Ice streams have been compared with taps that would fill a bath tub, and Nature Geoscience adds that ice streams are arteries in ice that move faster than the surrounding ice. Researchers at Durham University report the shape of channels within ice sheets transporting ice to the sea influences this delivery process and adds to rising sea levels. The streams can be hundreds of kilometers long, draining 90 percent of the ice that reaches the sea. Scientists studied the seafloor of the Antarctic Peninsula, discovering a rapid period of receding ice 13,000 years ago. The retreating ice stalled numerous times, lasting from decades to centuries. Computer modeling found ice dragging slowed the ice stream. This research will aid in understanding ice extent and global sea level changes. Fastcast: Warmer.