Acta Seismologica Sinica

, Volume 5, Issue 3, pp 587–595 | Cite as

Secular and seasonal changes in transfer function at Guangzhou geomagnetic observatory

  • Mei Lin
  • Shaojing Gong


Time changes in transfer functions of short period geomagnetic variations in 28 years from 1960 through 1987 are studied, systemically and in detail in this paper. The results indicate that: (1) It is evident that seasonal and secular changes in the transfer functionsA at exist the Guangzhou Geomagnetic observatory. The characteristics for seasonal changes are large in summer and smaller in winter with main cycles of 12 and 6 months. The characteristic for secular change is a descend with a rate of 0.0025 per year. The seasonal and secular changes in transfer functionsB are not evident. (2) The direction of Parkinson vector at Guangzhou geomagnetic observatory is clearly affected by the ocean, and is associated with coastal effect. (3) The values of the transfer function A and B are related to geomagnetic activity ata=0.05. Secular change is not related to geomagnetic activity, maybe it is affected in a great measure by earth conductivity change.

Key words

geomagnetic short-period variation transfer function secular changes seasonal changes the coastal effect 


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Copyright information

© Acta Seismologica Sinica 1992

Authors and Affiliations

  • Mei Lin
    • 1
  • Shaojing Gong
    • 2
  1. 1.Seismological Bureau of Guangdong provinceGuangzhouChina
  2. 2.Seismological Bureau of TianjinChina

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