Module IX - Terrestrial Cryosphere Introduction

Essential Question:
How are climate, terrestrial ice and Alaskan indigenous cultures all connected?

Ice Land
The story of terrestrial ice (ice on land) and its associated cultural connections is very different from that of the seasonal ebb and flow of polar sea-ice. Quite apart from the fact that terrestrial ice is formed from frozen fresh water instead of saline sea water, terrestrial ice also has a complex time scale because of its different set of variables.

Changes in temperature along with changes in latitude, altitude, precipitation and the different heat capacities of land and water all interact to create the dynamic realm of terrestrial ice; glaciers, permafrost, rivers and lakes.

Just as Arctic cultures have developed a unique and vital relationship with sea ice, similarly vital relationships are formed between people who live along, and rely upon, terrestrial fresh water systems - some of which cycle between solid and liquid on an annual basis - and others which have freeze/thaw cycles lasting hundreds to hundreds of thousands of years....or more!

Besides the science of how these complex systems interact, this module will explore how the different kinds of terrestrial ice are connected to climate change and to culture.

Module IX - Cultural Connections

Essential Question:
How are climate, terrestrial ice and Alaskan indigenous cultures all connected?


ENGAGE

Cultural Connections
Long before Captain George Vancouver sailed into Icy Strait in 1794 on the HMS Discovery, ancestral Tlingit had discovered the region with its wealth of resources that allowed them to thrive in a challenging environment.

The present village of the Huna Tlingit is located on Chichagof Island 25 miles SE of Glacier Bay. But their oral tradition tells the generations old story of how their ancestors were chased out of Glacier Bay hundreds of years ago by the rapidly advancing ice.

Though they now live across Icy Strait from their ancestral lands, their stories and culture still hold a deep connection to Glacier Bay. Fortunately, scientists - glaciologists, geologists, anthropologists, climatologists, etc. - have tapped the deep well of cultural geographic knowledge found in Tlinget oral tradition, providing valuable information about changes taking place in Glacier Bay over the centuries.

Tlinget place names in Glacier Bay, and their associated stories, help to inform and reveal the processes and sequence of events that have left their marks on this incredibly dynamic region. No wonder wise scientists have partnered with local Tlinget to create a more holistic understanding of climate, glacial activity, people and place.

EXPLORE

ANKN
The Alaska Native Knowledge Network has a wealth of resources about Alaska's indigenous peoples. Check out this detailed historical map of Tlingit lands and see how it relates it to the region claimed by the Huna Tlingit. Then Google Earth.

Google Earth

• Find Glacier Bay
• Find Hoonah, Alaska
• Explore the landscape of the Huna Kwaan in 3D
• Measure the distance from Hoonah to Glacier Bay

Helpful Hint: Glacier Bay National Park hosts an excellent website with a large quantity of quality, user-friendly resources. From ancestral cultural information to glaciers, wildlife, geology, biology, and oceanography, there's a lot going on in Glacier Bay and they show it. There's even a section specifically for educators!


Alaskool
Alaskool.org -- Online materials about Alaska Native history, education, languages and cultures is a rich, valuable site for any teacher looking for information, ideas and resources from an Alaska Native perspective.

Helpful Hint: While you're visiting Alaskool , allow yourself a dozen clicks or so to poke around the site. It's real Alaskan and real cool. It's Alaskool!


Helpful Hint:Alaska History and Cultural Studies provides great resources for any teacher looking to make connections between people and place in Alaska. There is a great section on geographic materials including climate and permafrost information.

Teachers' Domain
We've learned quite a bit about how changes in sea ice systems affect Alaska's coastal cultures. Here are two TD videos describing impacts of climate change for some of Alaska's more interior indigenous peoples.


Changing Arctic Landscape





Losing Permafrost

EXPLAIN

• How does climate change affect Alaska's interior forests?
• What are some of the physical effects of climate change in Alaska's interior?

EXTEND

• Everyone benefits when local Native elders have opportunities to teach your students.
  

EVALUATE

• How valuable are these resources for helping your students make connections between traditional Native knowledge and western science?
  

Module IX - I Only Have Ice For You

Essential Question:
How are climate, terrestrial ice and Alaskan indigenous cultures all connected?

ENGAGE

Water You Thinking?
Let's approach this science segment by revisiting a familiar theme in this course--Water. Water, water everywhere, but how much can you drink? How much of Earth's water is in the ocean? How much is fresh? How much is in the atmosphere? How much is in lakes, rivers, or underground? How much of Earth's fresh water is stored frozen as permafrost and glaciers?


A Drop in the Bucket
How would you estimate the planet's supply of water is distributed if it were reduced to 1000 drops. Give a try before you peek!

• _____ drops are in the oceans and inland seas
• _____ drops are in glaciers
• _____ drops are in ground water and soil moisture
• _____ drops are in the atmosphere
• _____ drops are in lakes and rivers
• _____ drops are in all living plants and animals
• 1000 drops total.
  

(Find answers at USGS,Water on Earth)


1000 Snow Flakes
More than 2/3 of all fresh water on Earth is stored in glaciers. If all present glaciers were represented by 1000 ice snow flakes, how would you estimate the distribution of glaciers on Earth? Give a try before you peek!

• _____snow flakes in Antarctica
• _____snow flakes in Greenland
• _____snow flakes in N. America
  
• _____snow flakes in Alaska
• _____snow flakes are in Asia
• _____snow flakes in S. America, Europe, Africa, New Zealand, etc., etc.
  
• 1000 snow flakes total
  

(Find answers at USGS, Introduction to Glaciers)


EXPLORE

Teachers' Domain
What better way to study terrestrial ice than to start with the only continent completely covered by it. Earth's Cryosphere: The Antarctic is a TD video that focuses on the global role of Antarctic glacial ice, which is vastly different from the sea-ice dominated Arctic.

Earth's Cryosphere: The Antarctic






Helpful Hint: Visit NASA's Antarctic Ice Bridge Blog for current research and new technologies being used to measure the extent and thickness of Antarctica's ice.

EXPLAIN

• How much of the world's fresh water is stored as ice in Antarctica?
  
• How are ice shelves different from sea-ice?
• How do ice shelves regulate glaciers on land?

EXTEND

• Why is the Antarctic the coldest place on Earth?
• What other online resources are useful for exploring the most remote continent?
  

EVALUATE

• How important is it for Alaska students to understand Antarctic processes?
  

Module IX - Ice Ages

ENGAGE

Glacial Ice Ages
Pleistocene epoch, ice age, interglacial period, last glacial maximum--it's all a bit confusing until we tease out what these different terms mean and how they help us understand the long history of terrestrial ice on Earth.

Put simply, ice ages are longer periods of colder climate during which ice sheets cover much of the Earth. Interglacial periods are shorter periods of time in which glaciers periodically advance or recede in response to shorter-term climate cycles within the present ice age.

The maximum extent of the last glaciation (LGM) occurred about 18,000 years ago. Except for comparatively brief recent periods, glacial recession has been the norm for quite a while--ever since the last interglacial period ended about 12,000 years ago.

During the LGM, a person could have walked from Alaska to New York across an uninterrupted ice sheet, in places thousands of feet thick. Now, except for the return of seasonal snow each winter, the landforms of most of North America are clear of most of the snow and ice that covered so much it for about 100,000 years.

Thousands of years ago, Earth's climate was again beginning to warm for reasons related to large complex climatic cycles that have regulated ice ages over millions of years.

With just a few million people world-wide at the beginning of agricultural settlement about 10,000 years ago, humanity's carbon footprint was the tiniest fraction of our present scale of carbon combustion. But as populations grew and people migrated, humans became part of the post-glacial biological succession, naturally, as ice sheets and glaciers receded and people advanced into the emerging landscapes.

EXPLORE

Teachers' Domain

Climate Change is a TD video that tells the story of climate change as documented in ancient ice stored for thousands of years in Greenland's ice sheet.




Taking Earth's Temperature is a TD video that correlates several methods scientists are using globally to measure the rate and extent of climate change.





EXPLORE SOME MORE....

Visit NASA's Earth Observatory to see their animation of global seasonal snow coverage between the Feb. 2000 and Sept. 2009 and observe the interesting patterns of seasonal snow distribution on Earth.



Visit the Alaska PaleoGlacier Atlas and find paleoglacier maps detailing regions in Alaska. Observe the modern, late Wisconsin and the maximum extent of Alaska's glaciers during the last glacial period.



Helpful Hint: Check Alaska Climate Summaries or National Snow and Ice Data Center for excellent data regarding weather and climate data in specific regions.


EXPLAIN

• Why is change sometimes sudden?
• What are some of the ways Earth's temperature is measured daily?
  
• Why does one hemisphere get so much more snow than the other?

EXTEND

• What methods and resources do you use to help students understand geologic time?

EVALUATE

• What digital resources regarding ice ages are most useful for your purposes?
  

Module IX - Ice Sages

ENGAGE

Glaciologists--Ice Sages
Imagine a mountain valley catching the moisture that falls within its boundaries and funnels it down into a lake sprawling across a low lying area. When the precipitation exceeds the capacity of the lake, it spills over into a river that flows down toward sea-level. Sounds reasonable and familiar. We've all seen it.

But what if the moisture that falls in the high mountain valley is snow that doesn't melt each spring? What's different? Erosion and sedimentation processes notwithstanding, any glaciologist will tell you, not too much is different -- if you've got the time to watch.

Snow falling at high elevations probably evaporated from the surface of the tropical ocean no more than a couple of weeks prior. This accumulating young snow compresses under its own increasing weight over time turning into dense, clear ice.

When the lake of ice (ice field) fills to overflowing, the plastic river of ice flows out of the confines of its upper reaches and meanders slowly and massively downhill, grinding its own deep valley along the way on its journey to the sea. Same-same.

Inland glaciers flowing out of high mountain valleys until they reach lower, warmer elevations liberate their solid water as liquid rivers off to find the sea. Alaska's coastal mountain ranges host many glaciers that surrender their centuries old cache of water directly into the ocean as ice--tidewater glaciers.

Whether indirectly by river or directly by glacier, water is constantly rejoining the ocean for the first time in many, many years. And it's doing so at a rate that presently exceeds the rate at which it is returned to the mountains as snow.

And like a river, a glacier's rate of flow is determined largely by the amount of precipitation accumulation that fills its reservoirs . Advancing glaciers are driven by accumulation rates that exceed its melting, or ablation, rate.

The Great Recession
Unlike liquid rivers, glaciers frequently change phase abruptly as they descend to warmer elevations. Glaciers that melt faster than they advance are called receding glaciers. This dance between accumulation and ablation, advance and retreat, is expressed over time as a glacier's mass balance.

Most glaciers have been receding since the LGM. But ice sages studying the mass balance of glaciers world-wide have noted recent acceleration in the ablation rates of glaciers, indicating overall increased rate of reduction in glacier mass balance.

Lyrical Lexicon
Left behind the receding ice are the curious landforms unique to the forces of glaciers: esker, drumlin, kettle, moraine, cirque, tarn, kames, varve and arete are just part of the lyrical lexicon of glaciologists describing specific processes and formations that result from the advance and retreat of glaciers. You might be surprised by how many of these post glacial landscape features are part of our common geography.

From the Great Lakes to Cape Cod. From Long Island to Lituya Bay, each is a geologically recent product of the work of glaciers. And each was settled for the first time by the earliest north Americans shortly after the ice melted.

EXPLORE

Teachers' Domain
Earth System-Ice and Global Warming







Documenting Glacial Change






Fastest Glacier







EXPLORE SOME MORE....

Don't Go With the Slo Flo
Glaciers are often compared to rivers in terms of their motion, but to most of us they look solid and static. But what if you could speed-up time?

That's just what the scientists at the Extreme Ice Survey did by placing remote cameras focused on glacial landscapes and leaving them for more than a year. What emerges in the compressed sequence of images is the fluid motion of ice.

Visit the Extreme Ice Survey website and watch a time lapse Vimeo of the Mendenhall Glacier during the 16 months between May 2007 and September 2008.




Helpful Hint: Find out if any Alaska Glaciers are advancing. Visit the USGS - Alaska Glacier Repeat Photography Project. It's an engaging collection of recent and old photographs contrasting many of Alaska's Glaciers over time.


EXPLAIN

• What different kinds of ice loss are evident?
• What factors affect a glaciers mass balance?
• How does glacial melt affect sea level?
  

EXTEND

• Use Google Earth to explore and photograph examples of post glacial features.
  

EVALUATE

• How well do these resources help students understand glacial processes?
  

Module IX - Sea Level

ENGAGE

Glacier Ice--Sea Level
It is estimated that sea-level could rise as much as 80 meters if all land ice melted and returned to the sea. How would you estimate the distribution of glaciers effects:

• If all of Alaska's glaciers melted, sea level would rise ~ _____ meters.
• If all of Greenland's glaciers melted, sea level would rise ~ _____ meters.
• If all of Antarctica's glaciers melted, sea level would rise ~ _____ meters.

(Find answers at USGS Glaciers and Sea Level)

Glaciers have been melting for many thousands of years. And sea-level has been rising for thousands of years. And we're arguably better off without continental icesheets sprawling over northern Europe, Asia and North America. But, as it turns out in so many cases, timing is everything.

The gradual pace of change over many generations can create a lulling effect. Changes which occur slowly over many years often go little noticed and can be more easily adapted to. Thousands of years ago, people and their settlements were able to move in gentle response to gradual sea-level dynamics. And thousands of years ago people were more accustomed to moving around in response to resource availability anyway.

However, not all change is gradual. And as we are now learning, many of the variables that cause climate change often have associated positive feedback mechanisms which dramatically alter the rates at which changes occur. And some changes are further compounded by specific physical thresholds which can trigger immediate and profound effects.

For example, gradually warming ice stays solid, but only up to a certain point--then it becomes a liquid, rapidly. The increased rate of melting of continental ice sheets or glaciers, and the resulting influx of enormous quantities of fresh water formerly stored on land, causes, among other things, a corresponding rapid increase in sea-level.

And this is a concern for many low-lying areas across the much of the planet. Many coastal areas, unlike those of our more mobile and nomadic ancestors, are highly capitalized and densely populated. Miami, New Orleans, and Venice Italy just to name a few on the list of large cities at great risk for increases in sea-level.

EXPLORE

Teachers' Domain
If the Ice Melts, is a TD interactive resource that demonstrates graphically how sea-level has changed in the past 20,000 years, as well as predicted changes as more terrestrial ice melts and returns to the sea.

Try This Trick!

Here's another in our exciting series of science activities,
Watching Ice Melt!





Drip...Drip...Drip....

1. Partially fill a suitably large glass container with water so you can see sea level.
   
2. Mark sea level on the side of the container with tape or a marker.
3. Suspend several ice cubes in a screen, sieve, mesh, cheesecloth or food colander so that melt water drips directly into the glass container.
4. Observe changes in sea level as ice melts.
5. For effect, try placing a facsimile "sea level city" in the container at the start.
   

Information is Beautiful
Take a look at this creative and informative portrayal of endangered coastal cities, time, sea level changes, causes and coastal profiles all in one attractive and accessible graphic.

Information is Beautiful.


EXPLAIN

• How does Florida's coastline compare relative to a sea-level changes?
• What cities are most vulnerable to sea level rise?
  
• How is the effect of melting terrestrial ice on sea level different from that of melting sea ice?

EXTEND

• Find out why isostatic rebound causes sea-level to drop near Glacier Bay .
• Use Google Earth to explore 200 years of glacial recession in Glacier Bay.
• Try adding the Extreme Ice Survey layer to your Google Earth menu of features.
  

EVALUATE

• How important is the issue of sea level rise?
  

Module IX - Seasonal Ice--Rivers & Lakes

ENGAGE

Seasonal Terrestrial Ice--Rivers & Lakes
Besides glaciers, other terrestrial surface ice includes seasonal ice on lakes and rivers. The thickness of ice and the time of year at which lakes and rivers freeze and thaw is also changing rapidly due to the accelerated affects of climate change. These affects are in turn connected to other affects in the ecosystem and cultures connected to those places. Because, Everything is Connected.

They Say that Breaking Up is Hard to Do.
One sure way to get a hundred years worth of valuable ice data is to have annual high stakes gambling on the time for an annual river ice break-up. Since 1917, Alaskans have placed their bets for when the Tanana River would break up at Nenana. Over $10 million has been paid out in the last 92 years.

EXPLORE

YouTube
Captured by regular folks with video cameras, these three YouTube videos give you an idea of what three different annual river ice break-ups are all about.
Check out one or all.

• Tanana River Breakup 2009
• Ice Breakup on the Nenana River
• Breakup on the Yukon in Galena, Alaska

Do the Math
Analyze the breakup log for dates and times of the Nenana Ice Classic for the Tanana River annual breakup. Students could use this data to look for statistical trends in river breakup dates. Maybe one of them will get the science and math of it and make good!

EXPLAIN

• What is the earliest break-up date?
• What is the latest break-up date?
• What is the most common break-up date?
• What is the most common time of day?

EXTEND

• Try making and posting graphs using the Nenana Ice Classic data.

Helpful Hint: With the help of USGS, you can monitor Daily Streamflow Conditions around the state.


EXPLORE SOME MORE....

Fire and Ice
We've discussed the pesky positive feedback problem associated with melting permafrost and methane. And as most any prankster with a Bic lighter can tell you, it's flammable! Now go to YouTube and check out what happens when you give grown-ups a lighter and send them out on a frozen lake.

YouTube
Check out one or all of these YouTube videos relating to the relationship between lakes and methane. Some are pro and some are not.

• Methane flare from a lake in Fairbanks, Alaska
• Burning Methane from a Frozen Lake
• Burping Lakes
• Melting Permafrost Accelerating Global Warming

Teachers' Domain
In this TD video we'll learn how students across Alaska are engaged in relevant and useful scientific measurements. They are helping to track local climate change in their region by measuring heat flux in lake ice across Alaska.


Students Measure Changes in Lake Ice and Snow

EXPLAIN

• Why is lake ice important in regulating climate?
• What is the relationship between lakes, ice and methane?
• Why is lake ice and snow a good indicator of climate change?
• What are some of the benefits of having students gather data?

EXTEND

• What other geoscience programs engage students doing real science?
  

EVALUATE

• What is the utility of any of these resources in your, or your students' learning?