Crust Crust 10 70 km acidic composition Upper

地球の層構造 地震波速度分布にもとづくと： • 地殻　Crust: Crust ~10– 70 km, 珪長質　acidic composition (上部地殻　Upper crust of continent) 苦鉄質　basic (mafic) composition (下部地殻　Lower crust 　　 of continent及び　海洋地殻 Oceanic crust ) • マントル　Mantle: Mantle ~2800 km, ultramafic composition • 外核　Outer core: core ~2200 km, liquid iron (with light elements) • 内核　Inner core: core ~1500 km, solid iron (with light elements? )

Sir Harold Jeffreys, FRS[1] (22 April 1891 – 18 March 1989) Jeffreys was born in Fatfield, Washington, County Durham, England. Beno Gutenberg (1889– 1960) He joined the laboratory in 1930 and, at the same time, became a Professor of Geophysics at the California Institute of Technology.

地球の層構造 Bullen, Keith Edward (1906 - 1976) 29 June 1906, Auckland, New Zealand Bullen(1936)は地殻をA層、マントルをB層, C層, D層、外核をE層, F層、内核をG 層に分け、速度分布、密度分布を求めた。 A層　地殻　Crust --モホ面　Moho　discontinuity-B層　上部マントル　Upper mantle --410 km地震波不連続面--- 410 km seismic discontinuity C層　マントル遷移層　Mantle transition zone --660 km地震波不連続面---660 km seismic discontinuity D層　下部マントル　Lower mantle --D”層　核マントル境界　Core-mantle boundary (CMB) E層　外核　Outer core --F層　内核境界　Inner core boundary (ICB) G層　内核　Inner core

ABC A 層～G層 D D” E F G A層　地殻　Crust --モホ面　Moho　discontinuity-B層　上部マントル　Upper mantle --410 km地震波不連続面--　　410 km seismic discontinuity C層　マントル遷移層　 　　Mantle transition 　zone --660 km地震波不連続面--　　660 km seismic discontinuity D層　下部マントル　Lower mantle D”層　核マントル境界　 --Core-mantle boundary (CMB) E層　外核　Outer core F層　内核境界　 --Inner core boundary (ICB) G層　内核　Inner core

地球の化学組成・鉱物組成 Composition of the Earth 地震学的研究によると密度は：Seismology tells us about the density　of rocks: • 地殻　Ｃｒｕｓｔ 　　大陸地殻　Continental crust: crust ~2. 8 g/cm 3 　　海洋地殻　Oceanic crust: crust ~3. 2 g/cm 3　 • リソスフィア　Lithosphere: Lithosphere Crust + Uppermost crust • アセノスフィア　Asthenosphere: Asthenosphere ~3. 3 g/cm 3

Seismograph Record of P, PP, S, and Surface Waves 地震計の記録：P, PP, S, 表面波

P-and S-wave Pathways Through Earth 地球内部のＰ波とＳ波の波線（Ray path) Fig. 19. 3

核の影　Ｐ波 P-wave Shadow Zone Fig. 19. 2 a

核の影：　Ｓ波 S-wave Shadow Zone Fig. 19. 2 b

内核の発見(1936) Dr. Inge Lehmann (1888 -1993), 内核の 発見者　　Born in Denmark in 1888 The existence of an inner core distinct from the liquid outer core was discovered in 1936 by seismologist Inge Lehmann[3] using observations of earthquake-generated seismic waves that partly reflect from its boundary and can be detected by sensitive seismographs on the Earth's surface.

地震の大きさ：マグニチュード Maximum Amplitude of Ground Shaking Determines リヒタースケール Richter Magnitude Charles Francis Richter (/ˈrɪktər/; 1900– 1985), was an American seismologist and physicist. California Institute of Technology 最大振幅（ミクロン）の常用対数 1増えると振幅が10倍、エネルギーは 31. 62倍 2増えると振幅は 100倍、エネルギーは 1000倍 A mm at d= 100 km

プレートテクトニクス Mosaic of Earth’s Plates Peter W. Sloss, NOAA-NESDIS-NGDC 24

World Seismicity, 1963– 2000 Fig. 18. 14

Upper Mantle Convection as a Possible Mechanism for Plate Tectonics ここまで　2010/11/1 Fig. 19. 8