ELF

{
  "id": "MLC-T-MET-005346",
  "term": "ELF",
  "field": "Meteorology and atmospheric science",
  "definition": "An acronym for Extremely Low Frequency, referring to electromagnetic radiation with frequencies ranging from 3 to 300 hertz. These waves have very long wavelengths, typically from 1,000 to 100,000 kilometers. ELF waves can penetrate seawater and are used for communication with submarines, but their atmospheric propagation is influenced by the Earth-ionosphere waveguide.",
  "see_also": [
    "radio frequency band"
  ],
  "url": "https://mlchart.com/terminology/meteorology/elf/"
}