The year 2023 has witnessed soaring temperatures, with scientists pointing towards an underwater volcanic eruption of Hunga Tonga-Hunga Ha’apai in the South Pacific in 2022 as one possible explanation. This event raises vital questions concerning the relationship between volcanic activities and global warming, alongside important considerations about types of volcanoes.
Insights into the Hunga Tonga-Hunga Ha’apai Volcano
Situated in the western South Pacific Ocean, west of the primary inhabited islands in Tonga’s Kingdom, the Hunga Tonga-Hunga Ha’apai volcano is a noteworthy submarine volcano. It is one amongst 12 confirmed submarine volcanoes along the Tofua Arc, a part of the broader Tonga-Kermadec volcanic arc that emerged due to the subduction of the Pacific Plate beneath the Indo-Australian Plate. The undersea volcano comprises two minor uninhabited islands, Hunga-Ha’apai and Hunga-Tonga.
The Impact of the Hunga Tonga Volcano on Earth’s Temperature
Substantial volcanic eruptions typically push down temperatures by ejecting enormous volumes of sulfur dioxide, forming sulfate aerosols that reflect sunlight back into space, thereby temporarily cooling Earth’s surface – a phenomenon commonly known as Sun dimming. However, the Hunga Tonga eruption, occurring underwater, had a distinctive effect by causing the biggest atmospheric explosion ever recorded. This eruption produced a 58 km-high plume and injected significant amounts of water vapor, a natural greenhouse gas, into the stratosphere. The aerosol and water vapor influence the climate system in contrasting ways, but some studies suggest that the eruption could result in temporary net surface warming due to the larger and more enduring water vapor plume it produced.
Historical Impact of Volcanic Eruptions on Global Climate
According to the Intergovernmental Panel on Climate Change (IPCC), the last 2,500 years have witnessed approximately eight eruptions of greater magnitude. For instance, the Tambora eruption in Indonesia in 1815 led to a ‘year without a summer,’ causing crop failures from France to the United States. Even worse, the Samalas eruption in Indonesia around 1257 triggered famines and might have initiated the Little Ice Age, a uniquely cool period lasting until the 19th century.
Understanding the Types of Volcanoes
Volcanoes can be categorized based on the nature of their eruption and their eruption periodicity. The type of eruption primarily depends on the magma’s viscosity. Basic magmas are dark-colored, rich in iron, and magnesium but poor in silica, forming broad shield volcanoes. On the other hand, acidic magmas are light-colored, low-density, high in silica, and generate familiar cone volcano shapes.
Concerning eruption frequency, active volcanoes erupt regularly, such as Mount Stromboli, known as the Lighthouse of the Mediterranean because it continually produces gas clouds. Dormant volcanoes, like Mount Kilimanjaro in Tanzania, have not erupted recently but may do so in the future. Extinct or inactive volcanoes haven’t erupted in the distant geological past, with many having their craters filled with water, thus forming lakes. An example of an extinct volcano is the Deccan Traps in India.
The Wider Impact on Global Temperatures
Various phenomena can influence global temperatures, ranging from El Niño conditions in the Pacific Ocean to Siberian wildfires. The Hunga Tonga-Hunga Ha’apai eruption could push the temperature beyond 1.5°C of warming. However, this doesn’t imply that the Paris Agreement has failed; instead, it shows how close we are to reaching our agreed-upon tipping point.
