2004), Hawaiian hot-spot swell structure from seafloor
Seafloor magnetotelluric (MT) data were collected at seven sites across the Hawaiian hot spot swell, spread approximately evenly between 120 and 800 km southwest of the Hawaiian-Emperor Island chain. All data are consistent with an electrical strike direction of 300◦, aligned along the seamount chai...
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| Format: | Text |
| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.512.3548 http://marineemlab.ucsd.edu/resources/Pubs/swell_preprint.pdf |
| Summary: | Seafloor magnetotelluric (MT) data were collected at seven sites across the Hawaiian hot spot swell, spread approximately evenly between 120 and 800 km southwest of the Hawaiian-Emperor Island chain. All data are consistent with an electrical strike direction of 300◦, aligned along the seamount chain, and are well fit using two dimensional (2D) inversion. The major features of the 2D electrical model are a resistive lithosphere underlain by a conductive lower mantle, and a narrow, conductive, ‘plume ’ connecting the surface of the islands to the lower mantle. This plume is required; without it the swell bathymetry produces a large divergence of the along-strike and across-strike components of the MT fields, which is not seen in the data. The plume radius appears to be less than 100 km, and its resistivity of around 10 Ωm, extending to a depth of 150 km, is consistent with a bulk melt fraction of 5-10%. A seismic low velocity region (LVR) observed by Laske et al. (1999) at depths centered around 60 km and extending 300 km from the islands is not reflected in our inverse model, which extends high lithospheric resistivities to the edge of the conductive plume. Forward |
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