Tsunami Data

Tsunami gauge data records sea level variations using a pressure sensor.

Owenga Wharf, site of the Chatham Island tsunami gauge.



Two pressure sensors are installed at each station to guard against failure of one of them.

The tsunami gauge data are available via anonymous ftp from ftp.geonet.org.nz/tsunami. Two pressure sensors (streams 40 and 41) are installed at each station 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 other Pacific data centres.

File formats

CREX

The tsunami gauge data are stored as day files in CREX format. 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.

Quality control

Additionally, 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.