Radial viscous fingering of hot asthenosphere within the Icelandic plume beneath the North Atlantic Ocean ...

• Main Authors: Schoonman, CM, White, NJ, Pritchard, D
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier BV 2017
• Subjects: viscous fingering; Iceland; mantle plumes; dynamic topography; Norway; North Atlantic
• Online Access: https://dx.doi.org/10.17863/cam.43697; https://www.repository.cam.ac.uk/handle/1810/296649

© 2017 The Icelandic mantle plume has had a significant influence on the geologic and oceanographic evolution of the North Atlantic Ocean during Cenozoic times. Full-waveform tomographic imaging of this region shows that the planform of this plume has a complex irregular shape with significant shear wave velocity anomalies lying beneath the lithospheric plates at a depth of 100–200 km. The distribution of these anomalies suggests that about five horizontal fingers extend radially beneath the fringing continental margins. The best-imaged fingers lie beneath the British Isles and beneath western Norway where significant departures from crustal isostatic equilibrium have been measured. Here, we propose that these radial fingers are generated by a phenomenon known as the Saffman–Taylor instability. Experimental and theoretical analyses show that fingering occurs when a less viscous fluid is injected into a more viscous fluid. In radial, miscible fingering, the wavelength and number of fingers are controlled by ...