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The slowing factor s is 4, and the correlation includes all 12 harmonic degrees

The slowing factor s is 4, and the correlation includes all 12 harmonic degrees.

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The slowing factor s is 4, and the correlation includes all 12 harmonic degrees

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  1. The slowing factor s is 4, and the correlation includes all 12 harmonic degrees

  2. Examples of “Hindsight Heresy”in which a hypothesis is constructed after looking at a data set, and then using the same data to support and test the hypothesis, to prune the data or change parameters (Burke 2008; Torsvik at al. 2006; Lithgow-Bertelloni & Richards 1998; Courtillot et al 2003; Coutier et al. 2007; etc.). 1. Courtillot, V. et al. Three distinct types of hotspots in the Earth's mantle. Earth Planet. Sci. Lett. 205, 295308 (2003). 2. Torsvik, T.H. et al. 2006. Large igneous provinces generated from the margins of the large low-velocity provinces in the deep mantle. GJI 167, 1447–1460. 3. Burke, K. et al. Plume generation zones at the margins of large low shear velocity provinces on the core–mantle boundary. EPSL 265, 49–60 (2008). 4. Lithgow-Bertelloni, C., Richards, M.A., 1998. The dynamics of Cenozoic and Mesozoic plate motions. Rev. Geophys. 36, 27–78. 5. Cottaar, S., B. Romanowicz, An unsually large ULVZ at the base of the mantle near Hawaii, EPSL, 355-356, 213-222, 2012. 6. Courtier, A. M. and 14 others. Correlation of seismic and petrologic thermometers suggests deep thermal anomalies beneath hotspots. EPSL 264, 308-316.

  3. Pacific hotspots & backtracked plateaus Indian Ocean hotspots & plateaus Atlantic hotspots Present day ridge-related low wavespeed regions correspond to red-brown age regions

  4. Area covered, insulated & polluted by Pangea Even the largest igneous events can be explained by extracting magma from the upper 200 km LIPs

  5. LIPs & hotspots are associated with continental breakup • reconstruction at ~ 30 Ma • dual volcanism • on breakup • ~ 30 Myr later • oceanic plateaus form ~ 1,000 km offshore • = rising of delaminated root?

  6. The slowing factor s is 4, and the correlation includes all 12 harmonic degrees

  7. The integrated density under many ridges is high Ridges are fed by upwellings from the transition zone Seafloor flattening is due to lateral density gradients below 200 km

  8. Even the largest igneous events can be explained by extracting magma from the upper 200 km Vs 80 km depth

  9. 6 ‘aberrant’ hotspots (“outside of plate boundary related low wavespeed areas) P<10-8 100 km depth true within-plate hotspots are underlain by average or fast mantle at 100 km depth. 14 ‘aberrant’ hotspots Core-mantle boundary (CMB) P=1.47x10-7 Burke et al.

  10. Ridge, slab related 100 km depth Using the same parameters as Burke, the correlation of hotspots & backtracked LIPs with tomography is higher for the uppermost than for the lowermost mantle

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