The tsunami gauge data are collected by two pressure sensors (labelled streams 40 and 41) at each station. This provides a backup in case of failure of one of them. The tsunami gauge stations may be viewed on the network maps, and the site locations and operational dates may be found in DELTA. New Zealand's tsunami gauge data are shared in real time with overseas data centres and their warning systems.
CREX is the name of a character code for the representation and exchange of meteorological and other data.
It is vital that tsunami data is received from our network as quickly as possible. View graphs to see how the tsunami gauge network is performing.
GeoNet tsunami publications.
De-tiding the tsunami gauge data
The tidal portion of the observed sea levels can be removed by using predicted tidal heights. The tides at a given site can be modelled using the "Harmonic Analysis" method if a sufficiently long sea level record is available. Mathematical techniques such as Fourier spectral analysis or least squares fitting are applied to the recorded tidal heights to deduce their various tidal components. These components, or "constituent tides", are represented as an amplitude and a phase. These constituents have been given codes, such as "M2" & "S2" which are the two main Lunar and Solar components of the tide. The height of the tide for any given time can be calculated by summing the constituent components calculated for that time. This height can be subtracted from the observed sea level to produce the "detided" data stream.