Comparison between two sediment X-ray Fluorescence records of the Late Holocene from Disko Bugt, West Greenland : paleoclimatic and methodological implications

• Main Author: Jäckel, Oskar
• Format: Other/Unknown Material
• Language: English
• Published: Lunds universitet/Geologiska institutionen 2009
• Subjects: Disko Bugt; X-ray fluorescence; mineral magnetism; magnetic susceptibility; paleomagnetism; bromine; productivity; Medieval Warm Period; Earth and Environmental Sciences; Arctic; Greenland; Disko bugt; Magnetic susceptibility
• Online Access: http://lup.lub.lu.se/student-papers/record/2302080

Popular summary: X-raying the climate archive of Disko Bugt. Disko Bugt is a large bay in West Greenland north of the Arctic Circle. Because of the influence of the relatively warm ocean current coming from the south; the West Greenland Current, it has a mild climate despite its latitude. Over the last 4000 years the climate has varied significantly in the area, which was most likely caused by changes in the strength of the West Greenland Current. By studying the sediments that have accumulated on the sea floor of Disko Bugt over the last millennia, it is possible to acquire more knowledge about the changes in climate, environment, and ocean currents that have occurred in the region. The sediment can be studied in sediment cores. They are obtained by pressing a long cylinder in the sea floor and pulling it out again. Two of these cores were investigated in this study. The almost 10 meter long cores were taken at the same location, in an 855 meter deep submarine trough. One core was split onboard of the ship, and also sampled and analyzed onboard. The other core was taken to Sweden for analysis. Both cores were subjected to a relatively new research method: X-Ray Fluorescence (XRF) scanning. With XRF scanning the composition of chemical elements can be acquired fast and with a high resolution. For either core a different type of XRF scanner was used. In addition to that, various other methods, such as mineral magnetism, were used to study the composition of the sediment. The XRF results showed quite different data for both cores, while the mineral magnetic properties indicated that the composition of the two cores was identical. This would mean that either one or both of the XRF scanners provided erroneous data. From further analysis and comparison it became quite evident that the XRF data from the core scanned onboard was probably wrong. So for the interpretation only the XRF data from Sweden was used. Of the XRF data the most interesting record was provided by the element bromine. The presence of bromine in ...