GeoNet Equipment

The GeoNet project uses a wide variety of sensing equipment located throughout New Zealand, supported by computers running both open source products and tailored applications.

VSAT dish and instrument shed at Wether Hill Road (WHZ), Southland.

Seismograph Stations

Seismographs are used to measure accurately the magnitude, location and other characteristics of earthquakes. The New Zealand National Seismograph Network will be made up of 46 backbone stations located throughout the country to provide a uniform location and data collection capability. Each site consists of:

• Guralp (CMG3-ESP) or Streckheisen (STS-2) broadband seismometer;
• Kinemetrics Episensor strong-motion accelerometer;
• Quanterra Q4126 or Q330 six channel 24 bit data logger;
• High speed data connections using standard internet protocols (TCP/IP) to the data centres.

Regional seismograph networks provide enhanced volcano monitoring and improved depth control for subduction-related earthquakes along the Hikurangi margin. They will use predominantly short period seismometers, remote digitisers and spread-spectrum radio links to backbone stations or directly to the data centres.

Strong-Motion Instrumentation

Over 250 strong-motion recorders will monitor how structures perform in earthquakes. The network of strong-motion recorders will use or facilitate:

• Near real-time data links using cell phone or internet telemetry;
• Altus (Etna) instrumentation for:
• free-field sites,
• near fault monitoring of four major active faults, including the Alpine fault,
• urban and microzone monitoring;
• Structural arrays using low-cost recorders triggered from a central point.

Measuring soil CO₂ flux on the summit of Mt. Ngauruhoe.

Volcano Surveillance

Seismic, geochemical, GPS survey and remote sensing techniques are used for early detection and monitoring of volcanic unrest. This will be achieved through:

• Upgraded volcano seismic networks at selected volcanic centres in the North Island;
• An upgraded fluid and gas analytical laboratory and portable instruments for baseline monitoring and remote sensing (including InSAR);
• Digital cameras at major volcanic centres to provide a record of activity.

The continuous GPS installation at Hicks Bay (HIKB).

Tsunami Detection

In addition to seismometers capable of characterising tsunami-causing earthquakes, a network of tsunami gauges will be established. These will use:

• Quanterra Q330 six channel 24 bit data loggers;
• Druck pressure sensors. 

Geodetic Monitoring

The Global Positioning System (GPS) network is used to pinpoint where strain is building up or being released in the earth's crust. There will be:

• About 30 nation-wide continuous GPS stations (in collaboration with Land Information New Zealand);
• A densely spaced GPS network along the east coast from East Cape to Marlborough, some co-located with an upgraded Wellington region seismograph network;
• An intensified GPS network in volcanic centres and borehole tilt/strainmeters deployed around Ruapehu volcano.

Data Management Centres

The Data Management Centres perform round the clock operation of the monitoring system:

• The National and Regional network seismographs telemeter data continuously to two independent Data Management Centres (at Avalon and Wairakei), providing backup in the event of a large earthquake in Wellington or an eruption near Taupo;
• The telemetry uses both satellite (VSAT) and terrestrial broadband links, as well as high speed ethernet radios, to provide robustness through diversity;
• Sun and Dell servers store the incoming data and forward detected earthquakes to the New Zealand version of the CUSP analysis system running on Compaq Alpha servers, thus providing real-time event data for auto-location and detailed analysis;
• The strong-motion data stream is fully integrated and analysed with the existing seismograph data;
• GPS data are telemetered on shared links where possible and are archived as Rinex files in the data centre.