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Concept information

Preferred term

ultralow frequency  

Definition

  • Ultra low frequency (ULF) is the ITU designation for the frequency range of electromagnetic waves between 300 hertz and 3 kilohertz, corresponding to wavelengths between 1,000 to 100 km. In magnetosphere science and seismology, alternative definitions are usually given, including ranges from 1 mHz to 100 Hz, 1 mHz to 1 Hz, and 10 mHz to 10 Hz. Many types of waves in the ULF frequency band can be observed in the magnetosphere and on the ground. These waves represent important physical processes in the near-Earth plasma environment. The speed of the ULF waves is often associated with the Alfvén velocity that depends on the ambient magnetic field and plasma mass density. (Wikipedia, The Free Encyclopedia, https://en.wikipedia.org/wiki/Ultra_low_frequency)

Broader concept

Entry terms

  • ULF

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URI

http://data.loterre.fr/ark:/67375/MDL-RN0HCZ1W-5

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