Tonga Volcano
Context:
The Hunga Tonga volcano erupted underwater in January 2022, causing a tsunami and sending global shockwaves.
- Unlike typical eruptions, it emitted vast amounts of water vapour into the stratosphere instead of smoke and sulfur dioxide.
Relevance:
GS-01 (Physical Geography)
Key Highlights:
- The eruption introduced a significant amount of water vapour into the stratosphere, which acts as a potent greenhouse gas and contributes to complex climate effects.
- Researchers used climate models to predict the volcano’s influence on future climate patterns. They compared scenarios with and without the added stratospheric water vapour to understand its impact on ozone depletion, regional weather patterns, and global temperatures.
- The study forecasts a range of impacts on regional weather patterns worldwide. For instance, northern Australia may experience colder and wetter winters until around 2029, while North America could see warmer winters.
- Scandinavia may face colder winters than usual, attributed to changes in atmospheric wave patterns caused by the eruption.
- The unusual weather patterns and climate effects resulting from the eruption are expected to persist for the rest of the decade, indicating a long-term influence on global weather systems.
Types of Volcanoes
Classification by Type of Eruption:
- Basic Volcanoes: Eruptions produce dark-colored, iron and magnesium-rich basaltic magma with low silica content, forming broad shield volcanoes.
- Acidic Volcanoes: Eruptions yield light-colored, silica-rich magma, forming the familiar cone-shaped volcanoes.
Classification by Eruption Frequency:
- Active Volcanoes: Frequently erupting volcanoes, mainly found around the Ring of Fire. Example: Mount Stromboli, known as the “Lighthouse of the Mediterranean.”
- Dormant Volcanoes: Currently inactive but have the potential to erupt in the future. Example: Mount Kilimanjaro in Tanzania, the highest mountain in Africa.
- Extinct Volcanoes: No longer active and unlikely to erupt again. Often, their craters are filled with water, forming lakes. Example: Deccan Traps in India.
Viscosity and Magma Characteristics:
- Eruption type is influenced by magma viscosity, with basic magmas being more fluid and acidic magmas being more viscous.
Geographical Distribution:
- Active volcanoes are primarily located in regions like the Ring of Fire, which is a major area in the basin of the Pacific Ocean.
Impact on Landscape:
- Basic magmas create expansive, broad shield volcanoes, while acidic magmas form steep, conical volcanoes, significantly shaping the surrounding landscape.
