The power of "slow-slip'' earthquakes lasting up to a year to contort New Zealand's landscape has been highlighted in fresh data.
GPS survey sites, monitored as part of the Government-funded National Hazards Research Platform Project, have showed the gradual subsidence occurring in Dunedin and across other parts of New Zealand.
But the data also showed a series of slow uplifts, lasting months or even a year, in Wellington and around other parts of the North Island's subduction zone, University of Otago School of Surveying lecturer Dr Paul Denys said.
Measurements in Christchurch highlighted the sharp uplift resulting from the 2011 earthquakes.
And, in Dunedin, the power of earthquakes occurring hundreds of kilometres away in Fiordland to lift the city had been recorded.
The uplifts were first noted in 2002, and most could be measured in millimetres, but on graphs they resembled a caterpillar that moved by hunching its back, he said.
"The overall subsidence is going down ... but periodically there's a small correction upwards,'' he said.
GNS Science geologist David Barrell said the data was significant, as "we're measuring things that could never be measured before''.
"It's just astonishing that these earthquakes, which we might feel here in Dunedin if we're awake at the right time, coming from 200km or 300km away, have actually shifted the ground measurably.''
In Dunedin, the data suggested parts of the city might be subsiding by between 1mm and 5mm a year, despite periodic uplifts, particularly in reclaimed areas of South Dunedin.
But Dunedin and wider New Zealand were not alone - satellite data had also shown China's capital, Beijing, was sinking by up to 11cm a year.
The subsidence was blamed on excessive pumping of groundwater from under the city of 20 million, The Guardian reported last month.
The subsidence was predicted to raise safety concerns if it continued, with a strong impact on train operations among the outcomes.
