Science Centres: Coasts and Oceans

Monitoring the sea level

Sea-level monitoring station at Charleston (west coast).

NIWA coordinates a network of 20 open coast sea-level recorders around New Zealand, including the Chatham Islands, and Antarctica (Scott Base). The recorders collect accurate measurements of sea level and tides for monitoring coastal hazards such as storm surge and tsunami, and studying longer-term coastal processes, including El Niño effects and sea-level rise. Data are uploaded nightly and some sites are displayed at www.niwascience.co.nz/services/sealevels. The data are also used for processing hydrographic surveys of the seabed topography and field monitoring of invasive species such as mosquitos at the high water mark.

Some of the recorders have been tsunami-enabled to store sea-level measurements quickly at 1-minute intervals to better describe the various waves that make up a tsunami event. Currently, any emergency response in detecting and confirming a tsunami is undertaken on a best-endeavours basis with the Ministry of Civil Defence & Emergency Management. NIWA is currently assisting Land Information New Zealand to develop a round-the-clock sea-level service as part of a new national tsunami early-warning system.

The present network is supported by several regional councils (Environment Canterbury, Northland Regional Council, Auckland Regional Council, Environment Waikato, Hawke’s Bay Regional Council, Otago Regional Council, Environment Southland), port companies (Westgate, Primeport-Timaru, Lyttelton), territorial authorities (Tasman District Council), Antarctica NZ, and Australia’s National Tidal Centre.