1. Geodynamics, Seismology & Plumes Gillian R. Foulger University of Durham, UK

2. 2 The classical model

3. 3 The alternative model

4. 4 PlumePlate

5. How can we test these hypotheses?

6. 6 Model Predictions Plume 1.Uplift 2.“Plume head” eruption 3.“Plume tail” to the CMB 4.Time-progressive volcano chain 5.High temperature Plate 1.Extension 2.Volume: source fusibility

7. Seismology

8. Downwellings (slabs)

9. 9 Ritsema et al. (1999)

10. 10 Ritsema et al. (1999)

11. Upwellings (plumes)

12. 12 The “Superplumes”

13. 13 The “Superplumes” are not hot. They are dense, chemical anomalies. Trampert et al. (2004) Vs Density

14. Smaller-scale features

15. 15 The Iceland mantle plume

16. 16 … oops … where did it go?

17. 17 Truncation & colour scales Bijwaard & Spakman (1999) Hudson Bay plume?

18. 18 Problems with tomography Insufficient resolution Poor data coverage Ambiguity in interpretation

19. 19 Resolution Pilidou et al. (2005)

20. 20 Poor data coverage (“banana doughnut” tomography) “Finite-frequency” tomography

21. 21 Finite frequency tomography Montelli et al. (2004)

22. 22 “plumes” = seismic stations van der Hilst & de Hoop (2005)

23. 23 Ambiguity in interpretation Phase –Mineral –State Composition Temperature

24. 24 Basin & Range Province, USA

25. Azores

26. 26 Huge vertical exaggerations 200 km Silveira & Stutzmann (2002)

27. 27 Azores plume tail? P-wave model no S-wave model Yang (2006)

28. … and a plate model for the Azores?

29. 29

30. 30

31. 31 http://www.mantleplumes.org/ Resources

32. That’s all folks