This image was captured by the Sentinel-1A synthetic aperture radar (SAR) satellite in VV polarization over the Tonga island archipelago on 14 January 2022 at 17:08 UTC, 13 hours after the initial eruption, and relayed to the University of Miami Rosenstiel School’s Center for Southeastern Tropical Advanced Remote Sensing (CSTARS) facility in southwest Miami-Dade County. CSTARS performed an enhancement of the image to delineate clearly the circular wave patterns, likely internal waves, emanating from the volcano (large, bright spot on the left bottom) and diffracting around the islands and coral reefs of the Tonga archipelago as well as interacting with each other.
Newswise —
The 2022 eruption of a submarine volcano in Tonga was found to be more powerful than the largest nuclear explosion conducted by the United States, according to a study led by scientists at the University of Miami Rosenstiel School of Marine, Atmospheric, and Earth Science, in collaboration with the Khaled bin Sultan Living Oceans Foundation. The study likely used a combination of data, including seismic readings, satellite imagery, and other measurements, to estimate the magnitude of the volcanic eruption. The findings highlight the immense energy and force associated with underwater volcanic eruptions, and the potential for significant impacts on marine ecosystems and surrounding areas. The comparison to a nuclear explosion serves as a stark reminder of the powerful and unpredictable forces of nature that can shape our planet's geology and impact human communities.
The volcanic explosion from Hunga Tonga-Hunga Ha'apai, which is one of the largest natural explosions in over a century, resulted in a mega-tsunami with waves reaching up to 45 meters (148 feet) along the coast of Tonga's Tofua Island. Additionally, waves as high as 17 meters (56 feet) were observed on Tongatapu, which is the most populated island in Tonga. The impact of this volcanic explosion and tsunami on the islands of Tonga was significant, with widespread devastation and potential long-term effects on the affected communities and ecosystems. The scale and magnitude of this event highlight the immense power and destructive potential of natural disasters.
In a groundbreaking study published in Science Advances, researchers from the Rosenstiel School utilized cutting-edge techniques such as before-and-after satellite imagery, drone mapping, and field observations collected by scientists from The University of Auckland, along with data from the Khaled bin Sultan Living Oceans Foundation Global Reef Expedition, to create a tsunami simulation for the Tongan Archipelago. The findings revealed that the unique shallow bathymetry in the area acted as a low-velocity wave trap, resulting in a colossal tsunami with waves soaring up to 85 meters (279 feet) just one minute after the initial volcanic explosion. This research sheds light on the complex dynamics of tsunamis in the Tongan region and highlights the need for further understanding and preparedness for such natural disasters.
The submarine volcanic eruption of Hunga Tonga-Hunga Ha'apai, a part of the Tongan island chain formed by the convergence of the Pacific and Indo-Australian tectonic plates, has been likened to the infamous 1883 eruption of Krakatau in terms of its magnitude. The eruption of Krakatau resulted in the tragic loss of over 36,000 lives, and now the eruption of Hunga Tonga-Hunga Ha'apai is considered to be on a similar scale. This highlights the immense power and impact of volcanic eruptions, especially in submarine environments, and underscores the need for understanding and preparedness in regions prone to such natural hazards.
"Despite being a mega-tsunami with long duration, Hunga Tonga-Hunga Ha'apai's impact on lives was minimal," noted Sam Purkis, marine geosciences professor and department chair at the prestigious Rosenstiel School. "This can be attributed to the unique location, the global COVID-19 pandemic, and heightened evaluation drills and awareness campaigns conducted in Tonga leading up to the eruption."
The simulation also suggested that the eruption location relative to urban centers saved Tonga from a worse outcome.
"In 2022, we may have dodged a bullet, but there are other submarine volcanoes that could still pose a threat of generating mega-tsunamis," warned Sam Purkis, chief scientist at the esteemed Khaled bin Sultan Living Oceans Foundation. "The recent eruption of Hunga Tonga-Hunga Ha'apai provides valuable insights for studying past and future tsunamis, not only in Tonga but also in other regions. It served as a natural laboratory to test hypotheses and models that can be applied to improve disaster preparedness in the future and enhance our understanding of ancient and geologically recorded eruptions and their associated tsunamis."
The research paper, titled "The 2022 Hunga-Tonga Megatsunami: Near-Field Simulation of a Once-in-a-Century Event," has been published in the prestigious April issue of Science Advances. The esteemed authors of the study include Sam Purkis and Nathan Fitzpatrick from the University of Miami Rosenstiel School, Alexandra Dempsey from the Khaled bin Sultan Living Oceans Foundation, Steven Ward from the University of California, Santa Cruz, James Garvin and Dan Slayback from the NASA Goddard Space Flight Center, Shane J. Cronin from the University of Auckland, and Monica Palaseanu-Lovejoy from the U.S. Geological Survey.
The study was supported by grants from the Khaled bin Sultan Living Oceans Foundation - Global Reef Expedition, NASA Goddard Space Flight Center and the University of Auckland, and the New Zealand Ministry of Business, Innovation and Employment, Endeavour Fund Project.
About the University of Miami
The University of Miami is a private research university and academic health system with a distinct geographic capacity to connect institutions, individuals, and ideas across the hemisphere and around the world. The University’s vibrant and diverse academic community comprises 12 schools and colleges serving more than 17,000 undergraduate and graduate students in more than 180 majors and programs. Located within one of the most dynamic and multicultural cities in the world, the University is building new bridges across geographic, cultural, and intellectual borders, bringing a passion for scholarly excellence, a spirit of innovation, a respect for including and elevating diverse voices, and a commitment to tackling the challenges facing our world. Founded in the 1940’s, the Rosenstiel School of Marine and Atmospheric Science has grown into one of the world’s premier marine and atmospheric research institutions. Offering dynamic interdisciplinary academics, the Rosenstiel School is dedicated to helping communities to better understand the planet, participating in the establishment of environmental policies, and aiding in the improvement of society and quality of life. www.earth.miami.edu.
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