Search this Site

###### Culture, Climate Science & Education

# Lab Eight

## Assessing Climate Change Impacts on Glaciers in Glacier National Park

The Earth's climate has warmed rapidly over the past 100 years, dramatically affecting glaciers around the world. In 1850, there were around 150 glaciers in Glacier National Park, for example. By 1966, the number dropped to 50. Only 25 remain today. In this lab you will use a spreadsheet tools to predict when one of these remaining glaciers, Grinnell Glacier, will disappear due to the effects of climate change.

### Step 1: Learn about glaciers and what makes them grow and recede.

Glaciers are masses of ice, snow, water, rock and sediment that move under the influence of gravity. They are formed when snow and ice accumulation exceeds summer melting. They "retreat" when melting outpaces snowfall.

In the park, scientists are studying the dynamics of glacier recession and the impacts that losing glaciers will have on park ecosystems.

Today, the park's glacially fed streams provide a constant flow of cold water throughout the summer season, maintaining necessary water levels and regulating stream temperature for fish and other aquatic species. Plant and animal species throughout the park rely on this flow. Based on current trends, glacier recession models predict that by 2030 or 2040, Glacier National Park will be without active glaciers (i.e. those large enough to be moving).

##### These photos show the trend:

Blackfoot-Jackson Glacier 1914 (left) and 2009 (right)

Boulder Glacier 1910 (left) and 2007 (right)

Grinnell Glacier 1938 (left) and 2009 (right)

### Step 2: Calcuate the percentage decrease in the number of glaciers in the park.

**1 Download the Excel spreadsheet and complete questions 1 and 2.**

Click on the button below to download an Excel spreadsheet. Open the spreadsheet and answer questions 1, 2a, and 2b.

**2 Answer questions 3 and 4 in the Excel spreadsheet you downloaded.**

Question 3: Complete the empty values in the Excel spreadsheet table by using the formulas below to convert the meter

^{2 }(m

^{2}) values into km

^{2}, miles

^{2}, and ft

^{2}.

One square kilometer = 1000000 square meters

(so km

^{2}=m

^{2}/1000000)

One square mile = 2589988.11 square meters

(so mi

^{2}=m

^{2}/2589988.11)

One square foot = 0.09290303999749462 square meters (so ft

^{2}=m

^{2}/0.09290303999749462)

Question 4: Use interpolation to calculate the size of

Grinnell Glacier in 1900.

Once you answer question 3, the chart or graph will show a plot of the line and the equation for the line that fits the trend of the data (this type of equation is called a quadratic equation). In the equation, x is the date and y is the area of the glacier for that date. Use the equation to determine the size of the glacier in 1900 by clicking on cell in the spreadsheet the cell and entering the formula into the formula bar. Talk to your instructor if you need assistance in building your formula.

**3 Answer question 5 in the Excel spreadsheet you downloaded.**

Question 5: Use the same equation you used in question 4 to predict when Grinnell Glacier will be completely gone.

In question 4 above, you used the equation to interpolate data. The same equation can be used to extrapolate data. Extrapolation is an estimate of the value of a variable outside a known data range. You can extrapolate the area of Grinnell Glacier in the year 1800 by substituting 1800 in the equation for x and solving for y. You could also estimate the year in which Grinnell Glacier’s area was 2.50 km

^{2}by substituting 2.50 into the Excel equation for y and solving the formula for x. But to answer this question (question 5), you will extrapolate the year the area becomes 0, in other words, the year the glacier completely melts or disappears.

### Step 1: Learn about glaciers and what makes them grow and recede.

Glaciers are masses of ice, snow, water, rock and sediment that move under the influence of gravity. They are formed when snow and ice accumulation exceeds summer melting. They "retreat" when melting outpaces snowfall.

In the park, scientists are studying the dynamics of glacier recession and the impacts that losing glaciers will have on park ecosystems.

Today, the park's glacially fed streams provide a constant flow of cold water throughout the summer season, maintaining necessary water levels and regulating stream temperature for fish and other aquatic species. Plant and animal species throughout the park rely on this flow. Based on current trends, glacier recession models predict that by 2030 or 2040, Glacier National Park will be without active glaciers (i.e. those large enough to be moving).

##### These photos show the trend:

Blackfoot-Jackson Glacier 1914 (left) and 2009 (right)

Boulder Glacier 1910 (left) and 2007 (right)

Grinnell Glacier 1938 (left) and 2009 (right)

### Step 2: Calcuate the percentage decrease in the number of glaciers in the park.

**1 Download the Excel spreadsheet and complete questions 1 and 2.**

Click on the button below to download an Excel spreadsheet. Open the spreadsheet and answer questions 1, 2a, and 2b.

**2 Answer questions 3 and 4 in the Excel spreadsheet you downloaded.**

Question 3: Complete the empty values in the Excel spreadsheet table by using the formulas below to convert the meter

^{2 }(m

^{2}) values into km

^{2}, miles

^{2}, and ft

^{2}.

One square kilometer = 1000000 square meters

(so km

^{2}=m

^{2}/1000000)

One square mile = 2589988.11 square meters

(so mi

^{2}=m

^{2}/2589988.11)

One square foot = 0.09290303999749462 square meters (so ft

^{2}=m

^{2}/0.09290303999749462)

Question 4: Use interpolation to calculate the size of

Grinnell Glacier in 1900.

Once you answer question 3, the chart or graph will show a plot of the line and the equation for the line that fits the trend of the data (this type of equation is called a quadratic equation). In the equation, x is the date and y is the area of the glacier for that date. Use the equation to determine the size of the glacier in 1900 by clicking on cell in the spreadsheet the cell and entering the formula into the formula bar. Talk to your instructor if you need assistance in building your formula.

**3 Answer question 5 in the Excel spreadsheet you downloaded.**

Question 5: Use the same equation you used in question 4 to predict when Grinnell Glacier will be completely gone.

In question 4 above, you used the equation to interpolate data. The same equation can be used to extrapolate data. Extrapolation is an estimate of the value of a variable outside a known data range. You can extrapolate the area of Grinnell Glacier in the year 1800 by substituting 1800 in the equation for x and solving for y. You could also estimate the year in which Grinnell Glacier’s area was 2.50 km

^{2}by substituting 2.50 into the Excel equation for y and solving the formula for x. But to answer this question (question 5), you will extrapolate the year the area becomes 0, in other words, the year the glacier completely melts or disappears.

© 2018 SKC | Contact Us