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Fletta eftir efnisorði "Jarðskorpa"

Fletta eftir efnisorði "Jarðskorpa"

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  • Wolfe, Cecily J.; Bjarnason, Ingi Þorleifur; VanDecar, John C.; Solomon, Sean C. (Wiley-Blackwell, 2002)
    Earlier inversions of body wave delay-time data recorded during the ICEMELT portable broadband experiment imaged a cylindrical plume-like low-velocity anomaly extending to at least 400 km depth beneath Iceland, but the depth extent of the anomaly ...
  • Hauri, Erik H.; Maclennan, J.; McKenzie, D.; Gronvold, K.; Óskarsson, N.; Shimizu, N. (Geological Society of America, 2017-11-16)
    Primitive basalt melt inclusions from Borgarhraun, northern Iceland, display large correlated variations in CO2 and nonvolatile incompatible trace elements (ITEs) such as Nb, Th, Rb, and Ba. The average CO2/ITE ratios of the Borgarhraun melt inclusion ...
  • Darbyshire, Fiona A.; Bjarnason, Ingi Þorleifur; White, Robert S.; Flóvenz, Ólafur G. (Oxford University Press (OUP), 1998-12)
    The crustal structure of central Iceland is modelled using data from a 310 km long refraction profile shot during summer 1995. The profile traversed Iceland from the Skagi Peninsula on the north coast (surface rocks of age 8.5–0.8 Myr) to the southeast ...
  • Bjarnason, Ingi Þorleifur (Iceland Glaciological Society and Geoscience Society of IcelandJöklarannsóknafélags Íslands og Jarðfræðafélags Íslands, 2014)
    A day and a half after the earthquake (mb=5.3, MS=5.6, MW=5.6) in the Bárðarbunga central volcano on Sept. 29th 1996, a volcanic eruption broke out under the Vatnajökull glacier. The eruption was located approximately 20 km SSE of the earthquake ...
  • Bjarnason, Ingi Þorleifur (Iceland Glaciological Society and Geoscience Society of IcelandJöklarannsóknafélags Íslands og Jarðfræðafélags Íslands, 2008)
    Is Iceland a hotspot, with ridge-centered plume? In Iceland vigorous volcanism has built up a plateau 3.0 km higher than at a normal mid-ocean ridge with 3 to 4 times thicker crust than average oceanic crust. This volcanism can be associated with ...
  • Kleine, Barbara Irene; Stefansson, Andri; Halldorsson, Saemundur; Barnes, J.D. (Elsevier BV, 2020)
    Oceanic crust is a major transport medium of water into the mantle wedge and the convecting mantle. Yet, the water content of the oceanic crust remains uncertain. Active geothermal systems situated at on-land spreading centers provide a unique opportunity ...
  • Bjarnason, Ingi Þorleifur; Schmeling, Harro (Oxford University Press (OUP), 2009-07)
    1-D models were calculated for the velocity of shear waves, polarized vertically (SV) and horizontally (SH) from dispersed Rayleigh and Love surface waves. These had been recorded in Iceland by the ICEMELT broad-band seismic network, with about half ...
  • Arnadottir, Thora; Haines, John; Geirsson, Halldor; Hreinsdóttir, Sigrún (American Geophysical Union (AGU), 2018-12)
    The South Iceland Seismic Zone (SISZ) accommodates E‐W translation due to oblique spreading between the North American and the Eurasian plates in South Iceland with ruptures on N‐S faults. Strain is released in earthquake sequences that last days to ...
  • Menke, William; Brandsdóttir, Bryndís; Einarsson, Páll; Bjarnason, Ingi Þorleifur (Oxford University Press (OUP), 1996-07)
    Two shear-wave profiles, E and G, collected during the 1977 Reykjanes Ridge Iceland Seismic Experiment have played an important role in models of the Icelandic crust. They were originally interpreted as indicating very low shear-wave velocities and ...
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    Bjarnason, Ingi Þorleifur; Menke, William; Flóvenz, Ólafur G. (American Geophysical Union, 1994-09-10)
    The central question discussed by Gudmundsson [this issue] can be succinctly stated: "Is the temperature of the shallowest upper mantle of Iceland at the peridotite solidus" (nominally, 1200°C). The traditional view, as developed by numerous authors ...
  • Shen, Yang; Solomon, Sean C.; Bjarnason, Ingi Þorleifur; Nolet, Guust; Morgan, W.Jason; Allen, Richard M.; Vogfjörð, Kristín; Jakobsdóttir, Steinunn; Stefánsson, Ragnar; Julian, B.R.; Foulger, G.R. (Elsevier BV, 2002-04)
    Shear waves converted from compressional waves at mantle discontinuities near 410- and 660-km depth recorded by two broadband seismic experiments in Iceland reveal that the center of an area of anomalously thin mantle transition zone lies at least 100 ...
  • Kleine, Barbara Irene; Stefansson, Andri; Halldórsson, Sæmundur Ari; Whitehouse, M.J.; Jónasson, Kristján (European Association of Geochemistry, 2018-04)
    Quartz formation processes in the Icelandic crust were assessed using coupled δ18O and δ30Si systematics of silica deposits formed over a wide temperature range (<150 to >550 °C). Magmatic quartz reveals δ18O (-5.6 to +6.6 ‰) and δ30Si (-0.4 ± 0.2 ‰) ...
  • Kreutzmann, A.; Schmeling, Harro; Junge, A.; Ruedas, T.; Marquart, G.; Bjarnason, Ingi Þorleifur (Oxford University Press (OUP), 2004-12)
    The dynamic and melting processes of a ridge-centred plume have been investigated in a companion paper by Ruedas et al. (hereafter referred to as Paper I) in a set of 3-D numerical fluid dynamic models with varying plume excess temperatures and melt ...
  • Bjarnason, Ingi Þorleifur; Menke, William; Flóvenz, Ólafur G.; Caress, David (American Geophysical Union (AGU), 1993-04-10)
    The 170 km South Iceland Seismic Tomography (SIST) profile extends from the west and across the Mid‐Atlantic Ridge spreading center in the Western Volcanic Zone and continues obliquely through the transform zone (the South Iceland Seismic Zone) to the ...
  • Sigmundsson, Freysteinn; Pinel, Virginie; Grapenthin, Ronni; Hooper, Andrew; Halldórsson, Sæmundur Ari; Einarsson, Páll; Ófeigsson, Benedikt G.; Heimisson, Elias; Jónsdóttir, Kristín; Gudmundsson, Magnus Tumi; Vogfjörð, Kristín; Parks, Michelle; Li, Siqi; Drouin, Vincent; Geirsson, Halldor; Dumont, Stéphanie; Friðriksdóttir, Hildur M.; Guðmundsson, Gunnar B.; Wright, Tim J.; Yamasaki, Tadashi (Springer Science and Business Media LLC, 2020-05-15)
    Large volume effusive eruptions with relatively minor observed precursory signals are at odds with widely used models to interpret volcano deformation. Here we propose a new modelling framework that resolves this discrepancy by accounting for magma ...