ESR scientists are monitoring the Pacific for airborne radioactivity resulting from yesterday's underground nuclear test in North Korea.
Wim Nijhof from the Institute of Environmental Science and Research said the explosion detected yesterday was believed to be stronger than North Korea's previous tests in 2006 and 2009.
"There is not expected to be any threat to New Zealanders from any release as the amount of any radioactivity detected will be low, given that the test was carried out underground."
A range of data is collected and analysed to identify a nuclear test, Dr Nijhof said. Radioactivity monitoring involves measuring radioactivity in particles and gases collected from the atmosphere.
Airborne radionuclides from the 2006 North Korean event were picked up on the monitoring system in Canada several days after the explosion was detected.
