The radar sends radio wave pulses into the ice sheet, and the waves bounce off buried features, informing researchers about the characteristics of the snow and ice layers.

ENGADGET: NASA's GROVER eco-rover to examine Greenland's ice sheet (video)

Clearly buoyed by their first-period comeback, the Penguins raced up ice time after time in waves.

WSJ: Kunitz's 2nd PP goal gives Pens OT win over Isles

The frozen lake not level but mounded along the shore, as if the waves had turned to ice in the act of falling.

NEWYORKER: Amundsen

Huge blocks of ice calved off and collapsed into tidal waves of icy slush.

BBC: Patagonia��s ice-carved waterways

The altimeter fires pulses of electromagnetic waves down on to the ice, which reflects them back up to a receiver on the satellite.

BBC: Arctic ice thickness 'plummets'

It said independent tests in Arctic conditions have shown that ice can slow oil weathering, dampen waves, prevent oil from spreading over large distances, and allow more time to respond.

BBC: MPs' call to halt Arctic drilling amid safety concerns

Ice cream in Argentina owes its existence to Italian immigrants who came to the country in two waves, first in the late 1800s with the general migration of Europeans to the New World, and again in the 1940s after World War II.

BBC: The summertime scoop on Buenos Aires ice cream