In the darkest regions of deep space, the temperature is a chilly -450° Fahrenheit. Closer to our Sun, temperatures reach thousands of degrees Fahrenheit. What makes Earth’s climate so moderate? Separating Earth from the extreme and inhospitable climate of space is a 500-mile-thick cocoon of gases called the atmosphere.
All planets have an atmosphere, a layer of gases that surrounds them. The Sun’s atmosphere is made up of hydrogen, while Earth’s is made up primarily of nitrogen and oxygen. Carbon dioxide, ozone, and other gases are also present. These gases keep our planet warm and protect us from the direct effects of the Sun’s radiation. Without this regulation, Earth could not sustain life.
Today we will start to learn WHY the earth’s atmosphere is so important to life. We will also discuss the major gases in the atmosphere and learn why each of them is so important.
From here we will then do an online activity called AstroVenture!
And when you have finished the AstroVenture Assignment,
This week we will be watching the movie SUPERVOLCANO as a final salute to geology! It’s a great story about the eruption of the massive volcano underneath Yellowstone National Park. With all you have learned in your geology unit and our park projects, you should really enjoy the movie. Click on the title above to see the movie at home on YouTube.
Ckick HERE to go to the Yellowstone Volcano Observatory Website
Processes at Earth’s surface and heat within Earth cause rocks to change into other types of rocks.
All rock started as magma. The rock cycle started with the cooling of the earth’s magma billions of years ago. But after that, it has no end. Rather, it is an ongoing cycle in which rock — driven by tectonic processes such as volcanoes and earthquakes, the surface processes of weathering and erosion, and compaction — is created and destroyed.
For this assignment, you will go to the following web site:
Open the Interactives Rock Cycle in a different window.
This interactive web site will help you to review the types of rocks and the processes that occur within the rock cycle. Instructions given on the web site will lead you through the different sections of material.
In this part of the tutorial, when you click on the rock sample, you will be provided with the name of the rock as well as information on how the rock forms and where it can be found. Make sure to add the rocks to your collection.
The next section, “Identify Rock Types”, will allow you to test your ability to recognize rock characteristics and types. Note: this section is timed (six minutes…more than enough time to complete the activity).
When you have completed this self-test, go on to the next section, which describes How Rocks Change. Be sure to view the animation sequences provided for each rock family!
At the end of this section, complete the self-test Transform the Rock to see if you can identify the processes that can change rocks from type to another.
This self-test is timed (six minutes); to complete the sequence, click and drag your answer into the appropriate box.
The next section describes the rock cycle and also includes a self-test Complete the Rock Cycle to see if you can name the different parts of the rock cycle.
The final activity at the web site is a Test Your Skills assessment to see how much you have learned.
Enter your first and last name in the space provided. When you have completed the assessment, print out your results. Make sure that you print out the complete results. Do not just print your score. You must show your teacher the printout with all of the graded questions to get credit.
This will then become your Study Sheet!
Alternate Assignment:Rocky’s Journey
You are now a well-educated geologic student of The Rock Cycle!
These are a few videos and presentation tools produced by last year’s 8th graders for their National Park Projects. We’ve been exploring different tools to use more of today’s Web 2.0 technology in our classroom work, and the park projects have created a great opportunity for many of you to explore and push yourselves. Hopefully the work below will motivate you to work with the tools this year!
This week we are completing our study of Earthquakes as an example of a rapid change to the earth’s crust. Below is a Study Guide for this week’s Chapter 2 Test. All the background detail is in your Notes Packet – the outline below provides the main bullets.
Click on the picture below to see an animation of how a seismograph works.
What shakes, and what doesn’t?
Click on the picture below to see
HOW TO FIND THE EPICENTER of an EARTHQUAKE
THIS WEEK’S LESSON
Earthquakes are a form of wave energy that is transferred through the crust. Motion is transmitted from the point of sudden energy release, the focus, as seismic waves that travel in all directions outward. The point on the Earth’s surface directly above the focus is termed the epicenter.
SEISMIC WAVES AND THE SLINKY
P-waves or primary waves are formed by the alternating compression and expansion of the crust. They are the first to arrive at a seismograph station, and travel in a straight line. Think of the slinky we did in class!P-waves also have the ability to travel through solid, liquid, and gaseous materials.
S-waves or secondary waves are formed by the side-to-side movement of the crust. They are the second to arrive at a seismograph station, and travel more slowly. Think again of the side-to-side slinky we did in class, or look at the example below.
S-waves have the ability to travel through solids, but stop at liquid and gaseous materials.
What does that mean as the waves travel through the earth’s layers?
What happens at the Outer Core?
What does this help geologists to know about the Outer Core?
Surface waves are something like the waves in a body of water — they move the surface of the earth up and down. This generally causes the worst damage because the wave motion rocks the foundations of manmade structures. Surface waves are the slowest moving of all waves, so the most intense shaking usually comes at the end of an earthquake.
1. Go to the USGS – Earthquake Center Website, this shows all the activity for the past 7 days. Find yesterday’s earthquake data.Click on the map above, or the link above, to open that web site.
2. Choose 3 different earthquake locations, with magnitudes of 3.0 or higher, and plot them on the map provided using a colored pencil.
3. Each date will be a different color, for example 11/24/14= red, 11/25/14= blue, etc… On your map, create a key to indicate when those earthquakes occurred.
4. Continue until you have 5 days plotted on your map (25 data points total).
You will find the earthquakes for each day this week, record the earthquake data, and then plot the location of the earthquake on the map you received in class. By the end of the week you will have all 5 charts completed.
We will use the information from the chart, and what we had discussed in class, for a WORM activity on Monday, December 14.
If you cannot find your map, click on the map below for another copy.
If you cannot find your worksheet, click here for another copy.
You may also use an APP that you find for your Smart Phone or Tablet. Look for “Earthquakes” apps that provide real time data.
Click on the picture below to take you to
Read the article and complete the answers on the screen.
Keep trying until you get 8/8 correct!
When you get them all correct, print out the page that looks like the picture below, or complete the worksheet from class.
In class this week we will look at the movement of the Earth’s crust along a crack in the crust called a fault. The earth slips, slides or drops along these faults depending on the stress involved, and the direction of movement. We discussed three types of stress – tension, compressionand shearing.
WORM NEXT WEEK!
Click on the picture above to see the animations of the Fault Motions. Think and answer the following questions:
Along what type of plate boundary might you find COMPRESSION stress? _________________
Along what type of plate boundary might you find TENSION stress?
Along what type of plate boundary might you find SHEARING stress? _________________
(Credit to Mr. Parr – creator of many YouTube Videos for students)
Convection Currents in the Earth
As we were studying Continental Drift, we learned that although Alfred Wegener had a great theory, he was not able to explain HOW the continents moved. About 60 years later geologists started to look at the ocean floor, and they discovered that the ocean had a very long range of mountains which they called the Mid-Ocean Ridge. Scientists also learned more about what was happening in the mantle, and found that the heat of the core was creating Convection Currents n the mantle.
The tectonic plates rest on the asthenosphere, a layer of soft rock. Rock in the asthenosphere and in the rest of the mantle moves from convection.
Convection is energy transfer by movement of a material. Heat causes material to become less dense – it then rises, cools, becomes denser and then sinks, only to repeat again. In a pot of boiling water, the water gets heated at the bottom, rises to the top, cools when it hits the air, and then sinks again, forming a looped current.
Click on the picture to see the animation.
The core of the earth makes the heat. It causes the molten material in the mantle to rise, cool and then sink back to the center, where it gets heated again. Notice how the convection currents in the earth are all around the mantle, heated by the core.
The lithosphere is broken into tectonic plates, and these float on the asthenosphere. As the convection currents flow, the floating plates also move, very slowly, about an inch a year. This is what caused the continents to move! Look closely at the diagram, and then clink on the link below to see the movement.
As you can see by the animation, the convection currents in the mantle make the plates in the lithosphere move. Some of them move together to collide at a CONVERGENT BOUNDARY to form mountains, and some of them move apart at a DIVERGENT BOUNDARY to form cracks in the crust. Magma comes up through these cracks, creating a Mid-Ocean Ridge on the sea floor.
Click on the link below to see how new ocean crust is being made at the Mid-ocean Ridge, and that the new crust is pushing the older crust away. The farther you go from the ridge, the older the crust is. This is one way that scientists can prove that the plates are actually moving!
Click on the picture above to see the animation.
In class we then took notes on the Smartboard to review the convection currents in the mantle, their effect on the plates of the lithosphere, and we had an introduction to DIVERGENT and CONVERGENT boundaries. The plates move because of the convection currents in the asthenosphere (mantle) forcing the plates to flow with the current.