Indirect ways of assessing past temperatures, using so-called temperature proxies, take measurements of responses to past temperature change that are preserved in natural archives such as ice, rocks and fossils.
Wikipedia has an article on: Reorder tone. Wikipedia. fast busy signal â(plural fast busy signals) (telephony) An audible signal on a voice phone line that sounds more frequently than a standard busy singal, indicating that no transmission path to the called phone number is available.
This type of busy signal usually occurs during the aftermath of a natural disaster that creates exceedingly high call volume. Fast busy signals usually subside within hours of the unexpected event, when the cellular phone company restores the circuits or opens more circuits to meet the high-volume call demands.