Download A glacier is a slow-moving, extended mass of ice

Climate Change and Glaciation: Proposal
Group Members:
Katy Friedman
Lauren Marzocca
Elliot Rozen
From the way in which they grow and change to the literal pieces of the past they store
inside them, glaciers are incredibly valuable natural indicators of climate change. A glacier is a
slow-moving, extended mass of ice formed by accumulated snowfall over many years. Glaciers
fall into one of three main categories: alpine glaciers, ice sheets, and tidewater glaciers. A
alpine glacier forms on a mountain slope and can also be referred to as a mountain, niche, or
cirque glacier. Valley glaciers are alpine glaciers that fill a valley, and larger glaciers that cover
entire mountains or volcanoes are called ice caps or ice fields. Ice sheets, also known as
continental glaciers, are the largest type of glacier. Found only in Antarctica and Greenland, ice
sheets are enormous continental masses of glacial ice and snow expanding over 50,000 square
kilometers. Ice shelves are areas of floating ice generally located at the margin of an ice sheet,
and ice streams are fast-moving portions of an ice sheet that can be several hundred kilometers
long. Tidewater glaciers are glaciers that terminate in the sea, most of which are outlet glaciers
of ice caps and ice fields. As tidewater glaciers reach the sea, pieces of the ice break off (or
calve) and form icebergs. Glaciation is the process of glacier growth and establishment.
Glaciers advance during glacial periods (periods of global cooling known as Ice Ages)
and retreat during interglacial periods (periods of global warming). Today, the earth’s climate is
in an interglacial period, thus it is a natural occurrence for the earth’s global temperature to be
increasing. However, the rate at which the earth’s temperature is increasing, and that rate at
which most glaciers are retreating, is of much concern.
While in New Zealand, our group will be focusing on glaciers (how they have advanced
and retreated over the centuries, and how they are changing now) as well as local species (both
current and extinct) in order to assess both short-term and long-term climate change in the area.
Several stops on our itinerary will allow us to get a firsthand look at some of the aspects of our
topic. We will visit Lake Matheson (formed by glaciation approximately 14,000 years ago) and
Lakes Pukaki and Tekapo (formed when the terminal moraines of receding glaciers blocked their
respective valleys). Perhaps more relevantly, we will visit three glaciers – Franz Josef Glacier,
Fox Glacier, and Tasman Glacier – all of which give different yet valuable insight into climate
change.
Franz Josef Glacier is a 12-kilometer-long valley glacier terminating 19 kilometers from
the Tasman Sea. It is one of the few glaciers in New Zealand that is still growing, due to strong
snowfall. Most other glaciers in New Zealand, especially those east of the Southern Alps, are
retreating heavily, a process that has commonly been attributed to global warming. Fed by four
alpine glaciers, 13-kilometer-long Fox Glacier is another of the few New Zealand glaciers that is
advancing; it has been doing so since 1985 at an average rate of about one meter per week.
Tasman Glacier, another alpine glacier, is the largest of seven glaciers flowing south and east on
the South Island of New Zealand and has shown major retreat over the past 15 years.
The first question we ask ourselves, and our third-grade partners, is “What can glaciers
tell us about how the earth’s climate is changing?” Glaciers are highly sensitive to changes in
temperature and precipitation and can consequently be very useful in mapping local and global
climate change over both short and long periods of time. Direct observation of glaciers can help
determine climate change in the short-term; the rate at which glaciers advance and retreat is
generally a good sign of the direction and severity of temperature change.
For knowledge about long-term climate change, scientists look at glaciers a little more
closely. Samples called ice cores are taken by drilling deep into a glacier or ice sheet. These
samples contain trapped air bubbles that serve as time capsules, providing us with facts about the
state of the earth’s climate hundreds of thousands of years ago. The composition of these air
bubbles, particularly the presence of hydrogen and oxygen isotopes, gives information including
data on temperature, precipitation, chemistry and gas composition of the lower atmosphere,
volcanic eruptions, solar variability, sea-surface productivity, and a variety of other climate
indicators. Ice cores contain more climate information than tree rings, sediment layers, or any
other natural recorder of climate.
More questions we might ask ourselves are “How is the earth changing now? And is this
the same as or different from the past?” We hypothesize that the earth’s temperature is
increasing at an alarming rate. To start answering these questions and test our hypothesis, we
can compare data of average temperatures and precipitation in New Zealand and the United
States to the rate at which glaciers in New Zealand and the United States are advancing or
retreating. This will help determine whether there is a direct correlation between glacier
dynamics and particular aspects of climate change. Although the size of a glacier is not directly
related to the local temperature, we hypothesize that glacier size is linked to the amount of
precipitation in the region. What can precipitation tell us about climate change? It is possible
that warmer temperatures can bring about more evaporation of oceans, lakes, rivers, etc., and
thus cause more precipitation. We can ask our third-grade partners to do some research on the
last ice age and to find out about the different flora and fauna that lived during the period, how
much of the earth was covered by glaciers, how humans lived, and what the temperature and
composition of the atmosphere was relative to now.
We also ask ourselves “How are people affecting the way the earth’s climate is changing?
And what can we do to avoid repeating the mistakes of the past?” We can address these
questions while in New Zealand by observing the differences between the way New Zealanders
live (their levels of pollution and greenhouse gas emissions, their efforts toward “greening” their
environment, etc.) and the way Americans live. To involve our third-graders in this study, we
can ask them to conduct a research poll: How many students in the class are driven to school,
and how many students take the bus? Which is better for the environment? We can answer
similar questions about the New Zealand lifestyle and share our findings with the students. We
can also ask the students to think of ways that they can cut back on greenhouse gas emissions
and other activities that are harmful to the environment in their own lives.
Once we have gathered our data and traded information with our third-grade partners, we
can determine whether our hypotheses were accurate and draw conclusions from there about the
relationship between climate change and glaciation.