Deep Earth Expedition Lab Sheet Deep Earth Expedition
Modeling the Layers of Our Planet
NAME: _________________________
DATE: _________________________
MISSION OBJECTIVE
Today, you will act as a geoscientist to visualize the vast scale of Earth's interior. Using data from the Crash Course Geography video, you will calculate the relative thickness of each layer and create a precise scale model using register tape.
REQUIRED GEAR
Register Tape (min. 1 meter)
Calculator
Meter Stick / Ruler
Colored Pencils
Quick Warm-Up
Recall from the video intro: Earth's atmosphere is considered the "first shell." List the four layers beneath the atmosphere mentioned in the journey to the center:
Phase 1: Field Data Collection
Watch the first 3 minutes of the video. Record the data provided for each layer below.
EARTH LAYER THICKNESS (KM) COMPOSITION (Major Elements) STATE OF MATTER Crust (Combined) Varies (use ~40km) Solid Mantle Solid (Plastic) Outer Core Inner Core ~1200km
Phase 2: Scaling the Planet
SCALE FACTOR:
1 cm = 100 km
Example: If a layer is 500 km thick,
Calculation Workspace
<table class="w-full text-center"><tbody><tr class="bg-slate-50 text-xs font-bold text-slate-500"><td class="py-2 border">LAYER</td><td class="py-2 border">ACTUAL KM</td><td class="py-2 border">MATH (Divide by 100)</td><td class="py-2 border bg-emerald-100 text-emerald-900">MODEL CM</td></tr><tr><td class="py-4 border font-bold">Crust</td><td class="border">40 km</td><td class="border text-slate-400">40 / 100 =</td><td class="border font-black text-emerald-700 bg-white"></td></tr><tr><td class="py-4 border font-bold">Mantle</td><td class="border">2900 km</td><td class="border text-slate-400">2900 / 100 =</td><td class="border font-black text-emerald-700 bg-white"></td></tr><tr><td class="py-4 border font-bold">Outer Core</td><td class="border">2400 km</td><td class="border text-slate-400">2400 / 100 =</td><td class="border font-black text-emerald-700 bg-white"></td></tr><tr><td class="py-4 border font-bold">Inner Core</td><td class="border">1200 km</td><td class="border text-slate-400">1200 / 100 =</td><td class="border font-black text-emerald-700 bg-white"></td></tr></tbody></table>
Total Length Required:
Phase 3: The Cross-Section Model
1
Measure the total length from your math on the register tape. Mark your start (Surface) and end (Center).
2
Use your ruler to mark the boundaries of each layer based on your CM calculations.
3
Label each layer and include its State of Matter (Solid, Liquid, etc.).
Color Coding Key:
Silicates (Rocks/Sand)
Iron & Nickel
Field Reflection
Scientists note that the Inner Core is roughly 5,200°C—even hotter than the liquid Outer Core!
Why is the Inner Core solid if it's hotter than the liquid Outer Core?
Deep Earth Expedition Slides Deep Earth Expedition
7th Grade Earth Science
EST. 4.5 BILLION YRS AGO
MISSION OBJECTIVES
1
Identify the thickness and composition of Earth's four internal layers.
2
Calculate and draw a scale model to represent relative size accurately.
3
Explain how pressure affects the state of matter at Earth's center.
Warm-Up (5 min)
The video mentions the atmosphere is the "first shell."
Can you name the four layers that lie beneath our feet?
1. _______________
2. _______________
3. _______________
4. _______________
Phase 1: Observation
0:00 - 3:00
Embedded media
Look & Listen For:
Thickness in km
Composition (Elements)
State of Matter
The Scale Challenge
Our Scale Factor:
1 cm = 100 km
Earth is too big to draw on a regular piece of paper. To see the whole interior, we use Scaling.
Practice:
200 km 2 cm
2,900 km ? cm
Rule: Divide the actual thickness by 100!
Assembly Instructions
1
MEASURE
Mark your "Surface" start. Use your cm math to mark layer boundaries.
2
LABEL
Write the name and state of matter (Solid/Liquid) for each section.
3
COLOR
Grey/Brown = Silicates
Orange/Red = Iron
The Core Mystery
Why is the Inner Core solid if it is hotter than the liquid Outer Core?
Hint: Pressure vs. Temperature
Deep Earth Expedition Transcript Expedition Transcript
Video: Crash Course Geography #18 (0:00–3:00)
[00:00]
Narrator From towering mountains to the gravel and pebbles along a river, Earth's solid exterior is made of a huge variety of rocks.
[00:41]
Alizé Carrère Way back 4.5 billion years ago, when the solar system was forming, the Earth solidified as a swirling nebula of dust and gas... the Earth formed its spheroid shape made up of different shell layers.
[00:57]
Alizé Carrère In fact, even though we sometimes think of it as being separate from the Earth, the atmosphere is really the first and lightest shell with its own set of layers.
[01:05]
Alizé Carrère At the bottom of the atmosphere, things start to feel more solid and we hit Earth's crust. Compared to the rest of the planet, the crust is extremely thin and has a low density...
[01:28]
Alizé Carrère There are actually two types of crust: Continental and Oceanic. Continental crust... is made of light-colored and lightweight rocks rich in silicon and aluminum.
[01:46]
Alizé Carrère Oceanic crust is made of heavy, dark-colored iron-rich rocks that also have a lot of silicon and magnesium. It's denser... but only a few kilometers thick.
[01:59]
Alizé Carrère Beneath the crust is the much thicker mantle. It stretches for roughly 2900 kilometers and is rich in elements like iron, magnesium compounds, and combinations of silicon and oxygen called silicates.
[02:20]
Alizé Carrère The last layer in our journey to the center of the Earth is the core, made of iron and nickel. The 2400 kilometer thick outer core is so hot, all that iron becomes molten and turns to liquid.
[02:31]
Alizé Carrère But the hot, dense inner core of iron... is always solid because of the tremendous pressure.
[02:38]
Alizé Carrère No one has been to the center... but scientists study how seismic waves from earthquakes travel through the planet to model the interior.
Quick Reference Table
Crust
~40 km
Mantle
2900 km
Outer Core
2400 km
Inner Core
~1200 km
Deep Earth Expedition Teacher Guide Teacher Guide
Lesson ID: EARTH-INT-07
Deep Earth Expedition
FACILITATION & MODELING GUIDE
Lesson Overview
This lesson challenges students to create a mathematically accurate scale model of Earth's interior using register tape. By converting actual kilometers to centimeters (1cm = 100km), students visualize the overwhelming thickness of the mantle and core compared to the razor-thin crust we live on.
Pacing
Warm-Up: 5 min
Video/Data: 10 min
Math/Scaling: 10 min
Modeling: 20 min
Debrief: 5 min
Materials
• Register tape (1 meter/student)
• Meter sticks or 50cm rulers
• Calculators
• Colored Pencils (Grey, Red, Orange)
Key Concept
"The crust is extremely thin and has a low density... Igneous rocks make up about 90 percent of the Earth's crust."
State of Matter Hook:
Emphasis that despite extreme heat, the inner core is SOLID due to the weight of everything above it (pressure).
Phase 1 & 2: Answer Keys
Video Data Key
Layer Thickness Elements Crust ~40 km Si, Al, Fe, Mg Mantle 2900 km Fe, Mg, Silicates Outer Core 2400 km Iron, Nickel (Liquid) Inner Core 1220 km Iron (Solid)
Math Key (1cm = 100km)
Layer Model Size Crust 0.4 cm (4 mm) Mantle 29 cm Outer Core 24 cm Inner Core 12.2 cm TOTAL 65.6 cm
Expedition Log: Teaching Tips
The "Crust" Problem
Students will struggle to measure 0.4 cm (4 mm). Use this as a teaching moment! Earth's crust is so thin compared to the rest of the planet that we can barely represent it at this scale. Have them draw the thinnest line they can with their pencil.
The "Plastic" Mantle
Students often think the mantle is liquid because of "magma." Clarify that the mantle is solid rock that can "flow" very slowly over millions of years (like silly putty or cold honey).
