Bulge in the ocean

Abstract

Some giants are so big, they are practically invisible. Geophysicists have discovered one of them — a huge hump of water in the South Pacific that is imperceptible to the naked eye. Satellites aided scientists in tracking the phenomenon. Carmen Böning and her colleagues at the California Institute of Technology (Caltech) have reported a bulge in ocean waters that extended over an area the size of Australia for some months, and measured up to six centimetres in height (C. Böning et al. Geophys. Res. Lett. 38, L04602; 2011). A “record” or an “unusual maximum”, say the researchers. The discovery can be attributed to the satellite programmes Gravity Field and Steady-State Ocean Circulation Explorer (GOCE) (http://go.nature.com/ZOJZup) and Gravity Recovery and Climate Experiment (GRACE) that measure the Earth’s gravitational pull. These programmes have provided the most precise atlas of the Earth’s gravitational field so far.