Mount Pinatubo eruption (1991)
Topic: Interior of the Earth: Earthquakes, Volcanoes and the Layered Earth · NCERT: Beyond NCERT
Meaning
The Mount Pinatubo eruption was a huge, explosive eruption in the Philippines in June 1991. It threw about 15-20 million tonnes of sulphur dioxide (SO₂) into the stratosphere, the calm upper layer of the atmosphere above the weather. There the gas turned into a thin haze of sulphate aerosols, which are tiny droplets that reflect sunlight back to space. This cooled the global average temperature by about 0.5 °C for 1-2 years. It shows how one large eruption can change the world's climate for a short time.
Example
Mount Pinatubo is on Luzon island in the Philippines, on the Pacific Ring of Fire. After the 1991 eruption, the sulphate haze spread around the world and lowered global temperatures for the next year or two.
Don't confuse with
- Hunga Tonga-Hunga Ha'apai eruption (2022): this eruption put mainly water vapour into the stratosphere, which warms the earth. Pinatubo put mainly sulphur there, which cooled it.
- Tambora (1815): a much older eruption in Indonesia that caused "the year without a summer" in 1816. Pinatubo is the modern, instrument-measured example of volcanic cooling.
Related concepts
- Ring of Fire
- Hotspot volcanism
- Barren Island volcano
- Mud volcano
- Hunga Tonga-Hunga Ha'apai eruption (2022)