Impact of the Hunga Tonga-Hunga Ha’apai Eruption

Source- This post on Impact of the Hunga Tonga-Hunga Ha’apai Eruption has been created based on the article “Tonga volcano could cause unusual weather for rest of decade: study” published in “The Hindu” on 1 June 2024.

Why in News?

Recently, a study was conducted in the Journal of Climate to investigate the climatic effects caused by the eruption of Hunga Tonga-Hunga Ha’apai volcano. It erupted on January 15, 2022, in Tonga, generating a tsunami and triggering warnings across the Pacific basin.

Findings of the study

1. Ozone Layer Effect: From August to December 2023, there was a large hole in the ozone layer partly because of the Hunga Tonga eruption. This effect on the ozone was short-term and not expected to last past 2023.

2. Weather Changes: The eruption caused some unusual weather changes:

i) Australia had a wetter summer in 2024, which is not usual for an El Niño year when it’s typically drier.

ii) The global average temperature only went up by a tiny bit, around 0.015 degrees Celsius.

3. Regional Climate Effects:

i) Northern Australia might experience colder and wetter winters than usual up to 2029.

ii) North America could see warmer winters during the same period.

iii) Scandinavia might have colder winters.

4. Atmospheric Changes: The eruption changed the way air moves in the atmosphere, which could affect weather patterns.

How is Hunga Tonga Different from Typical Volcanic Eruptions?

1. Unique Eruption: Hunga Tonga-Hunga Ha’apai is an underwater volcano that erupted on January 15, 2022. This eruption was extraordinary because it shot a huge amount of water vapor high into the sky, into the stratosphere (about 15-40 kilometers above the Earth).

2. Usual Volcanic Effects: Typically, volcanoes release smoke and sulfur dioxide which leads to a cooling effect on Earth. This happens because sulfur dioxide turns into tiny particles that float in the air and reflect sunlight away from Earth.

3. Hunga Tonga’s Impact: Being underwater, Hunga Tonga didn’t produce much smoke but sent 100-150 million tonnes of water vapor into the stratosphere instead.

4. Effects of Water Vapor: In the stratosphere, water vapor can harm the ozone layer and act like a greenhouse gas, which might warm the Earth.

About Hunga Tonga-Hunga Ha’apai volcano

1) Location: The Hunga Tonga-Hunga Ha’apai volcano is situated in the western South Pacific Ocean, west of Tonga’s main inhabited islands.

2) Type of Volcano: It is a submarine volcano, one of twelve along the Tofua Arc, part of the larger Tonga-Kermadec volcanic arc.

3) Geological Formation: This arc is formed by the subduction of the Pacific Plate beneath the Indo-Australian Plate.

4) Composition: The volcano includes two small, uninhabited islands named Hunga-Ha’apai and Hunga-Tonga.

UPSC Syllabus: World geography, Environment