Visit the Polar Research Portal to read about current Swedish expeditions in Antarctica.
The purpose of the project was to collect multibeam bathymetry and sub-bottom profile information along the western continental shelf of Greenland in order to characterize the shape of the seafloor and uppermost sediment properties. The main goal was to increase our understanding about potential pathways of relative warmer water influx towards Greenland’s many outlet glaciers. A program involving both seismic data aquistion, multibeam mapping, coring and seismic reflection profiling was conducted in order to study the past behaviour of the Petermann Glacier.
Petermann Glacier is connected to the inland ice through an ancient (perhaps pre-glacial) channel system, which extends from Petermann Fjord, deep into the inland ice along a pathway near the NEEM and NGRIP ice cores. This implies that the expedition with icebreaker Oden, targeting the longer-term marine history of the Petermann system, is constrained near its inland-ice source by well published deep ice-core data.
The expedition examined the relatively unexplored outlet end of this large system, by documenting changes in the grounded Petermann Glacier, its buttressing ice shelf, and ocean conditions since the end of the last glacial period. Primary scientific questions included:
- How sensitive is Petermann ice shelf extent to documented climate changes within the Holocene?
- Is ice-shelf response independent of, or linked to, variations in the grounded Petermann Glacier, ocean thermal conditions, or relative sea level (i.e., sill depth)?
- What are the rates of change and variability of these systems in response to early Holocene warming, Neoglacial cooling, and post-Neoglacial (late 19th century to present) warming?
College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, USA
Department of Geological Sciences, Stockholm University
Swedish research projects
Towards an improved quantification of the Greenland meltwater discharges
The Greenland glaciers are currently experiencing large changes coincident with seaward surging of the Greenland Ice Sheet. A possible reason for the decline is warm salty deep ocean currents that accesses the floating glaciers as it intrudes at the bottom the Greenland fjords. Due to limited in-situ data, the magnitude and time scales of variability for the warm water intrusions are poorly known, as are its effects of the glacier discharge and meltwater production. The project is a pilot study in preparation for a later full-scale field project. The aim of this pilot project was to:
(i) Deploy five bottom landers in key positions along the Petermann fjord, setting them to pop up two every summer for five years thus providing data for the coming field program.
(ii) Perform extra hydrographic measurements and sections from small work boat if opportunity arises, by mini-CTD, MSS or XBT.
(iii) Perform opportunity-based hydrographic sections from CTD on board the Oden.
The obtained temperature time series from the bottom landers will be used to estimate the magnitude and time scales of temperature variability, and give a first inclination of the covariance between the warm water inflows and meteorological forcing.
Department of Marine Sciences, University of Gothenburg
Development and testing of bottom-landers, LoTUS
Currently, there is a shortage of reliable measurements of oceanographic data from the seabed in the polar regions. The reasons for this are many, but the remoteness of the polar areas is naturally a significant hurdle. Cost and availability of suitable probes is another. An innovation project in collaboration between University of Gothenburg, KTH Royal Institute of Technology, and Stockholm University are developing technology and methodology for so called bottom-landers – the LoTUS system. These bottom-landing probes are to be deployed from boat or aircraft and sinks to the sea floor where registration of data is done for up to five years. After the prescribed measurement time, the probe releases the anchor and floats up to the surface where the data is transmitted to land using a satellite link. The innovation in the project is mainly focused on system robustness and cost effective methodologies which is reached through tailored design.
KTH Centre for Naval Architecture, KTH Royal Insitute of Technology
Trace gas biogeochemistry
The flux of the greenhouse gases carbon dioxide and methane from shallow oceanic sources to the atmosphere is an important part of the global carbon cycle. The researchers will make high accuracy continuous measurements of carbon dioxide and methane before and during the main expedition, including along the west coast of Greenland to the Nares Strait and Peterman Fjord.
This will allow characterization of the off-continent flow from boreal North America, and intercomparisions with the long-term high Arctic atmospheric monitoring stations at Alert, Canada and Summit, Greenland. The collected data will also expand the currently limited dataset of high-resolution in situ carbon dioxide and methane measurements in the near sea-surface atmosphere above shallow Arctic continental shelf areas. The data will be useful for inverse modelling of greenhouse gas dynamics in the climate sensitive Arctic.
Department of Geological Sciences, Stockholm University
The researchers in this project intend to clarify the potential consequences of global warming for terrestrial Arctic ecosystems.
We all joined Oden Wednesday last week. Not knowing when our first CTD station would be, we immediately – well, after fika – started unpacking to be prepared. But first, let me explain to you what a CTD is.
We left Thule Air Base about a week ago and after a lot of ice, fantastic views, company from a polar bear and around 40 seals, we finally reached the Petermann Glacier in the northwest of Greenland.
Most of the measurements done during the Petermann expedition on Oden give scientists either a pictures of the current situation or they enable them to look back into the past, often for several thousand years. But what about future developments, what is happening here when we are leaving?
The first LoTUS bottom lander surfaced and transmitted its data!
All of the scientific crew that will take part in the Petermann Glacier 2015 expedition will travel to Greenland tomorrow in order to meet up with Oden in Thule.
After two nights in Kangerlussuaq I think we know the town. But we certainly do not know the amazing surrounding nature!
After leaving Thule Air Base we had a smooth ride up to Smith Sound in Nares Strait where sea ice clogged the entire passage northward. This happened somewhere around 78°30’N.
After passing the sea ice clogged passage at the southern end of Nares Strait, the transit to Petermann Fjord went quite fast.
An ice shelf is a floating glacier. Most ice shelves are formed as extensions of one or several ice streams that drain glaciers and large ice sheets by transporting ice to the ocean.
Onboard the Oden we have the RV Skidbladner, a 6.4 m long aluminum boat equipped with a bow mounted high-resolution multibeam echo sounder and sub-bottom profiler.
Over 50 sediment cores have been obtained from the seabed in and outside Petermann Fjord, Greenland. Martin Jakobsson from Stockholm University, explains how to use multicorer, pistoncorer and gravitycorer to retrieve sediment cores from the sea floor.
A brief overview of the Petermann 2015 expedition. The aim was to increase our understanding about potential pathways of relative warmer water influx towards Greenland’s many outlet glaciers and to study past behaviour of the Petermann Glacier.
Petermann glacier was investigated during Petermann expedition summer of 2015. A perfect area to study the changes that are happening on Earth.
Short movie from the Petermann 2015 expedition showing how Seafloor mapping was done.
We see lots of indications that there is an increased melting of Greenland ice sheet. If ice would disappear it would have a major impact on the sea level. In 2010 and 2012 the ice tongue extent was reduced by 30–40% through calving. The glacier has retreated in the past, but how much have humans affected the climate?