Mould Bay (MBC) Magnetic Observatory

Name Mould Bay
IAGA alphabetic code MBC
IAGA numeric code 014241
Geographic coordinates 76.315° N, 240.638° E
Geomagnetic coordinates (IGRF-12 (2015)) 80.01° N, 90.86° W (2015.0)
Elevation 40 m
First year 1961
Status closed in 1997
Observatory data link

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In the summer of 1961 the then Division of Geomagnetism of the Dominion Observatory (now the Geomagnetism Program of the Geological Survey of Canada) established a combined magnetic and seismic observatory in the vicinity of the Joint Arctic Weather Station, Mould Bay, Prince Patrick Island, N.W.T. (76.2 N.,119.4 W). The observatory at that time served principally as a control station for magnetic and seismic surveys mounted by the Polar Continental Shelf Project and the Dominion Observatory.

An insulated wooden building of non-magnetic construction, 8 metres by 5 metres in size, and resting on a gravel pad, serves as the magnetic observatory building. This building is situated with its long axis approximately geographic east-west and is connected by a 7 meter corridor to the seismic observatory. The magnetic components of the instruments and power distribution facilities are located at the end of the corridor remote from the magnetic observatory. A light-tight room, 4 metres by 3 metres, is partitioned off in the magnetic observatory to accommodate a set of the photographic variometers used in the early years of the observatory. The variometers and absolute instrument are mounted on concrete piers set into the permafrost. Care was taken to ensure that the piers were decoupled from the wooden floor.

The building is electrically heated by thermostatically controlled glass heating panels, capable of maintaining the temperature constant within 2 °C under normal conditions.

A three-component photographic variometer recorded the changes in the geomagnetic field. Instability in the Z variometer and suspicion of the damping effect of the hitherto undiscovered magnetic anomaly precluded continuous recording until July, 1962. Hour marks on the photographic records were provided by a Mercer chronometer.

Since late 1975, a digital recorder has been in operation in the Mould Bay Magnetic Observatory as a digital standby magnetometer. The introduction of telephone service for rapid communication to the technical services in Ottawa made the installation of an EPB AMOS MK III a logical up- grading of the Observatory. The changeover took place in July, 1985.

The combined Mould Bay Geomagnetic and Seismic Observatory had been staffed by personnel from the Geological Survey of Canada. With the introduction of the AMOS equipment, daily attendance to the Magnetic Observatory was no longer necessary. Changes within the Seismic program also resulted in less of a demand on daily personal attendance. These workload reductions resulted in the transfer of the actual data reduction to Ottawa and the Observatory operation being done by Atmospheric and Environmental Service (AES) personnel. AES has operated the Mould Bay Observatory since May, 1989.

In early 1997, the decision was made by Atmospheric and Environmental Services of the Government of Canada to close the Mould Bay weather station. In effect, there would be no staff left on the station. Therefore, the Geomagnetic and Seismology programs of the Mould Bay Geophysical Observatory were terminated in June, 1997.

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