Lithospheric Control on Asthenospheric Flow From the Iceland Plume: 3‐D Density Modeling of the Jan Mayen‐East Greenland Region, NE Atlantic. Issue 10 (13th October 2018)

• Record Type: Journal Article
• Authors: Tan, Pingchuan; Sippel, Judith; Breivik, Asbjørn Johan; Meeßen, Christian; Scheck‐Wenderoth, Magdalena
• Is Part Of: Journal of geophysical research. Volume 123:Issue 10(2018)
• Page Start: 9223
• Page End: 9248
• Publication Date: 2018-10-13
• Subjects: Kolbeinsey Ridge -- Iceland plume -- 3‐D gravity modeling -- plume‐ridge interaction; Geomagnetism -- Periodicals; Geochemistry -- Periodicals; Geophysics -- Periodicals; Earth sciences -- Periodicals; 551.1
• DOI: 10.1029/2018JB015634
• Languages: English
• ISSNs: 2169-9313

Abstract

Abstract: The density structure of the oceanic lithosphere north of Iceland is key for understanding the effects of the Iceland plume on the greater Jan Mayen‐East Greenland Region. We obtain the 3‐D density structure of the sediments and the crust from regional reflection and refraction seismic lines. The temperature and related density structures of the mantle between 50 and 250 km are derived from a shear wave velocity (Vs) tomography model. To assess the density between the Moho and 50‐km depth, we combine forward and inverse 3‐D gravity modeling. Beneath the Middle Kolbeinsey Ridge (MKR) region, a deep, broad negative mantle density anomaly occurs under the Kolbeinsey Ridge. It is overlain by a narrower uppermost mantle NE‐SW elongated negative density anomaly, which is increasingly displaced eastward of the spreading axis northward. It crosses the West Jan Mayen Fracture Zone and becomes weaker approaching the Mohn's spreading ridge. The effect of this anomaly is consistent with significantly shallower basement on the eastern side of the MKR. We interpret this as the result of thermal erosion of the lithosphere by hot asthenospheric flow out from the Iceland plume, possibly the main driver for several eastward jumps of the MKR during the last 5.5 Ma. The cause for the deviation of the flow may be that the West Jan Mayen Fracture Zone is easier to cross in a region where the difference in lithospheric thickness is small. That implies that the bottom lithospheric topography exerts a regional but not local influence on upper asthenospheric flow. Key Points: A 3‐D density model of the greater Jan Mayen‐East Greenland region was made based on crustal seismic, mantle tomography and gravity data A low‐density anomaly deviates to the east from the Kolbeinsey Ridge across the West Jan Mayen Fracture Zone to the Mohn's Ridge The bottom lithospheric topography exerts a regional influence on upper asthenospheric flow driven northward by the Iceland plume