Retreating glaciers observed through sensor networks in National Geographic grant
Professor Kirk Martinez, from the School of Electronics and Computer Science (ECS), is monitoring glacier behaviour through custom-built sensor networks thanks to funding from National Geographic.
“Glaciers all over the world are retreating, but the rate they do so is dependent on numerous factors,” Jane explains. “These adjacent glaciers in Iceland are retreating at different rates and both have rapidly growing lakes, which threaten to cover the whole glacier front, and affect their stability.
“Through our unique connected real-time GPS developed in ECS, we hope to determine what is controlling the glacier velocity, the rate of lake growth, how this growth is affecting ice retreat and how we can record the shrinking terrestrial marginal geomorphology before it is submerged.” In a recent field trip, researchers deployed sensors onto the different parts of the glaciers to provide daily data. Ground penetrating radar was also used to understand water content, while drone photography surveyed the glacier and time-lapse cameras were set up to visually record changes. “Data is coming in steadily and we aim to make a two-year comparative record of ice velocity from both glaciers, related to temperature, rainfall and discharge to better understand patterns of meltwater flow through the glacier and its relationship with speed-up events throughout the year,” Kirk says.
Glacsweb’s unique dGPS system uses just a fiftieth of the power of traditional dGPS recordings, opening the possibility of year-round monitoring. “Traditional dGPS systems are expensive and data is normally stored on a memory card and downloaded manually months later,” Kirk explains. “We have designed a lower cost real-time kinematic dGPS so that more sites can be monitored for the same cost. It also means the loss of one unit in a glacier has a reduced financial impact.
“Our system automatically provides location measurements from synchronised dGPS units, which wait for a static RTK fix and then sleep between sessions. The readings are sent once per day to a web server via the Iridium satellite network, allowing the system to operate anywhere in the world. The fixes are accurate to around 2cm and they take less than two minutes to acquire, with only 50 bytes to transmit compared to hundreds of kBytes with traditional dGPS recordings. The systems use a low power Arm-based computer running MicoPython and a small solar panel to recharge the battery.”
The technology has the potential to monitor other remote environments and is already part of other Southampton research into the use of the Internet of Things (IoT) in environmental sensor networks to understand the response of the environment to global warming.