Examining evidence of past volcanic behavior is the key to improved knowledge of future geohazards in Northern Patagonia and their impacts on marine ecosystems.
Chaitén, Chile— An international team of scientists is reconstructing the impact of the 2008 Chaitén volcanic eruption on the marine environment following an expedition onboard Schmidt Ocean Institute’s R/V Falkor (too). During the 21-day research cruise in September, scientists found eruption debris more than 25 kilometers (15 miles) away from the volcano, transported into the sea via the local river system and then dispersed by ocean currents. Their findings provide new insights into the fate of volcanic debris in marine environments and the strength of the current systems in Chile’s Northern Patagonian Sea. This, along with new seafloor maps, will help scientists understand volcanic hazards in Southern Chile and how they have changed over time.
After 9,000 years of dormancy, the Chaitén Volcano erupted without warning on May 2, 2008. Ash spewed 30 kilometers (18 miles) into the air and blanketed the landscape. Heavy rain in the following days triggered devastating volcanic mudflows known as lahars that cascaded down mountainsides and into the Northern Patagonian Sea. The town of Chaitén evacuated as the powerful mudflows inundated and transformed the landscape, flooding the city with mud and destroying the buildings on the southern side.
Using a vibrating coring device mounted on the Schmidt Ocean Institute’s ROV SuBastian, the scientists gathered seafloor sediment cores from the Northern Patagonia Sea offshore to the Peru-Chile Trench. Layers of mud within the cores provide a record of the region’s geologic and oceanic activity. Volcanic ash and debris indicate the occurrence of past eruptions in the area. These event layers are better preserved in ocean sediments than on land, shedding light on past events and providing the data needed to predict future volcanic hazards and assess how eruptions impact the marine environment.
“Our observations will allow us to explore how active volcanoes affect marine environments and infrastructure, ranging from fisheries to communication cables,” said the expedition’s chief scientist, Sebastian Watt, from the University of Birmingham in the United Kingdom. “A range of hazards can impact communities in the aftermath of volcanic eruptions, and the information we gather from studying the 2008 Chaitén eruption is relevant for coastal and island volcanoes globally.”
The international team included scientists from the United Kingdom, Chile, the United States, Italy, Malta, and New Zealand and was co-led by Dr. Rodrigo Fernandez of the Universidad de Chile, Dr. Rebecca Totten of the University of Alabama (United States), and Dr. Giulia Matilde Ferrante of the National Institute of Oceanography and Applied Geophysics (Italy). Throughout the expedition, scientists from three Chilean universities and the Chilean Geological Survey (SERNAGEOMIN) worked closely with the local Chaitén community to raise awareness of volcano science, geologic hazards, and the local marine environment.
“Communication with local communities and a broader global audience was just as important as the science activities of our expedition,” said Fernandez. “Months before the expedition, we introduced the project to the local schools. On our science team, we also included a teacher, Danny Leviñanco, who experienced the 2008 eruption from her nearby home of Chuit Island. With her help, we conducted lessons and ship tours with almost every child in this rural, remote region.”
The scientists mapped an area of seafloor approximately 2700 square kilometers (1042 square miles) in the fjords of the Northern Patagonian Sea and collected subseafloor data, imaging meters below the seafloor, to assess the build-up and movement of sediment. The mapping revealed a stunning, glacially sculpted seafloor. Scientists have long known that the area was carved by glacial erosion but were surprised by the magnitude of observable ice scouring.
Other findings include undersea mega-dunes made from volcanic sediment outside a river delta transformed by the Chaitén eruption. The mega-dunes cover an area approximately three times the size of New York City’s Central Park. The scale of the dunes paired with high-resolution maps indicates a strong current system capable of moving large quantities of sediment.
“Approximately half of the earth’s volcanoes are islands or located near coasts, like Chaitén,” said Schmidt Ocean Institute’s Executive Director, Dr. Jyotika Virmani. “It is amazing that as recently as 2008, this volcanic eruption wasn’t predicted. Understanding volcanic activity and its footprint on the offshore ecosystem provides data to more readily predict the frequency and severity of events, which is essential to saving lives and cultures.”
About the Organizations
Schmidt Ocean Institute was established in 2009 by Eric and Wendy Schmidt to catalyze the discoveries needed to understand our ocean, sustain life, and ensure the health of our planet through the pursuit of impactful scientific research and intelligent observation, technological advancement, open sharing of information, and public engagement, all at the highest levels of international excellence. For more information, visit www.schmidtocean.org.
The University of Birmingham is ranked amongst the world’s top 100 institutions. Its work brings people from across the world to Birmingham, including researchers, teachers and more than 8,000 international students from over 150 countries.
The University of Chile was founded on the 19th of November, 1842. It is the oldest higher education institution in Chile. Generating, developing, integrating and communicating knowledge in all the areas of knowledge and culture are the mission and basis of the activities of the University. This makes up the involvedness of their work and directs the education they impart. Learn more at https://uchile.cl/
The University of Alabama, part of The University of Alabama System, is the state’s flagship university. UA shapes a better world through its teaching, research and service. With a global reputation for excellence, UA provides an inclusive, forward-thinking environment and nearly 200 degree programs on a beautiful, student-centered campus. A leader in cutting-edge research, UA advances discovery, creative inquiry and knowledge through more than 30 research centers. As the state’s largest higher education institution, UA drives economic growth in Alabama and beyond.
The National Institute of Oceanography and Applied Geophysics (Italian: Istituto Nazionale di Oceanografia e di Geofisica Sperimentale), commonly referred to as OGS, is an Italian public research institution under the supervision of the Italian Ministry of University and Research. It specializes in conducting research in the fields of earth science and oceanography on an international level. Its expertise is applied in the field of earth, sea and polar sciences to contribute to the dissemination of scientific knowledge and to solve environmental, economic and social problems. Learn more at https://www.ogs.it/en
This piece was prepared online by Panuruji Kenta, Publisher, SEVENSEAS Media