Areas of science
Ultra-slow spreading ridges
Understanding their formation and evolution
The oceanic crust covers almost 70% of the surface of our planet, but has remained largely unexplored. Advances in seafloor technology, such as novel sonar systems for mapping and remotely controlled robots capable of collecting samples at 3000 meters water depth, now make it possible to study the processes responsible for the formation of oceanic crust at mid-oceanic ridges.
In our research group, we specifically focus on the ultra-slow spreading ridges (full spreading rate of less than 20 mm/year) of the Arctic Mid-Ocean Ridge system in the Norwegian-Greenland sea. This system consists of several ridges with different degrees of volcanic activity, enabling us to study the interplay between volcanism and tectonic activity.
To accomplish this, we use detailed maps generated by AUVs (autonomous underwater vehicles) and analyze basalt samples collected by ROV (remotely operated vehicle) for their age, major and trace element geochemistry and radiogenic isotope ratios in the Bergen Geoanalytical Facility.
This research is done under Work Package 1 of the K.G. Jebsen Centre for Deep Sea Research “Crustal accretion at ultraslow spreading ridges”
Arctic hydrothermal vents
Monitoring and sampling vents in the Arctic
Seafloor hot springs were first discovered in the late 1970’s and about 600 hydrothermal vents have been discovered since. Previous work by our group has shown that hydrothermal activity at ultra-slow spreading ridges is much more abundant than previously believed, and four active venting sites have been identified so far in the Norwegian-Greenland sea.
Our research group focuses on the monitoring and sampling of hydrothermal vents on the Arctic Mid-Ocean Ridge to understand the diversity and functioning of such sites on ultra-slow spreading ridges. We perform long-term monitoring of seismic activity and fluid temperatures to better understand subsurface processes and constrain fluid fluxes. In addition, we sample hydrothermal fluid using isobaric gas tight samplers and analyze their geochemistry in on board and on land laboratories.
This research is done under Work Package 2 of the K.G. Jebsen Centre for Deep Sea Research “Diversity and functioning of hydrothermal systems”
Seafloor mineral resources
Exploration and environmental impacts
Growing global demands for metals such as copper and zinc require an increasing amount of mineral resources. Exploitation of deep-sea sulfide deposits formed in hydrothermal areas may provide a solution but needs careful assessment of their economic potential. In addition, environmental impacts of deep-sea mining need to be studied to determine effects on fragile ecosystems.
Our group studies potential mineral resources in the Norwegian-Greenland sea using AUV mapping and geochemical tools. As part of the EU-MIDAS project, we have set up experiments on the seafloor to study effects of sulfide weathering.
We are also actively working on assessing environmental pollution from mine tailings deposited in Norwegian fjords.
This research is done under Work Package 3 of the K.G. Jebsen Centre for Deep Sea Research “Deep sea mineral resources”.
Hydrothermal experiments
Simulating sub-seafloor reactions in the lab
The geochemistry of hydrothermal fluids and deposits is largely controlled by processes happening below the seafloor, such as rock leaching, boiling and redox reactions at high-temperatures. Studying these processes thus requires simulation of hydrothermal conditions in the laboratory to be able to understand what is happening at depth.
Our group uses heated and pressurized reactors to study both inorganic and organic reactions in hydrothermal systems. We investigate the behavior of metal stable isotopes (Fe, Cu, Zn) in hydrothermal reactions to enhance our understanding of ore-forming processes, and we study the hydrothermal generation of small organic compounds that can provide fuel for the deep biosphere. This work makes ample use of analytical facilities in the ICP lab, Clean lab and Biogeochemistry lab that are part of the Bergen Geoanalytical Facility.
This research is done under Work Package 4 of the K.G. Jebsen Centre for Deep Sea Research “Hydrothermal reactions”.
Deep marine sediments
Unravelling the deep biosphere
The deep biosphere remains poorly characterized, yet imposes significant controls on the geochemistry of the Earth’s surface and deep subsurface.
Our group combines geochemistry with microbiological techniques to study the microbial ecosystems in deep marine sediment cores from the Norwegian-Greenland sea. We study sediments that are influenced by hydrothermal activity and deep marine pelagic sediments and use on board and on land laboratories for geochemical characterization of pore fluids. Microbiological analyses are done in close collaboration with our colleagues from the Institute for Biology.
This research is done under the BFS project awarded to Dr. Steffen Leth Jørgensen and Work Package 5 of the K.G. Jebsen Centre for Deep Sea Research “Geochemical energy landscapes and life”.
Evolusjon av jorda som system
Å forstå koplinga og endringa mellom di ulike komponentane i jordas system
Planeten vår er eit komplekst system vi kallar geosystemet. I dag forstår me kor viktig det er å ikkje berre studera dei ulike komponentane i geosystemet (litosfære-hydrosfære-atmosfære-biosfære), men også korleis dei er kopla saman, og korleis desse koplingane har endra seg. Å auke forståinga for desse samankoplingane er svært viktig for å forstå globale miljøprognosar, inkludert klimaendringar, forsuring av havet, havnivåstigning, tap av biologisk mangfald og masseutslettingar. Slike dramatiske omveltingar har funne stad fleire gonger i jordas historie. Forskarar undersøker derfor den geologiske lagrekka for å få innsikt i årsakar, konsekvensar og tidsskalaer for global endring i fortida.
Gruppa som arbeider med evolusjon av geosystemet søker ny fundamental innsikt i koplinga mellom dei ulike komponentane på ulike tidsskalaer. Dei utviklar og testar empiriske metodar for å kvantifisera komplekse interaksjonar direkte frå observasjonar, og nyttar desse metodane på geologiske data som spenner over tusenvis til fleire hundre millionar år.
Forskinga vært utført under BFS prosjekt tildelt Dr. Bjarte Hannisdal og Arbeidspakke 5 under K.G. Jebsen-senter for Dyphavsforskning «Geokjemiske energilandskaper og liv».