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Glacial meltdown

  • Key Stage 3
  • Popular Activity
  • Topical

Type: Activity
Learning Strategy: Planning
Topic: Atmosphere & climate change

Global warming gets everywhere - even to the 'roof of the world.' The Himalayan glaciers are melting at an alarming rate. The lakes they feed are filling up. If their walls are breached, flash floods will send billions of gallons of water pouring into the valleys below.

The effects will be catastrophic. Lives will be lost and the local infrastructure destroyed. We must be prepared for the worst. The most vulnerable lakes have to be identified so the situation can be monitored. In this planning exercise, pupils decide how this could best be done.

Published: 4th January 2005
Reviews & Comments: 5

Learning objectives

Pupils will be aware of the effects of global warming on the Himalayan glaciers and be able to formulate a plan for an exploration.

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11 - 14 (KS3)
Unit 8G Rocks and weathering
That rocks fragments become sediment grains which can be transported by water currents and deposited where the energy is dissipated.

Yr8 YTO Sc1
Identify more than one strategy for investigating questions and recognize that one enquiry might yield stronger evidence than another. Recognise that a range of sources of information or data is required and use secondary sources of information.

Running the activity

Starter activity: Page 1 is a stimulus page to be projected. It sets the scene for the activity. Pupils should be given time to identify what the photograph shows and discuss the consequences of glaciers melting. There are nearly 5000 glacial lakes in the Himalayas and 44 have already been identified as potentially dangerous.

Main: Page 2 shows what a flash flood could do and sets the pupil task. They have to plan a search for problem lakes. The terms erosion and deposition could be introduced at this stage. A small overflow from a glacial lake rapidly erodes its edges and the water empties completely. On the flood plain, the water's load of mud and rocks is sorted and deposited as the torrent slows down.

Page 3 needs photocopying for each pupil. It shows the data sources pupils could use for their exploration and provides a structured template to help them decide on a strategy. Pupils could work individually or in pairs.
Factors that could make a lake likely to flood are: a high and rapidly rising water level; overhanging ice that could snap off and fall into the water, or a weak barrier holding the water in place. In order to decide what to observe, pupils need to reframe these as questions that can be investigated e.g. How does the water level change from month to month; are there any cracks in the ice above the lake; is there a relationship between the air temperature and the rate at which the water level rises in the lake. Then they consider how each data source could help answer their questions. They summarise their ideas by proposing a strategy for the exploration.

A good strategy would be to begin by using the satellite images to locate lakes that could flood heavily populated areas. A high resolution image downloadable from shows the sort of terrain these lakes are found in. A combination of aerial photography and ground surveys could be then used to verify the extent of the problem for each lake. Repeat measurements would be needed to determine the rate at which water was accumulating in a lake and pupils should be encouraged to consider graphing the results to spot the overall trend.

The lake featured on Page 1 has six times the area it had 50 years ago and threatens the lives of 10,000 villagers living 108 km downstream. A network of sensors and sirens has been set up around the lake and engineering work is being carried out to lower its water level by 30 metres.

Plenary: Pupils present their plans for the exploration to the rest of the class.

News links

BBC News
Himalaya glaciers melt unnoticed.
BBC News
Further BBC news page with lots of quotes and statistics about glacial lake outburst floods in the Himalayas.
Lake outburst
A series of photographs showing the second largest glacial lake outburst in recent times.
Nepal flood
Moving images of a glacial lake outburst flood in Nepal.

Reviews & Comments

Write your online review to share your feedback and classroom tips with other teachers. How well does it work, how engaging is it, how did you use it, and how could it be improved?


May 18th, 2011

4 Star

Great for project based learning in our school, pupil used and developed many skills in this project such as research, analysing data and problem solving. Thanks.

Reviewer: Xue Han

Glacial Meltdown

May 20th, 2008

4 Star

Students were able to use their knowledge to look at a problem. Most worked well and were able to complete the task to a good standard. It was an excellent way of assessing understanding and reinforce knowledge.

Reviewer: Tracey Holmes


Feb 23rd, 2008

4 Star

Great resource for engineeringpupil interest. It made the lesson come alive

Reviewer: Olufemi Ladeinde

Glacial Meltdown 6/7/2007

Jul 8th, 2007

4 Star

I used this activity in the post examination session with a year 8 group.

I put together a PowerPoint containing lot of pictures of glaciers, glacial lakes and so on. This played on the PPT with some suitable music and the pupils had to decide what the problem was! They came up with the idea of flooding due to melting glaciers and the lakes bursting. I then used the Glacial meltdown slide to discuss the problems. We then watch a short clip from the Al Gore film show the problem of melting glaciers. This is a stunning film and really caught their attention.

We then followed the lesson much as it is written. I did make some laminated aerial map for them to study.

All in all an excellent exercise - that made them think.

Reviewer: Jeremy Randell

glacial meltdown

Mar 22nd, 2007

5 Star

my year 8s loved it from the level 3 right up to 6s. they were very engaged in thinking about the devastation that it would cause and i extended the activity so that they could come up with a strategy for either preventing or dealing with the problem. it was a great end to the rocks and weathering module abd certainly made them bring all their ideas together

Reviewer: debra johnson