Day 21: 11 July 2020
We’re in the middle of our transit to the Reykjanes Ridge region south of Iceland. This is a good time to talk about the bigger picture, why we chose Iceland as a research area and what it’s all about!
Iceland sits right on the northern Mid-Atlantic ridge, where the Eurasian and the North American plates are drifting apart. It is still active, meaning that the seafloor is spreading at the mid-ocean fracture zone and new crustal material is being produced from the uprising magma. All of these plate tectonic processes involve volcanic activity and the formation of hydrothermal fields, above as well as below the sea surface. Particularly in the case of the latter, the volcanic geology attracts numerous species that make up the delicate biodiversity of the North Atlantic benthos. Hydrothermal vent areas, where hot water escapes the earth’s mantle and meets the cold deep-sea waters, can be home to unique fauna that is rarely found anywhere else. Also, the topography on and around Iceland is exceptional: the island is surrounded by the deep Denmark strait channel on its western continental shelf, triggering a massive submarine waterfall about 600m high. On the island’s south-east side, ridge and sea mound structures prevail and cause a complex pattern of different water flows, from among which one of the most important is the north Atlantic overflow – a very strong and deep water current. The Norwegian Basin north of Iceland is the deep, ‘calm’ abyssal plain. Hence in terms of geomorphology, biodiversity and oceanography, the North Atlantic is a natural laboratory which holds the key to so much information about the formation and origin of life and our planet.
There have been numerous cruises to this area before and with IceAGE3. We are trying our best to fill data gaps and build upon a database of samples and models that has been existing for many years – aiming to find explanations for the distribution and population variations of species (and what could be a better indicator for that than isopods?), how and where they travel and how they react to a changing climate, and human impacts. So far it has been discovered that isopods wander from Norway to Iceland and then head down the Reykjanes Ridge – the part of the Mid-Atlantic ridge located just south of Iceland and is basically the extension of the faults on the island. This is where we are steaming to now, ETA tomorrow morning. We will spend the next three days in this area searching for hydrothermal vents and hunting gas bubbles that are emitted from their chimneys. Using hydroacoustics and imagery from ROV dives, we hope to discover more of this mystical under water world beauty.
