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Browsing by Subject "Jarðskjálftar"

Browsing by Subject "Jarðskjálftar"

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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 ...
  • Bjarnason, Ingi Þorleifur; Cowie, Patience; Anders, Mark H.; Seeber, Leonardo; Scholz, Christopher H. (The Seismological Society of America, 1993)
    We have mapped in detail surface ruptures of the 1912 magnitude 7.0 strike-slip earthquake in south Iceland. This earthquake ruptured fresh basalt flows that had covered the pre-existing fault. The observed style of surface fracturing closely matches ...
  • Bjarnason, Ingi Þorleifur; Pechmann, James C. (The Seismological Society of America, 1989)
    We have completed a comprehensive study of focal mechanisms of digitally recorded earthquakes (M, -_< 4.4) that occurred in the Wasatch front region in Utah during 1980 to 1986. Single-event solutions for 24 events were determined using recently ...
  • 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 ...
  • 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 ...
  • Ioannou, Ioanna; Bessason, Bjarni; Kosmidis, Ioannis; Bjarnason, Jón Örvar; Rossetto, Tiziana (Springer Science and Business Media LLC, 2018-07-18)
    In June 2000, two Mw6.5 earthquakes occurred within a 4-day interval in the largest agricultural region of Iceland causing substantial damage and no loss of life. The distance between the earthquake epicentres and the fault rupture was approximately ...
  • 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 ...
  • 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 ...
  • Tryggvason, Eysteinn (Hið íslenzka náttúrufræðifélag, 1954)
    The seismic activity was relatively low in Iceland during this year. No large shock occurred, and no damage was done by earthquakes. The largest shock came on February 10th, with epicenter off the north coast (about 66°40'N, 17°0'W), origin time l ...
  • Tryggvason, Eysteinn (Hið íslenzka náttúrufræðifélag, 1959)
    During this period, three seismograph stations were operated in Iceland, at Reykjavík, Akureyri and Vík. A new seismograph station was erected at Kirkjubæjarklaustur (Síða) in 1958, where one vertical Willmore seismograph is operated. The seismic ...
  • Tryggvason, Eysteinn (Hið íslenzka náttúrufræðifélag, 1956)
    The seismograph station at Reykjavik was operated with three short period Sprengnether seismographs during these years. New stations were erected at Akureyri (65°40.3' N, 18°06.0' W) and at Vík (63°25.3' N, 19°01.0' W). At both these stations, one ...
  • Woods, Jennifer; Donaldson, Clare; White, Robert S.; Caudron, Corentin; Brandsdóttir, Bryndís; Hudson, Thomas S.; Agustsdottir, Thorbjorg (Elsevier BV, 2018-05-15)
    The 2014–15 Bárðarbunga–Holuhraun rifting event comprised the best-monitored dyke intrusion to date and the largest eruption in Iceland in 230 years. A huge variety of seismicity was produced, including over 30,000 volcano-tectonic earthquakes (VTs) ...
  • 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 ...
  • Shen, Yang; Solomon, Sean C.; Bjarnason, Ingi Þorleifur; Wolfe, Cecily J. (Springer Nature, 1998-09)
    Iceland, one of the most thoroughly investigated hotspots1,2,3, is generally accepted to be the manifestation of an upwelling mantle plume4. Yet whether the plume originates from the lower mantle or from a convective instability at a thermal boundary ...
  • Bjarnason, Ingi Þorleifur; Silver, Paul G.; Rümpker, Georg; Solomon, Sean C. (Wiley-Blackwell, 2002-12)
    We report on observations of upper mantle anisotropy from the splitting of teleseismic shear waves (SKS, SKKS, and PKS) recorded by the ICEMELT broadband seismometer network in Iceland. In a ridge-centered hot spot locale, mantle anisotropy may be ...
  • Einarsson, Páll (Frontiers Media SA, 2018-05-08)
    Networks of seismographs of high sensitivity have been in use in the vicinity of active volcanoes in Iceland since 1973. During this time, 21 confirmed eruptions have occurred and several intrusions where magma did not reach the surface. All these ...
  • Barrière, Julien; d'Oreye, Nicolas; Oth, Adrien; Geirsson, Halldor; Mashagiro, Niche; Johnson, Jeffrey B.; Smets, Benoît; Samsonov, Sergey; Kervyn, François (Frontiers Media SA, 2018-06-19)
    Since its last effusive eruption in 2002, Nyiragongo has been an open-vent volcano characterized by the world’s largest persistent lava lake. This lava lake provides a unique opportunity to detect pressure change in the magmatic system by analyzing its ...
  • Bjarnason, Ingi Þorleifur; Einarsson, Páll (American Geophysical Union (AGU), 1991-03-10)
    The May 25, 1987, Vatnafjöll earthquake occurred on the Mid‐Atlantic plate boundary, at a junction between a transform (the South Iceland Seismic Zone) and a spreading segment (the Eastern Volcanic Zone). The South Iceland Seismic Zone has had the most ...