In January 2022, the mostly underwater volcano Hunga Tonga-Hunga Ha’apai, located in the Kingdom of Tonga, erupted, creating an event of such magnitude that it captured the attention of the entire world. This eruption, now considered one of the most significant volcanic events in recent history, provided a unique opportunity to understand the impacts and risks associated with underwater volcanic eruptions. New research has offered even more insights into the destructive power of this eruption.

Scale and Intensity of the Eruption: The Hunga Tonga-Hunga Ha’apai eruption was exceptional in both explosiveness and global impact. Scientists estimate it at VEI-6 on the Volcanic Explosivity Index, which could signify the most significant eruption since the Tambora volcano eruption in 1815. Notably, the ash column from this eruption reached an impressive height of 58 kilometers, well into the stratosphere, surpassing the column height from the Mt Pinatubo eruption.

Global Resonance: The eruption caused a powerful audible boom heard as far as Fiji, detected worldwide by instruments typically used to monitor nuclear tests. It also generated a 5.8 magnitude earthquake, comparable to a powerful atomic bomb. This once-in-a-century event had its sound heard even 11,500 km away in Florida, underscoring its immense power.

Environmental Impact: The eruption had a multidimensional impact on the environment, encompassing both atmospheric phenomena and profound oceanic changes. It produced an extraordinary number of lightning flashes, contributing to 80% of global lightning in the peak hour. The eruption also triggered unique tsunamis that circumnavigated the globe, affecting distant locations and challenging existing tsunami models.

The impact on marine life and ecosystems was profound. Scientists warn of long-lasting damage to coral reefs, coastal erosion, and disruptions in fisheries. The eruption released gases such as sulfur dioxide and nitrogen dioxide, leading to the formation of acid rain that can further affect marine and terrestrial life. It also resulted in the deposition of large volcanic ash sediments, suffocating coral reefs and promoting the growth of harmful algae, exacerbating these ecosystems.

Perhaps the most striking impact occurred on the seafloor. The eruption caused a rapidly moving and destructive underwater debris flow, cutting almost 200 kilometers of critical submarine telecommunication cables. It radically altered the seafloor, creating deep channels and erosions, indicating the strength and extent of underwater volcanic flows.

This event highlighted the urgent need for better understanding and preparedness regarding underwater and shallow-water volcanoes. The Hunga Tonga-Hunga Ha’apai eruption serves as a significant case study to assess the threats posed to submarine vessels and critical seafloor infrastructure.

The eruption in 2022 vividly underscores the power and unpredictability of underwater volcanoes. Its far-reaching impact on the atmosphere, oceans, and marine life emphasizes the need for comprehensive research and preparations to mitigate the risks associated with such colossal natural events.