The recent eruption of the La Soufriere Volcano in the Caribbean has raised fears over increased pollution levels and possible acid rain in North India. This is due to the Sulphur Dioxide (SO2) emissions from the volcanic eruption reaching the country. The Caribbean region, where the eruption occurred, lies south of the United States, east of Mexico, and north of Central and South America.
About La Soufriere Volcano
La Soufriere Volcano is an active stratovolcano situated on the Caribbean island of Saint Vincent, within the nation of Saint Vincent and the Grenadines. A stratovolcano is a high, conical volcano that comprises layers of hardened lava, tephra, and volcanic ash. These volcanoes are known for their steep profile and periodic, explosive eruptions.
Saint Vincent and the Grenadines, located in the southern part of the Caribbean, encompass more than 30 islands and cays, nine of which are inhabited. The La Soufriere Volcano is the highest peak in Saint Vincent and since 1718, it has been recorded to have erupted explosively five times, with the most recent eruption taking place in April 2021. Before this, its previous eruption was recorded in 1979.
Impact of the Eruption on Global Temperatures
Volcanic emissions that reach the stratosphere have a cooling effect on global temperatures. Significant climate impacts resulting from volcanic injections into the stratosphere are caused by the conversion of sulphur dioxide to sulphuric acid. This is followed by rapid condensation in the stratosphere to form fine sulphate aerosols.
These aerosols enhance the reflection of radiation from the Sun back into space, subsequently cooling the earth’s lower atmosphere or troposphere. Larger volcanic eruptions during the past century have led to a decrease in earth’s surface temperature of 0.27 degree Celsius or more for up to three years.
Sulphur Dioxide and Pollution
SO2 emissions can cause high concentrations of SO2 in the air, which often leads to the formation of other sulfur oxides (SOx). In the atmosphere, SOx reacts with other compounds forming small particles. These particles are known to contribute to Particulate Matter (PM) pollution. If these small particles penetrate deep into the lungs in sufficient quantities, they can potentially contribute to health problems.
Sulphur Dioxide and Acid Rain
Acid rain is the result when sulphur dioxide (SO2) and nitrogen oxides (NOX) are released into the atmosphere, and then transported by wind and air currents. The SO2 and NOX react with water, oxygen, and other chemicals creating sulfuric and nitric acid. This reaction further mixes with water and other substances before falling to the ground as acid rain.
