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Christensen, Fluid dynamics of Earth and Planetary Interiors, Kyoto, November 2006 1.1

Journey to the centre of the Earth

Ulrich R. Christensen

Christensen, Fluid dynamics of Earth and Planetary Interiors, Kyoto, November 2006 1.2

Dante Alighiri,Divina Comedia14th century

Christensen, Fluid dynamics of Earth and Planetary Interiors, Kyoto, November 2006 1.3

Athanasius Kircher, 17th century

Christensen, Fluid dynamics of Earth and Planetary Interiors, Kyoto, November 2006 1.4

Jules Verne:Journey to thecentre of theEarth, 19th century

Christensen, Fluid dynamics of Earth and Planetary Interiors, Kyoto, November 2006 1.5

Continental deep drill hole,Germany 9042 m

Christensen, Fluid dynamics of Earth and Planetary Interiors, Kyoto, November 2006 1.6

Entrance to the oldseismological obser-vatory in Göttingen,Germany(E. Wiechert, 1903)

Message from far awaybrings the shaking rock:read the signs !

Christensen, Fluid dynamics of Earth and Planetary Interiors, Kyoto, November 2006 1.7

Registration of the San Francisco, 1906, Earthquake taken in Göttingen

Christensen, Fluid dynamics of Earth and Planetary Interiors, Kyoto, November 2006 1.8

mantleouter inner

core

focus

shadow zone

Seismic wave propagation through the Earth

Christensen, Fluid dynamics of Earth and Planetary Interiors, Kyoto, November 2006 1.9

Christensen, Fluid dynamics of Earth and Planetary Interiors, Kyoto, November 2006 1.10

Formation of magnetic lineations at mid-oceanic ridges

Basaltic crust

Partial (≈10%) melting of mantle rock

Christensen, Fluid dynamics of Earth and Planetary Interiors, Kyoto, November 2006 1.11

Comparison of relative movement in mm/yr obtained by GPS measurements and (in parantheses) from geophysical information

Christensen, Fluid dynamics of Earth and Planetary Interiors, Kyoto, November 2006 1.12

5 cm

Mantle xenolith: 60 – 70% Olivine (Mg(1-x)Fex)2SiO4 x ≈ 0.11

Christensen, Fluid dynamics of Earth and Planetary Interiors, Kyoto, November 2006 1.13

Two end-member models of convection in the Earth‘s mantle

Christensen, Fluid dynamics of Earth and Planetary Interiors, Kyoto, November 2006 1.14

Christensen, Fluid dynamics of Earth and Planetary Interiors, Kyoto, November 2006 1.15

Anomaly of P-wave velocity

Cross-section through tomographic image of the mantle: Japan, Korea, Northern China:Subducted Pacific plate stagnates in transition zone ?

Earthquakes

α→β transition

γ→pv+mv transition

Christensen, Fluid dynamics of Earth and Planetary Interiors, Kyoto, November 2006 1.16

Anomaly of P-wave velocity

Cross-section through tomographic image of the mantle: Middle America and Carribean:Subducted Pacific penetrates into lower mantle

Christensen, Fluid dynamics of Earth and Planetary Interiors, Kyoto, November 2006 1.17

Anomaly of P-wave velocity

Cross-section through tomographic image of the mantle: Tonga-Fidschi:Subducted Pacific plate is retarded, but eventually penetrates

Christensen, Fluid dynamics of Earth and Planetary Interiors, Kyoto, November 2006 1.18

5 cm/a 2 cm/a

660 km

2D numerical model of slab subduction through a phase boundary