Linking Tonga’s Eruption to Atmospheric Disturbances Over India

Context:

A recent study has uncovered a surprising connection between the Tonga volcano eruption in the South Pacific Ocean and the formation of Equatorial Plasma Bubbles (EPBs) over the Indian subcontinent. This discovery highlights the far-reaching impact of volcanic activity on atmospheric phenomena.

Relevance:

GS I: Geography

Dimensions of the Article:

1. Key Highlights of the Tonga Eruption Study
2. Understanding Equatorial Plasma Bubbles (EPBs)
3. Key Facts About the Tonga Volcano
4. About the Ring of Fire

Key Highlights of the Tonga Eruption Study

Ionospheric Disturbances

• The Tonga eruption significantly influenced space weather, impacting satellite signals through ionospheric disturbances.
• The eruption generated strong atmospheric gravity waves that ascended into the upper atmosphere, creating favorable conditions for the formation of Equatorial Plasma Bubbles (EPBs).

Atmospheric Dynamics

• Gravity Waves: These waves occur when buoyancy forces air upward and gravity pulls it back down, leading to oscillations that propagated extensively due to the eruption.
• Detection of Plasma Blobs: Increases in the ionospheric eastward electric field at dusk were observed, indicating further disruptions in the ionosphere.

Understanding Equatorial Plasma Bubbles (EPBs)

Nature and Formation

• EPBs are formed through plasma instabilities in the equatorial ionosphere, manifesting as regions of depleted plasma.
• While they originate in the equatorial ionosphere, EPBs can extend and affect the global ionosphere up to 15° north and south of the Earth’s equator.

Impacts on Communication

• EPBs can scatter radio waves traveling through the ionosphere, leading to significant signal degradation.
• This scattering is a critical issue for systems dependent on high-frequency radio waves, including satellite communications and GPS.

Variability

• EPBs are most frequently observed during the Winter solstice and are least common during the Summer solstice, indicating significant seasonal variability.

Key Facts About the Tonga Volcano

• Situated in the western South Pacific Ocean, west of Tonga’s main inhabited islands.
• Part of the Tofua Arc, which itself is a segment of the larger Tonga-Kermadec volcanic arc, known for its active subduction zone dynamics.
• The volcano is part of the Ring of Fire, formed by the subduction of the Pacific Plate beneath the Indo-Australian Plate.

Volcanic Features

• Submarine Volcano: Comprising two small uninhabited islands, Hunga-Ha’apai and Hunga-Tonga, it highlights the undersea nature of volcanic activity in this region.

About the Ring of Fire

• Many volcanoes in the Ring of Fire were created through a process of subduction. And most of the planet’s subduction zones happen to be located in the Ring of Fire
• It is a string of at least 450 active and dormant volcanoes that form a semi-circle, or horse shoe, around the Philippine Sea plate, the Pacific Plate, Juan de Fuca and Cocos plates, and the Nazca Plate.
• There is a lot of seismic activity in the area.
• 90 per cent of all earthquakes strike within the Ring of Fire

-Source: Indian Express