|
|
 |
|
|
Ann. Geophys., 23, 1881-1887, 2005
www.ann-geophys.net/23/1881/2005/
© European Geosciences Union 2005
Results of the Rio de Janeiro magnetic observations 1781−1788
J. M. Vaquero1 and R. M. Trigo2,3
1Departamento de Física, Escuela Politécnica, Univ. de Extremadura, Avda. de la Universidad s/n, 10071 Cáceres, Spain
2Centro de Geofísica da Universidade de Lisboa, Lisbon, Portugal
3Departamento de Eng. Civil da Universidade Lusófona, Lisbon, Portugal
Abstract. We have compiled a relatively extensive catalogue of geomagnetic declination
measurements performed by the Portuguese Bento Sanches Dorta in Rio de
Janeiro (Brazil) between 1781 and 1788. All the information was retrieved
from printed documents compiled in the first three volumes of the Memories
of the Portuguese Royal Academy of Sciences. During this period Sanches
Dorta performed roughly 20000 individual observations, however, only a
fraction of this data is presently available. In this work, all available
information about these measurements is analysed. The annual change
(variability and trend) and the daily cycle of geomagnetic declination at
monthly scale are discussed.
Keywords. Geomagnetism and paleomagnetism, History of
geophysics, Geomagnetic field declination
Full Article in PDF (428 KB) |
|
|
