New Zealand’s Magnetic Observatories
GNS Science currently runs a magnetic observatory at Eyrewell, north-west of Christchurch, and at Scott Base in Antarctica. These observatories provide measurements of the three components of the magnetic field every second, with data telemetered every few minutes. As a quality check, independent instruments measure the total magnetic field strength every five seconds at each observatory.
GNS Science also supports the Apia magnetic observatory in Samoa, which is run by the Samoan Government, with assistance from New Zealand and other countries.
The observatories in New Zealand and Samoa provide the only continuous data from about a 90° arc of the Southern Hemisphere, one eighth of the globe. Their continuing operation is essentially a contribution to the world scientific community.
Magnetic data from these observatories is sent to INTERMAGNET, an international organisation that archives and disseminates magnetic observatory data.
Long term changes
Part of the value of magnetic observatories is in having a long record to define very long term changes. GNS Science can produce a continuous reference series of geomagnetic measurements back to 1902.
Data from Eyrewell can be combined with that from previous observatory sites in Amberley and the Christchurch Botanic Gardens to produce a continuous reference series back to 1902.
Short-period magnetic variations
Eyrewell is one of two Southern Hemisphere stations which contributes to the planetary index Kp, which is an indication of the strength of the magnetic variations in every 3-hour interval.
Read more about short period magnetic variations and magnetic storms.