I started by returning to a Core Sample from Interpreting Earth's Layers, and asked what type of information could be learned about our earth from samples like these (what types of land, whether there was water, what types of living things were there in the past). Then I ask them to make a prediction about what type of information scientists might be able to get from glaciers.
Next, showed them Melting Mountain Glaciers from Science360.gov, and asked them to look for similarities and differences. It's a little high, but I paused it frequently to allow them to process through discussion. Following the video, I gave them Glacier Questions, and asked them to work together with their tables to answer questions. To simplify, you could also have students complete Comparing Core Samples (See my reflection for an explanations).
When all groups had their questions turned in, I brought them over to discuss the question "What do glaciers tell us about earth's history?" I did this because we would be starting a new writing prompt tomorrow, Responding to Arguments with Evidence Day 1, and glaciers provide key data about how our planet has changed.
I use "Teach!/Okay!" from Whole Brain Teaching for quick discussions, rather than "Think-Pair-Share" because it includes a physical response, activating the motor cortex, and it imparts a sense of urgency, moving us all through the activity more quickly.