Teacher Notes Activity title: Volcanoes on Mars: Lava Layering Target Age Group: Preparation: Activity Description: Scottish S1 S4 (approximately 12 16 years) Collect materials, download associated PowerPoint & Volcanoes on Mars Geology In A Minute video, print student worksheets The focus of this activity is observing and identifying the sequence of lava flows produced by multiple volcanic eruptions. Fluid lava flows are simulated and then modelled with various colours of play dough used to identify different eruption events. Students will be asked to observe where the flows travel, make a model, and interpret the stratigraphy. Time: 5-10mins introduction/preparation, 40mins activity, 5-10mins reflection Total: 50mins - 1 hour Learning Outcomes: Follow a procedure to produce a sequence of lava flows Materials: Think critically in order to construct a realistic model of a volcano Use observation, recording, and sampling techniques to construct and interpret the history of a volcano - containers for the centre of the volcano, to contain the eruption [probiotic/yoghurt drinks bottles, like yakult, work really well] - squares of cardboard - playdough, soft clay, or salt dough (see recipes below) [ideally at least 4 different colours] - tape and card/paper for building up the body of the volcano - baking powder, vinegar and food colouring - spoon for baking powder, beaker/plastic cup to measure vinegar - paper towels - marker pen, paper, pencils - (extension: clear plastic straws ideally fat ones, scissors) Student Organisation: This activity may be done individually or in small groups, depending on class size groups of around 4 usually work best Salt Dough: 2 cups flour, 2 tablespoons oil, 1 cup salt, 1 cup cold water, food colouring You can either use the quantities above to make one large batch of a single colour, or divide the ingredients in half to make 2 colours (ideally you need 4-6 colours of dough in total the quantities given make enough dough for approximately 4 palm sized balls). Mix all ingredients and knead until smooth and elastic. Store in air tight containers/plastic bags until ready for use.
Instructions: Lava Layering Activity Instructions [NB: steps 1-3 can be prepared in advance, or during a previous class] 1. Take the eruption container and secure it to the cardboard square 2. Using card/paper, build up the volcano shape around the container 3. Mark North, South, East, and West on the edges of the cardboard 4. Place a large spoonful of baking soda in to the eruption container (fold a piece of paper in half and use this to tip in the powder) 5. Pour vinegar into a plastic cup until approximately half full Optional: fill several cups and of vinegar and add a different colour of food colouring to each matching the playdough colours if desired 6. Set aside 4-6 palm sized balls of playdough, each in a different colour You are now ready to create an eruption! 7. Pour the vinegar into the container and watch the eruption 8. Draw around the edge of the lava flow with a pencil or marker 9. Use paper towels or a cloth to mop up the excess fluid from the flow 10. Using a thin layer of playdough, cover the entire area where lava flowed (matching flow colour/playdough if using food colouring) 11. Record information about the flow - indicate shape, flow direction, thickness, texture (is it foamy, with lots of bubbles or smooth), and also indicate where this flow is in the sequence flow 1, 2, 3 etc. 12. Repeat steps 7-11 for each colour of play dough available 13. Discuss the progression of flows, noting that the youngest flow of lava is deposited on top and the oldest is on the bottom of the lava successions 14. Sketch the volcano on the sheet provided, and answer the questions about volcanoes on Earth and Mars Extension Task: Swap volcanoes with another person/group so that you have a series of lava flows in front of you that you have not seen erupt. Take a clear plastic straw and carefully cut it in to three equal sections. Chose three points across the volcano and core the succession of lava flows by cutting through them with the end of the straw and lifting it out to reveal the layers of plasticine/playdough. Use the information collected from the cores to try to work out where the older lava flows (now covered) flowed can you recreate a map of all of the lava flows at this volcano using just the core information? Additional extension: Investigate the differences between types of lava by varying the relative amounts of bicarbonate/vinegar or adding washing up liquid etc.
Pupil worksheet 1. Look down on your volcano (birds eye view) and describe what you see. Illustrate/map out the different lava flows and add annotations, including observations of flows covering or overlapping other flows. Indicate direction (which way is north?) and add a scale bar (to show how far the flows have travelled) to your sketch. 2. Did the flows always follow the same path/flow the same direction? (be specific)
Pupil worksheet 3. What do you think influences the direction and path of lava flows? 4. If you had not watched the eruptions, how would you know that there are many different layers of lava? 5. Underline the reasons listed above that could be used to identify real lava layers on Earth. 6. What are other ways to distinguish between older and younger layered lava flows on Earth? 7. Which of the reasons above (from questions 4 and 6) do you think could be used to identify lava layers on Mars?
Pupil worksheet 1. Look down on your volcano (birds eye view) and describe what you see. Illustrate/map out the different lava flows and add annotations, including observations of flows covering or overlapping other flows. Indicate direction (which way is north?) and add a scale bar (to show how far the flows have travelled) to your sketch. North Flow 4 Volcanic neck West Flow 3 East Flow 1 Flow 2 Scale: 1cm = 2 cm South 2. Did the flows always follow the same path/flow the same direction? (be specific) No - some lava flows traveled in similar directions, but none took exactly the same path [e.g.] Two lava flows (flow 2 & 3) came out to the West of the volcano and spread out down the side, one came out of the East (flow 1) and only made it half way down the side of the volcano.
Pupil worksheet 3. What do you think influences the direction and path of lava flows? Steepness and shape of the sides of the volcano Angle of volcanic neck Path of previous eruptions Wind direction Obstacles in the way (takes easiest path) 4. If you had not watched the eruptions, how would you know that there are many different layers of lava? Different characteristics (colours in this case, textures/composition and subtle colour differences in reality) Overlapping - can seee edges of one flow being cut over by another flow Shape and direction of flows, several paths = several flows 5. Underline the reasons listed above that could be used to identify real lava layers on Earth. 6. What are other ways to distinguish between older and younger layered lava flows on Earth? Coring - may show top surface of lava flow/s undeneath (chilled crust from being in contact with air) Dating techniques to show ages of the flows are different Chemical analysis - different crystal chemistry might show different sources of lava 7. Which of the reasons above (from questions 4 and 6) do you think could be used to identify lava layers on Mars? Shape/direction and overlapping of flows (mapped from photographs) - similarly identification of different characteristics if photography is detailed enough Basic chemical analysis/coring could be used if rover mission visits