Tracking Magnetic Storms from the Scottish Lowlands
How the Eskdalemuir Observatory is used to monitor earthquakes, pollution and the Earth’s magnetic field
The Eskdalemuir Observatory began operation in the Scottish Borders in 1908 and its remote location allows for the monitoring of a variety of processes that affect people all around the globe. The original purpose of the observatory was the measurement of the geomagnetic field in the United Kingdom, but it is also currently used to track seismological activity and meteorological parameters.
With electric tramways spreading across London and interfering with the accuracy of the magnetic measurements at Kew Observatory, the National Physics Laboratory faced pressure to find a new location, at least 10 miles away from any sources of magnetic disturbances. Eventually, in 1903, five years after proposals for the tramways were announced, the site of Eskdalemuir was selected. The relocation was partly funded by a compensatory donation from the tramway company, and the Duke of Buccleuch offered a perpetual lease of the land. Eskdalemuir is well known for frequently being identified as the wettest or coldest location in the UK on given days, due to the elevation and exposure of the site, which is near the end of a long valley. The construction of the observatory brought to the area the first telephones and metalled roads.
Monitoring the magnetic field of the Earth is necessary for multiple modern industries and processes. For example, values of declination (the local direction of the north magnetic pole) are included in most maps and are essential for compass navigation. In the petroleum industry, drills must be directed towards small targets in oil reservoirs. This can be achieved using magnetic tools, but, in order to achieve the high levels of accuracy required to avoid well collisions, several properties of the Earth’s magnetic field must be taken into account, including daily variations and magnetic storms.
These storms can damage technological systems on Earth due to geomagnetically induced currents. As well as this, magnetic storms lead to a heating of the Earth’s atmosphere, resulting in drag that can alter the orbit of satellites, requiring expensive corrections. During the 2003 magnetic storm, caused by dramatic changes in the solar wind, Eskdalemuir recorded a fluctuation of the declination of 5° in as little as six minutes, demonstrating the importance of monitoring and predicting magnetic activity. Eskdalemuir is part of INTERMAGNET, a global network of observatories that cooperate to monitor the Earth’s magnetic field.
Tracking seismic activity is another purpose of the Eskdalemuir Observatory which would have been made impossible by the movements of the trains and trams at Kew. The new site was much better suited to these measurements due to its remoteness and the very low occurrence of even very small earthquakes. Eskdalemuir is a base station for a network of seismometers which monitor activity in the UK. The instruments in the network recorded the magnitude 4.7 Longtown earthquake on Boxing Day 1979, as well as the aeroplane crash that resulted from the Lockerbie bombing in 1988. Roughly 3 km north of the main observatory is an array established by the United Kingdom Atomic Energy Authority as part of an international network, which monitors compliance with the Comprehensive Test Ban Treaty by detecting nuclear tests from their seismic signatures.
The Met Office was responsible for the operation of the Eskdalemuir Observatory from 1910 to 1967, and the site has always been at the forefront of meteorological technology. When control of the observatory passed to the Natural Environment Research Council (NERC), Met Office staff remained on site. The synoptic meteorological station installed there measures levels of atmospheric pollution, as well as solar radiation. The site was the Met Office’s first automatic weather station and contributes data to models which predict the weather in Britain. Eskdalemuir is also often chosen as a site to test new equipment, due to its reputation as one of the coldest and wettest places in the UK.
This all gives an indication of how a carefully chosen site can provide excellent conditions to explore several different branches of science. Eskdalemuir still plays an important part in various networks and organisations over a century since it began operation, as it continues to adapt to new technologies over the years.
References:
- One hundred years at Eskdalemuir — David Booth, 2004, NERC Planet Earth
- Eskdalemuir Observatory — I. K. Dawson, 2005, Weather
- Recording observations for over 100 years — Met Office
- Eskdalemuir Magnetic Observatory — British Geological Survey
- INTERMAGNET
- The Earth’s Magnetic Field: An Overview — British Geological Survey
