Senario / Background
Point Defiance Zoo & Aquarium is situated on a hilltop, overlooking Commencement
Bay, at the North end of Tacoma Washington. Mt. Rainier can be seen in the distance
from our entry. We are home to four polar bears, 2 males that were rescued as cubs
from a Barrows Alaska and 2 older males that were rescued for a circus in South
America. We have been working closely with Polar Bears International and others
for several years, sending both zoo keepers and young students to Churchill to
participate in research activities. We have made it our goal, in alliance with several
Zoo’s in the NW to bring forth the same climate change messaging as these
messages apply to the species within our respective organizations.
Polar bears are our species to focus on. The mission is to effect behavior change customers choosing to change their behavior in some way to help reduce carbon.
There is a wing wall in the exhibit area we are just now starting to develop content
for. The Nisqually Glacier will be part of that project, to bring home climate change.
To make a connection between what we do here has effect somewhere else.
Nisqually is something we can see, touch and hear. Locally in the NW, everyone
knows about salmon and their decline, from a cost/dinner perspective at least. The
Nisqually Glacier feeds important habitat at the Nisqually delta, as described in the
narrative below.
I hope this sign panel, for reading level of 6-8th grade, will help visitors understand
what an important resource the Nisqually Glacier is and how climate effects it’s size.
Maybe what I’m trying to say is that: Their backyard is Our Backyard.
Below is a really rough draft of how these pieces could come together.
Nisqually Glacier, Mt. Rainier in the Pacific Northwest, 70 miles from Tacoma,
Washington.
Mt. Rainier can be seen from the north end of Tacoma, across the bay toward the
east, in the Cascade mountain range that runs across the horizon to Canada. It is
capped with snow year round. Each of its rising peaks and snow covered glaciers
have been named and measured. If you know where to look, you can see some the
glaciers and recognize the peaks.
The Nisqually Glacier is one of them. Its melting water mixes with other streams of
water to form the Nisqually River. The final home for the glacier-melt is trails into
900 acres of salt marsh between Tacoma and Olympia, in the Puget Sound. It’s
waters are essential to the existing habitat. Nourishing plants and animals alike,
from its solid ice origin, up on the mountain, to its liquid sate, it travels all the way to
the sea, some ______ miles.
It is one of the most accessible glaciers on the mountain, you can get really close and
see what a glacier looks like, in person. You will feel small, standing high on the
mountain slope, looking up at the mountain-top ahead of you and over the Cascade
mountain range to the sides. You’ll not only see the snow and ice, you’ll feel the
strength of great glacier - it’s great, thick mass of solid ice, speckled with soot. On
cloudy days, you may not be able to see as far, but you will walk in the clouds. (I
have a photo from a climb I did in the spring, May be good to add)
Prior to 1990, the Nisqually Glacier was home to a magnificent ice cave. Beautiful
photos have been taken through the ice sheet. (May have to omit the ice cave, but it
is a good way to talk about the melting and the shape of healthy melt versus rapid
melt.) Travelers came to the mountain just to see the caves, climbing from an
elevation of 5450 at the trail-head of Paradise. The way the glacier was melting
formed a nice opening at the mouth, stretching back, under the ice and branching off
into smaller tunnels, water ran out of the opening. At that time, people walked right
along the sides of the stream-bed. Now a very nice trail is provided to protect fragile
plants that grow in the rocky surface.
The shape of the Nisqually Glacier is changing, at a rapid pace. It is not an isolated
case of glacier melting, most ice forms in the world experiencing change. Can you
imagine Mt. Rainier without glaciers on it? How do you think it matters if a glacier
melts and is gone? Could make the flip signs specific to this.
The Nisqually Glacier is a frozen reservoir of water, a large, heavy, perennial mass of
ice that flows. It was formed because more snow accumulated than was lost each
year. New snow fall buries and compresses the snow underneath, changing it from a
fluffy grouping of ice crystals into dense, hard ice.
Most of the glacier snow falls on the upper part of a glacier, at higher altitudes, in the
“accumulation zone”, and is covered with snow year-round. Ice in the accumulation
zone flows down hill to the lower elevations (ablation zone), where more snow is
lost than accumulates. In late summer, when the seasonal snow has melted away
from the surrounding valley walls, bare ice of the ablation zone is exposed. Check
out the diagram below. It shows some of how a glacier is made and moves.
Cross section of an alpine glacier, showing snow being converted into glacier ice
(the left side of the figure) and the two major zones of a glacier’s surface. The red
arrows show the direction and relative speed of different parts of the glacier. The
longer the arrow, the faster ice is moving.
Climate determines how much snow a glacier receives and how fast it melts.
Nisqually gains snow October-May and melts June-September. Has this changed like
it has in the Arctic?
There is a difference between “weather” and “climate”. Weather is a short-term,
day-to-day condition of a particular place. It is what the atmosphere is doing over a
short period of time (i.e. cloudy, rainy, or sunny; cool or warm today). This
atmosphere can be observed and predictions can be made.
Climate is the long-term behavior patterns of the atmosphere; the long term
averages of temperatures and precipitations of the weather conditions – but climate
is brought forth through a complex system of triggers and reactions between earth
and the sun through a Feedback processes that can enhance (positive feedback) or
weaken (negative feedback) the effect on climate change triggers. Some of which we
understand, and some of which we are only beginning to understand. (Manitoba
Eco-Network, Climate Change Connection). The Atmospheric Model Layers below,
created by the National Science Foundation, is an example of Feedback process and
some of its triggers. You’ll notice the lack of human activity in the illustration.
The Nisqually Glacier receives its snow fall because of the atomopheric activities
going on in the world, as seen in the model above. It melts and retains snow and ice
because of the same Atmospheric conditions. More snow has to fall and less can
melt to keep this glacier on the mountain. It originates at the summit of Mount
Rainier at about 14,400 feet altitude and descends to about 5000 feet. It’s historic
range could be added with images here.
The Nisqually Glacier volume is an important because it is a frozen reservoirs of
water, important to water resource planning and to the wildlife that live along the
shore of the Nisqually river. The glacier-fed river has a relatively constant flow
compared to streams from ice-free valleys. It provides a steady source of nice cold
mountain water year round for the fish that live and spawn in the river. In the hot
summer glaciers generate lots of meltwater, keeping the flow going. The ecosystems
that develop along the glacier-fed streams and rivers are dependent on this steady
source of cold freshwater.
There are many glaciers on Mt Rainier. The Tahoma is what we see from Tacoma,
Nisqually is just around the side of the mountain to the right. See map below
The location of a glacier affects the amount of glacier change in response to climate.
South facing glaciers on Mount Rainier, like the Nisqually, have retreated faster
than north facing glaciers over the past 80 years. Need to explain why. The glaciers
on the south side are generally smaller and lower in elevation (on average) than
the north side glaciers, making them more susceptible to changes in the freezing
level.
One way to measures ice thickness is to use a portable ice-penetrating radar
transmitter/receiver that can be towed or carried across the glacier’s surface. As the
unit travels over the surface, it sends a radar pulse through the snow and ice until it
hits the base of a glacier. The pulse bounces back, sending data to the receiver.
Using this tool is one way we can figure how much water is in the glacier.
Operation of Ice Penetrating Radar
Need to do more with events – no changes at this time.
H>L>H>A>L>
Snow fall (H) on the mountain (L) is from water evaporation (H) from the west. It is
carried through the atmosphere (A) over the land (L) until it is deposited on the
mountain. Changes to the quantity of precipitation (L) would have an impact on the
plants and animals (B) in the area, as well as down stream.
H>H>H>L>B
The amount of snowfall (H) must be greater that the amount of melt off (H) for a
glacier to maintain its size and supply water to the habitats below. Reduced or
increased water supplies in the streams and rivers (H) will effect both the terrain
(L) and composition of plants and wildlife (B).
H>L>H>B>B>B>B>L>H>L>
Melting ice (H) from the glacier run downstream to the (L) salt marsh in Puget
Sound (H), creating essential fish habitat (B) for fish. The fish (B) are food for larger
fish (B), which created food for humans (B) and the fishing industry. The salt marsh
(L) area filters water (H), returning clean water to the water table in the earth (L)
below and sends fresh water to the sea (L).
Resources
1. Mt. Rainier National Park, Nisqually Glacier; by Frank D. Granshaw (Geology
Department at Portland State University) and Dr. Andrew G. Fountain (PSU
Departments of Geology and Geography). Assistance was provided by Thomas Nylen
(PSU Department of Geology), Barbara Samora and Darin Swinney (Mt. Rainier
National Park), and Carolyn Driedger (Cascade Volcanic Observatory)
2. http://www.nps.gov/archive/mora/ncrd/glacier/Basics00.html
3. Recent glacier and climate variations in the Pacific Northwest, Stephen C. Porter,
Quaternary Research Center, University of Washington
4. Burbank, D. W. (1982). Correlations of climate, mass balances, and glacial
fluctuations at Mount Rainier, Washington, U. S. A., since 1850. Arctic and Alpine
Research
5. USGS Science for a changing World; USGS/Cascades Volcano Observatory,
Vancouver, Washington
6. add resources from the senator climate senario.
Problem Statement –
The shape of the Nisqually Glacier is changing, at a rapid pace. If a glacier melts and
is gone, does it matter?