Nasa satellites have helped scientists to learn about the hard-to-find Antarctic Ocean "oases" where penguins feast and thrive, researchers say.
These "oases" are actually warm patches in the normally ice-covered ocean along Antarctica's coast, enabling vast stretches of open water to support the microscopic plants that are the base of afood chain that ultimately feeds penguins, whales, seals and other animals.
Some of these stretches of open water, known as polynyas, are as big as mini-oceans themselves - at least one is the size of California - but because they are surrounded by ice, they are impossible to see by ship.
For this reason, Stanford University scientists used satellite data to analyse the plant life in these areas.
Using a special formula, researchers figured out that if the water was green, it was full of phytoplankton, the tiny plants that nourish minuscule, shrimp-like creatures called krill.
Krill are on the menu for many larger Antarctic creatures, notably the Adelie penguins whose population thrives on some of these oases.
