LOMROG III

The results of the LOMROG III cruise

Chief scientist: Christian Marcussen, GEUS

In the summer of 2012, the Danish Continental Shelf Project in co-operation with the Swedish Polar Research Secretariat completed the LOMROG III cruise on board the icebreaker Oden. This cruise was a continuation of the LOMROG I and II cruises, which took place in 2007 and 2009, respectively. Costs were split between Denmark (80%) and Sweden (20%). (LOMROG is an acronym for Lomonosov Ridge off Greenland.)

The main objective of the cruise was to acquire different types of data necessary to document a potential claim concerning an extension of the continental shelf beyond 200 nautical miles, and this included:

1. acquiring bathymetric data with Oden’s multi-beam echo sounder on the flank of the Lomono­sov Ridge in order to document the foot of the continental slope and the 2,500 m depth contour
2. acquiring seismic reflection and refraction data in the Amundsen Basin in order to be able to map the thickness of the sediments below the seabed
3. acquiring supplemental bathymetric data using the ship’s helicopter
4. acquiring gravimetric data onboard the ship and on the ice
5. dredging in order to acquire geological samples from the Lomonosov Ridge
6. CTD data (Conductivity, Temperature, Depth) in order to be able to process the acquired multibeam data
7. Supporting Danish and Swedish research projects (read more about the Swedish projects in the yearbook from the Swedish Polar Research Secretariat).

The LOMROG III cruise started on 31 July 2012 in Longyear­byen, Svalbard, where it also ended on 14 September 2012.

Bathymetric map showing the LOMROG III ship track (orange line) in 2012 as well as the location of other projects north of Greenland from 2006 to 2012. Green line – LOMROG I ship track (2007); red line – LOMROG II ship track (2009); light blue lines – bathymetric profiles acquired by helicopter in spring 2009 and during LOMROG II and III (2009 and 2012); yellow lines – seismic data acquired during LORITA (2006 – refraction) & LOMROG I, II and III (2007, 2009 & 2012); white stippled lines – unofficial median lines. Background map: IBCAO.

By agreement with the Norwegian Fram 2012 expedition led by Yngve Kristoffersen, University of Bergen, Oden pro­vided fuel and other supplies to the expedition’s hovercraft, Sabvabaa, twice during the LOMROG III cruise. One member of the Fram 2012 expedition boarded Oden on the way back to Longyearbyen on Svalbard.

The many results of the LOMROG III cruise could not have been obtained without the excellent co-operation between the crew of Oden, the helicopter crew, and the science party. The co-operation between the various science groups made it possible to make very efficient use of the resources on board Oden and the helicopter.

Refuelling of the Fram 2012 expedition’s hovercraft Sabvabaa during the first rendezvous 3 August 2012. (Photo: Björn Eriksson)

LOMROG III was the last cruise with the Swedish icebreaker Oden to the area north of Greenland as part of the Continental Shelf Project of the Kingdom of Denmark. As such, it represents the end of a very successful co-operation between the Geological Survey of Denmark and Greenland (GEUS) and the Swedish Polar Research Secretariat.

We hope that the valuable experience gained by collecting data in ice-filled waters during the three LOMROG cruises (in 2007, 2009, and 2012) and the EAGER cruise (2011) can be useful for future cruises of Oden to the Arctic Ocean.