Variations of Baseline Values of Geomagnetic Field Observations and tilt-change of the sensor at Syowa Station

• Main Authors: Shin Arita (Kakioka Magnetic Observatory, Japan Meteorological Agency), Tomofumi I (Seismology and Volcanology Department, Japan Meteorlogical Agency), Junpei Oogi (Kakioka Magnetic Observatory, Japan Meteorological Agency), Kosuke Takahashi (Seismology and Volcanology Department, Japan Meteorlogical Agency), Akira Kadokura (National Institute of Polar Research), Yasuhiro Minamoto (Laboratory for Environmental Research at Mount Fuji, NPO Mount Fuji Research Station)
• Format: Article
• Language: English
• Published: National Institute of Polar Research 2020-01-01
• Series: Antarctic Record
• Subjects: baseline value; geomagnetic field observations; tilt-change; syowa station
• Online Access: http://doi.org/10.15094/00015820
• ISSN: 0085-7289; 2432-079X

At Syowa Station, Antarctica, the baseline values, or the difference between the absolute and continuous measurements, vary relatively significantly in summer. They are possibly due to artificial disturbances from magnetized objects, and/or changes of the instrumental environment such as involving the tilt and temperature of the sensor for continuous observations. To evaluate the effect of the sensor tilt, we continuously monitored its behavior with electronic tiltmeters over two successive summer seasons (Jan.-Feb. 2013, Nov. 2013-Feb. 2014), while also intensifying the frequency of the absolute observation. The variability of the tilt was found such that, its angular changes in the East-West and North-South directions were 30 to 50 and 10 arcseconds, respectively. The observed variations of the baseline values can be attributed primarily to the sensor tilt changes, with its contribution estimated to be up to 60 to 100% for the D component and 30 to 40% for the H and Z components.