This is the VOA Special English ENVIRONMENT REPORT.
New measurements show that ice in West Antarctica is thickening. Scientists concerned about global warming had worried that higher temperatures could melt the huge ice sheet in Antarctica. That could cause sea levels around the world to rise. However, some experts have said there is little evidence that global warming is responsible for melting the ice sheet.
Antarctica is the continent that surrounds the South Pole. It is the coldest and iciest area in the world. Stormy waters of the Atlantic, Indian and Pacific oceans separate Antarctica from other continents.
The Antarctic icecap is a thick layer of ice and snow that buries most of the continent. If the ice melted, the earth's oceans would rise and flood coastal cities around the world.
Large, flat sheets of the icecap called ice shelves float in water near Antarctica. The Ross Ice Shelf is the largest one. Several rivers of the West Antarctica ice sheet flow into the ice shelf. Huge pieces of the ice shelf break off and slowly melt into the sea. The West Antarctica ice sheet currently covers more than nine-hundred-thousand square kilometers.
The new study was done by researchers at the California Institute of Technology and the University of California at Santa Cruz. They studied several ice streams in West Antarctica that lead into the Ross Ice Shelf. The ice streams are similar to large flowing rivers of ice. The researchers used new satellite radar to measure the thickness of the ice.
Earlier studies suggested that the ice was thinning and quickly moving toward the sea. However, new satellite information found that the Ross ice streams are gaining ice, not losing it. Scientists said there were an average of twenty-six-thousand-million tons more ice each year. Earlier studies showed a loss of almost twenty-one-thousand-million tons a year.
The scientists said they found strong evidence of ice growth. Yet, measurements taken by researchers have shown that the ice sheet has been slowly melting since the end of the last ice age about eleven-thousand years ago. Some researchers say they believe the Earth's internal heat may be causing the ice sheet to thin or thicken over time.
This VOA Special English ENVIRONMENT REPORT was written by Cynthia Kirk.