Possibly because of my obvious job description “Meteorologist” I have seen this phenomenon in most all of its various forms in nature, on video, or in pictures. There is one form, however, that many people don’t know exists. It is this type that my column highlights now.
What I refer to is lightning, but a specific type of lightning. In past columns I have discussed how lightning forms and just how dangerous it can be. I did mention that there is a situation in which lightning forms that most people didn’t know about. If you lived in Oregon or Washington state back in 1980 you should remember that on May 18, 1980 Mt. St. Helens erupted with much sound and fury. I have a painting hanging in my living room that was done by an artist named Charlie Palmer from Spokane, Washington. As I explained in a previous column, I commissioned him to paint a smaller version of his large painting of the eruption of Mt. St. Helens. Besides the size of the painting there is another difference between the first one and mine. The first one was his concept of the ash cloud over the mountain during the first eruption while the second painting was done after a subsequent eruption that he saw video eruption video replayed on the news. What was that significant difference? It was lightning which formed due to the hot gasses and particulates expelled when the volcano exploded.
An article I found on Yahoo! gave me the inspiration to discuss this topic. It was titled “The mystery of volcanic lightning continues to intrigue researchers” and was written by Michael Kuhne of AccuWeather and published January 17, 2019. Kuhne explains that the lightning we are all familiar with is an electrostatic discharge between two electrically charged clouds or between a cloud and the ground. Lightning can also occur within a cloud. As the electrical charge of the lightning courses through the air it can heat the air to 50,000 degrees F. That’s five times hotter than the Sun’s surface.
The author quotes the 2016 book Volcanic Ash: Hazard Observation “Emitted plumes readily become electrically charged, but the relationships between volcanic parameters, meteorological conditions, and lightning type and rate are not well understood.” And continuing “It seems likely that the meteorological mechanisms generating lightning in thunderstorms are enhanced by the presence of ash, a mechanism that we refer to as the ash-rich icy electrification system (ARIES).”
Stephen R. McNutt, a researcher at the University of South Florida and a contributor to the book The Encyclopedia of Volcanoes, explained that there are three kinds of volcanic lightning. “The first are vent discharges, which are small, short duration flashes that occur at the time of the eruption. Near-vent lightning is similar and flashes above the vent during the first few minutes of the eruption. Plume lightning, however, occurs in a much larger scale and has a longer duration beginning several minutes after the eruption starts and lasts after the plume drifts downward.”
Lightning produces radio signals that travel long distances at the speed of light which has been known for quite some time.
That’s how lightning detection systems can triangulate and pinpoint lightning strikes in real time. With at least three detection sites the exact strike location can be determined. McNutt says “lightning has been documented from at least 400 eruptions at 152 volcanoes.
To summarize these findings the scientists have determined that the lightning produced over volcanoes an be not only detected, but monitored and located. This knowledge gives the geologists and volcanologists another means of detecting volcanic eruptions besides the usual means of seismographs and eye witness accounts. The sooner the eruption can be detected the quicker people can be warned that the volcano is erupting possibly saving lives n the process.
Let me know what you would like me to talk about or explain. You can email me at: [email protected].