Geothermal noise at Olkelduhals, SW Iceland
2010 (English)In: Jokull, ISSN 0449-0576, Vol. 60, 89-102 p.Article in journal (Refereed) Published
Seismic noise was recorded at 19 sites along a roughly linear array crossing the geothermal area at Olkelduhals, SW Iceland. Noise in the frequency range between 3 and 7 Hz was identified as associated with the geothermal activity based on amplitude decay with distance and timing of energy in intra-station cross-correlation. This geothermal tremor is very stable in time, both in its amplitude and correlation relations. Differences of amplitude-spectral shape from one station to another and between the different components of motion at each station indicate a complex structure of the wave field, possibly due to a distributed source and scattering effects. The cross-correlation constrains horizontal group velocity weakly at about 1 km/s. Based on particle-motion diagrams and three-component polarization analyses the noise appears to be primarily composed of surface waves. The spatial decay of the noise away from the inferred source implies an elastic quality factor of Q similar to 10 assuming the geometrical spreading of a surface wave in a laterally homogeneous Earth.
Place, publisher, year, edition, pages
2010. Vol. 60, 89-102 p.
Earth and Related Environmental Sciences
IdentifiersURN: urn:nbn:se:uu:diva-150740ISI: 000288232100006OAI: oai:DiVA.org:uu-150740DiVA: diva2:408490