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Volcanic Lightning

By: Shaina Grover


Anyone who’s read a horror story before is bound to be familiar with the following words: “It was a dark and stormy night.” And, of course, we can’t forget the booming thunder and blinding lightning that is bound to accompany these words! However, luckily for you, this is not a horror story. In fact, this article will actually be focusing on lightning: more specifically, volcanic lightning.


Now, while regular lightning is seen during a storm due to an imbalance of charges between the storm clouds and the ground, as mentioned before, there is actually another type of lighting formed by volcanoes, which is referred to as volcanic lightning.


Image Credit: Wikimedia Commons @ Oliver Spalt

However, before getting into volcanic lightning, it’s important to understand how volcanoes function. Now, as you may know, the Earth contains many tectonic plates, which are always slowly moving. And below these plates, there is a flowing substance known as magma, which is essentially melted rocks. These rocks melt at the base of the tectonic plate due to the high levels of heat and low pressure located under the plate. Interestingly, since magma is a liquid, it is both lighter and less dense than solid rock. Additionally, the particles that compose magma tend to be further apart than the particles of solid rocks. As a result, magma tends to rise above the solid rocks that compose the tectonic plates; as it does so, gas bubbles begin to form inside of it. These bubbles exert a large amount of pressure that help bring the magma even higher towards the surface. This is, in essence, what a volcanic reaction is. Now, depending on the type of magma—whether it’s runny or thick—the volcanic reaction will differ. Runny magma will erupt by rising through vents, openings, or weak spots in or between the tectonic plates, becoming what is known as lava. However, if it is thick magma, the gas bubbles will be unable to escape, causing the pressure to build up until it explodes. When the volcano erupts, small particles of rocks, minerals, glass, etc. are released into the air, but the particles are so small that they rise above the volcano in a cylindrical structure of volcanic ash and gas, known as an eruption column.


This eruption column is directly related to volcanic lightning in the sense that it is what creates volcanic lightning! Let’s now take a look at how eruption columns create volcanic lightning. So, the particles of the eruption column are not only densely packed together, but are also ejected with a significant amount of force and speed, causing them to rub against each other and, in turn, create large amounts of heat and friction. This friction causes the particles to become ionized, giving some of them a positive charge and others a negative charge. After this has occurred, the negatively charged particles will rise up in the eruption column, rising higher than the positive ones due to the fact that they weigh less than protons. This results in the distance between the charged particles increasing, thereby creating a voltage. Eventually, the separation between the two becomes so great that anything in between them automatically begins to conduct electricity. In most cases, the substance in between them is air. Once the air begins to conduct electricity, there is an extremely quick exchange of charges, which our eyes perceive as a lightning strike. And that is how volcanic lightning is created!


Something to note is that in each strike of volcanic lightning, 1020 electrons are being exchanged. Furthermore, the duration of these strikes is fairly unpredictable. They can be a one-time event, or they can be continuous, lasting for various periods of time, ranging from a few minutes to several days. Something interesting to note is that there is still a lot of ambiguity in regards to the creation of volcanic lightning. For instance, some scientists believe that a volcanic plume (eruption column) is required for there to be lightning, but there have been instances of it occurring without the presence of a volcanic plume, and we still don’t know why.


Volcanic lightning is a truly beautiful phenomena that is a result of a mixture of physics and geology. However, volcanic lightning is not only beautiful, but can also be extremely destructive and harmful. With this in mind, it’s important that we continue to learn more about it and gain a better understanding of it. One can only imagine what we will learn about in the years to come.




Question 1: What has more mass, protons or electrons?

Protons have a greater mass than electrons. The mass of an electron is so small that when calculating atomic mass, electrons typically aren’t even included. Atomic mass is calculated by adding together the number of protons and neutrons. The mass of a single electron is 9.10938356 × 10^-31 kilograms which is 1,836 times smaller than a proton.


Question 2: What are some other ways to ionize particles?

Ionizing particles does not always require the eruption of a volcano. Collisions with other atoms, molecules and ions, or through the interaction with electromagnetic radiation can cause ionization, which refers to the atom losing its electrons. A simple example of this is rubbing a balloon on your hair. When you do this, some of the electrons from your hair will stick to the balloon, giving it a negative charge. When it comes in contact with another molecule that has a positive charge (ex. confetti) they will stick together due to their opposing charges.


Citations:

usgs.gov/faqs/how-do-volcanoes-erupt?qt-news_science_products=0#qt-news_science_products

nationalgeographic.com/science/article/volcanic-lightning-can-help-warn-dangerous-eruptions-earth-geology


Image:

"File:Eruption 2.jpg." Wikimedia Commons, the free media repository. 28 Oct 2020, 22:45 UTC. 28 Mar 2021, 04:38 <https://commons.wikimedia.org/w/index.php?title=File:Eruption_2.jpg&oldid=505655778>., License: Creative Commons Legal Code


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