Geomagnetic Data

Geomagnetic Dashboard

This dashboard shows the rate of change, vertical and horizontal components, from the magnetometer site located West Melton, Canterbury. The site is also known as Eyrewell Geomagnetic Observatory (EYR) that is part of the global Intermagnet network. The data delivery target is 5 minutes from data collection to display. The data displayed is 1 minute time series data derived by computing the raw magnetometer data sampled at 1Hz (one sample taken every second) and calculating an average across 1 minute. The dashboard is updated with this data every minute. There is a display threshold set for 100 nano Tesla per minute (nT/min) for the rate of change, you can set your own threshold limit that will be saved in the browser you use. The rate of change maximum value displayed is based on the selected time period. The maximum value is also marked in the rate of change plot as a green (below the threshold) or a blue dot (above the threshold) value.

To view more geomagnetic data, you can use our Tilde Data Discovery Tool for 1-minute average data computed since 1 April 2024, or the Intermagnet website for all historic 1-second and 1-minute average data.

The graph shows time based on your browser's time zone.


Understanding the Data

The magnetic field measured by a magnetometer on the ground is typically described by a vector field, with the intensity being different for the different vector components.

Magnetic intensity is measured in nanoTesla (nT) units.

The horizontal intensity (H) of the magnetic field is derived from the measured horizontal magnetic field components magnetic north (X) and magnetic east (Y).

The magnetic field rate of change is the variation in intensity of the horizontal magnetic field from one minute to the next.

During the 10-11 May 2024 solar storm, we saw a maximum rate of change value of 320 nT/min, read more on that here.


Solar Tsunami Endeavour Programme

This geomagnetic dashboard was developed as part of the Solar Tsunami Endeavour Programme, an international collaboration led by the University of Otago to understand how New Zealand's energy infrastructure will be impacted by an extreme space weather event.

Helpful Links

Tilde Time Series API

Use our common time series API to create calls to get data you need to integrate with third party software.

Intermagnet Data Portal

View and download historic geomagnetic data and information from other geomagnetic observatories around the world at Intermagnet.

Explore & Download More Data – Tilde Data Exploration Tool

If you want to download data or explore other data types, including Seismic Waveforms, try our Exploration Tool.

New Zealand Geomagnetic Database

If you want to know what other geomagnetic datasets are available for New Zealand explore the Geomagnetic Database.