Sounds of Tonga eruption heard worldwide spark global concern

In January 2022, the Hunga Tonga-Hunga Ha'apai volcano erupted with unprecedented force, producing shock waves that traveled globally. The eruption sent a massive cloud of ash and debris into the atmosphere, profoundly affecting not only the immediate vicinity of the volcano but also places as far away as Alaska, New Zealand, and Germany. A significant aspect of this event was the sound associated with the eruption, which was reported to have reached volumes exceeding 90 decibels in some areas, comparable to that of a lawnmower. A research team operated by GNE Science, a state-owned entity, quickly gathered data on the eruption's audible characteristics through a survey they distributed within a week following the explosive event. The survey featured 39 questions aimed at understanding how the sound traveled and was perceived by individuals across various regions. The researchers received an impressive nearly 2,000 responses, providing detailed insights into the experience of the affected populations. Approximately 37% of respondents described the sound as an explosion, while others noted it resembled everyday noises like a door slamming or a running dishwasher. This diversity in auditory experiences illustrates the widespread impact of the eruption on human perceptions of sound. Notably, around 25% of survey participants indicated that they heard sounds louder than 90 dB, highlighting the eruption's intensity. The impact was not solely auditory; about 5% of those surveyed reported unusual animal behavior in response to the eruption. Pets exhibited strange behavior in the days surrounding the event, suggesting that local wildlife also sensed the seismic disturbance. Interestingly, scientists noted a remarkable phenomenon: a Rayleigh wave, a type of shock wave, was detected about 15 minutes before the eruption, indicating the eruption's approach. The data from both the survey and the seismic stations contribute valuable insights into understanding such extraordinary geological events and the acoustic phenomena they generate. Furthermore, this study serves to underscore the challenges of commercial supersonic air travel, as it illustrates the potential for noise to disrupt living beings over vast distances. The findings highlight both the human and environmental impacts of one of nature's most powerful events, emphasizing the value of rapid research responses to natural disasters. The Tonga eruption remains a relevant case study in geological and environmental sciences, as its effects reverberate throughout various ecosystems, showing that Earth's processes can profoundly affect both the environment and human life.