A more recent version of this post can be found at https://inventorsoftomorrow.com/2017/01/30/earth_quakes-2/
Our theme this week was the Earth and earthquakes. As always, we began class with Discovery Time, where we let kids explore all our activities hands-on (activities are described later in this post), before we talk to them about the day’s concept or the scientific theories we’ll be discussing. This raises their curiosity, allows for a-ha moments of independent learning, and raises questions which helps them engage more with the answers we give. Then we have opening circle, then tinkering time to explore more.
Today’s question: What causes an earthquake?
To answer the question, we have to step back a little and talk about the plates of the earth’s crust. Before we do that, we have to step back and explain what the earth is and what it’s composed of. (When working with young children, it’s important to do this stepping back – don’t assume they already know science basics – be sure to cover them!)
So, the order of ideas we wanted to express were:
- Earth is the planet that we live on.
- It’s shaped like a ball, but the ball is made up of many layers.
- We live on the top layer, the crust.
- The crust is made of several big plates that fit together like a puzzle.
- When those plates bump up against each other, or rub against each other, they cause earthquakes. Little earthquakes happen all the time, and mostly don’t cause damage.
- But, a big earthquake can knock over trees and buildings, so we do need to know what to do to stay safe if we feel an earthquake.
In the morning, we tried leading an interactive discussion of all these topics, with props, and it worked OK, but the kids were kind of squirrelly and un-focused. In the afternoon, we instead used a book to guide the discussion. The familiar routine of settling down around a book helped to settle the class energy and keep them more focused. We read Earthquake! by Bauer, which covered all the ideas we wanted to cover in simple-to-understand terms. It had pictures of buildings that had fallen over or been damaged in earthquakes, but they were not frightening (many kids’ books about earthquakes have pictures or words that could cause a lot of fear and anxiety.) When reading through the book, you can incorporate hands-on visual aids. There was a picture of a globe, and if you have one, you could pause a moment there to explain what a globe is. When it discussed the layers of the Earth, we showed our model magic sphere (see below) – we could have also used the rainbow puzzle (see below). We then passed around the sphere for them to touch. When the book talked about how the crust is broken into pieces that fit together like a jigsaw puzzle, we showed our tectonic plate jigsaw (see below). When it talked about plates bumping up against each other, we showed with a cracker what happens. (As described on Mad Sci Network. There’s a more complicated graham cracker demo on Homeschool Den.) The book also showed a picture of a seismograph, so we reminded them to check out our DIY seismograph in the other room.
Tumbling Mat Demo of Tectonic Plates: We had set up the mats on the floor in advance for the kids to sit on during circle. At this time, we had them get off the mats, and told them to imagine that the blue mat and the rainbow mat were two tectonic plates bumping up against each other… we pushed each one toward the other… The rainbow mat buckled up to relieve the pressure – creating a mountain!
Earthquake Drill: We talked about the fact that today we’re playing with the idea of earthquakes, and having fun knocking over Duplo houses and plastic trees with fake earthquakes. But, we said, real earthquakes can be scary when they happen and can be dangerous, and you need to know what to do. We explained that when the ground shakes it can knock you over, and also things can fall on you, and you could get hurt. So, if the ground starts shaking, you need to drop, cover and hold on. We practiced doing this together during circle (in a room with no tables) and then practiced again later in the day while the kids were in a room with tables.
For adult reference, here’s the current recommendations on what to do (source):
- DROP down onto your hands and knees (before the earthquakes knocks you down). This position protects you from falling but allows you to still move if necessary.
- COVER your head and neck (and entire body if possible) under a sturdy table or desk. If there is no shelter nearby, only then should you get down near an interior wall (or next to low-lying furniture that won’t fall on you), and cover head and neck with your arms and hands.
- HOLD ON to your shelter (or to your head and neck) until the shaking stops. Be prepared to move with your shelter if the shaking shifts it around.
What NOT to do: Do NOT stand in doorways. In modern buildings, the doorways are no stronger than other parts of the house. You are safer under a table. Do NOT go outside. Although it is safer to be near an interior wall, away from windows, it’s not a good idea to run to another room during an earthquake. It’s better to drop, cover, and hold.
“Rabbits in the Hole” story. Preschools and parents of little ones can use a story to frame their earthquake drill. You can make up your own story about a mama rabbit that warns its babies of danger and tells them to run into the hole to be safe, and then extend that idea to hiding under a table, or “making your own hole” by covering the back of your neck and head. Then when it comes time for earthquake drills, you could call “bunny in a hole” have the kids practice drop, cover, and hold.
I have written a Bunnies in the Hole book you can download and print. Here’s the PDF.
Weekly Engineering Challenge – Every week, we have a challenge activity which encourages kids to build something, test it, re-build it…
Duplo Shake Tables: I built two shake tables (earthquake simulators). For the first, I took two duplo base plates and rubber-banded together, back to back. Then inserted four rubber bouncy balls in between them, one at each corner. For the second, I cut the cover off an old three ring binder to get two stiff “boards.” Then I placed two dowels between them for them to roll back and forth on, then rubber banded that together, and taped a Duplo base board to it. On both shake tables, if you bump a corner or pull back then let go of one side, it would jiggle and shake.
We had Duplos out, so they could build Duplo towers. If they built a very tall tower, the “earthquake” would knock it down. Unfortunately, Duplos are pretty sturdy, and it was easy to buid towers that could withstand the shake. We’ll bring the shake tables back in our unit on Engineering: Towers and try other materials on the shake table that are more challenging to make earthquake proof.
For detailed instructions on building shake tables, and related activities / discussions, see www.scientificamerican.com/article/bring-science-home-earthquake-proof-engineering/ or www.pbslearningmedia.org/resource/kqed07.sci.ess.earthsys.lpquakes/living-with-earthquakes/ or the video here: www.raftbayarea.org/ideas/Shake%20Table.pdf#)
Science Exploration Activities (during Discovery Time and Tinkering Time)
Earthquake on Sand: We filled a large pan with sand, then placed nearby plastic fences and trees and some flat rocks. We also put a back massager tool next to it that could be used to create a vibration. If you held the back massager to the side of the pan just right, the sand would start to jiggle, then shift and move, knocking over the trees and fences, carrying the rocks across the pan – flowing almost like water. Clear evidence for why not to build on loose soil in an earthquake zone!
Seismograph: On the table with the back massager activity, we placed our home-made seismograph which could be used to track the vibration of the “earthquake.”
The seismograph is built with a cereal box, a plastic champagne glass, string, pennies for weights, and a marker. You feed adding machine paper through slots, and the marker tracks the vibration. (A seven year old in the class also built one at class, using a cup from an egg carton as a substitute for the plastic champagne glass.) Here’s the sign I made to go with the seismograph. Find directions to make your own seismograph here: https://www.mrsec.psu.edu/sites/mrsec.psu.edu/files/education-outreach/make_a_working_seismograph.pdf
Understanding Earth’s Layers. We put out 4 ways to illustrate earth’s layers – an illustration, nesting easter eggs, a model of the earth, and a puzzle of nesting rings. The model was made with Model Magic – on Monday, I made a ball of white clay for the inner core and let it dry overnight. On Tuesday, I covered that with a layer of red for the outer core – you’ll see that my proportions are off – I need less white or more red. On Wednesday I added the yellow “mantle” and let it dry. On Thursday, I painted it – the paint layer is the Earth’s crust. On Friday, I very carefully cut it in half with a bread knife.
Understanding Tectonic Plates – a jigsaw puzzle. This is easy – just find an illustration online of a world map with the plates shown. Print it, laminate it, cut it along the fault lines.
Make a Tsunami Wave – we filled the water table with water and some glitter. You can create a wave by simultaneously lifting and pushing one end of the table. (The kids can also just splash in the water.)
Rock Sifting: In the sensory table, we put sand, then tossed in some pebbles and bigger rocks, then added scoops and sifters. They could fill the sifter with sand, shake it till all the sand fell out, and see the pebbles and rocks. Optional: You can talk about rock formation with this… here’s a site that discusses erosion, transport, deposition and cementation: http://education.usgs.gov/lessons/schoolyard/RockSedimentary.html
Observation Table – Rocks. One of the key skills we need to build in a young scientist is observation – learning how to look at an object in depth, describe it, and sort it by multiple criteria. Rocks are a great opportunity for this. We put out a collection of rocks, magnifying glasses, and a book to help them learn more: We used Rocks: Hard, Soft, Smooth, and Rough by Rosinsky. The older kids were very actively using the book as a resource for their exploration. Other good resources on rocks are: School Yard Geology and Every Pebble Tells a Story.
Art Activities (Process-focused – not beautiful products!)
Puffy Paint Earth: We mixed shaving cream, Elmer’s glue, and green liquid watercolor to make puffy paint to paint on to blue cardstock circles. We had a photo of the Earth posted next to the table for inspiration. You could do more with this by having cotton balls to pull apart to make clouds, and pebbles to build mountain ranges on your continents.
Coffee Filter Earths: We put out coffee filters, liquid watercolors and pipettes, plus pictures of the Earth for inspiration. Kids could drip on watercolors. With little ones, they tend to use a LOT of watercolor when working with pipettes, and soak the trays, so after they finish with a coffee filter, you need to use paper towels to mop up their extra color. You could reduce this issue by using eye droppers with a slow flow rather than pipettes. If it’s warm out, you can hang coffee filters on a string, and let kids spray them with spray bottles of diluted colors.
As well as being a fun process, this also produces a nice product – worthy of gift giving, so you could choose to do this project right before a holiday and make them as gifts. (See photo at top of post.)
Students were asked to bring a clean glass jar from home, such as a peanut butter, spaghetti sauce, or applesauce jar. We explained that the earth was made of layers of different kinds of rocks, and this layering activity was a way to experience that. We set it up assembly line style, where kids went down the line, and put in first sand (this is an optional layer – it’s an inexpensive way to fill a little space at the bottom of the jar), then rocks and pebbles (important for drainage), then charcoal (to reduce odors and mold), then soil, then the plant. (We used cacti and succulents.) When you remove the plant from its little pot, you do need to shake off some of the extra soil to expose the roots and make it easier to nest down into your soil. You should pack the soil in a little around the plant, or water it to compress it a bit – otherwise, the first time they water it at home, the soil compresses and leaves the plant poking up out of it a bit.
Note: This project is more expensive to do than most of the projects I discuss on this site. (Especially if you buy all the products at a specialty garden store two days before the class…) As an FYI, here’s the products / quantities we used to make 20 terrariums.
Horticultural Sand – 1 quart ~ $6. (If you have clean play sand, that may be a cheaper option.) Decorative garden rocks – 2 pounds of pebbles, 1 quart of larger rocks ~ $9. (Again, you could probably “wild gather” your rocks, but you’d want to clean them so the terrarium is a pretty clean system.) Horticultural Charcoal – 1 quart – $10. Cactus Soil – 3 quarts ~ $9. (Note: those are approximate costs you’ll pay in a store – if you buy from Amazon, you may have additional shipping costs.) Succulents – 20 – $30. (The $30 is if you order a week in advance from Amazon – I paid $60 buying them at the garden store just before the event.) So, it works out to $3 or more per kid. ($5 the way I did it… )
Snack – Layers. You can either do a yogurt parfait where kids layer together yogurt, fruit and granola, or a mud cup where they layer together chocolate pudding, bananas, crumbled graham crackers, and a gummy worm.
Closing Circle – Younger Kids (3 – 4 year olds)
Book: If You Find a Rock by Christian. “If you find a rock – a big rock – by the edge of the water, then you have found a splashing rock. When it hits the surface, the water jumps out of the way… the bigger the rock, the wetter you get. If you find a rock – a great rock – that towers over you, then you have found a climbing rock. Hold on with your toes and fingers, grip hard as you stretch up and pull until you reach the top, where you feel much grander than you did on the ground.”
If you can’t find this book, a nice alternative is Everybody Needs a Rock by Baylor. This is a lovely book about finding a very special rock to carry with you. “Don’t get a rock that is too big. It won’t fit your hand right and it won’t fit in your pocket. A rock as big as an apple is too big. A rock as big as a horse is MUCH too big. Don’t choose a rock that is too small. It will only be easy to lost, or a mouse might eat it, thinking that it is a seed…”
(Either book would also be a great read before a hike to somewhere your child could find a special rock. They both do a nice job of making rocks feel special and uniquely important to a child.)
Rock Exploration: We brought in the rocks from the exploration table, and discussed as a group their colors, we found the biggest and smallest ones, we picked out all the rough ones from the smooth ones, and so on. This is great pre-academic skill building. Another activity you could add here is to ask each child to pick out one rock to study in detail and talk over with their parent or another child. Then put all those rocks into a basket of rocks, pour it out on the floor, and ask them to find their own rock again. This is a good test of their observation skills, and teaches visual discernment of details.
Parachute earthquake: Get out a parachute. Throw a soft ball or other object in it. Make an earthquake, shaking and shaking till the object flies out. Repeat endlessly. 🙂
Optional – could also read Round Like a Ball, a nice book about the Earth.
Closing Circle – Older Kids (age 5 – 7)
Book: Either Roslyn Rutabaga and the Biggest Hole on Earth! by Gay – a fun little book about digging a hole to the center of the earth, or Pandas’ Earthquake Escape by Perry, which is about a mama panda and her babies escaping an earthquake. The nice thing about this book is its an engaging story about a mother and her children (the kids really enjoyed listening to it), but I think it’s a bit long for circle, and it also shows animals running away in an earthquake to try to find safety, when we’ve just taught that the best thing is to drop, cover and hold.
Slinky Waves: You can use a slinky to illustrate two kinds of earthquake waves. For a p-wave, you stretch it out, then give a quick push-pull on one end – the wave travels to the other end and back again. For an s-wave, you swing it side to side – this works better if the slinky is laid on a table than if it’s held in the air. Here’s two detailed discussions of this activity: http://web.ics.purdue.edu/~braile/edumod/slinky/slinky.htm and http://earthquake.usgs.gov/learn/kids/RockShakeyGround.pdf (Note: this second link is also just a great overall resource about earthquakes.
The Human Wave: This is good IF the kids have recently studied States of Matter. Have the kids put their arms over each other’s shoulders, chorus line style. (They’re solid matter.) Put one teacher on each end of the line. Push on the shoulder of the kid on the end – they all rock toward the other teacher – she pushes back… this is how a P wave moves through solid. Then have the last person in line bend forward at the waist, then straighten up again – that spreads down the line – this is an S wave moving through solids. Then have kids stand shoulder to shoulder but without linking up – they’re now a liquid. The p-wave will still travel through them, but the S wave will not. Learn more here: www.iris.edu/hq/files/programs/education_and_outreach/aotm/6/Activity-HumanWaves.pdf)