| These waterfowl migrate early in spring and move northward from their wintering grounds as soon as wetlands become ice-free. |
| Halifax has long been a bustling international port and naval base, as well as being the only ice-free port on Canada's eastern seaboard. |
| The extra shelter from the riverside developments saw the walkways stay ice-free last week. |
| In winter, a sunny location will help an electric heater keep the water ice-free. |
| By 12,000 years ago, they had made their way south from the interior of Alaska through an ice-free corridor to the high plains of North America. |
| Canadian and New Zealand scientists have found living microbes in the soil of an ice-free region of Antarctica. |
