Seamounts of the Atlantic Ocean

Seamounts of the Atlantic Ocean
Name	Seamounts of the Atlantic Ocean
Location	Atlantic Ocean
Type	Submarine volcanoes

Contents

Seamounts of the Atlantic Ocean

Seamounts in the Atlantic Ocean are isolated submarine elevation features that rise from the seafloor and influence Mid-Atlantic Ridge, Azores Plateau, Rockall Plateau, Cape Verde Basin, and Brazilian continental margin environments. These volcanic and tectonic structures occur along plate boundaries such as the Mid-Atlantic Ridge and in intraplate settings near the Azores Triple Junction, Iberian Peninsula margin, Canary Islands, Mauritanian Basin, Grand Banks, and the Scotia Sea, shaping marine biodiversity and regional ocean circulation patterns. Scientific study of Atlantic seamounts integrates data from institutions like the National Oceanic and Atmospheric Administration, British Geological Survey, Woods Hole Oceanographic Institution, Scripps Institution of Oceanography, and research cruises from vessels such as the RV Polarstern and RRS James Cook.

Overview and Distribution

Atlantic seamounts are distributed along convergent and divergent settings including the Mid-Atlantic Ridge, fracture zones such as the Charlie-Gibbs Fracture Zone, and hotspot chains linked to the Iceland plume, Azores hotspot, and Canary hotspot. Regions with high seamount density include the North Atlantic Deep Water corridors near the Rockall Trough, the Equatorial Atlantic near the Fernando de Noronha and St. Peter and St. Paul Rocks, and the South Atlantic near the Walvis Ridge and Rio Grande Rise. Catalogues created by organizations like GEBCO and projects under the International Hydrographic Organization and InterRidge have mapped many features, while others remain uncharted near the Lesser Antilles and Antarctic Peninsula fringes.

Seamounts originate from processes tied to the Mid-Atlantic Ridge spreading, hotspot volcanism (e.g., the Azores, Canary Islands, Cape Verde chains), and transform fault interactions like the Romanche Fracture Zone. Types include basaltic gabbro-capped volcanic cones, guyots capped by eroded carbonate platforms similar to those found near the Bahamas and Caribbean Sea, and composite structures associated with ophiolite complexes exposed on nearby continental margins such as the Iberian Peninsula. Geochemical signatures link seamount lavas to mantle domains studied by the Smithsonian Institution and geophysical surveys by the Lamont–Doherty Earth Observatory and Institut français de recherche pour l'exploitation de la mer reveal crustal thickness variations, seismic velocity anomalies, and hydrothermal alteration zones akin to those at Mid-Ocean Ridge vent fields.

Atlantic seamounts host diverse communities including deep-sea corals, cold-water coral gardens like Lophelia pertusa assemblages recorded off Norway and analogues near the Azores, sponges, ophiuroids, and fish aggregations such as Orange roughy and Atlantic cod juveniles. Faunal connectivity studies involve networks of institutions including Plymouth Marine Laboratory, NOAA Fisheries, and the European Marine Observation and Data Network. Seamounts form ecological stepping stones linking biogeographic provinces such as the North Atlantic Current-influenced shelves, Sargasso Sea gyre habitats, and the South Atlantic Gyre, supporting migratory species like tuna, bluefin tuna, swordfish, and marine mammals including sperm whale and humpback whale. Vulnerable benthic taxa have prompted conservation attention from bodies such as the International Union for Conservation of Nature and regional fisheries management organizations like the Northwest Atlantic Fisheries Organization.

Seamounts modify ocean circulation through topographic steering of currents including the Gulf Stream, North Atlantic Drift, and abyssal flows linked to Antarctic Bottom Water and North Atlantic Deep Water formation. These interactions enhance local productivity by upwelling nutrients that fuel phytoplankton blooms studied by NOAA, NASA, and European projects like Copernicus. Seamount-induced mixing affects heat transport relevant to Atlantic Meridional Overturning Circulation research undertaken by groups at GEOMAR, IFREMER, and the Max Planck Institute for Meteorology, with implications for regional climate, carbon sequestration in deep-ocean sinks, and the sequestration roles discussed in reports by the Intergovernmental Panel on Climate Change.

Human activities on Atlantic seamounts include scientific exploration by the RRS Discovery, RV Pelagia, and submersible missions such as Alvin and ROV Jason; commercial interests include deep-sea mining prospects for polymetallic nodules and cobalt-rich crusts investigated by companies and national programs from Russia, China, Japan, and Brazil. Fisheries exploit demersal stocks associated with seamounts, managed by bodies like the North East Atlantic Fisheries Commission and the South Atlantic Fisheries Commission, while bycatch and bottom trawling have caused habitat damage prompting closures enforced under conventions like the OSPAR Convention and Convention on Biological Diversity. Conservation measures include establishment of marine protected areas by the European Union and national governments, seamount mapping initiatives funded by the NATO Science Programme and academic consortia, and policy frameworks debated at United Nations forums including the UN Convention on the Law of the Sea.

Prominent features include the volcanic chain of the Azores seamounts, Sargasso Sea-adjacent elevations, the Great Meteor Seamount near the Azores Plateau, the Mount Vema complex, the Gorringe Bank off Portugal, the Rockall Bank and Hatton Bank near the United Kingdom, the Mid-Atlantic Ridge segment near Iceland and the Charlie-Gibbs Fracture Zone, the Walvis Ridge and Rio Grande Rise bordering South America and Africa, and the small volcanic outcrops at St. Peter and St. Paul Rocks off Brazil. Research on these features has involved expeditions by NOAA Ship Okeanos Explorer, the European Research Vessel Polarstern, and collaborative projects funded by agencies like the National Science Foundation and Horizon Europe.