iMirabilis2: Leg 0
Investigating seafloor spreading features around the Azores
Leg 0 of the iMirabilis2 expedition is led by the Task Group for the Extension of the Continental Shelf of Portugal (EMEPC) and will focus on the collection of multibeam bathymetry and geological and biological data on the north part of the Azores-Biscaya Rise (ABR). This area is part of a roughly linear NE-SW trending feature approximately 700 km long, rising up to 3,000 m above the surrounding seafloor (e.g. Whitmarsh et al., 1982). Very few studies have focused on the ABR and data on this geomorphological feature is still scarce, despite its importance during the opening and evolution of the North Atlantic basin over the last 75 million years, which was also influenced by the Azores hotspot. At present, the Azores hotspot has its most prominent expression at the Azores Archipelago, which is rooted on a bathymetric high that extends between the latitudes of the Hayes and Maxwell Fracture Zones (≈33˚N-48˚N, respectively).
During the ROV dives on this leg of the expedition we expect to observe and collect submarine volcanic rocks in order to characterise the geological environment at this location and study the mantle components and magmatic processes that generated the volcanism and created this major geological structure.
The bathymetric highs and seamounts in the North Atlantic also form hotspots of biodiversity, hosting deep-water coral reefs and deep-sea sponges that form complex habitats considered to be vulnerable marine ecosystems (VMEs). The collection of environmental baseline data in these areas is paramount not only to explore data-poor areas, but also for the development of a coherent multidisciplinary approach focused on the adoption of effective measures for protection and conservation of the marine environment. In recent years, EMEPC has been collecting environmental and biological data in different target areas of the North Atlantic. The team involved in iMirabilis2 Leg 0 aims to collect more data and information to map the distribution of sessile fauna (corals and sponges) at similar depths from the northeastern Azores, King’s Trough and ABR, to further expand our knowledge on this area of the North Atlantic. This research is not formally part of iAtlantic’s mission, but the ROV operations will form the basis for technical training in the use of this technology, which is part of iAtlantic’s capacity building programme.