Installation of the BGS Magnetic Observatory on Sable Island was funded as a joint venture between the British Geological Survey (BGS), Sperry-Sun Drilling Services and Sable Offshore Energy. The data collected at the observatory aid scientific research into rates of change of Earth's magnetic field and increase the accuracy of the BGS Global Geomagnetic Model. Data from the geomagnetic observatory on Sable Island are used by the offshore energy industry in, for example, precise positioning activities such as directional drilling. This involves drilling deviated wells towards often small targets in the oil and gas reservoirs. Accuracy is critical for not only economic reasons, but for safety - directional precision enables operators to avoid well collisions. Gyroscopic tools can be used but are expensive. Less expensive magnetic tools, however, provide the needed accuracy when magnetic field values are combined with an understanding of how magnetic bearings vary with fluctuations in Earth's magnetic field. Earth's magnetic field (or geomagnetic field), which varies between regions, and on time scales ranging from seconds to aeons, affects the natural world and human activity in many ways. Fluctuations in the geomagnetic field can have an impact on health, safety and economic well-being, including disruption of electric power utilities, and interference with modern communications and navigation systems. There are three components to Earth's magnetic field: Main field: Earth's core, which accounts for roughly 90% of the magnetic field, and is fairly consistent over broad areas. Crustal field: Earth's crust, which contains deposits of metals and is relatively stable (i.e. changes would occur over a very long period, a geological timescale). Details of this field are provided by survey of local geology. External field: the effects of the Sun, such as daily cycles and solar flares, which result in frequent fluctuations over a 24-hour period. The Sun constantly emits charged particles that, on encountering Earth's magnetic field, cause electric currents to flow in the ionosphere and magnetosphere - these currents disturb the geomagnetic field. At a geomagnetic observatory, magnitude and direction of Earth's magnetic field are recorded continuously, with a time resolution of one minute or less, over a long period of time. Sable Island is an ideal location for an observatory, not only because of its geographic position and magnetically clean environment, but because of the presence of the Sable Island Station. The observatory is situated in the instrumentation field just west of the office, and the station provides electricity, security and technical support for the program. In addition to weekly calibrations carried out by Sable Island Station personnel, a BGS scientist from Edinburgh visits Sable Island, once a year, usually in early spring, to do calibrations and maintenance.

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Monitoring and understanding geomagnetic field activity often relies on combining records from observatories around the world. In addition to its three long-standing geomagnetic observatories in the United Kingdom, the British Geological Survey operates three in the Atlantic, on Sable Island in the North Atlantic, and on Ascension Island and the Falkland Islands in the South Atlantic. The Canadian Geological Survey of Canada (GSC) maintains 13 geomagnetic observatories in other areas of Canada. The GSC installation closest to Sable Island is located at St. John's, Newfoundland. Information collected at the BGS observatory on Sable Island is shared with GSC.

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