Reference no: EM132793236

Lab - Glacier Mass Balance and Hypsometry

In this lab you'lllearn how to graph and analyse glacier mass balance, elevation and area data for a glacier in the Canadian Arctic: White Glacier, Axel Heiberg Island (79°27'N, 90°40'W) andaglacier in the Austrian Alps:Hintereisferner(46°48'N, 10°46'E).

Examples of graphs & calculations can be found in the lecture notes on Moodle, Lecture 4 "mass balance" and the Glacier Mass Balance. Tip: make sure you have the graph axes the right way around (elevation always vertical) and label all axes with the correct variable name and unit of measurement (e.g. AREA [km2]).

Number your answers corresponding to the question numbering, write concise answers in clear language and check your spelling. Paste graphs as ‘pictures' in your Word document (this reduces the file size considerably).

The completed lab is to be deposited in the Moodle folder "Lab2" as a Word document or PDF file

This lab will be marked out of 110marks.

1) Area and elevation

a) Download the data file from Moodle.
b) Open the datafilelab2_raw_data.xls.You will find the following column headers each glacier:
ELEV1: lower boundary of each elevation interval [metres above sea level]
ELEV2: upper boundary of each elevation interval [metres above sea level]
AREA: Glacier area [km2] in the corresponding elevation interval
1991, 1992, etc: Specific mass balance [mm/year] for each elevation interval for the year specified in the header.

c) Plot the area vs. elevation distributions of the two glaciers as bar charts with area on the x-axis and elevation on the y-axis. Tip: For each bar graph plot only one series with AREA on the x-axis and ELEV1 on the y-axis labels.
d) Calculate and recordthe total area, the elevation range and the average elevation for each of the glaciers.
e) Describe the area vs. elevation distribution for each glacier (e.g. is most of the area at higher elevations/lower elevations or is it quite equally distributed: use the proper terminology from the mass balance lecture).

2) Mass balance

a) Plot mass balance vs. elevation curves for 1991-2000 for each glacier (Note: White glacieris missing 1992 & 93). Use thechart type ‘Scatter with smooth lines and markers'and plot all graphs with the same mass balance range (so both glacier graphs are scaled the same for easy comparison). MB on x-axis, elevation on y-axis. Do not select the header rows when you select the data, as the years are read as numbers instead of text.
b) Write a short comparison of the mass balance curves (steepness, temporal trends, regional differences, etc).
c) Determine and record the range in equilibrium line altitude (ELAs) for each glacier. Which glacier is the most sensitive to these changes in ELA and why (tip: think about where each glacier has most of its area)?
d) On the basis of the area, total glacier area and mass balance data, calculate the net specific balance(area weighted) for each year for both glaciers.Tip: 3-step process: 1) for each elevation bin multiply the mass balance by its area (label column "MB"), 2) calculate the sum of these mass balances ("sum of MB"), 3) then divide the sum of the mass balance by the total glacier area ("net specific balance" NB). Plot NBfor each year of 1991-2000 for both glaciers as a column chart (years x-axis; NB y-axis) and describe the results. Note that White glacier has some missing years. For your answer notice differences between the glaciers in terms of total net balance and temporal trends.20 marks
e) Plot the full range of years (1960-2000) net specificbalances for White glacier as a column (bar style) chart. Describe the climatic trends and relate these to the lecture material.
f) For each glacier, calculate and record the mean mass balance gradient ofboth accumulation (how much does the accumulation (mm) increase per 100 m elevation rise) and ablation (how much does the melt (mm) decrease per 100 m elevation rise) areas. Calculate thesemean linear gradients based on the average of the years 1995-2000 and record the gradients in the unitsmm/100m.

Attachment:- Mass Balance and Hypsometry.rar