Intermittent Eruptions Observed on India’s Only Active Volcano

Last Updated on December 27, 2024 by Bharat Saini

Barren Island, located 140 km northeast of Port Blair in the Andaman and Nicobar Islands, is India’s only active volcano. After lying dormant for over 150 years, it erupted in 1991, marking the start of periodic volcanic activity. In 2017, scientists from CSIR-National Institute of Oceanography (CSIR-NIO), Goa, closely observed intermittent eruptions, further confirming the volcano’s active status. These eruptions, though small, are intense, with lava fountains and ash clouds frequently being emitted.

Barren Island: A Brief Overview

Barren Island is an uninhabited island devoid of vegetation, located in the Andaman Basin, an area known for strong seismicity, submarine volcanoes, and hydrothermal activity. The volcano sits atop a 106-million-year-old crust, and studies have shown that volcanic activity here has been happening for over 1.6 million years. It’s formed by rising magma deep in the Earth’s mantle, resulting from the melting of the sub-ducted Indian Ocean crust.

The eruptions in 1991 caused significant damage to wildlife, reducing bird populations and altering the local ecosystem. Scientists have closely monitored subsequent eruptions to understand the volcano’s behavior, which has remained active, with smaller eruptions occurring intermittently.

Recent Eruptions and Observations

In January 2017, two separate eruptions were observed—on January 23rd and January 26th. During these eruptions, only ash clouds were visible during the daytime, but as night fell, red lava fountains were seen shooting from the crater, along with hot lava flows streaming down the volcano’s slopes. These brief but intense bursts lasted between 5 to 10 minutes, continuing sporadically. The activity is consistent with the volcano’s pattern since it reawakened in 1991.

According to scientists, the Andaman Basin’s geologic setup supports such volcanic activity, including phreatic and phreatomagmatic eruptions, which occur when heat from magma causes superheated steam or when water interacts with magma.

Types of Volcanic Eruptions

Understanding volcanic eruptions requires knowing the different types of eruptions:

1. Magmatic Eruptions: These occur due to the decompression of gas within magma, forcing it upward.
2. Phreatic Eruptions: Driven by the heat from magma, these eruptions create superheated steam explosions.
3. Phreatomagmatic Eruptions: These occur when water interacts with magma, resulting in explosive reactions.

Global Comparisons of Active Volcanoes

While Barren Island remains India’s only active volcano, several other active volcanoes around the world offer valuable insights into volcanic activity. Here are some notable ones:

1. Kilauea Volcano, Hawaii: One of the most active volcanoes on Earth, Kilauea has been erupting continuously since 1983. The eruption has caused destruction and loss of life but remains a subject of scientific study.
2. Mount St. Helens, Washington: Known for its catastrophic eruption in 1980, this volcano reshaped the surrounding landscape. The eruption remains one of the most powerful in U.S. history.
3. Mount Fuji, Japan: Located in Tokyo, Mount Fuji is one of Japan’s most famous volcanoes. Its last eruption was in 1708, and its symmetrical cone shape makes it an iconic landmark.
4. Eyjafjallajökull, Iceland: This volcano, known for its 2010 eruption that disrupted European air travel, lies beneath an ice cap and offers an example of volcanic activity beneath glaciers.
5. Mount Pinatubo, Philippines: The eruption in 1991 was one of the largest of the 20th century, significantly affecting the surrounding environment and climate.
6. Mount Mayon, Philippines: Famous for its “perfect cone” shape, this active volcano has erupted numerous times, with the most recent significant eruption in 2018.
7. Krakatoa, Indonesia: The eruption of 1883 led to a massive tsunami and the destruction of nearby islands. The volcano continues to show signs of activity.
8. Mount Etna, Italy: One of the tallest and most active volcanoes in Europe, Mount Etna continues to erupt regularly, posing a significant risk to nearby populations.
9. Popocatépetl, Mexico: This volcano, located in Central Mexico, has been active for thousands of years and remains an ongoing threat to nearby cities.
10. Olympus Mons, Mars: The tallest volcano in the solar system, Olympus Mons stands at an astounding 27 km in height, offering insights into volcanic processes on other planets.

Volcanic Activity in the Andaman Basin

The Andaman Basin, where Barren Island lies, is an active back-arc spreading basin. This means the region experiences intense tectonic activity, with subducting oceanic crust giving rise to magma, resulting in volcanic activity. The region’s seismicity and associated volcanic eruptions have a significant impact on the surrounding marine life and ecosystem. Studies have shown that eruptions can influence the local climate, air quality, and animal populations, making these volcanoes crucial for scientific monitoring.

Future Implications of Barren Island’s Activity

While Barren Island remains uninhabited, it is crucial for scientists to continue monitoring its activity to understand volcanic behavior and mitigate any potential risks in the future. The ongoing eruptions provide valuable insights into the geodynamics of island arc volcanoes and help inform disaster preparedness for similar volcanic regions.

Conclusion

Barren Island’s periodic eruptions remind us of the dynamic nature of Earth’s geology. While it remains a significant natural feature for India, the volcano’s behavior offers lessons in the broader context of global volcanic activity. Understanding the types of eruptions, monitoring volcanoes like Barren Island, and studying their impact is critical for advancing our knowledge of volcanic science and its effect on ecosystems.