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Browsing Greinar- HÍ by Subject "Jarðeðlisfræði"

Browsing Greinar- HÍ by Subject "Jarðeðlisfræði"

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  • Bjarnason, Ingi Þorleifur (Hið íslenska náttúrufræðifélag, 1997)
    Heitur reitur er landsvæði sem einkennist af mikilli eldvirkni og jarðhita og stendur hátt yfir umhverfið. Ísland er einn af stærstu heitu reitum jarðar og gnæfir 2-4 km yfir venjulega hæð Norður-Atlantshafshryggjarins sem gengur í gegnum landið. Markmið ...
  • Batt, Catherine M.; Brown, Maxwell; Clelland, Sarah-Jane; Korte, Monika; Linford, Paul; Outram, Zoe (Elsevier BV, 2017-09)
    Archaeomagnetic dating offers a valuable chronological tool for archaeological investigations, particularly for dating fired material. The method depends on the establishment of a dated record of secular variation of the Earth's magnetic field and this ...
  • Bjarnason, Ingi Þorleifur; Menke, William (Society of Exploration Geophysicists, 1993-07)
    Cross-borehole tomography suffers from a well-known problem of data incompleteness: the limited ray coverage dictated by the poor experimental geometry implies that certain features of the velocity field are not determined by the data. Construction of ...
  • Till, Jessica L; Nowaczyk, N (Oxford University Press (OUP), 2018-03-08)
    The iron oxyhydroxide goethite is unstable at elevated temperatures and can transform to magnetite under reducing conditions. In this study, various heating experiments were conducted to simulate Fe-mineral transformations during pyrogenic or burial ...
  • 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 ...
  • Mankasingh, Utra; Gísladóttir, Guðrún (Elsevier BV, 2019-03-01)
    Andisols are carbon-rich soils that persist in volcanic regions with cool climates. They are the main soil type in Iceland, where there are also large areas of premature or degraded mineral soils with the possible potential to become andisols. This ...
  • Wilcock, William S. D.; Webb, Spahr C.; Bjarnason, Ingi Þorleifur (The Seismological Society of America, 1999)
    The mantle electromagnetic and tomography (MELT) experiment on the east Pacific rise near 17°S was the first large teleseismic experiment on a midocean ridge. During the six-month deployment, no compressional arrivals were well recorded above 0.5 ...
  • Benetti, Marion; Lacour, Jean-Lionel; Sveinbjörnsdóttir, Árný; Aloisi, G.; Reverdin, G.; Risi, C.; Peters, A. J.; Steen‐Larsen, H. C. (American Geophysical Union (AGU), 2018-03-10)
    We propose a framework using water vapor isotopes to study mixing processes in the marine boundary layer (MBL) during quiescent conditions, where we expect evaporation to contribute to the moisture budget. This framework complements the existing models, ...
  • Shen, Yang; Solomon, Sean C.; Bjarnason, Ingi Þorleifur; Purdy, G. M. (American Geophysical Union (AGU), 1996-12-01)
    P‐to‐S conversions from the two primary discontinuities near 410 and 660 km depth (P410s and P660s phases) are evident in particle motions and receiver functions of teleseismic body waves recorded by broadband seismic stations in Iceland. The average ...
  • Pogge von Strandmann, Philip A. E.; Burton, Kevin W.; Opfergelt, Sophie; Eiríksdóttir, Eydís Salóme; Murphy, Melissa J.; Einarsson, Árni; Gíslason, Sigurður R. (Frontiers Media SA, 2020-04-30)
    Lake Myvatn, Iceland, is one of the most biologically productive lakes in the northern hemisphere, despite seasonal ice cover. Hydrothermal and groundwater springs make up the dominant source to this lake, and we investigate their Mg isotope ratio to ...
  • Bjarnason, Ingi Þorleifur; Wolfe, Cecily J.; Solomon, Sean C.; Guðmundsson, Gunnar (Wiley-Blackwell, 1996-03-01)
    We present results from the first stage of the ICEMELT broadband seismometer experiment designed to determine upper mantle structure beneath Iceland, a hotspot located on the Mid-Atlantic Ridge. Relative delays of teleseismic body waves across Iceland ...
  • Björnsson, Sveinbjörn (Hið íslenzka náttúrufræðifélag, 1976)
    Larger earthquakes in Iceland occur mainly in two zones, a narrow E-W trending zone in S-Iceland and 75 km broad zone off the northern coast. Destruction and ground displacement due to the earthquake sequences of J784 (Ms 7.5-8), 1896 Mg 7-7.5) and ...
  • Pedersen, Gro; Höskuldsson, Ármann; Dürig, Tobias; Thordarson, Thorvaldur; Jonsdottir, Ingibjorg; Riishus, M. S.; Óskarsson, B.V.; Dumont, Stéphanie; Magnússon, Eyjólfur; Gudmundsson, Magnus Tumi; Sigmundsson, Freysteinn; Drouin, V.J.P.B.; Gallagher, C.; Askew, R.; Gudnason, J.; Moreland, William; Nikkola, P.; Reynolds, Hannah Iona; Schmith, Johanne (Elsevier BV, 2017-06)
    The 6-month long eruption at Holuhraun (August 2014–February 2015) in the Bárðarbunga-Veiðivötn volcanic system was the largest effusive eruption in Iceland since the 1783–1784 CE Laki eruption. The lava flow field covered ~84 km2 and has an estimated ...
  • 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 ...
  • Zielhofer, Christoph; von Suchodoletz, Hans; Fletcher, William J.; Schneider, Birgit; Dietze, Elisabeth; Schlegel, Michael; Schepanski, Kerstin; Weninger, Bernhard; Mischke, Steffen; Mikdad, Abdeslam (Elsevier BV, 2017-09)
    The Sahara is the world's largest dust source with significant impacts on trans-Atlantic terrestrial and large-scale marine ecosystems. Contested views about a gradual or abrupt onset of Saharan aridity at the end of the African Humid Period dominate ...
  • Aufaristama, Muhammad; Höskuldsson, Ármann; Jónsdóttir, Ingibjörg; Ulfarsson, Magnus; Thordarson, Thorvaldur (MDPI AG, 2018-01-20)
    A new lava field was formed at Holuhraun in the Icelandic Highlands, north of Vatnajökull glacier, in 2014–2015. It was the largest effusive eruption in Iceland for 230 years, with an estimated lava bulk volume of ~1.44 km3 covering an area of ~84 km2. ...
  • Jóhannesson, Tómas; Pálmason, Bolli; Hjartarson, Árni; Jarosch, Alexander H.; Magnússon, Eyjólfur; Belart, Joaquín M. C.; Gudmundsson, Magnus Tumi (Cambridge University Press (CUP), 2020-06-02)
    Non-surface mass balance is non-negligible for glaciers in Iceland. Several Icelandic glaciers are in the neo-volcanic zone where a combination of geothermal activity, volcanic eruptions and geothermal heat flux much higher than the global average lead ...
  • 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 ...