above the North Pole in 14,000 AD?

Vega

When you choose fruit at a supermarket, you might heft the fruit in your hand to test its weight. How does this tell you whether the fruit is dried out inside? How is that similar to using mean density as an indicator of the composition of the Earth's interior?

When you heft fruit for weight, you are estimating the mass. Since fruit are approximately the same size (same diameter means same volume), you are also comparing the density, which will be higher for fruit with more water inside because water is fairly dense compared to dry plant matter. You are taking the average density of the fruit to find its composition in the same way that we measure the mean density

What are the Van Allen belts, where are they located and how are they shaped?

a torus of energetic charged particles (i.e. a plasma) located around Earth starting at the poles and surrounds the earth, They are shaped like doughnuts starting at the poles of the earth

The hypothesis called where the continents move slowly over time?

continental drift