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SCIENTISTS ARE SUPERHEROES�“What is the history of the Greenland Ice Sheet in the Holocene”

Margie Turrin, Director of Educational Field Programs, Lamont-Doherty Earth Observatory

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OPPORTUNITIES

Connecting their curriculum to work being done on some of the most challenging real world questions (this will take some scaffolding)
Identify science as a tool for problem solving
Expanding their understanding of

who is a scientist
science careers

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CHALLENGES

Many types of reasoning/literacies that are involved

Geographic literacy – Students apply their knowledge of the polar regions to ‘develop understandings’ (MAP)
Spatial reasoning - Students make inferences from observations about the location, orientation, shape, configuration or trajectory of objects or phenomena.
Temporal reasoning- Students make inferences from observations about the timing, rates and sequence of Earth events and processes.

Geologic time literacy– Student place events/ occurrences into a deep time reference –(HOLOCENE)

Concept-based reasoning Students must tap into their knowledge of Earth Science concepts and apply this knowledge to the activity. (VOCABULARY LIST)
Quantitative reasoning – Students gain insights, or reason about, Earth processes through numerical information

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Why point out the challenges?

Teachers can use this information to:

to plan scaffolding for their students in advance of using the material,
as a diagnostic tool for student difficulties,
to target specific thinking skills in their lesson planning,

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What do you think you are looking at?

Do you know what type of map this is?
Describe what you are looking at?
What features can you identify?
Develop 3 observations.
Develop 3 questions you have after looking at this image.
What surprises you?

International Bathymetric Chart of the Arctic Ocean

l

Teaching Goal: We found that there was a persistent misconception that the Arctic was land in the center and not an ocean surrounded by land. Therefore this map was selected since it clearly shows the Arctic Ocean at the center.

Polar stereographic map. Also correct to say Bathymetric & Topographic (Multibeam echo sounding for the bathymetry)
Arctic - Arctic Ocean surrounded by land
Greenland, Arctic Ocean etc.
*Greenland is mainly in the Arctic above latitude 60; *Arctic is an ocean surrounded by land; * most of the borders of the Arctic are land, so only a few pathways for water to go in and out….
*Why is there no sea ice? *Why is there only ice on Greenland? *What is that high area in the middle of the Arctic (Lomonsov Ridge)
No sea ice!! Why? What was this map intended to do?

*IBCAO map – International Bathymetric Chart of the Arctic Ocean

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Geologist? What does that word mean to you?

List 4 words that come to mind when you think about a geologist.

GEOLOGIST?

Go to www.mentimeter.com & use code 6807 9344

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Meet Alia the geologist

Geologists travel around the world to study the Earth and Earth processes. Her work takes her ‘nose to nose’ with a helicopter while she collects Greenland rock samples.

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Alia samples mud from the bottom of lakes along the edge of the Greenland ice sheet to learn the history of the ice...

...through the history of the lake.

Teaching Goal: Introducing the concept that the history of the ice is LINKED to the history of the lake. THIS IS A PROXY!!! NOT A DIRECT MEASURE OF ICE RETREAT!!!

The two pictures on the left that first pop up on this page each contains elements of the story. Ask the students to make 2 to 3 observations about each one. Things they may include: (they collect a sample core first to be sure they hav organics and inorganics)

Sediment core image top left:

The mud is collected in tubes – Introduce that this is called a sediment core.
There are different colors/layers visible in the mud in the sediment core – patterns in the mud
Scientists use everyday things to provide scale in a photo – the yellow field notebook is an example against the core.

Allie and Alia bottom left:

The are on or near a lake (the lake on the edge of the ice sheet)
They are poking at what looks like mud that is mostly gray in color with some brown on one end.
It is two females – early career scientists!

Clicking on the slide again brings up Alia as a Superhero – this can be unpacked with the different elements

Alia pulls sediment cores out of lakes along the edge of the Greenland Ice Sheet
The different parts of the core in the image contain different climate information

Gray material is ground rock and inorganic material – created in colder environments
Brown material is organic in origin – created in warmer environments

Now that the meaning of the gray and brown material is explained go back to the image on the bottom left and ask what was the climate environment when most of this mud was collected? This helps close the link on the relationship between the history of the ice and the history of the lake.

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Alia’s study area for this project is focused on ice retreat in

southwestern

Greenland. She

will look at

lakes in

several

different

locations

along the

ice edge.

Arctic Map from a polar view.

(Source: ipcc)

Alia’s study area for the Snow On Ice Project.

Teaching Goal: Introduction to the study site

Introduction to Polar stereographic view.

This may need some introduction and orientation- point out key areas they may be familiar with like Canada, Alaska, Russia
We used a globe to help support this.
The dashed line represents one way of defining the Arctic (there are several ways that are all approximately similar in results)
The ice being missing over the Arctic Ocean in this image can be confusing for students but it is a great way to reinforce that the Arctic is an ocean surrounded by land. Generally we see images that show the sea ice that covers much of the Arctic Ocean in the winter and still a fair amount in the summer, but this image focuses on the persistent ice in the Greenland ice sheet.

Note: You may wish to check that the students understand that the phrase “ice retreat” means that the ice sheet has shrunk back in size over time. The understanding here is that the icesheet was once larger than it is today and we are trying to understand the history of its change through time. Recall the history of the ice is linked to the history of the mud in the lakes.

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The Greenland Ice Sheet is the largest expanse of ice in the Northern Hemisphere and one of two ice sheets remaining on Earth. Understanding how the ice has changed through time may provide important clues to our future!

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As the ice sheet retreats, ‘meltwater’ collects forming lakes along the ice edge.

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Over time, lakes and plants spread over the once ice covered landscape. But over how much time? Alia and her colleagues are trying to answer this question.

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The sediment coring platform is an inflatable boat, with a ‘drilling rig’ of an A frame support, core tube and a winch.

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The team camps where they work, about one site a week. At every campsite everything must be rebuilt!

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The core tube is wrestled into position to drop down into the water.

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Make 3 observations about this image

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Once Alia’s cores are collected they are packed up and ready to go back to the lab to be studied.

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Back in the lab they are refrigerated. They are sectioned & sent to the lab for analysis.

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Now it is your turn. Order the history of a sediment core from its origin to its collection.

Alia (left) and the science team are ready to head out at the end of their stay. The cores have been collected and are now safely stowed inside the helicopter.

Now its your turn! Use the images and descriptions to develop the story of Alia’s cores.

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THE RESULTS VARY, JUSTIFY YOUR DECISIONS!

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Alia the geologist

Big Ideas

Earth’s Climate has not always been the same.
The Earth keeps its own record of change!
Greenland was once covered in much more ice.

Learning Objectives – Understand that:

Geologists study changes in the Earth using materials, processes, products and physical nature of the Earth.
Earth’s sediments can be used to study the past including past climate. Different types of sediments tell us how they are created.
As ice melts the water pools in lakes along the edges where the land has been pushed down.

Key Understandings

We can use indirect measures of ‘proxies’ to understand climate in the past.
Ice moves, grinding the rock below as it does creating glacial clay.
The creation of a sedimentary record takes hundreds to thousands of years.

Essential Questions to Consider & Discuss!

What caused the large change in Earth’s climate in the past?
Will the past climate changes ever repeat – will glaciers and ice fully cover Greenland again?
How do scientist ‘uncover’ the meanings in proxies?

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Learning Standards for Alia

MS-ESS2-2. Construct an explanation based on evidence for how geoscience processes have changed Earth’s surface at varying temporal and spatial scales.
MS-ESS2-1. Develop a model to describe the cycling of Earth’s materials and the flow of energy that drives this process.
MS-LS1-5. Construct a scientific explanation based on evidence for how environmental and genetic factors influence the growth of organisms.

Cross Cutting Concepts Employed

Patterns (use of patterns in the core layering)
Cause & Effect (Events have causes & understanding this is central to developing our main understandings in science)
Stability & Change (climate is a major example of this)

Science & Engineering Practices

Analyzing & Interpreting Data
Developing & using models (through sequencing of processes)
Engaging in Argument from Evidence (through the small team discussion of the sequencing)
Obtaining, Evaluating & Interpreting Information (in the presentation of their ‘stories’

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3D LEARNING: DEEP DATA DIVE

AN INTRODUCTION TO PROXIES

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Alia Uses Sediment Cores to Peer into the Past

Meet Alia, geologist and superhero! Alia is interested in how the Greenland ice sheet has changed since the last glacial maximum. We don’t have any direct measurements of that change so she uses proxies to help us find the answer.

Proxies are an indirect measurement of a process or event. They are not exact measures and become more accurate when used with other proxies. Alia uses sediment cores as her proxy. The cores are collected from lakes that form from glacial meltwater along the edges of the ice sheet as the ice reduces in size.

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SNOW ON ICE PROXIES

ICE CORE IMAGE - NASA's Goddard Space Flight Center/Ludovic Brucker

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Snow on Ice proxies…

ICE CORE IMAGE - NASA's Goddard Space Flight Center/Ludovic Brucker

DINOCYSTS, FOSSILIZED MARINE

SEEDS

SEDIMENT CORES FROM SMALL GLACIALLY FED LAKES ON THE ICE SHEET EDGE

EXPOSURE DATING OF QUARTZ ROCK SAMPLES

LEAF WAXES FROM PLANT STEMS & SEEDS

Birch Pollen

ICE CORES THAT HOLD BITS OF PAST ATMOSPHERE

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Snow on Ice proxies…

ICE CORE IMAGE - NASA's Goddard Space Flight Center/Ludovic Brucker

FOSSIL FINDING FINGERS

XRAY VISION INTO THE SEDIMENTS

BERYLLIUM DRILLING ABILITY

PALEO PLANT POTION

PROXY PROCESSOR

OF POLLEN

EXTRACTING ANCIENT CLIMATE

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Introduction

Nuuk Region

Map 1 shows ice retreat around the edges of the Greenland Ice Sheet. You call see different colored contour lines each with a year listed in the color key. For example the light blue line shows the extent of the ice 12,000 years ago, the yellow 10,000 years ago etc. This is a look at the full ice sheet. Let’s step back through time.

But how do we know this is where the ice was? Using proxy data from several different proxies the ice edge is carefully and painstakingly reconstructed. The full map involves data from years and years of collection.

For Activity #1 you will work with data collected just in the Nuuk region of SW Greenland (see Map) though the Snow on Ice Project. You will be using proxy data from lake sediment cores on the next slide (Figure 1) to help reconstruct the ice extent in this region.

For this activity you will work with Figure 1 and Map 2. Start by examining Figure 1, the 2017 lake core data. Read about the data. When ready move on to Map 2 and follow the directions there.

Map 1

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Figure #1

Cores from pro-glacial lakes along the edge of the ice sheet. Gray is glacial clay created by the ice sheet grinding over the rock. Brown is organics blowing into the lakes.

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Activity #1 Nuuk Region, Western Greenland

Nuuk

KNS

AS

NS

Nuuk

Caribou Lake

Kap01

Map #2

Ice Sheet

Baffin Bay

Locate the current ice sheet edge on the map.
Using the inset map on Fig. 1 as a guide, label this map with the names & locations of the 7 sediment cores on Fig. 1.
6 of the core locations have an age. Locate the oldest age on each core & put that age onto the map using red text.
With a partner study & discuss your maps.

What surprised you?
Were the oldest ages where you expected them to be?
Did all the ages taken as a group make sense to you?
Together discuss what might cause the different in the ages.

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Activity #3

For this last activity you will be looking across the cores in Figure 1. Recall that repeat sections of gray in a core represent a re-expansion of the ice over the lake, for a long enough period of time to allow the ice sheet to grind additional bedrock material, contributing to the lake sediments.

Using the core data, discuss what you can infer about the Greenland climate during specific times over the last 13,000 years (be specific in your discussion).
As a class identify some strengths of using lake sediment cores as a climate proxy.
As a class identify some weaknesses of using lake sediment cores as a climate proxy?
What did you learn from working with this data?

Continue working with lake sediment core data found in Figure 1.

There are two sets of lake samples with ages that are located side by side:

KAP01 & Oajartariorssuaq.
Marshall & Goose Feather

With your partner:

Describe the core data in each pair. Identify what is the same and what is different between them.
Did anything surprise you in their relationships to each other?
Develop a hypothesis for each pair to support their behaviors.

Activity #2

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Alia the geologist

Big Ideas

Earth’s Climate has not always been the same.
The Earth keeps its own record of change!
Greenland was once covered in much more ice.

Learning Objectives – Understand that:

Geologists study changes in the Earth using materials, processes, products and physical nature of the Earth.
Earth’s sediments can be used to study the past including past climate. Different types of sediments tell us how they are created.
As ice melts the water pools in lakes along the edges where the land has been pushed down.

Key Understandings

We can use indirect measures of ‘proxies’ to understand climate in the past.
Ice moves, grinding the rock below as it does creating glacial clay.
The creation of a sedimentary record takes hundreds to thousands of years.

Essential Questions to Consider & Discuss!

What caused the large change in Earth’s climate in the past?
Will the past climate changes ever repeat – will glaciers and ice fully cover Greenland again?
What is the value in scientist using proxies to understand past climate?

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HS Learning Standards for Alia

HS-ESS2-2. Analyze geoscience data to make the claim that one change to Earth’s surface can create feedbacks that cause changes to Earth’s systems.

Regents Earth Science NYS:

STANDARD 1 Analysis, Inquiry, and Design/Scientific Inquiry: The central purpose of scientific inquiry is to develop explanations of natural phenomena in a continuing, creative process.

STANDARD 6 Interconnectedness Common Themes: Identifying patterns of change is necessary for making predictions about future behavior and conditions.�

Cross Cutting Concepts Employed

Patterns (use of patterns in the cores)
Cause & Effect (Events have causes & understanding this is central to developing our main understandings in science)
Stability & Change (climate is a major example of this)

Science & Engineering Practices

Analyzing & Interpreting Data
Constructing Explanations
Engaging in Argument from Evidence (through the small team discussion of the core data)
Obtaining, Evaluating & Interpreting Information (the centerpiece of the activity)

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Alia samples lake sediments along the edge of the ice sheet to learn the age of ice retreat.

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Estelle works with microscopic, fossilized dinocysts to determine past sea ice cover

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Nicolás samples rocks zapped by cosmic rays to determine when the ice uncovered them

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Allison samples leaf waxes from plants & water in surface lakes to determine past precipitation

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Jessica extracts ice core & past plant pollen records from around the Arctic to map climate

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Liza samples moss frozen by the advance of the ice edge years in the past to track the ice history

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Josh is the ‘proxy compiler’ with his lightening fast fingers pulling together data to build new models!

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QUESTIONS?

Margie Turrin

Lamont-Doherty Earth Observatory

mkt@ldeo.columbia.edu