Wireless Sensors Monitor Glacier Behavior

By Roland Piquepaille

In a world's premiere, an interdisciplinary team of the University of Southampton, GlacsWeb, has deployed a network of wireless sensors inside a Norwegian glacier to record its behavior. This news release, "Sensor Technology Comes in from the Cold" says that the sensor probes, housed in 'electronic pebbles,' are buried 60 meters under the surface of the glacier. And they transmit wirelessly their observations about temperature, pressure or ice movement to a base station located on the surface, which relays the readings to a server in the UK by mobile phone. The researchers think that similar sensor webs will soon be deployed around the world to watch what is changing in our environment.

This diagram shows you how this works (Credit: GlacsWeb).

Now, let's look at the goals of the project.

In the first investigation of its kind in the world the University of Southampton's interdisciplinary GlacsWeb team is recording glacier behaviour through a network of sensor probes installed directly into the glacier.

The GlacsWeb project is aiming to understand glacier dynamics and climatic change, as well as making advances in pervasive sensor networks. The GlacsWeb team, led by Dr Jane Hart, Dr Kirk Martinez and Dr Royan Ong, installed the sensor network last summer at the Briksdalsbreen glacier in Norway.

This glacier advanced 400 meters since 1988 over silty clay (lake bed). This is why the team will return to the glacier this coming summer to see if there are changes.

Let's turn to the details of the implementation.

"Our sensors are housed in 'electronic pebbles' which will behave as part of the glacier, enabling us to get the clearest picture possible of what is happening deep below the surface."

Here is one of these 'electronic pebbles' (Credit: GlacsWeb).

"We are using 'subglacial probes' beneath a glacier, communicating to the surface via radio links. They contain various sensors and their position and orientation is sensed by the surface system. This is the first time wireless probes have been put inside glaciers and it involves many challenges. The systems must feed data back to a server in the UK and contend with communication loss, power loss, noise and bad weather!"

The probes are installed in the sedimentary base of the glacier, about 60 metres under the surface through the use of a powerful hot water drill. They record temperature, pressure, speed and movement of the ice, and more importantly of the sediments at its base.

The probes emit signals carrying the data, which are relayed back to a base station on the glacier surface by radio communications, and then transmitted to Southampton by mobile phone.

What's next?

"A combination of technologies has made sensor webs possible," says Kirk Martinez. "These will eventually be spread around the world and will give us a clearer picture of exactly how we are changing our environment. In order to make successful sensor webs issues such as: communications, low-power, robustness and adaptability have to be solved through a combination of mechanical engineering, electronics, computer science and environmental science."

For more information about this project, you can read this presentation, "An autonomous multi-sensor probe for taking measurements under glaciers" (33 slides).

Source: University of Southampton news release, May 27, 2004