Plate Tectonics, Mid Ocean Ridges and Hydrothermal Vents

Clues About Earth Next Generation Science Standards

• This lesson is about plate tectonics and the investigative process scientists use to make hypotheses. • Next Generation Science Standards addressed include: – Earth and Space Sciences • The History of Planet Earth ESS1C • Earth Materials and Systems ESS2A • Plate Tectonics and Large-Scale Systems ESS2B – Engineering, Technology and Applications of Science • Developing Possible Solutions ETS1B

Outline • What physical evidence supports the theory of plate tectonics? • What are the three major ways to classify rocks? • How can plates move around? • communities and how technology changed what we thought we new about primary production. • Hands-on fun assembling a plate tectonic puzzle, complete with physical evidence of spreading, divergence and convergence.

A few details • Appropriate for grades 2-5 (level of detail can be adapted for each grade). • Duration: approximately 60-90 minutes for overview and activity (can be done over one or more days; will take longer the more detail students add) • The template for Earth’s plates can be found on slide #30. Supplies

• One foam board (the kind used to mount photos), approximately 12” x 15” per student. The size depends on if/how much you enlarge the plates in the template on slide #30. • Card stock paper: orange, light green, dark green, red, pink, yellow, blue (any seven colors, but be sure to color code correctly with the continent/plate names). Enough to make each puzzle piece for each student. NOTE: For the younger students, I cut the puzzle pieces prior to the lesson. • Glue, scissors, markers • Assortment of ‘evidence’ for students to glue onto the plate boundaries to support continental drift (I used shark teeth, sand, leaves, and pebbles (to show mountains/uplift at convergence zones). • Red and yellow tissue paper (magma) cut into small pieces to fill spreading centers in the ocean (Mid Ocean Ridges). • Assortment of art supplies to create hydrothermal vent (e.g., pipe cleaners, pompoms, gems, glitter—these can represent vent crabs, scale worms, tube worms, octopus, Pompeii worm, squat lobster…). • For each student, I print step-by-step instructions (slide #31) and on the back include the maps showing the different types of spreading centers (slide #32).

Do you ever wonder how we know what we know?

Clues About Earth First, we have an idea (hypothesis).

• Hmmm, there is something weird about these continents! Our great idea (hypothesis). • It sure looks like the continents have drifted apart! We look for clues.

• We need evidence for the continents spreading apart! • The pieces seem to fit like a jigsaw puzzle. Wow! Even the ocean pieces on the seafloor fit like a puzzle! More Clues

Rocks on both sides of the Atlantic ocean are similar (type and origin).

There are three kinds of rocks.

1. Igneous (fire) – Cooled magma or lava

2. Sedimentary ---Squished sand/pebbles that get pressed together

3. Metamorphic (changed rock) – Heat and pressure More Clues

• The fossils of animals and plants match on both sides of the Atlantic.

But wait! How could continents move? The answer is that Earth is made of different layers.

• Crust • Mantle • Outer Core • Inner Core

Each layer is made of different materials.

• Crust – Rock (granite, basalt) • Mantle – Hard rock, melting rock • Outer Core – Liquid iron and nickel • Inner Core – Solid iron and nickel

Crust+ Upper Mantle = Lithosphere

Plates are really the lithosphere! ‘Litho’ means rocky.

• The lithosphere “floats” on top of the softer lower mantle The plates are moving right now!

NASAs manned spaceflight mission Gemini XI view of the Red Sea and Gulf of Aden where the Arabian and African Plates are moving apart.

The plates move at about the speed at which your fingernails grow-- 2 cm to 10 cm per year. The places where plates meet are called boundaries. They interact in one of three ways. We put the pieces together to tell a story.

Our story is that Earth’s plates or continents move around like a conveyor belt or escalator.

In some places new crust is forming.

In other places old crust is being destroyed. It gets recycled in the mantle.

The story changes as we get new clues.

• What new clues will you find? We change our hypotheses as we get new information! • Until the 1970’s, we thought all “primary production” came from plants, using energy from the sun in a process called photosynthesis.

• With the study of plate tectonics, and new technologies to sample the deep ocean, scientists discovered hydrothermal vents near places where plates on the seafloor are spreading apart (Mid-ocean Ridges).

• Primary production here is not from photosynthesis, but from chemosynthesis. Instead of the sun, energy comes from chemicals, usually sulfide.

Hydrothermal Vents • We now know there are food webs far below the sea that rely on energy from a chemical compound, usually sulfide.

Technology let us go from a map of the sea floor to real pictures!

We find hydrothermal vents where the plates are moving away from each other. These spreading centers are called Mid Ocean Ridges. Some animals found at hydrothermal vents

Pompeii worm Alvinella Giant tubeworm Scaleworm

Eelpout cerberus Bythograea thermydron Squat lobster Munidopsis

Barnacle Neolepas

Octopus Vulcanoctopus hydrothermalis There’s a ‘hotspot’ under the Pacific Plate. It acts like a tunnel for magma to come from deep in the earth to the seafloor! The Hawaiian islands are the result of all that magma that cools. What will we do? • We will make a map using 7 puzzle pieces or ‘plates’ (even though we really know there are 15!) – African Plate – Antarctic Plate – Australian Plate (with Indian Plate attached) – South American Plate (with Nazca Plate attached) – Eurasian Plate – North American Plate – Pacific Plate

We will add arrows to show which way the plates are moving at the boundaries where they meet. 1. Toward each other • The Eurasian and Indian plates are converging. – The result is the Himalayan Mountains

2. Away from each other (diverge) • The Pacific and Antarctic plates are diverging • The South American and African plates in the South Atlantic • The North American and Eurasian plates in the North Atlantic These are called Spreading Centers and make up the Mid Ocean Ridges

3. Slide past each other • The Pacific and North American plates are sliding past in California

We will add ‘evidence’ to our map to support our continental drift hypothesis. • Add fossils to both sides of a plate boundary. • Add plants to both sides of a plate boundary. • Add the same sediment to both sides of a plate boundary. Bring your map to life!

• Add magma (lava) to the boundary between diverging plates in the ocean. • Add hydrothermal vent animals along these Mid Ocean Ridges. • Add mountains where the plates are coming together. • Show the “tunnel” (hotspot) below the Pacific Plate that is responsible for the Hawaiian Islands and add a few islands.

Step by step: Check each step as you go. 1. Write the names of the plates on each puzzle piece. For two pieces (yellow and pink), you will write TWO different names. African (orange) Eurasian (red) Pacific (blue) Antarctic (two pieces, both light green) North American (dark green) Australian and Indian (together on pink)

2. Glue your puzzle pieces to the black foam board.

3. Draw arrows at three places with different types of plate boundaries. Use the maps on the back of this page to help! – Plates moving toward each other (One example is the Indian Plate and Eurasian Plate.) – Plates moving away from each other (One example is the Pacific Plate and Antarctic Plate. Another example is the North American Plate and Eurasian Plate in the North Atlantic.) – Plates sliding past each other (One example is the Pacific Plate and North American Plate near California) 4. Add fossils to both sides of a plate boundary.

5. Add plants to both sides of a plate boundary.

6. Add the same sediment (sand) to both sides of a plate boundary.

7. Glue pebbles where the Indian and Eurasian plates are crashing together to represent mountains.

8. Bring your map to life! • Glue red and yellow tissue paper along a Mid Ocean Ridge to show magma at a diverging plate boundary in the ocean. • Add hydrothermal vent animals and minerals along these Mid Ocean Ridges. Use the different art supplies (pipe cleaners, pom poms, gems, glitter, etc.). Examples include vent crabs, scale worms, tube worms, octopus, Pompeii worm, and squat lobster. • Use your imagination to add the chain of Hawaiian Islands on the Pacific Plate. Use the map on the other side to help!

The red lines show where plates come together (converge). The pink lines show where plates slide past each other.

The lines show where plates move apart ordiverge.

The Hawaiian Islands are the result of a magma tunnel below the Pacific Plate. Work in progress! Questions or Comments?

Contact Chris Simoniello, Ph.D. GCOOS Outreach and Education Lead [email protected]