TY - JOUR
T1 - Long-term seafloor geomagnetic station in the northwest Pacific
T2 - A possible candidate for a seafloor geomagnetic observatory
AU - Toh, H.
AU - Hamano, Y.
AU - Ichiki, M.
N1 - Funding Information:
Acknowledgments. Japan Agency for Marine-Earth Science and Technology is greatly acknowledged for their support at the time of the sea experiments. The skilful aid offered by R/V Kairei and ROV Kaiko was essential to complete this work. The authors are grateful to Heather McCreadie and two anonymous referees for their valuable comments indispensable to improve our original manuscript. This work was supported by Grant-in-Aid for Scientific Research, Ministry of Education, Culture, Sports, Science and Technology, Japan (Nos. 08NP1101 through 13NP1101).
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2006
Y1 - 2006
N2 - For two years, geomagnetic variations have been measured at the seafloor in the northwest Pacific. The seafloor data consist of the geomagnetic vector field measured by a three-component fluxgate magnetometer and the absolute scalar total force measured by an Overhauser (1953) magnetometer with attitude measurements for both orientation and tilt. Using the attitude data, the geomagnetic data at a site in the northwest Pacific (41°06′08″N, 159°57′47″E, -5580 m), hereafter referred to as NWP, were converted into the same reference frame as land and satellite measurements. Short-period variations of the converted vector data were examined by Hamano's (2002) global time domain analysis method, which showed compatibility of the seafloor geomagnetic observatory data with the existing land observatory network. The smooth and gradual change of the Earth's main field (i.e., the geomagnetic secular variation) was also found consistent with those predicted by the latest International Geomagnetic Reference Field (IGRF-10; IAGA, 2005) and by Ørsted Satellite (Olsen, 2002) for not only the scalar field but also the vector field. This means that observation of the geomagnetic vector secular variation is now feasible on the seafloor.
AB - For two years, geomagnetic variations have been measured at the seafloor in the northwest Pacific. The seafloor data consist of the geomagnetic vector field measured by a three-component fluxgate magnetometer and the absolute scalar total force measured by an Overhauser (1953) magnetometer with attitude measurements for both orientation and tilt. Using the attitude data, the geomagnetic data at a site in the northwest Pacific (41°06′08″N, 159°57′47″E, -5580 m), hereafter referred to as NWP, were converted into the same reference frame as land and satellite measurements. Short-period variations of the converted vector data were examined by Hamano's (2002) global time domain analysis method, which showed compatibility of the seafloor geomagnetic observatory data with the existing land observatory network. The smooth and gradual change of the Earth's main field (i.e., the geomagnetic secular variation) was also found consistent with those predicted by the latest International Geomagnetic Reference Field (IGRF-10; IAGA, 2005) and by Ørsted Satellite (Olsen, 2002) for not only the scalar field but also the vector field. This means that observation of the geomagnetic vector secular variation is now feasible on the seafloor.
KW - Attitude data
KW - IGRF
KW - Long-term seafloor geomagnetic observation
KW - Satellite measurements
KW - Scalar and vector geomagnetic fields
KW - Secular variation
KW - The Earth's main field
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U2 - 10.1186/BF03351970
DO - 10.1186/BF03351970
M3 - Article
AN - SCOPUS:33745700824
VL - 58
SP - 697
EP - 705
JO - Earth, Planets and Space
JF - Earth, Planets and Space
SN - 1343-8832
IS - 6
ER -