Interaction of Tectonics and Magmatism in the Askja and Krafla Spreading Segments of Iceland

Robert S. White, Jon Tarasewicz, Tim Greenfield, Rob Green
2013
Interaction of Tectonics and Magmatism in the Askja and Krafla Spreading Segments of Iceland
This is a Full Scientific Report resulting from NERC Geophysical Equipment Facility Loan 914, principal investigator Prof Robert White.

Abstract

This loan comprised 40 SEIS-UK seismometers operating alongside 10 Cambridge-owned seismometers to provide coverage of 150 km of the Northern Volcanic Zone (NVZ) active spreading centre in Iceland, with denser local arrays around Askja and Krafla volcanoes, during July 2010 – September 2011 (Fig. 1). The loan of 30 SEIS-UK seismometers was extended to September 2012 to enable monitoring of increased seismic activity under Vatnajökull at the south end of the NVZ. We purchased a further 15 seismometers using NERC funding, thus maintaining a network of 55 instruments during the extension period. The work was supported by a NERC research grant and NERC post-doc and Ph.D studentships as well as several M.Sci. research projects. Preliminary results include: mapping of several thousand earthquakes along the rift zone in both the lower and upper crust; tomographic evidence for the magma chamber under Askja; detailed analysis of how strike-slip faulting accommodates shear in the transfer zone between rift segments; evidence for strongly non-double-couple source mechanisms at Krafla; demonstration of faulting in the brittle layer at extremely low stress drops of 1‒3 bars, probably caused by migration of carbon dioxide from an underlying magmatic intrusion.

Full Report

PDF Interaction of Tectonics and Magmatism in the Askja and Krafla Spreading Segments of Iceland (3.2 Mb)
Cite as:
White, R.S., Tarasewicz, J., Greenfield, T., Green, R., "Interaction of Tectonics and Magmatism in the Askja and Krafla Spreading Segments of Iceland", NERC Geophysical Equipment Facility, Scientific Report 914, 2013

Selected external publications resulting from this GEF loan

  1. Greenfield, T., White, R.S., Winder, T. and Agustsdottir, T., 2018, Seismicity of the Askja and Bardarbunga volcanic systems of Iceland, 2009–2015, Journal of Volcanology and Geothermal Research, doi: 10.1016/j.jvolgeores.2018.08.010
  2. White, R.S., Edmonds, M., Maclennan, J., Greenfield, T. and Agustsdottir, T., 2018, Melt movement through the Icelandic crust, Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 377(2139), p20180010, doi: 10.1098/rsta.2018.0010
  3. White, R.S., Edmonds, M., Maclennan, J., Greenfield, T. and Agustsdottir, T., 2019, Melt movement through the Icelandic crust, Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 377(2139), p20180010, doi: 10.1098/rsta.2018.0010
  4. Greenfield, T. and White, R.S., 2015, Building icelandic igneous crust by repeated melt injections, Journal of Geophysical Research Solid Earth, 120(11), pp7771-7788, doi: 10.1002/2015JB012009
  5. Schuler, J., White, R.S., Brandsdottir, B. and Tarasewicz, J., 2015, Shallow geothermal and deep seismicity beneath Peistareykir, NE-Iceland, Jokull, 65, pp51-59
  6. Mildon, Z., Tarasewicz, J., Pugh, D., White, R.S. and Brandsdottir, B., 2016, Closing crack earthquakes within the Krafla caldera, North Iceland, Geophysical Journal International, 207(2), p1137-1141, doi: 10.1093/gji/ggw325
  7. Green, R.G., White,R.S. and Greenfield,T., 2013, Motion in the north Iceland volcanic rift zone accommodated by bookshelf faulting, Nature Geoscience, doi: 10.1038/ngeo2012
  8. Martens, H. and White, R.S., 2013, Triggering of microearthquakes in Iceland by volatiles released from a dyke intrusion, Geophysical Journal International, 194(3), pp1738-1754, doi: 10.1093/gji/ggt184
  9. Mitchell, M.A., White, R.S., Roecker, S. and Greenfield,T., 2013, Tomographic image of melt storage beneath Askja Volcano, Iceland using local microseismicity, Geophysical Research Letters, 40, pp5040-5046, doi: 10.1002/grl.50899
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