Seafloor Benthic Mapping and Characterization: Enhancing our Understanding of Aleutian Islands’ Hazards, Potential Seabed Minerals and Deep Corals
A USGS-led expedition in the Aleutian Arc off Alaska will provide critical information on energy resources, underwater earthquakes and other hazards, seafloor habitats, and biological resources, including key fisheries, as well as potential seabed minerals.
What is the issue?
Despite contributing the largest area to the U.S. Exclusive Economic Zone (EEZ), Alaska waters remain some of the least explored places in the United States. In particular, the Aleutian Islands region, that begins at Unimak Island in the east and extends to Attu Island in the west, spans 1700 km, which is equivalent to the distance from Washington, D.C. to Denver, Colorado.
The region has the potential to host seabed minerals, although the hydrothermal systems that would form such minerals have yet to be located. Seabed minerals are of interest as potential future sources of Critical Minerals, which are essential to the nation’s economic and national security and have a supply chain vulnerable to disruption.
Previous expeditions in this area, such as on the Okeanos Explorer in 2023, suggest that communities on the seafloor include unique and diverse deep-sea corals and chemosynthetic communities that create fish habitat. Additionally, sponges are abundant and diverse, and some may contain important natural products such as biopharmaceutical compounds.
However, both geological and biological resources remain minimally explored and characterized. Additionally, the majority of Alaska’s 52 active volcanos are in the Aleutian arc, including volcanoes which have the potential to trigger tsunami waves which pose a public safety risk.
What is at stake?
Exploration of the Aleutian Islands region is likely to expand understanding of locations and extent of critical fisheries habitat, gas seeps, and seabed mineral occurrences. Future development of natural resources discovered in the area could provide economic benefits but may also pose risks to biological communities found on the seafloor. For example, given that corals and sponges are slow growing and long-lived, these species may be vulnerable to disturbances associated with resource extraction and subsequent recovery could take decades or be difficult to achieve.
At least 35 of Alaska’s active volcanoes are on islands and approximately 27 have potential for generating volcano-caused tsunami waves through a variety of mechanisms such as flank failures, debris avalanches, pyroclastic flows, lahars (volcanic mudflows), and submarine explosions. The impacts of volcano-caused tsunami waves can be severe locally (within 30 km of the source) and for larger events, the impacts can be transoceanic—affecting areas thousands of kilometers from the source.
In addition, the Aleutian Islands and Alaska Peninsula volcanos are located above one of the world’s longest subduction zones where the Pacific Plate descends back into the Earth’s mantle beneath the North American Plate. The likelihood of strong subduction zone and upper-plate earthquakes is high, and tsunami and submarine landslide hazard risks are significant. Some of the world’s largest earthquakes in the past 225 years have occurred in this region including the 1964 Prince William Sound M 9.2 earthquake, the Rat Islands M 8.7 earthquake of 1965, and the 1946 Aleutian Islands (Unimak) earthquake with M 8.6.
What is our approach?
In collaboration with the Bureau of Ocean Energy Management (BOEM) and the National Oceanic and Atmospheric Administration (NOAA), USGS will explore and characterize benthic communities including deep sea corals, gas-seep communities, and seamounts near volcanoes. The expedition will provide baseline biological, geological, and chemical information about the deepwater resources in the Aleutian Islands to federal, state, Tribal, and local communities, as well as private industry partners to support effective management and sustainable development related to fisheries, seabed minerals, and hazards.
This study will visit up to 16 unexplored or poorly explored sites along the Aleutian Arc using the research vessel (R/V) Atlantis and the human occupied vehicle (HOV) Alvin. The project will use multibeam sonar to map the seafloor and investigate the water column, which will be used to characterize species and habitats and as well as potential hazards and seafloor minerals.
Sampling is expected to occur on the submarine flanks of Bogoslof Volcano, a large, mostly submerged volcano that erupted explosively in 2016-2017 and has significant tsunami generation potential. Mapping its submarine flanks will reveal new information about this eruption and its earlier eruptive history, which may increase predictive ability for future eruptions at this and other volcanos.
A conductivity, temperature, depth (CTD) rosette sampling will be deployed at dive sites and other locations to collect environmental data and water that will be analyzed for nutrients and environmental DNA shed by local marine organisms. Dive operations will include video transects; still imagery; and targeted specimen, sediment, and water sampling. Sampling will include HOV biologic and geologic grab samples, sediment push-cores, biology suction samples, hydrothermal fluid samples, and seawater samples that will be used to characterize the chemical and biological environment. These collections will improve our understanding of the distribution of species and communities across this broad area and their environment controls.
Outreach and Community Engagement
The USGS conducted initial project planning in collaboration with the Qawalangin Tribe of Unalaska and the Museum of the Aleutians, and in communication with the Akutan Village Council. Several specific outreach and engagement activities have been planned, including ship and Alvin submersible tours for adults and children. Both the scientists and ship’s crew will be available to answer questions and to serve as guides. Expedition scientists will present an overview of the expedition and answer questions at the library in Dutch Harbor, AK. An activity called “Ocean Discovery Day” is scheduled at the Unalaska City School and will include a variety of hands-on activities, including learning about deep-sea creatures and volcanoes and building boats. NOAA OER also enables web coverage prior to and during the expedition, including blogs describing shipboard activities.
What are the benefits?
Local communities in the Aleutian Islands region are highly dependent on ocean resources. Our interdisciplinary expedition will yield information that is valuable to the public; scientific community; industry partners; emergency managers/planners; and federal, state, and local resource managers. Exploration of the Aleutian Islands will provide new observations and data that will refine understanding of critical fisheries habitat, gas seeps, and mineral forming systems as well as improve fundamental knowledge of Aleutian Island volcanoes and lesser-known seamounts including potential hazards posed. The exploration objectives provide opportunity for scientific discovery and will aid the resource management, protection, and stewardship needed to support a healthy economy in the Aleutian Islands region.
Mesophotic and Deep Benthic Communities: Habitat Assessment and Evaluation
Global Seabed Mineral Resources
USGS Role in DEEP SEARCH: Deep Sea Exploration to Advance Research on Coral, Canyon, and Cold-seep Habitats
Deepwater Atlantic Habitats II: Continued Atlantic Research and Exploration in Deepwater Ecosystems with Focus on Coral, Canyon, and Seep Communities. Part II: Genetic Connectivity and Oceanomic Studies
A USGS-led expedition in the Aleutian Arc off Alaska will provide critical information on energy resources, underwater earthquakes and other hazards, seafloor habitats, and biological resources, including key fisheries, as well as potential seabed minerals.
What is the issue?
Despite contributing the largest area to the U.S. Exclusive Economic Zone (EEZ), Alaska waters remain some of the least explored places in the United States. In particular, the Aleutian Islands region, that begins at Unimak Island in the east and extends to Attu Island in the west, spans 1700 km, which is equivalent to the distance from Washington, D.C. to Denver, Colorado.
The region has the potential to host seabed minerals, although the hydrothermal systems that would form such minerals have yet to be located. Seabed minerals are of interest as potential future sources of Critical Minerals, which are essential to the nation’s economic and national security and have a supply chain vulnerable to disruption.
Previous expeditions in this area, such as on the Okeanos Explorer in 2023, suggest that communities on the seafloor include unique and diverse deep-sea corals and chemosynthetic communities that create fish habitat. Additionally, sponges are abundant and diverse, and some may contain important natural products such as biopharmaceutical compounds.
However, both geological and biological resources remain minimally explored and characterized. Additionally, the majority of Alaska’s 52 active volcanos are in the Aleutian arc, including volcanoes which have the potential to trigger tsunami waves which pose a public safety risk.
What is at stake?
Exploration of the Aleutian Islands region is likely to expand understanding of locations and extent of critical fisheries habitat, gas seeps, and seabed mineral occurrences. Future development of natural resources discovered in the area could provide economic benefits but may also pose risks to biological communities found on the seafloor. For example, given that corals and sponges are slow growing and long-lived, these species may be vulnerable to disturbances associated with resource extraction and subsequent recovery could take decades or be difficult to achieve.
At least 35 of Alaska’s active volcanoes are on islands and approximately 27 have potential for generating volcano-caused tsunami waves through a variety of mechanisms such as flank failures, debris avalanches, pyroclastic flows, lahars (volcanic mudflows), and submarine explosions. The impacts of volcano-caused tsunami waves can be severe locally (within 30 km of the source) and for larger events, the impacts can be transoceanic—affecting areas thousands of kilometers from the source.
In addition, the Aleutian Islands and Alaska Peninsula volcanos are located above one of the world’s longest subduction zones where the Pacific Plate descends back into the Earth’s mantle beneath the North American Plate. The likelihood of strong subduction zone and upper-plate earthquakes is high, and tsunami and submarine landslide hazard risks are significant. Some of the world’s largest earthquakes in the past 225 years have occurred in this region including the 1964 Prince William Sound M 9.2 earthquake, the Rat Islands M 8.7 earthquake of 1965, and the 1946 Aleutian Islands (Unimak) earthquake with M 8.6.
What is our approach?
In collaboration with the Bureau of Ocean Energy Management (BOEM) and the National Oceanic and Atmospheric Administration (NOAA), USGS will explore and characterize benthic communities including deep sea corals, gas-seep communities, and seamounts near volcanoes. The expedition will provide baseline biological, geological, and chemical information about the deepwater resources in the Aleutian Islands to federal, state, Tribal, and local communities, as well as private industry partners to support effective management and sustainable development related to fisheries, seabed minerals, and hazards.
This study will visit up to 16 unexplored or poorly explored sites along the Aleutian Arc using the research vessel (R/V) Atlantis and the human occupied vehicle (HOV) Alvin. The project will use multibeam sonar to map the seafloor and investigate the water column, which will be used to characterize species and habitats and as well as potential hazards and seafloor minerals.
Sampling is expected to occur on the submarine flanks of Bogoslof Volcano, a large, mostly submerged volcano that erupted explosively in 2016-2017 and has significant tsunami generation potential. Mapping its submarine flanks will reveal new information about this eruption and its earlier eruptive history, which may increase predictive ability for future eruptions at this and other volcanos.
A conductivity, temperature, depth (CTD) rosette sampling will be deployed at dive sites and other locations to collect environmental data and water that will be analyzed for nutrients and environmental DNA shed by local marine organisms. Dive operations will include video transects; still imagery; and targeted specimen, sediment, and water sampling. Sampling will include HOV biologic and geologic grab samples, sediment push-cores, biology suction samples, hydrothermal fluid samples, and seawater samples that will be used to characterize the chemical and biological environment. These collections will improve our understanding of the distribution of species and communities across this broad area and their environment controls.
Outreach and Community Engagement
The USGS conducted initial project planning in collaboration with the Qawalangin Tribe of Unalaska and the Museum of the Aleutians, and in communication with the Akutan Village Council. Several specific outreach and engagement activities have been planned, including ship and Alvin submersible tours for adults and children. Both the scientists and ship’s crew will be available to answer questions and to serve as guides. Expedition scientists will present an overview of the expedition and answer questions at the library in Dutch Harbor, AK. An activity called “Ocean Discovery Day” is scheduled at the Unalaska City School and will include a variety of hands-on activities, including learning about deep-sea creatures and volcanoes and building boats. NOAA OER also enables web coverage prior to and during the expedition, including blogs describing shipboard activities.
What are the benefits?
Local communities in the Aleutian Islands region are highly dependent on ocean resources. Our interdisciplinary expedition will yield information that is valuable to the public; scientific community; industry partners; emergency managers/planners; and federal, state, and local resource managers. Exploration of the Aleutian Islands will provide new observations and data that will refine understanding of critical fisheries habitat, gas seeps, and mineral forming systems as well as improve fundamental knowledge of Aleutian Island volcanoes and lesser-known seamounts including potential hazards posed. The exploration objectives provide opportunity for scientific discovery and will aid the resource management, protection, and stewardship needed to support a healthy economy in the Aleutian Islands region.
Mesophotic and Deep Benthic Communities: Habitat Assessment and Evaluation
Global Seabed Mineral Resources
USGS Role in DEEP SEARCH: Deep Sea Exploration to Advance Research on Coral, Canyon, and Cold-seep Habitats