Why in the News?
A new study links the Tonga volcano eruption of 15th January 2022 to the formation of Equatorial Plasma Bubbles (EPBs) over the Indian subcontinent. Tonga volcano is a submarine volcano in the South Pacific Ocean. Researchers found that atmospheric gravity waves from the eruption triggered ionospheric disturbances affecting satellite communication.
Tonga Volcano
- Location: Western South Pacific Ocean, west of the main inhabited islands in the Kingdom of Tonga.
- It is one of 12 confirmed submarine volcanoes along the Tofua Arc, a segment of the larger Tonga-Kermadec volcanic arc.
- The Tonga-Kermadec arc formed as a result of subduction of the Pacific Plate beneath the Indo-Australian Plate.
- Submarine Volcano: It is an undersea Volcano consisting of two small uninhabited islands, Hunga-Ha’apai and Hunga-Tonga.
- It is a part of the Ring of Fire.
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Location of Tonga Volcano
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Equatorial Plasma Bubbles (EPBs)
- These are regions of depleted plasma density in the Earth’s ionosphere, typically occurring in the equatorial and low-latitude regions during the nighttime.
- These bubbles form due to instabilities in the ionosphere, often after sunset and can disrupt radio signals, including those used for GPS and communication systems.
- Their formation and behavior are influenced by factors like geomagnetic activity and solar conditions.
- They are most frequent during the winter solstice (21st or 22nd December) and least frequent during the summer solstice (21st June).
Ionosphere
- It is a layer of Earth’s upper atmosphere, extending from about 50 km to 1,000 km above the surface.
- The electrically charged atoms and molecules that are formed in this way are called ions, giving the ionosphere its name.
- It’s a very active part of the atmosphere and it grows and shrinks depending on the energy it absorbs from the sun.
- It is ionized by solar radiation, meaning it contains a high concentration of ions and free electrons.
- This layer plays a crucial role in atmospheric electricity and affects radio wave propagation, which is essential for communication and navigation systems.
- It is an electrically conducting region capable of reflecting radio signals back to Earth.
Formation of EPBs
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