Tsunami Data
Tsunami gauge data records sea level variations using a pressure sensor.
Owenga Wharf, site of the Chatham Island tsunami gauge.
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.
File formats
MiniSEED, SAC or plain text
Tsunami gauge waveform data may be retrieved from GeoNet's Common Waveform Buffer using a Java client to specify stations, times and durations. Please refer to our Waveform Data pages for further information.
CREX
The tsunami gauge data are also stored as day files in CREX format and are available via anonymous ftp from:
CREX is the name of a character code for the representation and exchange of meteorological and other data, and is defined by the World Meteorological Organization, an agency of the United Nations.
Two pressure sensors are installed at each station to guard against failure of one of them.
Each day file is accompanied by a qc ("quality control") file. This shows the number of samples expected in the file and the number of samples actually present. Ideally, a file is 100% complete; however, equipment malfunction or loss of communications links can cause data completeness to fall short of this.
