Molten rock is accumulating in a magma chamber beneath New Zealand, raising questions about volcanic hazards.
Ian Hamling and his colleagues at GNS Science in Lower Hutt, New Zealand, used satellite radar data to study ground motions in the Taupo Volcanic Zone, an area of high volcanic activity. They found one region, adjacent to this area, where the ground rose by around 5 millimetres per year from the 1950s onwards. That rate more than doubled to about 12 millimetres a year in the mid-2000s, and has since dropped back to the lower rate. Calculations suggest that about 9 million cubic metres of magma pushed its way into the crust each year during peak growth, about 10 kilometres below the surface.
It's not clear whether the magma chamber will increase the risk of volcanic eruptions.
For more on this research, see go.nature.com/28ew7kh