A team of 15 seals is to help British scientists sailing to Antarctica to investigate how melting glacier ice contributes to rising sea levels.

The ambitious £7.4m mission to the Pine Island Glacier will use cutting edge technology, including ground-mapping radar, ocean robots, and missile-like ice tracking probes.

But some of the most important data on sea temperature and salinity will be collected by seals with transmitter boxes glued to their fur.

The seals will capture information with their sensors as they swim to places inaccessible to the scientists.

As well as assisting Antarctic research, they will provide biologists with a better insight into their vulnerability to climate change.

Pierre Dutriex, from the British Antarctic Survey, said: "With moorings you have one point in space, whereas the seals are moving around.

"Basically, we catch some seals, and put the instrument on top of them. No harm is done to the animals.

"All through the winter, they record information as they dive and broadcast the profile of temperature and salinity."

Different species of seals with different behaviour patterns will be tagged, he said. Some migrate, while a group of elephant seals prefer to stay in one place.

Professor Mike Bentley, from the University of Durham, said: "Past experience shows that if you tag seals you do cover quite a large area.

"You can make measurements in winter in areas where you don't get ships."

Pine Island Glacier is thinning at the rate of more than a metre per year, and the speed at which it flows to the sea has accelerated in the past 15 years.

The glacier drains around a tenth of all the ice flowing off the west of Antarctica. It is already the single biggest glacial contributor to rising sea level, and its future impact could be significant.

In July, a giant iceberg measuring 720 square kilometres, roughly eight times the size of Manhattan island in New York, broke off the glacier.

Scientists want to know why the glacier is behaving as it is and what effect it might have in decades to come.

Final preparations are being made for a vanguard of around 35 British scientists taking part in the iSTAR mission to travel to the glacier.

They will spend 10 weeks journeying by tractor 600 miles across the ice sheet.

Starting in November, the researchers will map the bedrock beneath the glacier, and sail into the Amundsen Sea to probe the water conditions near the ice.

A fleet of ocean robots known as Seagliders will collect data at different depths, while an unmanned submarine dives beneath the ice shelf.

Rocket-like marker probes dropped by aircraft will "spear" the flowing ice and track its movement to the sea.

Scientists outlined the plans at the British Science Festival at the University of Newcastle.

Professor David Vaughan, from the British Antarctic Survey, said: "Global sea level is now rising at about 3.2 millimetres a year. Our expectation is that over the next century that rate will go up.

"We need to plan for future. The range of uncertainties in sea level rises is still quite large."

Although most sea level rise is caused by thermal expansion - warm temperatures heating the ocean and making it expand - glaciers such as Pine Island make a significant difference.

Understanding and predicting sea level rise is important to the fate of London, which is on a tidal estuary, said Prof Vaughan.

"We need to have a good idea of what sea level is going to do over 100 years," he said. "We started building the Thames barrier after the 1952 floods and it won't be replaced until at least 2030."

Pine Island Glacier is thought to add between 0.1 and 0.25 millimetres to global sea level each year.

"It might sound small but Pine Island is the one losing the most ice, and there are others," Prof Vaughan added. "They all add up and add to the thermal expansion of the oceans."

The contribution of polar ice sheets to rising sea level is also increasing, said the scientists. Ten years ago they accounted for about a 10th of its extent, but today they contribute a third.