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Correlation between Hot Spot Activities and Geomagnetic Paleointensity Correlation between Hot Spot Activities and Geomagnetic Paleointensity: Indicating.

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Presentation on theme: "Correlation between Hot Spot Activities and Geomagnetic Paleointensity Correlation between Hot Spot Activities and Geomagnetic Paleointensity: Indicating."— Presentation transcript:

1 Correlation between Hot Spot Activities and Geomagnetic Paleointensity Correlation between Hot Spot Activities and Geomagnetic Paleointensity: Indicating Mantle Plume Rising Speeds H. B. WANG, R. ZHU, Y. J. CHEN and W. J. MORGAN Peking University, C.A.S. and Princeton University 2006 WPGM, July 27th, 2006

2 Correlation between Hot Spot Activities and Geomagnetic Paleointensity Earth’s interior & Geomagnetism Field in the outer core extend to the surface

3 Correlation between Hot Spot Activities and Geomagnetic Paleointensity (Morgan, 1971) Mantle Plumes and Hot spots (Lay et al., 1998)

4 Correlation between Hot Spot Activities and Geomagnetic Paleointensity Long-term trends in paleointensity in the last 82 Ma, which is after the CNS ( use 90 Ma to calculate) Database: PInt03 (plus) and New SBG collections Data selecting criteria: (1) Age: from 90 Ma to present (2) Thellier method with positive pTRM checks (3) ≥ 2 specimens for each cooling unit (4) Exclude data during magnetic polarity transition (5) VDM or VADM error of each cooling unit ≤ 30% (6) Every 3 Ma window for averaging mean VDM or VADM Totally 823 and 96 data were selected. (Tauxe, 2006, in press)

5 Correlation between Hot Spot Activities and Geomagnetic Paleointensity Paleointensity variation

6 Correlation between Hot Spot Activities and Geomagnetic Paleointensity Stability tests on paleointensity, using various criteria

7 Correlation between Hot Spot Activities and Geomagnetic Paleointensity Hawaiian-Emperor seamount chain

8 Correlation between Hot Spot Activities and Geomagnetic Paleointensity Hawaiian hot spot activity: volume flux (Van Ark and Lin, 2004)

9 Correlation between Hot Spot Activities and Geomagnetic Paleointensity Hot spot activity correlates with geomagnetic paleointensity About 3~5 Ma phase lag.

10 Correlation between Hot Spot Activities and Geomagnetic Paleointensity Hot spot activity correlates with geomagnetic paleointensity About 3~5 Ma phase lag.

11 Correlation between Hot Spot Activities and Geomagnetic Paleointensity Louisville seamount chain

12 Correlation between Hot Spot Activities and Geomagnetic Paleointensity Louisville hot spot activity: volume flux

13 Correlation between Hot Spot Activities and Geomagnetic Paleointensity Hot spot activity correlates with geomagnetic paleointensity Already shifted phase lag of 9 Ma.

14 Correlation between Hot Spot Activities and Geomagnetic Paleointensity Hot spot activity correlates with geomagnetic paleointensity Already shifted phase lag of 9 Ma.

15 Correlation between Hot Spot Activities and Geomagnetic Paleointensity Discussions: Assuming the outer core and plume roots influence each other, then heat and magma rise slowly in plumes. Assuming when paleointensity is higher, the outer core convects more vigorously and conducts more heat and energy to mantle plumes. Fluid outer core plumes Influence each other Seamount chains Heat conducting Hawaii 7.4 Mg/s lag: 3 Ma Louisville 2.0 Mg/s lag: 9 Ma (Malamud and Turcotte, 1999)

16 Correlation between Hot Spot Activities and Geomagnetic Paleointensity Conclusions: (1) The correlations show the connection between crust and core (2) Some hot spots are originated from the CMB. Mantle plumes lead the connection between hotspots and outer fluid core. (3) With the ~3 Ma and ~9 Ma phase lags, we estimated average plume rising speeds of ~1.0 m/yr for Hawaii and ~ 0.3 m/yr for Louisville.

17 Correlation between Hot Spot Activities and Geomagnetic Paleointensity Acknowledgements: We thank: People in Paleomag Lab, IGG, Chinese Academy of Sciences People in ITAG, SESS, Peking University Drs. Jian Lin, Emily Van Ark, Keke Zhang and Lisa Tauxe This work was supported by NSFC grants (40221402), Chinese Academy of Sciences and Peking University. Wang, H. B., R. Zhu, Y. J. Chen and W. J. Morgan, (2006), Correlation Between Hotspot Activity and Geomagnetic Paleointensity, Eos Trans. AGU, 87(36), West. Pac. Geophys. Meet. Suppl., Abstract U44B-05

18 Correlation between Hot Spot Activities and Geomagnetic Paleointensity Thanks! http://www.paleomag.net wanghuapei@gmail.com


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