Editing Very low frequency (section)

=== Geophysical and atmospheric measurement ===
Naturally occurring signals in the VLF band are used by [[geophysicist]]s for long range lightning location and for research into atmospheric phenomena such as the aurora. Measurements of [[Whistler (radio)|whistlers]] are employed to infer the physical properties of the [[magnetosphere]].<ref>{{Cite web |title=AWDANet |url=http://plasmon.elte.hu/awdanet.htm |website=plasmon.elte.hu}}</ref>

[[Geophysicists]] use VLF-[[electromagnetic]] receivers to measure conductivity in the near surface of the Earth.<ref>{{Cite web |title=Geonics Limited - VLF Receivers |url=http://www.geonics.com/html/vlfsystems.html |access-date=13 June 2014}}</ref>

VLF signals can be measured as a [[Geophysics|geophysical]] [[electromagnetic]] survey that relies on transmitted currents inducing secondary responses in conductive geologic units. A VLF anomaly represents a change in the attitude of the electromagnetic vector overlying conductive materials in the subsurface.