The Earthquake Commission is funding the placement of two sensors on the seafloor at New Zealand’s largest plate boundary, to feed continuous readings to scientists over five years.

The sensors, placed 3500 metres down by a robot, will reveal activity at one of the nation’s biggest sources of seismic hazard and tsunamis, where the Pacific plate dives under the Australian plate off the east coast of the North Island.

“The Hikurangi subduction zone is New Zealand’s biggest ‘earthquake factory’,” commission GM Reinsurance, Research and Education Hugh Cowan said.

“The more we can understand its behaviour, the better communities can plan and prepare to reduce the impact of an earthquake or tsunami generated at sea from this zone.”

Scientists are installing “absolute pressure gauges” to monitor upward or downward movement, especially when there is a slow slip or “silent earthquake”.

The two gauges will provide an important baseline data set to help scientists strip out the effects of tides and currents on pressure readings.