FWSTx CD ?M_rootversiongetVersionOO? 8:S ~s>+g # K 5fZ&tB %Ru-[,1%&$ Y 4&%eJi8 ][RUA+˺+|n<쪀5DQpFDy_$ @0K$B)  &R_(".5g^nQPĬ) h%к_3{\ۖ5 SFbOAAMeW%ѻAm$C #.핀hQo" J[/Y]6I5fnZPU)R{CKuˡtۦYu Ք@$ cA-Py>*P|tJУFx+t%ϰ5`Vx=IQ\!/RR fSK8QYѨ5(z7h3*J+2T .V@hOh5lfx[@>BReT_E. F%XiE;օqeq IPA"7h1*J/2,)'8ݾ}m`sO򽻌 ) ƥ@5geHـM&4/}X JLp hnݠԪ(#pS`y˳Uh۸lNV,cJpZ׈֌&16*n.WKm`o@5gZ]Z{ӱ.tKWM yS Χ/J4JD bQknv\#294.݋%0jH,.1* J[Oerk ^z6$Z)FJ,,H,S@it~m5KMb֦ދd%I8_/+ro$b.%|Nں7Lw.K2Z i_Cd@4M3@UYrb ^NRS!$T :vFkAlbK@$*bEp5I]Oc .%Y@fR)?V ߔPw-͔a|553J Lz2a$рO dPD65fڜP Rƃ-ƅ;7G|5F OWL}\+ e'qΛ:xFnމh, *Ld)'Ɛ%ꉴ&e,6cV%Z]=ؤoq5F %ӭƤx&rQ(x23Uf2: Ugr4TިfZM\6.g_-Lbf5fb LY-k@06L 婾F@P;j؊Kf@5QN\~ H"|iSYъ` m KQ[Uup@5G exـȊ4@ S1S8CwN\Kdåri >LjD@&@-<m״'T`J!0`M`<9)À̶3Y$M@{-2 Tc`\u2Ҭi.`*Lxg1z@fSICZ-&0SLW*.H5bT[CTЀ8e8Xj邈wTRVec`}#7f*TͅX*;-~:$(Js u(EV=؇Kr;vV)CrWaN鯭wiF5bd8r>LO +d+ CX Q}Vtfsh}$:7k[JuJ ۴-:V ,#O7oEr45bS4:@)nGn֯lɣ(~ +pY~w}6u<]\5GD喹m&^ҀZlfsm#7kY6є?j;~Ty<ݽWe[/kZgU`kg&QLT" t,!VHp{FH!| vT7grL0UXr/ P r5cFSC`#~yu`I@5Ly" x$!X0:)nGtnT ! nTwh$16(*P i {FJv[oܞ]Zk]xz+  l5GP&B\7d(H%V ؘ`z`lnВ<93@|` {A,@M0]6mT ),5FI] [rL(2 KhѺT`X9:t;`tFފh+12$ H&g\]UvGpY@5JDSNha7m4-R@/  //$fc@?Z A^4 kNG*@Jm-XJ3s\nMo.*JB{R hgg3:5bwR z%xR@->CPP  ?RlN]p$ ^N6-p]SKAw5HmNp' HDkGHo4)ٟF\$/ ɫٽw@07fr瞚;֍`aIK@E@s)MKk\ʟ@5K mKh$lDG^bt+5ѷqd RB@-?+Vw5H4mmh- Xv]6$4SmmxVxsh[ms92.m`h:@!n#){&Y4m/Times New Roman 5:EFLMPSYacdefghilmnorstuvw|xE7@  f̬4JWS'<.]F0Bi\U.xx \\<"B!Zj[H[`&aD+MP)@?\h f&B;2xY<,PiʞP8ki5P թᇌ$Ci¤xQxyD0 Kc*5#\8ik&ff-†&ņ73@U@*@@@UU@j@@U@@@U@@? ikfo89vg:oe@@??N_rootsidescrollsidetextLayers of the Earth
The earth is made of concentric layers of rock with a core of iron-rich metal. How do we know this? What causes the layered structure of the earth? Study these animations and illustrations to gain a richer understanding of the interior of our planet.
*Cutaway: Using the seismic energy from earthquakes, we can "look" inside the earth and determine much about its interior. This cross-section and others in this module show how earthquake waves travel through the earth and tell us about its interior. scroll_rootNONNO?standalone<?`m2"dCQ+5JXRU;Xӵ0XSwM;` R ŧtZv/,U'vIiys@35ts1olh=I"<JFIFHHC    ! ''**''555556666666666C &&,$ $,(+&&&+(//,,//666666666666666 H !1AQ"aq2B#R5Sbrt3CT$c-!1A"Q2aq3B#b ?mAA)3KxAַ,lqh3] aE,N,##o2]ͤi,;ahT 4GM䛅vז3m]Y #;)Jk0_oZg}m =Ǡ^& k^9-JnVM>!Z)3BrBU2AZ\{ n/j gU>~ TO =2g0-Wn/I{>8ܭ&Z38}+Ni|nmTWf^}A*RR`vzu=MAu,(8g74"-s[Ä@8Ǽ Gkod=N#⥊+A,Fs%aQaRu&៍0iC"e<)t߳uoZQ봄lr8toCG#KknYI]] {0|n>aj)-]%rGqXٛsS>o v,39O#=,oY0sO̅{#ֈc߭om_wY,l{|B=x@c[[NP.2G}HKA(RӃ9b1dep)"c{fh>U*.Y;Sfw7"-.W-V6^4dXCuЛeUK1-'mY ä`񑄜fӭ%Y 9e~*nR=ZL: l 1YgM8oDj^A=^˕$jJŮ09\ϻoM'և\b&3+]bdǗkrNF j|TPFXi8q-: &\ubxzXꌭ;Y/Jr&0URӱ|2͢KxY,.9]؋(>Հ~ÿm\'z? c%9bd=I3bpW~D{GІ8^;)dic dp!ī9TU]/5h;^@+ SZJ7v=K5cv3ŊT2֡ӷ}{WҺUe ]#<\39X(u=Lс~#!Đ4kZz%c;<-#znb*0YZzˠwy+贮|Y~\fkߚq&>!lQG1'S˯ ާowB_'Z.s7zcLB~I#t[VeMea3q#uFGl3vw(ndVաHKm{@o4|T4z `4 Naj$F5lz+~1AJ4rs/38ן ^p {-6]5SE͟,y·}Ge^-ыv!}]dLWQgPnc~`(8pTMtfqܐ~;Z[QM Vy/ܽ1j3r[{<àSt ьv7jҡcٌ{?8]p-MSI;\cs3Weee+CMT8䳜mO-k(OSj 4`Yv1k.owQUx{\Q?чO&z?B_,dǰ0iMY]aտ^9jfcAuRJm{%uv Cxc`#C1'E9L* dh'sKMV6NVy^z⭗,PMM+e9Y\7]%u}.q 'Q9k9tcRL8ts [}Xjkhu'-Sy]|u;j%{2\MH֞qWj嘿4{#AtGYϏښX$}拮2i_sdsk:NӍ<;nKR"f50-[PTNT qy+m-9t I$ެS*xy]i^wZw#t"n5Q(EfǐV.q7p/G_/M-eq诱,|GOWs87yX1f,-n5WOC;\o~DGLܴƼGc<#%*hlы _{9_5`bO=rѡvX%k1xܓ0N+ O Fٚ"X_c]UNqu=-l%͜9ݏTTlA9]L<FW+=,Jha^^mHg#{&u芙n*JzV0{9\w5S,r{0;lxCS+ߒz3|80In/V9cO,kp^ G)ŵL4bVc<Zʘg99mt ̠;쏧ٰAl"t^iǨ>T.5' -7UD0U1)V=k yِly4l5|4Q&@ KHW8ĈKHda8ZYĂ\mv3Aǂ2§p:JQgq L7ͮi≭0Kj1ktmTxm&)n+Ŀ>^s\4_p=Gt /#O s!frt+mGڬG3:b=LmJ4f6Lm$ɹh\{3L2rӭֶ8L&Ict᪩ -#{,:ak n9OjZ_[fg݆̈uk,6'>Y> c|ltMW}2/`Cm^5pVU觚ZY *ʢV5 \czK'(彬F/:qNVHX?twer,*[wn{99 ig1>Rjck%sah+y 9Mc,8i<,JiH,꥔%"fՉmVZhAae".#؟ی\ӻ 5"Wÿ:j|j84ϓ+CZӶm{L},DrsQGVgF擡g3qE kLrnG3|PLul:6Ieb\2ϖ,:zl&k9]h)k"5lyHu E8㧈M7@oOE F9..|^IzK q7cchg 5%sRTUS6ce4ך\ # o#Gnϰ'᮫ݤykM`tm8i#wSɊKs;C]>\w4uݺHBEU d1D3t"PRGRpymI" džQl4;~z+:x*T L z<Gf#jh0ikGR6[Hs{c^iޢZih/5\ቚsj8SAh;1yM$km[.^#X$FѠ}Kr/W5d @@sR4uAdpG smeIc3r~a0C2o{F_gO&[ ףOW .}M\NJoY"I"wZSČ6-S=66Ux6xn+bc9]ۀ/: hM:ahCL1X:ƸuaS7j_ },1yoV"k\XGbj'%{dby@ϟEO2z2y Yߤt] fcp8i٥ HHb XiUw,̸OK辮9e6Ļ!J((U pGtTn Gi[^}|񈩋](g/ms0F?W6üCE8|K}+ R [dTPDȫ#.c(\VC\b?yO%Ѿa5ڂ 㣼:QnnELLc6_W ,#>~YMdmm暘c8qc3'tuq>2)J΁DVnx419Z:\5w9KG{HHcS9Ϸqf_suQ5 [5lO"~[)_P~E+⹽ tq%!;F\Ӕ`Hgq*^57b<ˮt祩ך+uwYs- cb,VZ#M3f;4.t{^}ڱޯ!ks XW+>)W1cy_ ,yc15=;͢~$`trɿ*M1]E;G kO[ss.m8dU1EWͨzޮ H_%ps R <fߗLjY /r,7fzL-J ?F~RG%l7^\|/xwdm^q m(+J-*(eA2mB ,@%Z)gIٛ˘8XRE[Hsz&.k|ҩh$:{/ \%OR/]n{;b\Xᐼ/cQQMg[-]=>c ι9foB\.b%'F:θvu\%I5V{}\頊xp{l_k9QOK 4,k1ߪQls2j50,Wztp<8LjGz*Sl9-6:xQ8sOGXM|p4:HO؀ <5uof/cqOK=!h[۵ۅtLs}Gx{|7)^BQ,9Jʖp\ 7U$jeS^ϖcjc9n2]KG3 @w&FgmQۦw|E#aˏԇ\ɉ"(oGk{Azt}Te?.4hŗ&'%^; /Ȕ#px)8%;|@AWӜ'_YU0<5;1Yyi]̯9sÌKI ve㲗RϕE%MỶoWl1#?O9e3?$L:emkz_GmeiYzkvO;g zv5vVA+^ߚ7[K0紐rpԘ8ˮ:c۔es3I!]m8^BLdnAr.yu.}\A2Fbݼ%(h{ *e% q⊤PrjtD,!U %!@`B nZz =T`]ErB.D2s fM,.K͑Gc\NwemzmWՌF I7oY^laiō5fjq h/gGAJz}o.zs.)«7|etS -@s9KOQLD3 7uSn>!wLYO41u2 g(]1`L/f2 ΚsXkXfg4-.I:lB.nAj&g*u9ıyj Im>kۛ__CKB0y[^s:seycJk)TlC]`j3ljk tq6xO#6V/?2ǩm|PRݞǗrusv~?hc'69b!,P*(}KY@, (E8Z*c6펎_a?3xă%uݪL,3-XkM;tpÑ%뇣OO1Dɣ:_.=\yNG1y(tltM^r.7<:~yuIb%ϼO9sx񝎰v@H-DB@Z0r3It 4f1iж\J7oljt<#Pk| J΢>H-sLo~]Nko\75\7l->8zoL',ICy=ǿ붎~]/}GbPZf5n>GþcO.6G&YZ,ܷ9|o^c뗟)KCEɝ *Z(c "芖P۠%Dd tE[GT)QBƦ;k\λta!FLӾ})]j͙8^JXsVv0#;Eyzp㗖Ir\y/,/'[c?9D Zxa!vo$Q-v@] )߄,{P%4[#g }/r?nZ'b^A ڪG );\bK8/D sH7rLm imYOQKn8飼vmlpp|IP3Ez&fܸ^S7}=|miYJJc(7y>yNqPj &6Ts7!>W_c熟tUqXm}6oQ53SQ åC~Ԯz\5 (1Βk^ VYtcc{spڇH l>u׌q.Z),F~&`@5w|2Ǩ9=f^pmڵT%Al6?je^?>7+6K)́@nER=NLX-?9^Q_c\lOq^|&-|vD,2˖4O-c Uaoϒϣtл[;|ZE ~ 9|גӜn%Tw;8ݷa1s3-u 8ζvl763e]:lrCJ*P) u*x*f,O ~+>9.8Yr|/ikXG&4 ԯs{Ю$}ΟR%}͹7@΀t5 RER_̣+;Lnȹ?Rfl_Nr9qWWP307֞4e̒G5Ϳe/Mo>zpKT +i?R6.]o3OnA3 !d2 @s!At蠀i!fK[ prZ_kim3eko0+3v3U2ec$nih:Nko1TᯫFf\Iuxj(\ )\nTEFg4MLKWFr#:Y}=vV^H]t˩3+zmʌ2(3(rPL' dƞf;`zzsZjb]ʌb\/-uUCeWPAhݽֵ,Ǿ]y̌ /ܴ\fSyJ>^Q}M? t^$ .6n)o䠣1>%nfA3 999̅ z{q㸸i tU2^ƮѹF Gd|͟)NyslA~'sxbyJ2 s\} -)x#)ۏPC* nX\?X?˹1|Pw^MJ"].( tBs"%Vřb$wE 2S+ߺ?{y}#R>?3#˔C̅KͫtrTQD.D!7QCTT%?ʔ&A}!V tPDUO, e襉bsN˹H4/?OYjg1ۜ]שZlS\.f.&oU㹕fB͖Bcm0>^S)e1BKEKQ$LȂ^K5K i|i!sJ/'q5b5廹8\.8ÝcapkbZ:l~'sé1q+@ (AB ">ـ~ÿm^l~z/C@ %K ( J*E4Ѹz9;nN^k-iNV$I#sܑEKԬ\= ׮^*f1QؠQFꡂ QS)E 4@*(&̼\Gfݚ畏MQGDPt@K 9P0qpR#wDkts{0kaH"m7xgsu^bTjAȨ`@E `Q*I$ '5lyYC"F{kg F+9B5hXG0A,`UA.jr^&!, kIK(3+k.QQ,KJ_RmcWz4RJbE4 l/}{PELK(DixK6bG1K(BRf%K(.!6T8s^4T@.9[JKJET.AR2g:YNV iA>!1O;)FUgvF"d$HZRY(k ̀J,5ue)C|>c{4rGVCPOpaq=͔Z1ލL$:m:6%Siqy!ߚ݅3bqZ sןz3 ]!cϹr~,Zp@'vs;$dHl ,-&?'Y@imEh(dٕ3{xljkW o/eIY_UMRŽ)p4iR͆S附m3D!ˢ\(d* d eK"l./511S5RKaԸTަf9ҺfQSJ$&rUQ#>ÿm\: zBܲ\m4V!X/KM$nZ>;(zA01GyQjZϔmR]5\qK}\-6k[9USl D&i;Cd/E ̐e#ٺOTik\Gɵ35cܿh&/_͓2Jg4~#[V"{FcL:>KleyuY-᧥e'-zaB xeKJC q~Ijhvb~FְQV>*Qd3eV!YHj"F>쬍6&7+@cGa b[q,ߒRصIخG!Ҭ28R)wR.0MAATܵT}`#zi3@_Hb9[ m/Rhs|]eJA1-&C<_۩pek=M[mg_U6['"ia Cb%Y`u?m6I 3[N S6bӳgxe9j!ڱLmk,T@Ugk`[ # x?0C{Xw(N[&%-M=$.xj@ *Em7tf\ArVMXY6py J^&kvg-@C]w^&*|2-=B5I݃o>'mمE..Orm5g/}O( 6L5 @3`ezRoF|e OLUݘ{p` -q^X(5H= 5h"d^-@TMQ1ps!5L|5$ Su +O2];` %|H e>H S5a .97~5`wo4اxMap=;ùx hا،xN 5g2rVW/e@Ti ɬ%%ONYZsؗ=p&:˘)fiM@XT`Ħ *4c@ ҀL4Y-p Kε%̐@:锦e0-w~5jۄr^5xi82dv+ U'a-}k3 r}pSI/f/@ >c"5fjv^ V~eIƩLk>` *tK.yr:1q< -tMʡc65O-#C 5i']Hn8KH5FP7-q)$\6Sn[8l x5cjV峖%5.ul{NW]n1݈ܠqꍱ`5iO^/-)Jr5l6VۖrϷTw{$+Ą75jJV寍pۗnZG=\0(5cf?~c pg p¥ :*l̋Ʋ:b2Na2s9,%x=tO*3HJfBʀ5g2Ӛ睲{; ;4JG8 0+JUbp κٹm#}AŠn[9iz+*ۀ5fv~Fn~5J?P 򀷷T4 }`,i å`qȍUwQ[ ]}Zbk el| Π’(5fe 7NavM%hlKyM&ސLPE1ARMk؞ x5f%?=i9'Eɑ@w85fS峖Ia9>5jJXO^&YE\+Y9ڗfw,l ࣒Zܨ;+3ʃ0{SmT[@5kӖ叟nr$ܰs4q/o~8FØ@5df^.qbh"\RLC(t$n]u󯧻帎)kj It/%LK]Obnԟ)3e( 7˳||sKZnc]pRJX C-B{\UI V5lrd'yU|zeWrϬ^G\-ԛ"¹f7@5Keb"MJryy%nR?5h4u]Fۀ>|䵼+cʜKqמ#5H lD2{6;o@;1| '7ړCArial ()-/0123456789?ABCDEHIKLMNOPRSTUWabcdefhiklmnopqrstuvwxyz&` * ,qOgLJ}T)SJ)5fe 7NavM%hlKyM&ސLPE1ARMk؞ x5f%?=i9'Eɑ@w85df^.qbh"\RLC(t$n]u󯧻帎)kj It/%LK]Obnԟ)3e( 7˳||sKZnc]pRJX C-B{\UI V5lrd'yU|zeWrϬ^G\-ԛ"¹f7@arial Saesvw#` ,,SΔvp :D qc`}p>@:   _root.main+` 8X , QfJ-[ħO2 (D EƗ@A&C} X@ЁtH7L+`n!×eY\`Oç h PWLR!!@D?d [$#8ax\$8 Jcp Yd|Rr`j"Ip E-&Ź5H@ 56 S`I}V %*0k|O /4Y-I0en_ EGQ߽{׾=4}{?~ 18gǀ\>ц}鯞!PG=o ߎKK;jQZzFwzb_V=~0! ?0q!?1Fa QiH@@QD^;cX]$sqpzj)RA3)*_ޣdSıGb8 E *P$.IA@Ep&@rQcncqDU|z1L>yvSԡc6+l OsT!ܱ0⤑ VTWz9H䙹:!C:"7bUuoK3dB.}dٴ_jO,y4 Xj>DFya`y jA(pwZo(Uh4ЊϚ<0V{DZ*H eD /~ݝ ch64$4D3JrJF!s"*h)׻Y T[SI`e 63F%{` tv4j#CҭO+eR{SHIgkjs]b`ZQ_'!`E| Єs)J=NeۯV&DO {̈t۷fį;nڈ%t{8+G/IR?˧qx~wOrEvsm6]]AoR~U;ϲ ~ɔ)J!^Yvtd5쌞R;>R'Lr!LDyP%?"VKZ6Γ3#EV5"DVt^V"q Kbќ-Ӯ*҃~y/zUQJed`L]H׿]Y+RL^럡&]m #b<(b` H+Q% m2og:Xu썐S3}gwު[3'Z:u~~B&nqE<-u_z=cM&Xn8 ~\(UwPsjk## ӂ2-]mYulrO@Ҍ-mkkH{l荻{g۵ ̨"{(ಱQ ^("#+іOWcg'r8ө4AVYd;LVTBHynaTbfe*leK$3 \+(4Mԡ$J dy]Ǫ^#sߦ Җk!{e~Qj7{LȵzՑצ7JYSuіB #\)J=^̀D$LEժ3{¡(כ|}Y]y"%?õɦXYoS:ac@RC8| fT(50F=CfUto49I[mi3p0 wՇ5Ϲab(dK5W(NmբܯzF:} R9_yRJYotLݝ<i-J 3j~(aT&HCSЩI$=R-brc|ϪYb1vwZu38igẋSDǗ+*·E/L*  f.S3 AcHhKN"2 #}oE#s.ooOftbY_sVvkQBTZ*Y^frZYXq=K{ z<0ʹlf(oi\D;@G4_lMk݉ꦗm|[ z(Hĭr\vvICǬ b>vN-/e#CB`}"⾅Ё@nV,gKOV}ܙoϟ茌~f zÄ<-`挥$* }CZƖͷТUYn{|86h}Rɮsg}ufٙf=Q k:A r<٘.P#_lTs3kB8pVf;\9CR@AmD"+Ee,,Y@͉o ~<0%yl=GVja0jmj{̷I9vB F@ X0lP5?Qg5mbc9Iquf8 ƻ-`u#Oo)mjhP:䪝A(`^_h-pY1s&6#wpv~ؤg<|6Tvǖ6Y+fD_i`J<8vM )!y6Fwjp&rZ0z : >*$3=U9 Ce@q2Fzm&[d~ hXkD& D @LvD]P-,fk3#jBrfe&@fx `qf3333̠̙353,T1R9e@嵒_h d_)riׯK鿁RGL;Ӫj4R9 oKeDOP("-@嵒^RfQ[KBBxjL5L+AC(/Bv׆]>vLt. k B.`! Ͱ : sŠKhO&صZ B'EJ%` WEU]`K[fڞIRyx65@(_UP`d{njbLgKFs+Q1XZ,?:@+.b PX nej<୹}7mͭb|V^Kۇh/mps.Kn8)8C?kDnio]RyX jnBxvv{t3"|Lӭp D @'f7&p3333!iLwD |BD^oP YWA n@+5nVK=ܛ#*jk9+yq<L6ujugDu͝fYhvu2["YQaS͏V34$xY$|sviÀ w^TZ苜\)Q$4ˤKg\!ٓuږ^ z(S" ɮcUBrll D @ v|TGv!?TXL-MBr>#,hP29E<`O\tS 6؆}@6,W >ĎP)@S;A=qO\7!w)r)%Ƌ80(Ohz{).m.T m9hIPd07U'*d)P  U)ߨOѫl? .[nأ+~^N e<$;8IRf1Dn,Bd4z(x Rm2֥F,Λ*u`7T[Nc_VZYzMF 뢦+ sOԴjSɄhTc^3,lUoSQT R6=-S"n +f%Ė'X`gj! zzJ9jS'E0[`u+8HNlvVg*̽zwO6 ZhJ <F9H V$>s,G{ /퀒g˺f-*(+ڂ|7axLK~:2 #D "@ $v!?TXvHWSL-؆}MBr>#,hP29E<`O\tS 6"@6,W >ĎP)@S;A=qO\ %vHWSvjwY'pL-"MBr>#,hP29E<`O\tS 6Vر\t,W#P 9BƎma04[<5E=r` &vjwY'pvN[M-V@6,W >ĎPa@Dc ĎPa@^-%;L 4!_hG Y5 y5}2nrh8*Ɔ(|Qtw"h2 mzO.Sz8 JigLIl-o') ? v\,gGp"U;4YҊs/5M'_v{ *vaqHv/(g-HGA}t@}K'ܿ uHW;Qq6=Gp"U:@G"W_u= xE آ-#4*# p .vQ$Q\vpP%k-;WW`idTESάQu:E7 HP1"'TM:dsF4@85M5X`;'mP4$@ΐ](^T5A<0M68EScDU(4q,e>~iW7ޠ 0vp1vp@Al-BW^xREJV5>XT;j P3J:MypyO wSy TJM4tz O|ZsBE\=q=|>o;'PVAZ]xu7|G^M8IcD(q+>~ieWh 1vp@Avp@Rl-BGW\ixOuE=τ[>oT;}PVE=sMןSyt'J4|z O T;~-PV=3M7p@)A51ίG>Bҽ\=`%|>Tr;(P#VAZ~h{]7e@N6$=ձ yc}U IUA'y^5z>$p 3vp@ovp@Ȁn-BҿWXxI}E%τgU>9T;PV%=^MxP<Ӆ͉ulH=^XUy|wPIWM^?` B5\=Wu|eT;)iP%V AZ>nt{7kaAN$AU!ycUImA'quz> p[ 4vp@Ȁvp@Ȥn-B7WUxF]Eom>ZT; fCPV=^MP@SUlH@XywPIo^\?VB~а/X|!;*P*VuAZ{{7xaA!N$Hձ!#yd!UxI-A'`sUz=p 5vp@Ȥvp@Ȥo-B_,/ V.z5>ʢT; PVw=MPHS}5lHHYUyv PI'^s\?BB~а/X|!;*P*VuAZ{{7xaA!N$Hձ!#yd!UxI-A'`sUz=p g6vp@Ȥd{={۽›<0 $jؐ<$OG~k~~F=TJaPµ7w)rx%Ƌ80(Ohz{).m.T m9hIPd07U'*d)P  U)ߨOѫl? .[nأ+~^N e<$;8IRf1Dn,Bd4z(x H4Jv)Mbw@>pF;ߎ @]urny*79ftVT5o ەeEAnm 4xm]0Xo{vPL 'CF .zV#U n|Vbuڊ6j[(eyXgT Fr$ r򠮸;d%i%WY^;ѧuM߭4%v hւ9g)]!^  X-3(Xq|d=LYWJA ?8D F !&# pwaverays@r@8@UU@q@9@@@@F$6# pwaverays@@33@L@ff@@@3@@f@F%6# pwaverays@@33@L@ff@@@3@@f@F&6# pwaverays@@33@L@ff@@@3@@f@F'6# 'pwaverays@@33@L@ff@@@3@@f@F(6# 1pwaverays@@33@L@ff@@@3@@f@F)6# ;pwaverays@@33@L@ff@@@3@@f@F*6# Epwaverays@@33@L@ff@@@3@@f@F+6# Opwaverays@@33@L@ff@@@3@@f@F,6# Ypwaverays@@33@L@ff@@@3@@f@F-6# cpwaverays@@33@L@ff@@@3@@f@F.6# mpwaverays@@33@L@ff@@@3@@f@F/6# wpwaverays@@33@L@ff@@@3@@f@F06# ʁpwaverays@@33@L@ff@@@3@@f@F16# ʋpwaverays@@33@L@ff@@@3@@f@F26# ʕpwaverays@@33@L@ff@@@3@@f@F36# ʟpwaverays@@33@L@ff@@@3@@f@F46# ʩpwaverays@@33@L@ff@@@3@@f@F56# ʳpwaverays@3@f@ @ @@3@f@@@ @3#@f&@)@,@0@33@f6@9@<@@@3C@fF@I@L@P@3S@fV@Y@\@`@3c@ff@i@l@p@3s@fv@y@|@@3@f@@͌@@3@f@@͜@@3@f@@ͬ@@3@f@@ͼ@@3@f@@@@3@f@@@@3@f@@@@3@f@@@F66# pwaverays@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@?7@ 9v|TGv!?TXL-MBr>#,hP29E<`O\tS 6؆}@6,W >ĎP)@S;A=qO\ :v!?TXvHWSL-؆}MBr>#,hP29E<`O\tS 6"@6,W >ĎP)@S;A=qO\ ;vHWSvj^'L-"MBr>#,hP29E<`O\tS 6Vر\t,W#PB"c"R+o6i{E=_` <vj^'vMۗM-V@6,W >$Pû@Xȭ;cMZ{^OW܌ر\t,W#P 9BƎM}_p345;39O:6 =vMۗv %N-܌@6,W >ĎP_@ ;NL|Sή̀w4=(2qI&RF1s%u2X6{O # >v %vo`\P-w@#0vM&dpJ& R`ɰ9A E;IpL 6m{mS=: *LI,e}aW /:ix^ {1:OI ?vo`\vA]qHw-{o@tjpv[ҲRvHB} vUy`y:HB]<ϱLqLs= 9, TJ qias/4,vۜߐ^x @vAqHv޿hg-jHGA}t@(}uHZg<ј=;GlK-TK_x:Q^xOߝSدp`P آ|ϳzuL򸟮A8&qFi|n|H9dP!ENѩ[SZ}+lH Bv\ݯvdވ-WHiWgV)JY E &e)W836E!EymG,L ZMQ8+~ TPm {{NS6oFYJz-5 (%C'R?4ZeJ7SUO\{]9@M P%4:wžP_z0BT}8]Nڰ)TT|\ Cvdވv@Qg-7H _RͽE6 "/rS_ c.%«ZTyNU\qS=O:E7Pߜ8@]L$?_:g)mxꚜN}-[GDiTG@ Dv@Qvp=S%i-WW`idTESάQu:E7)P8'A5: 3qOΙ qj^jy:Kniy88 \qS=O:E7Pߜ#"@]2Vgs }Tl6AMN~S-o#4*# p Evp=S%v?Ei1k-8W`idTESάQu:E7ȧP#"L:eYuF`U8_MuX`;'mP띰Z$Afp4|;#^M8EScDU(4q,e>~iW7ޠ Fv?Ei1vp@Al-W^xREJV5>XT:l)PYF :1l;NSyTJM4tz O|ZsBE\=q=|>o;'PVAZix7|(oM8IcD(q+>~ieWheGvp@AҾK{4{MJo?k$鱢Ni8?XxrÇ6ꋾ{|v+R  HD F9!@F@.@E@]@]t@@@/@t@@F:@9@r@*@8@G@UU@c@q@@9@r@@@@U@@@F;@y @@l(@5@^C@P@Q^@k@Cy@@6@@(@@@@ @@F<@ @@f&@33@@@L@Y@ff@3s@@͌@@f@3@@@@f@3@F=@ @@f&@33@@@L@Y@ff@3s@@͌@@f@3@@@@f@3@F>@ @@f&@33@@@L@Y@ff@3s@@͌@@f@3@@@@f@3@F?@ @@f&@33@@@L@Y@ff@3s@@͌@@f@3@@@@f@3@F@@ @@f&@33@@@L@Y@ff@3s@@͌@@f@3@@@@f@3@FA@ @@f&@33@@@L@Y@ff@3s@@͌@@f@3@@@@f@3@FB@ @@f&@33@@@L@Y@ff@3s@@͌@@f@3@@@@f@3@FC@ @@f&@33@@@L@Y@ff@3s@@͌@@f@3@@@@f@3@FD@ @@f&@33@@@L@Y@ff@3s@@͌@@f@3@@@@f@3@FE@ @@f&@33@@@L@Y@ff@3s@@͌@@f@3@@@@f@3@FF@! @C@d!@,@7@B@M@ Y@-d@No@oz@@@ӛ@@@8@Y@z@@@@?FG@I<M735`O0Ei=xR)UMtLlQpYL$X5R#4Z z~ #O`TZwW|mZۓa:u*hSI67R]TőDWG=CXg -i)L`uS4ݹ^Ӊ 9JM>_x?aO7733%l9[~MBRaʿ <K_x?aOgզ7733%~MBi0e_&(h( <LgզgŧX 7733%&_vcL52Bt= >MgŧX o̮tR7733%L:s:DUh771 @No̮tRo !7733%DVt|QEl~ְ mOo !oS)27733%QF^9ZUܨEL9^#P)wP](QB5]M OP>/yV lPoS)o֒;V37733%]](Y yjX ~+OhTz_f(Yxsc؋Ҵ mQo֒;VoVg_17733%hz~= Ƴp,9MEPXZxuIc#*T2е$A77Ac߿i pRoVg_w>T47733%u*A lhZsc؋ҴR}޶q4-|HۨP6jPX[ pSw>Tw&(47733%ϩw|x|o[8$m(5,{ -USDu$qT-|PۨP6jPX[ pTw&(we47733%U:xJ|[8(m(5,{ -ӨqSs݁ l46ȍ"*/Px۠ oUwewƜ47733%Өq߹nچ6mw]Fh|cV<[,SoM0p7)OΧ">,8#@ mVwƜwc)$X37733%,7qin8jgSNzC0aSjpX8 2eN&ә&T vWwc)$Xw&0Bp;7733%0a8{rF©atz\U,ive( 6@3RI}] K;A)fzGSzx YXw&0Bpwp@P,7733%3︼{r@=t؄:_՗UNR=[^ LYwr@PwDX"7733%:_w^R`ʾSlnE=Oo MZwDXK"7733%ʾ7X"'sԆ?Iቯ8&[K73%CO ל !\D ?2-_root.main.coreclip.shadows.pshadow@0#FIJ@r@8@UU@q@9@@@@K@@33@L@ff@@@3@@f@L@@33@L@ff@@@3@@f@M@@33@L@ff@@@3@@f@N@@33@L@ff@@@3@@f@O@@33@L@ff@@@3@@f@P@@33@L@ff@@@3@@f@Q@@33@L@ff@@@3@@f@R@@33@L@ff@@@3@@f@S@@33@L@ff@@@3@@f@T@@33@L@ff@@@3@@f@U@@33@L@ff@@@3@@f@V@@33@L@ff@@@3@@f@W@@33@L@ff@@@3@@f@X@@33@L@ff@@@3@@f@Y@@33@L@ff@@@3@@f@Z@@33@L@ff@@@3@@f@??G_rootstandalonemainSalpha_root.main.coreclip.shadows.pshadow100N INN I @#FI[@ ]D @@@@@@@@@?0waveswaves165  @$ @#6\w waves@?0waveswaves155  @$ @#@?0waveswaves145  @$ @#@?0waveswaves135 @$ @#@?0waveswaves125 @$ @#@?0waveswaves115 @$ @#@?/waveswaves15 @$ @#@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@?@^w~737356e>~rN8kSD"2A!i*iIjD'" cO[iFϔJ0|GM F ,xZyl_x?aO7733%l9[~MBRaʿ <`_x?aOgզ7733%~MBi0e_&(h( <agզgŧX 7733%&_vcL52Bt= >bgŧX o̮tR7733%L:s:DUh771 @co̮tRoА%!7733%DVt|QEm?~* mdoА%!oS)27733%QFaj~IK5W2AFQ@](QB5]M OP>/yV leoS)o֒;V37733%]](Y yjX ~+OhTz_f(Yxsc؋Ҵ mfo֒;VoVg_17733%hz~= Ƴp,9MEPXZxuIc#*T2е$A77Ac߿i pgoVg_w>T47733%u*A lhZsc؋ҴR}޶q4-|HۨP6jPX[ phw>Tw&(47733%ϩw|x|o[8$m(5,{ -USDu$qT-|PۨP6jPX[ oiw&(w247733%U:xJ|[8(m(5,{ -ӨqSs݁ l46ȍE䱢/ njw2w~ֱ37733%Өq߹nچ6mw]Fg"Xzŀ߷CSoM0p7)OΧ">,8#@ nkw~ֱw .37733%߷C7qin8jgSNzC߷CSoM0p7+TP e!Aw-G6lw .73%߷C7qin8jA(j2 m D ?2-_root.main.coreclip.shadows.sshadow@0#@@@@@@@@@F^_@y @@l(@5@^C@P@Q^@k@Cy@@6@@(@@@@ @@`@ @@f&@33@@@L@Y@ff@3s@@͌@@f@3@@@@f@3@a@ @@f&@33@@@L@Y@ff@3s@@͌@@f@3@@@@f@3@?U_root standaloneNI*&_root.main.coreclip.labels@100#b@ @@f&@33@@@L@Y@ff@3s@@͌@@f@3@@@@f@3@c@ @@f&@33@@@L@Y@ff@3s@@͌@@f@3@@@@f@3@d@ @@f&@33@@@L@Y@ff@3s@@͌@@f@3@@@@f@3@e@ @@f&@33@@@L@Y@ff@3s@@͌@@f@3@@@@f@3@f@ @@f&@33@@@L@Y@ff@3s@@͌@@f@3@@@@f@3@g@ @@f&@33@@@L@Y@ff@3s@@͌@@f@3@@@@f@3@h@ @@f&@33@@@L@Y@ff@3s@@͌@@f@3@@@@f@3@i@ @@f&@33@@@L@Y@ff@3s@@͌@@f@3@@@@f@3@j@ @@f&@33@@@L@Y@ff@3s@@͌@@f@3@@@@f@3@k@ @@f&@33@@@L@Y@ff@3s@@͌@@f@3@@@@f@3@?G_rootstandalonemainPalpha_root.main.coreclip.shadows.sshadow100N INN I @#l@ 1nD ?2SwavesSwaves155 @$ @#.mѴSwaves@@?2SwavesSwaves145 @$ @#@@?2SwavesSwaves135 @$ @#@@?2SwavesSwaves125 @$ @#@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@?@:oD$ 5M(Kݠ,( fJo2`h pD o@ qD p@@ i@4@ i@h@ i@@ i@@ i@p@ i@@ i@@ i@\@ @ i@4@ i@h@ i@@ i@@ i@p@ i@@ i@@ i@\@ @ i@4@ i@h@ i@@ i@@ i@p@ i@@ i@@ i@\@ @ i@4@ i@h@ i@@ i@@ i@p@ i@@ i@@ i@\@ @ i@4@ i@h@ i@@ i@@ i@p@ i@@ i@@ i@\@ @ i@4@ i@h@ i@@ i@@ i@p@ i@@ i@@ i@\@ @ i@4@ i@h@ i@@ i@@ i@p@ i@@ i@@ i@\@ @ i@4@ i@h@ i@@ i@@ i@p@ i@@ i@@ i@\@ @ i@4@ i@h@ i@@ i@@ i@p@ i@@ i@@ i@\@ @ i@4@ i@h@ i@@ i@@ i@p@ i@@ i@@ i@\@ @ i@4@ i@h@ i@@ i@@ i@p@ i@@ i@@ i@\@ @ i@4@ i@h@ i@@ i@@ i@p@ i@@ i@@ i@\@ @ i@4@ i@h@ i@@ i@@ i@p@ i@@ i@@ i@\@ @ i@4@ i@h@ i@@ i@@ i@p@ i@@ i@@ i@\@ @ i@4@ i@h@ i@@ i@@ i@p@ i@@ i@@ i@\@ @ i@4@ i@h@ i@@ i@@ i@p@ i@@ i@@ i@\@ @ i@4@ i@h@ i@@ i@@ i@p@ i@@ i@@ i@\@ @ i@4@ i@h@ i@@ i@@ i@p@ i@@ i@@ i@\@ @ i@4@ i@h@ i@@ i@@ i@p@ i@@ i@@ i@\@ @ i@4@ i@h@ i@@ i@@ i@@ i@h@ i@4@ @rpFqm5gep 3쓀 ) Nb YGbn#^|vyY3FS$S(/81OAR@@$8gNgͥ5iOfB/\G}pp䈔4Rnځ";$JORsѷ($&@4NdVYWܘp` Mٷo4,5gZW6>e@c9.#`#( l:b@9of=ێ}v{G0ERdV[Àh'0a p iN5KcZ5ٗUf;ǘhjFEB@pB8,ǀ5hnv{MArhlR Sh/;v<Zo#(n&]I]pͪS藡n#04.]/o5Kw9hfLZ11&vC@6d#.R7K`I4r( KN.:e/): .G4n|Ij1.]M( 0Jv=ҳ@〥×S ݱ &5XH5djwjP D "Bp-w΄6W58eSZ bj"2u[stV~tkH%hTtO78 !RV\¦۹5G`/jn2wX{IWa&*]噍/WKMD %3M(6vC4]ڸEv285c*.\ @ Z]% ZeӨ @`/RPP'ӕ7n18W)@2:QcQKrt}w ( y5cjyR, (AhѺG>Eu;w5G-?}{襹ѺG3 D+8|ѻqTՐ%ZYO U.%`iN`  !F&[wlO0f~t0*]3%5FK|ʭ62L50?&q6hH*VaZTUHK9X `~t~Z 9aWJ a6RུnϾQ]@Pᄥ?)zF&L\5TU5JTAO_7 4_%btQl&S% ]rO4)-•@K|zkL՝ +.NC*t(Hc!\Qorp)-Yu%L-+ҍz5crwU{ v$xR@(221'G@%@\ <ϼS}Z!+kgʲz!rTimes New Roman OPSTadeilmpst,s`  r s䓕i6F !t_n` (r(time /ug!7 r(TextField5minutes FvD ?M _rootmainSalphaelapsedcoreclipPwavefrontwavesSwavefrontSwavestimeNN I<NNNN" ?%u 7NNNN" ?%u  sAvt@ƀ Fh AxܘȴܸȼܠܘČ3~hm@ƀ Fh aI3 ˛2/nPܙ2f@(hЮ FhIČx D w]ww ww,w<wKx yW0@ zXpu` {_ |^m }d~[FeI@7oaFF!5v;>hॸiZz 1p&`>) q%zV&`>'  FFy%zV -D Zng@?tWuHfff-hdh-iWyaz8*wo[kheDI~$80o,ul|SI8B5-#!yI'pPu"@uuVm|fP5cZ+|k ºe]頢AjlchyJ VwP9^  {  5 D H < Nn5DJ60&͂^f'za~)7/r\k 5/le>` .Ix[3/>L8?5"'fZ5,Lebgfka5dvojЭ5gf@mO,,i` ;I@p7jVc]U ]XbUtAk??DZZ ǒx*8N֋[h5eyW7-Ö~Nseq8 G@5herw+mb- 1Z6U!RSИA7gyyUG6P\ո@&'dmS'SdLzw15g:ys'^dC `C Tj y1vzL JE*TMJʓj_{د"Xpetv)Wb P``%H}xL#Lu1r25+3FJih@5J]᭸jVj;5Ta'cS؝WSnx, 5g-,ZI 0!!̄02L+0N`MG{`Rb9S#lds+ӛWRZ.=6z~eX5g^ܳ(@`1-SMw*JC0- !L~0/丝?6a5u  a;?2-c3t &,G(yRNW ҘH` M}IlT5`ji'ݞH9W>[v( :c[. d5ge*irVd1bC@&^@Li@ (&$И=Yڗ-:ʘ%fXRh P+@pJ zM,yk*P D%HQH @ *WVmMk5bf1NUJ5f(_JZ AYN#JxsaWMT6NVE>nSPe? J`*QHѺ\蛖@&R` +ɐo&H;'5F|fݤě~ V-23HyŻ#W"@5fvn[w[O4( K%N.P 2fB$/P -R%bͱAG-#DT3cJUڅ*EHG(.Ro~@m5hfܶlrIQf]Fmc40 @tf837D[hMmK6 ŕsU(L3pYg̻h5g"ܳr ^Rc<0(lxrڅ+X+GUcهSA\*ባvp^q 婀5ix$-5n-nKHʸ5EgSv'i߲9nn 5cV-#a5hWvU#nZGʡ5l"V-.O>Yd9S-#Isinx%|5hR۷d}#fGLlr>rnmV.tj 7MZ]5qm WkTͭT?8bb&2)̢`V5gv}nQ8Pmn`Jk+E6TK ^A@7()V-#EvJS@5gBfܫ`[-fwhRdOP48'fpk=iq|JrFȴ>+ ʯ\r/l.Էw&f\\@HABS(e _Db04`|]j5jFZfA)Xi ɯy/f6xZye"aU|f żۆYa5j;rR=b 'xOc^05i2yalr[ݚn+W2g٩A*5fNT@Jh*RBD|,TKHThM{( $JKݒړ)|;if E[n.1j ȀbCن%hNTi'fQ@Eտ6xv))+D0C5djW7,ܰ=CmHta. Mxc6L e&3!J<oY slC: /g@*o;}5g‘Vf`e.8Sq`WLb70ƻ@A|-2, f1iUlT&)O[6Za5DEJ&ޛW2X@+*T/Dt2nRٱ i&y_^im&jDIH!4X&W,/V@5bQ&x\݊nbfa?VD% (ۨuʃSUvkZ7y 5X5bzPy%vYV&a"Cb\xe eSIx"ئ{ @5bzP7-Zal-llS5)wuMHZ-YFîlHo5brV7-#Z5k*,[[6)k)@JM))%i@SMnP5bV)%Ipo"`Ob(lfʭ&3*cLF2xY`5bVS&:oPDJh* M^Olk,K}],Ā )7-Q5Cb$0 sf,wS:m< @4̦3fC92.+#$?Lw.Q͊At48R܀5bZQe;a&Rhd@B9Ɛ&@LG n$9d"Z`.8P=nZC [`bTvWΘ4V` lkNX*6L5gV7 .KhPQ^Zϻ/X`Jr [` {7; fg+3[7%rU s'&˖%)̀@5bRTe?Mn@U©-I%%)lXs‹lSr݅5e^HKm@d.=3KRLH%!gN}QT?)cJneQ<4VZ5V|QzWgp߶i}lۂ]YB,v@5d"Q)Sy@& .2-gZCSK<^2K_gl_ll!nvenv5gPņ͔KRctl.̾,K05 O00(̢Q+)ŠJ=r>ۀ75gt'Yϛ^݅#}iڼ\5kr'EǗ8>{vx.."jf365gd97q a+.@ko^b56"|l0MrZ/Z5K4g6'ٷl^qX_]fߊ>>Arial ()-./0123456789ABCDEFILMOPSUVZacdefhiklmnopqrstuvwyzCp訁, hi}zTz Tz}zzzTzzz "D @?tW}THfff-hdh1VȒ/>{W'28ֶC~U-;KyC$:⭡^veҞ麧 ~_i lHƀވ6n9u#S=@:nq%&|8ّ\/N(TA| fP5cZ+|k ºe]頢ܠCp言, zhm}zTz Tz}zzzTzzz "D @ ED .i@pshadow.}i@sshadow@ D ?B _rootmainSalphaswavefront0sraysPalphapwavefrontrays100NN I @# @#NN I' @# @# @ #BͳNh!HT@ IlYA &8@rays. H i@srays&]ppwavefront&n swavefront&qO(flashervɱhRN!<.F0i@labels+W &/ 8shadows@? + xԜouRf%"u%K$GE]iIudu{HZMREfQj1鰭i`[nC0 붟Sx=y"}rH))χsY/x;O-18'~_D`'GU1^:(S~Oi~M x}?xC|KbXL|aF -QI__?q#%~7xcBdvbŸy(˗/ bjuyDbd%{[Lŕ~!|ׯvQ]aJP_}"^Zio~h?Ѿ'Z1ɈorOOR쿵!ӏgbDظxGWg tɎHK{pBd."s}> KY 8gHЋMJ$<%Z(sG@{onι'#el&zpDOy \FAdYz$8מ0ŋ,N-7AQP=3< FX@$dKt6G'rdk:f ;;***"t gc ]x|}*y^:LBc޾j8R.{fz|lyvvaC_4ze1xҘNDYϣSnB0 >1X <Ǩ<[ }b`(5-MNBGcՇILAi7a2P@on4KKw8hP2n8̤ G̜*d gWYysq1>,@ 9< $'LCt,98pC zm4KR9&gUrusFH9]% T#zI/Q,sa#iW]5\ vX"h?':)46ZNɴD\P4+yBgjcil;{Lx nbS_OG2Okim@D-94$} +4"7 ʹAIr` Wkh5Bns@dP"dMMTj~E%۽QV "-{&9cٻ-Hd}ʷ͓2Yh*BE 76Q [r㭸U͕CH/?U4Y ;Ζ*5r馈qizg *:{_xnr6Z9tcr--֒*idVrp0?uP* je(<u$H9HjsN; ևbN٢ `.O0/O=RY׵ס&5dpݧ66R) l4܎,=IDJ2jshZtf |S<hOz .I3`{<ygW^F#zxk(EЌá'ED[7"+C.MNbH?$K[hA2bb1aMO ~{mO:pDQ9]qGCK^Cm*tfPY"<*lru5)UmoybnQbLF :!f&lPCEsĝӯ L739xtzZ3\Ϣy&` d6d摛p[P:@d'ݫpo+-/9\^xhqQAZق™ +!^'%DFg:h{ʕ n .9ģh*ރ'G'c߶zpppБJxM7 Q;##RXL3ֹMsh4GG|yi_{~\py[DzDl[ģ6"{(:xSy ]*@T<~kkrKK9|w76]aRacch:;;waZo.kÓ.GS?22|<}< y='©YS@) QpgBLֺ/]J In׋~: (TpIau9N\g-SZy;==>>~Sl[9A I}yYWiWWɖJ,}3ȳ[\: Z^m|EL)6{ae0q~|vyy ԐCvtMU<xP'x^x `y^[a;χ8|jiy 0 pQ3;w@-i &XWҶǩiwGUCGV꼅OdHHDU <Q9+++gKݪZ988F&+T 5yg֑p#PhZH5$]IlNiS;8t'RffwgmHho$23ۻ/^,:'Vב舭WWDH$3/On OMko 7 heqqqӿo<{33j%̹k Ǐ yd?LRx$2``ES3<,y>Л͕|= w #! LT8<<keF=jVB+s9ߦ9=x: ig>.ݤRT$Z o؈i4''0WMO}y/Q#jw= Y$%E$Z$Hy(2+zƍW "M< & -DNxd%v¼T`>%Zr"6xqWɼ Ba1%_ (GIJAx&Phmy\ni~>9KʓCC>ܾwT6c5kWD ֽ{^r-"1|r FڐrF# *$Я$@v 0~~M@CPNEY&MPx*άMO7}#ccyExDFwt[?>|x*Nv L*w9^htOVC gM5+\vC'oq7UA!MO< ]Uc_v 1DR?͕Sӑ`x  8 6.P)x?4Tyq8v8F￶;t3ʓy,!onI O&?3r~۷F,zgm0VEИhk{Y֦"PWu9w[ߓܛvxa菈Bd BF2rkcg=IvUɠ!xYcxJ[>#.cfC#9DvjI B4:7Ԏi(X5<'qФG%#v:DsK2sCƏ>ezjwF_Ǿ i5F@&YSa0MsI+`x$χ!G"8skgtT5M}i^O}x*aXţtR>ţ#7cnU^5ۛ7Wފn++Oo౐ý22¥Ar-٭cDz6#f1u&8rO 4Ƕω:j\Y+쯥c<(N'{dIN#>- SςIՓ$ȇG*'#NacV6ڝP\ DVjNփzbGd| ";O^ԃr*† $8aN6}|6ō:u*98qՓZxRPW{ p53:mՓV%G0,y'U6O..~欵b <=dR|/ Zlj*tVBFX[<Hcd'џj~b&cE~`1<؃4*d0@ g4nxo?"Lm|kKY7Kz/w&VZ](acZ;N_^dRt F ςk68Ȩӣ04Й$XXHb~G|ǍQK^G}a#8F,0p KB%AlˎU@V$vc&<g)^&NDHD.b4is]5%vZމI9$UibB"ҽOBSm1J:x_ []MX]<$jD 3*GX\o<@hN>qUc#2p(BVli(rp?-X΂Qf&_KKkLpB@b( jи7i4#|ܧAiZ_-cQSiZ-@gIzI謳~C̫4i4 8.9jk_ 'yl48s[9 PFqif҈H;p d%i@TP&-hBC@i&p_ 'II=*|kPDmƺsӀޏ<}("@&i]AHyUZ+0׮$ J}r)` q@3Dv8 ?Xv+AS22;բA6$WM\4%WU\4%W[d8=% 3t%JrHտ6mX<A@A@ b ENJx 3D ?H Palpha< Salpha< full<tripped< ɷm ה6@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@?l._rootstandalone_root.main.mainstart1000NI @# @#?t2_rootstandalone_root.main.pswavebuttons1000N I @# @#?6:=ӯ&pswavebuttons6A54&mainstart@?this tripped1O@6 V%g(coreclip91@9"ר@9k @9 @9U@9@9@9ZK@9Z@?l._rootstandalone_root.main.mainstart1000NI @# @#?t2_rootstandalone_root.main.pswavebuttons1000N I @# @#?9Z@@ 9:A?1@6mainqx ܀fX&SB!=р/6Br%ʴhGjd;e_:w\עs;^tlPWM ݛ<")+pC ;wP*(sidetext

M1iLZ4gh-t`M1iLZf Lp-tŠM1Ld,g|8hNv._root.sidescroll.downscriptX_root.sidescroll.downscriptM1iLZ4ŧiLq- `M1iLZf4ŧiLq- `%M1iLZ*YUpS4)^S]`r,_root.sidescroll.upscriptX_root.sidescroll.upscript D ?@?]#_rootsidescrollsidetextscrollNNNNN O@?@ D ?@?]#_rootsidescrollsidetextscrollNNNNNGO@?@ gD kq=M@#B&8upscript&Rdownscript@6D@qsidescroll7p0f59DS6',M #}?sM"  N2LM{Lh}G(  SyLdpG  thisspinnerOSyL`5h}G%b' ,EE=Jpţ5N%b8=  ,i2u>f@Š^9A%b @ ,Tٸ Š^%~?h  P "@a˅,O,,Üg3] 9@TjIJ*@@CMN??_rootsidescrollsidetextSeismic Waves
We have very little direct knowledge of the earth's interior - it's just too remote and difficult to get to in person. Occasionally, continental collisions or explosive volcanic eruptions bring up mantle rocks from hundreds of kilometers deep. The deepest hole ever drilled (in northern Russia) is about 13 kilometers deep, or 0.2% of the way to the center of the earth. Almost everything that is known about the interior of the earth has been determined by observing seismic waves produced during earthquakes.
* Make your own: Click the button here to create a small earthquake. Pressing the button initiates motion along a fault - the friction of the two blocks of earth as they move causes vibrations in the rock, and these vibrations are the seismic waves that travel out in all directions through the earth and are recorded worldwide by sensitive seismometers.scroll_rootNONNO{x ܀fX&SB!=р/6Br%ʴhGjdC;e_:w\עs;^tlPWM ݛ<")+sChw\:  faultMb3 +`p  QAe x$Ią 2OH"?>C   %# , #&')*)-0-(0%()(C   ((((((((((((((((((((((((((((((((((((((((((((((((((( }!1AQa"q2#BR$3br %&'()*456789:CDEFGHIJSTUVWXYZcdefghijstuvwxyz w!1AQaq"2B #3Rbr $4%&'()*56789:CDEFGHIJSTUVWXYZcdefghijstuvwxyzٿJFIF22" ?&]G?yVRߍ N:_8|hna\ ]A#|A܃SA5Rb|~M?n|io#=IB:qԌkD7hqEW(I7n)ܒ:TI*8R01iyS[?$w4cW雼XABPtMO߃، j)Y⧌|ɡ 4qPWeYȐ6 gidT7dnʢ3/T|iXU,ɫ9dfG+Ӳ2SLvs2i`N럑2&nު05IY> SLj!&Fo} @ :f< ɂrNI}O t^2(Ȓ@3 ܌PFl-c/ЊK'N\榕Ŋp:4j庌㈬'g5RH NqK ”rtj庌㈬4K[I&3tFv3Niv8+@Rs"\J㎗\Q+\QqY+ ㎗\Q+q͞WR—@V1c3W-`Gb?iYdpMY+Jd]%!sT+HԄ}sU-Ԁ /2+E"-TR;5RH N"fyn'Hxiy5"Ԯs28R&,@Ku ):CKvI%w-Ԁ /3X"}of s#=y*_&Һ"He[I$Qg+H^[I(#;[6òPV e!p![6C:ЅDg;}b">#=yn'Hx #tn'HxHF*D+*}@ %Gn-Ŷ<ѓWoc-:,T H{bbyPءX϶(` f]SbaSءXD/UYms6bcL>ءZ,_{dŀJFIF((" ?-'=i9u+ )eGf~ǹq쭵Q!v+QRtpNy@cT#Nzb`2 øag$uG2308XSK!vf3f# 0f3fȂ41f3f"f3fЃ!f3fW/"aZf3f2f3fZPf3fАf3fȾf3fհf3fnf3ff3fհf3fUpf3f߰f3fɮf3fɚf3fɚf3ff3fʩ0f3ff3fvf3f:f3fPf3f@p6CȂ.e'Pf3fį@f3fd@f3f@f3fT@f3f|@f3f4-@f3ff f3fPf3fzf3fi@f3fPf3fȂ2Tf3fNf3fʲf3fԠ@f3fˢ!f3fJf3fLPf3f[Pf3fUf3fȂ3f3fBf3fJKf3fJVPf3fY]f3fϲ]f3fϞnf3fNpf3f s7C`xHBgD ֹߜAnp@l^-(&{Qv -ѯx1&I@OXAq6gJL9 ԗRR7Ȇ ,BDQiP y>{]>5%TT!/9mt0 ֳw[. Yu2 *"PF-/Ƭ gz*x/#LB1NYFڂg*)kuAw` /SA,H(8yu)"D4p3B$Zp>qKf[Ie㎗XFgb|B),9sbcTR<4ja5/1n'8+iyKu ):CVTR<4Ȭ-w4L=uBH :sRմv듷 <=p /3n'Hx Ӡ ^ϗE%.sN6FŎ "y,g3Rm1iޅ*(Bɭ!᥄xhD ӀD^@BA;"1#.l ␬.I-`dHcey i(ãn'8+)RȑFKu)9Y^ZD0>[I81 A9‭k#A9Q]I8"aSi"L=j dV32$QF1F HK!TQq":1sC)Il͜ҹ>* ["EtcQ-`E]8c$Hc%㈫v8ȑFi<8"XKpZ_Ku)9(Åe ㌉aь}DQ+-IgdHc%Y}`[I8ȑF gdHc%YZ@[I8ȑF }wO(hE%'6rJgce F$QF1F NqVV70Rs2$QF1.&$Hc%"(10Rs2$Q"M庌㌉aь}@))t3"aь}DQqD%㌉aь}@4Q}yCB)-9zW VqL":10Rs#n'8"EtcP;=zB<8#.V~C0Rs2$QF1[ȤIv hVzŌc%㌉aτ %d4 t4-AW!qAhE.gI4a_Y .Ge=DtΒ}_z`ןs a۠,pZ]<:ך4ZeH&ftt^q)( `DK۠ vvc{] cIp. 5CydLזך,vݮH  r$(kF1E YhfLSI@- dT;[FM01E YhИh=n9@P-KmY;dNND2WC Aa +J)ZVVEUzdX1E Yh LSI@- dT;[FM0Yl!?3fff-ua ?C|6==mpH}P{t(edC6ŮG*( NH~!ukxHXffffff%9@[9Sy86hY@$j\ ɘ@[9Sy86hY@$j\ ɘz_kl &+$f2f2X3+ה-u@-yCHn_kl &+$f2f2X3+ה-u@-yCHnRukxHfff%ˀ:ܠf75jk6i3`j^\ 8<D F@W@@ @[@@ @_@"@ '@d+@/@4@h8@<@A@lE@I@N@qR@V@[@u_@c@#h@yl@p@'u@~y@}@+@@ي@0@@ݗ@4@@@8@@@=@@@A@@@E@@@J@@@N@@@R@@@1E Yh3LSI@- dT;[FM0 oE YhE Yh;3-J'k`H "i܀7jrZI(%(*vȝ#`&rݩjr$[l oE YhE Yh;3-J'k`H "i܀7jrZI(%(*vȝ#`&rݩjr$[l oE YhE Yh;-J'k`H "i܀7jrZI(%(*vȝ#`&rݩjr$[l oE YhE Yh;-J'k`H "i܀7jrZI(%(*vȝ#`&rݩjr$[l oE YhE Yh;3-J'k`H "i܀7jrZI(%(*vȝ#`&rݩjr$[l oE YhE Yh;33-J'k`H "i܀7jrZI(%(*vȝ#`&rݩjr$[l1E Yh3LSI@- dT;[FM0 {FD ?@@8'@6hwaveaction@@?waveactionaction1@$@@?waveactionaction1@$@@?waveactionaction1@$@@@?waveactionaction4@$@@?waveactionaction5@$$@%I@m@I@۶@n@@ @@@`@@@@@@I@$@6@%I@n[@m@@I@@۶@%@n@@@% @I@n@$@-@6@@@%I@IR@n[@d@m@v@@%@I@n@@@۶@@%@I@n@@@@@ FFD ?}ؿ.+i@focus@ +i@D@ +i@@ +i@@ +i@@ +i@T@ +i@@ +i@@ +i@$@ +i@h@ +i@@ +i@@ +i@4@ +i@x@ +i@@?focus +@{!*@xhȇ+@v! @s+@q""@n`Y@l"|+@i܇zZ&@g#wd+@dXuZ@+@@@+@@+@@@+@@+@@+@@@+@@+@@@+@@+@@+@@@+@@+@@@+@@+@@+@@@@@@@?@6Pxfault?  " 2LM{LR   thisspinnerOSyL`55hSt P "@ x՘YȲYY"ԲȲ@MOP??i'_rootsidescrollsidetextP-waves and S-waves
During an earthquake, some of the rocks near the focus are compressed. Because rocks are elastic, they then expand momentarily beyond their original volume, compressing the adjacent rocks. This wave of compression and expansion travels away from the focus of the earthquake in all directions.
* Press the buttons: Primary waves, or P-waves (also described as compressional waves), are the fastest seismic waves, traveling through the crust at 6 to 7 km per second. Secondary waves, or S-waves (also described as shear waves), travel away from the earthquake in all directions, just as P-waves do. However, as they move through the rock, they cause a snakelike side-to-side vibration. The rocks move perpendicular to the direction that the wave is traveling. S-waves travel more slowly than P-waves, so they arrive later at the seismometers (and that's why they are called "secondary" waves).
* Strength of materials: Rocks, liquids, and gases all have compressive strength: they resist being compressed. It is this property of having compressive strength that allows P-waves to travel through them. For example, sound waves that travel through the air to your eardrums are simply P-waves. However, only solids have "shear" strength -liquids and gases have no resistance to a shearing motion. Because of this, S-waves only travel through solids (such as rocks) and are absorbed by liquids and gases -S-waves can't pass through liquid or gaseous materials. We do not hear S-waves with our ears because they cannot travel through air. As we will see soon, this difference in properties between rock and liquids enables us to use seismic P-waves and S-waves to tell some important properties about the earth's interior.scroll_rootNONNO2pNf;%mpY&Ζ xG#R?*܀M@8*` Lmٶmd]b'ff-f7wQovs`\ p Ld]bmٹ'ff-s`_¨pE5fBTH Mmٹmٶm'ff-fЬ*3Rf7#FEۘ?!mٶmff7y" ,D ?@r@8@UU@q@9@@@@@@33@L@ff@@@3@@f@@@33@L@ff@@@3@@f@@?gt!pf%`kzY:̙3f35bXM cc5 3'ظL2zx)p̙3f35Hwb5|63X؀HL c2} '8>ŀ̙3f35b+'8Lb5|63X؀HL c2} +]4uf^UᆲjYLŒ@y`@DTΫ5@{%!@3J@wj"*~@*edu0@TW*}@?gt!pf%ozY:̙3f3p̙3f3ŀ̙3f3!5+}=<` S&B` \&pOO`3HXcb!0}.8'̞0|)~d OOp>k ,lfA>#gk|1<%֠6Μw0 5D UTi@4@ ZTi@@ _/Ti@@ cSi@L@ hoS@mR@rR@wQ@}/Q@B@B@}@@#>@.=<@8:@B8@M=6@W4@a2@l]0@v0@4@@+@@t@U4@i@~@&@PQ@y@Q@Ѡ@Q@`@IQ@@rQ @@P@@4(@(@ @t@4@@]@ =i@T@ i@@ i@@ i@T@ |i@@? \i@@ 9 UD & sbond1&Dsbond2&Zsbond3&Ψsbond4& 8sbond5& ݚsbond6& ZFsbond7&sbond8&^sbond9&sbond10&psbond11&sbond12voh_ݢ^  w("=&#@wCsarrow@#@wC@#@wC}@#@wCE@#@wC @?-_rootsandpswaveclipsbond1sbond2sbond3NNN NNN NNN #@wBՀ@voN#@wC6&swavefront@?:swavefrontswavefront165 @$ @#vo3#@wC3@?:swavefrontswavefront255 @$ @#vo#@wCa@?:swavefrontswavefront345 @$ @#vn#@wC@vn䀎#@wC@vn#@wC@vn@vn@?-_rootsandpswaveclipsbond4sbond5sbond6NNN NNN NNN vnz@vn_B@vn_@vn_܄@vnـ_&@vn_@vo _f@vo!_@vo9_ڨ@voP_J@?-_rootsandpswaveclipsbond7sbond8sbond9NNN NNN NNN voh_@vo_J^`@vo_ڨ^Π@vo_^@vo_f^@vo؀_ƇoP@vo_&m@v`_܄lp@v`_j@v`2_Bi@?0_rootsandpswaveclipsbond10sbond11sbond12NNN NNN NNN v`H_ݢh@v`2_i u@v`_Zj t@v`_޸lp r@vo_m q@vo؀_poP o@vo_̇^ m@vo_(^ lp@vo_^Π j@vo_^` i`@voh_>^  g@_^ i`"=F@_^堇 j"<@_(^뀇 lp"<@_̇^@ m"<0@_p^ o";@_^ q";x@_޸^ r";@_Z^` t":@_^  u":b@_ݢ^ w(":@^  x":b@^` y":@^ {8";@^ |";x@^ }";@^@ H"<0@^뀇 @"<@^堇 B"<@^ C`"=F@^  D"=@ C`"=@ B">V@ @">@ H"?@ }"?b@ |"?@ {8" @ y" n@ x" @ w("!"@" @" n@" @"?@"?b@"?@">@">V@"=@?"_rootsandpN "=@ D ?7^@2-3 4fz5k23 7:@25?6Lpwaveclip2-f 5k23 @?6@swaveclip 23  5f @6NnR"@sandpAh P "@pY"ԲȲYÔYxY"ԲȲ@MN??y 7 _rootsidescrollsidetextCrust
The crust is the outermost layer of the earth. It is composed of a mixture of silicate-rich igneous rocks, with some metamorphic and sedimentary rocks. The crust is just a thin rind on the outside of the earth, as thin as the width of a chalk circle is to the size of a large circle drawn on a classroom chalkboard.
*Oceanic crust is thin (about 8 kilometers thick) and forms at divergent ocean ridges. Ocean crust consists primarily of igneous rocks (mafic in composition), with gabbro intrusive rocks in the lower 6 km and extrusive pillow basalts for the upper 2 km, and it is overlain by a thin veneer of deep-sea sediments (typically a few hundred meters or less). Locally, the crust is metamorphosed by high-temperature fluids (hydrothermal metamorphism), producing greenschist and serpentinite. Because ocean crust forms at ocean ridges and is normally subducted within a few hundred million years, the earth's oceans contain no oceanic crust older than 200 Ma.
*Continental crust is thicker than oceanic crust, ranging from 70 kilometers thick in mountain belts to about 20 kilometers thick in rift zones. Continental crust is a mixture of igneous, metamorphic, and sedimentary rocks that is highly variable in age and composition. The upper continental crust generally consists of a blanket of sedimentary rock covering a mixture of basalt, andesite, granitic intrusions, and metamorphic rocks, and is fairly silica rich in average composition (felsic to intermediate). The lower continental crust is a mixture of mostly intermediate to mafic intrusive igneous rocks and metamorphic equivalents.
*How do we know? Information on the composition of the deep crust comes from many sources:
1) Volcanic rocks: Rising magma commonly brings pieces of the deeper crust (and mantle) up to the surface without melting them.
2) Faults: During mountain building, faults commonly act to bring deeper portions of the crust (and, rarely, mantle) up to the surface.
3) Erosion: Old mountains, when eroded away after tens of millions of years, gradually expose rocks from deeper and deeper sections of the mountain core.
4) Seismic waves: Sensitive seismometers can tell us the velocity at which P-waves and S-waves travel through different parts of the crust. Because different rocks have different seismic properties, this information helps us confirm that the deeper continental crust is largely silica poor and metamorphosed, in contrast with the more variable upper continental crust.scroll_rootNONNO{x ܀fX&SB!=р/6Br%ʴhGjdC;e_:w\עs;^tlPWM ݛ<")+sChw\TJFIF22" ?a!:LvG$yi_2s>"ۘQƽ۶R$i"+ d*V@5^ d)!z$ʥ4qbMI ߘ)Fb4D#`2;sqE]&+ۅ֢8%r8Sױ:w#p*?+ )#B&:"U ~f34 EDU|nh|Ny3,aiF=9[rl8SҠ Ko9ޕ FNtbYN4I elEF C-(Ѝ{gQ Jwn=7T֛vI!a# ki- 1J̠ N$( ֙ΎF<R_ʥd==TڒB"\;OLM"!@kFO֢?E+U@`$9EbgBi)UVnؼ*O"QU"ETٿJFIF22" ?<(G(g ". ^wBSZ0Y wZ[K]ڶE`1TTkɲBu`etgҚ1W2JW158e?.epdQ]|كHgYwKS/oQхƣp1Eif͏cENh6ff N @\L>P#8TIc]GjDo.UGryS-bc;U'ۘm^u,#O1TGxhv)M^3odQˌcҫIp7bkJffFvX3 S% 0i3/"tzQXR'ˎrhOvF̾K*~<5NHKdL gG$VS@w˓UTX݌c p{Wkjs~f?݅ieNƘ2-A# sY)ȹS*QО5m|N$<_'k(}H=? ,jO!['1=31rNM@_N8qE+]kr3 xmC3 }[$AA1[m`O6ofHh=M6k+p-$X qM3M7\fX۷SRO# ҝ<1Eu[=)7LLaSi~e^}PԛqA\ؼTP#\V1y>QqZ&88?* 7l=$k]APK+ۓ n8Y\&5qAP!xCb ܗD@\s>)z O>ڧ8jK/9@zAR!0qh--V GQS/(|#tZ䓅4Q@/|}袂G-? 9,zEDʫp:zQE?ٿ-JFIF((" ?ϵNƬ' >?֕S!RFb~0<<ޣUDBpsx=l2)=W$1ʝL*yP=N*:)i%a~eIpQa}4“qeG; d냏ʊDa S48E= LERIУI;~sݎE41yb;G*%A힤ǥGIn!!?{u1֤Xft4k4J')8z#H!˙KX?ӎH6mL>=}1NI\ḑc03ӷO^peMg;yfE28^0ܜsZ2Hv١';cӧ^{}&a# J[uos(0Qa݉S' gЏ⤕CdL]3t`;d {E PZ;tv/PGQE& ٿlDf3@ :i(@AW=e @ݴ(mP9a($[LIoJ@33۠M|@U¢C4 K@܀R*=I/dh@^G@Ax2Jh@[eCx@^rKAo@*u1iYa^(p!޵NAm?+[{m`V~u L8l`LbBk<$MZ{ bSAGGj{r`9l/O@߮nαJo*iP-i 1ݦ N:_Xl] q\&!7!L]b\m(N,k#lPIހ3l;S?k2 QMtmЋ}tX8RZsɱ #s_+,+z|pO=w]}0Tl׎Xm9ݍ̗w1G/f(NY4{[XTbU~@<MsžԋNNҞϗj;^KӗF%2o[n׃4_Ӷm䷰7&7v`sYXa-vyM k0-[2ᱴ݂3o\TGN:kgƲiHލ7zV0JL+Ba9B'\vk@'OΪi[-O1߷}&AlۥIN,Ln\˯͢?T)q>9ۭ+ysIlYO.2w9g2g;uo4(-ON,Lnde'?~vJil\FRyq>&hQe۴.ݿZyCJil\FRyq>9۠[C7[-O.2w9g2g;t h+ysIN,Lnm3I9ۭ+ysIN,-w.s#)<8vKL8;uolc.2w9g2g;uo4.s#)8-#2)li{Kb:2ϔJlDۋD^ƙ{PlېzS}Kv} {CKb22ˌYi[[`K[-O.2w9g2g;t k,FRyq>9ۭ+yAmCo4.s#)9ۭ+ysҷ[9\drϼdv2[Y/i;^ϼdvJil\FRxkHyV'#`51G.܈b( RK·H&.́X;~P5#2)li{Kb:2czJil\FRyq>9۠[nvnb.s#)9ۭ*z1m([9 o={}gm~> >:@҈E2kW?.#v䨀Dn%V)d;~;ݔHJ-$Vr3Hh %Yk(,_/4-)Yā!:6ۅ D(vAo)[{df!\mM0]R1MBXnA2_z;J;$[V@m-I:J fX d8>;(38 h}v]ݠcRq;V1E(iHetU kbt#Ѕ#))VE ?fH I*Nn3Ӧ/ev;qJxd̂l[DHW:3PoȀd$w!Z;,*e'pcB 3KX 7 BGomxQ2$ߞ@s&t|ZԘ 4R;A2 ImX ᫵ "dCpco']_Dk. \J !`H;AX 1`A1^z[5 lv[\FC#obYlx/C pJ^n@mY:(D6$(2`2Gh"Ōv/:RL Y;`l<I"iI{I(JH'\5˒x})! MZwD6۵E/f(n/7U~L̍ss8@@;*\Mwo>,%SA l H]g=^6\r+i ycͩFFPtX%V 'U!i ~qJW{칎\)x'PA5Y"=M( :u;pOHi"vD>A-wΈ1 @5soBS'vs )K3=[7i6Mantle
Below the crust is the mantle, which makes up over 80% of the earth's volume. It extends from the base of the crust to the outer core, about 2900 kilometers below the surface of the earth.
*Composition: The mantle consists of ultramafic silicate rock, rich in iron and magnesium. On the right is a picture of peridotite (named after peridot, the gemstone of the green mineral olivine), an ultramafic rock from the upper mantle that was brought to the surface by plate collision. The chemical composition of the mantle remains relatively constant throughout, but it is so thick that it is subjected to a wide range of temperature and pressure. As depth increases, the physical properties of the mantle change, and so does its behavior. It goes from rigid in the uppermost mantle (down to 100 km) to plastic and partially molten (only a very small percentage is actually molten) in the upper part of the lower mantle and back to being fairly rigid (but still plastic) in the lower mantle. Although the composition by element of the mantle is nearly constant, the actual minerals that make up mantle rock change to denser forms as depth (along with temperature and pressure) increases.
*How do we know? Information on the composition of the mantle comes from many sources:
1) Volcanic rocks: Rising magma commonly brings pieces of the mantle up to the surface without melting them.
2) Faults: In a handful of places around the world, large faults from mountain building brought upper mantle rocks up to the surface where we can examine them.
3) Seismic waves: Sensitive seismometers can tell us the velocity at which P-waves and S-waves travel through different parts of the crust. Because different rocks have different seismic properties, this information helps us confirm that the mantle varies little in its seismic properties and hence is likely to have few variations in composition.
4) Experimental rocks: Geologists using powerful anvils and ovens can create laboratory conditions approximating the high temperatures and pressures found in the deep mantle and core. By examining the seismic properties of suspected mantle compositions under these high temperatures and pressures, geologists have found that a mantle of nearly uniform composition provides a best fit to the seismic velocity data derived from earthquake studies.scroll_rootNONNOTu_[""Ԭfk35߀#X5Ua_{X5)aHG@3%c%#.~ά*ªjVU u| %b9;~ڴRάz)ʳRq| ̙%U"LΪ6>jPm| 3g`f5L_LSNi4"+C/335n>C*p1EEEQ0 Tt+f$Glg?jRJ8:@DJFIFHHC   %# , #&')*)-0-(0%()(C   (((((((((((((((((((((((((((((((((((((((((((((((((((1D!1A"Qa2q#B$3rR45bC%ESs!!1QaA ?)E1*R"("q5YᚢX\Ǥ \r-bV--Tt+!H7oa ^ֵŽ!X<їTR615kn.vlXdI,hDmQΝ;32UTCmWv?K|JmrAW3LYBQ5 lD +$F D_U E WiZ(Ő#3i%n\\I#k*Uy"3d G{{ௗ3b#-ȰvY*@ܳ cm#HET5VTM :q_c|0~.GCJYl&_U^c5'Pʥi)~/5].WP"FzeYn~RAM%(Ju+pHV;rPEcg Z*U, ά]ŏR_,^|f[6u@ Ӿ, Qfg!^i`&rv⋔CS$QX$R+8;Ϙmn1*^ɚI)hCHF1H]^]ESVybD-7+SY(F&m /!l.@ {j]( I,`v ؑ}< ನ+MPtT 戋6~{V`"jEbf*t%Spno[9۬k*ThHupsߎ@`V!<57kmX}V5jPkUJ*B۝ o$YYU7mb\5rt"hvո ص |WbG+WHi\3*Z{\ƪJIiTxzD)6Imnhf.dzImnE_olLւAV[JӒEMV^uq }%ReSX-,q;r6mk\Z$ Rӈ? 0Mahc-,̈"R~ϧܼU(%:/ 6sp_UIG4#DjOD+TUARo*?7 w{`I3A5hVte&ۂE?A~cP[TRȋG*$%A?nM$o1l-Du/dr@Sی5Ն4"qR!)+rwk Qjh-4sx*xNҩutV᚞hࠬ ZVLR }Wʫ.hiْW(%Q`{ V'c)9(xzig$lddvvߌJẌ,J@i0"kOOJ&bK{qݸ:^=jBRM&Z̮I% .(!Mi$ X|rJSt4QD'AĿ~kbQͪhhDNa ͽMQa:tX,leZ 4UXN@k[C5()̂:vE.&ԴPĽk@fIb Iլ4ldI>[[֒:$XJMQrR"3V Y53V,K$R u fop91Ue+d Jsuf:8Ԑ!5ė"y[o.F\\Df2xySnLzܟ.j*+TT/I|woUr`4PnH>pe̥w&8nwCGSiR8vs߿$\TyL1\PB!Zچߝҕ5UVoVWFM:LG#1k;.e ̞>cm%S,0J[)_iuӅha 4 7P\#kVZxGZp$1ms6}6a״J5+1i?J}&zY u^$ ^jQ~M cC 7#٘ 4V &Ye){oә4P"G<cAr-}n%:IxrۨjGX$,n" JnH{|WYFdBĴb Ȱ:bopŽ9ꤙE<#VG[q0Dj)h-Ai%`I Hʒ|7[H$ woǨZ\qyT*hR*ƅ Nt[^ wה˙JQ쑆R6<pg5J$&+1=HԬks gT3Ydiߔ&__1fy4Ь- :W{bajjaQGU][1Ƥ+YI/dUjm ma=m,yKbA$ b Rh!V29a*F^ÍpV2ܲ*[E3_|u:UH%JZ#za%Ӥy77{qRQ+ W {;8o@`vcYG smqRz#fe;XQJ.hZfml؛Xn3zy֞D^K'Pn÷~1i.ɲM1Սl7#lEj.am=%z$, Ub,M%o,%Q1RTHiYR;a}*4f,.8WRZqzrEE=-"$fYEjGs x*V DM3ֵnvnO^R|@,n,w5`e=Z _u#Jױ>ar=%@𣢋?Q*mdӸq*T}m-Uv^@b,2$O8cH9U܀y_ U]Q "/M!H_Y oQ,VTTjtc7mK5W;Pj.XxlL$d'9];X[nC( HQK7w5@c]DD HH;Sz*uf*jQPo%c.\hd%6a4!U^[g[te'v `?Z;٭lATWQ-|I-5ā˱}hhRguMFv=]tai嚥Fy7Bm} lUd)e̥Ie$.Y`ov{1 *%A:ʌ[`m>`66x֢7W=,R/T,YfP\ŕ!EJӻB -g1P:ąb(P6A`}l{1BP)H 1*A%=}[SuEGyJ*h7*lwlQ*;7$Rϫ-aO!y Fa@̠fÿkcPqd5  t o-3U0(`bI aq٭5EM4S3)u,6"k:Hc){9sֳf&IQ5\Fz,1"MM3GVlI5X+ `qjWhc]5U+Q:HnjkŨXysEONC@dA&r(ʵCA}̭p3 -\lnA:퇲A35莪I^"ěN;cRG0,7M YS\dG!t}Fvu9:+%SJs͆M5v9d㨚2ν6}傁[SYUOTU QHUImnEڕO-oߩZ@Hg ]T)fr_~0V" st o͸נd̳8)..uX>|p 0x8C=ncHۋpqA=RPOT(E\Y%8 3FbEߋ?EU-e8TӤv}%YLMO3Fh̲RTiBn\f5ti2#$k[AjsTŵ+((yҲA:NTsk%|h/q)KP\־5מii)LYSDf|9y"c%P߂9.uVsS]b@ {}-ٞFx!hcӪBmDZj1bu~O4%:UNGQb[[i"6]QS$1U{۷蒪V^Й\=McQ-z$e4⥉y 1%Am#{1[f 3h֕eiґc%{z>76=,Q>"Pֶě~7i(YZ9+lwnEAQ<ԑ!Zzdn^͵WAJAEOD,U'ݼM2rI,ڇUuQ,"C^9HyVCTTCNyK >|LSŘTD QjQ;aMU!zXaim(+kln}w 2(S( y')zy` XYmMe-%D*C3y5]ȹ1YMVs#A\ԏM6,-/8'wԫjzjHIE Ky㵾H4uiS,wgbP,8,7|5qz/O݁>ÿ59^(jdwC2Msa[ުI֨=:)b:HwonQ/ i!uj[A SG,Q<}d (0V32 nl?&$/[j)wmJ I`+V1[KXm~=J5tY 4*Jɧ!87Z̒wyBk A`𜺉swAv@ MD5U? (۸TjY){ MlKf5pQ|$&"G;5-X[`Rت`$oZb@&4Ov'DP {`\`w3F[>J37 cAk]̠'ݰ6^iĭO!UUwߏXN*yYDFxErv=0VV)|:KHG("Sl[$HQD5 Mۋql5OGPtҲyDWjb=7XQY rm:)2HTUB"ԪXZZYASLG銕C j v[}6 |&O|j"BH%t {lh/Kku$QX$hS n q&BU+әUHu{ws3ϬS5T"v2ۃJU)ydT+CfQ';QW1Pwij@ 7U6B kv;]UNqi4+)"TMM;yQưmv ɩT%E6 /$l7V6|" G2Jft-まÞ*P]蠕K`dR@}c`ԚMUIiI$ЀL/3]Y-!39.#@HV/JO35vi,Z¦5bǭY"TfbuI7{c5:%UD )} y6<o KXJd̚jP\ )dxڙJvPjUipxƥY"ͪ!RX*3-Pa?~vNQ(.YsیnG.fYYҏ;#9VB kX_nxF*G*%zpҴ2Hc~q]$i1Gʼn6<qbR yM=: 6⢳eeKӱ~;}0XL։*G+-Rͫ8**edPM\]${ \j=&5qR}Q]@)>A 3h"Hm}m)$E!@dIDzqn0@W>VᆤJFJPw^,mĢqU/PTH4<)b*7,>TTPQuJM{T3U5uR,]M:5YDFu y|٥t<$#yc:za7GMO^)*D&k7_C:2TJInZ6Z5JLZfZ]OY[#%I#jWLX*]:ܛ 3ݺ-2TUuM4OEYh"#+O'Dm.%c4 GrQ˞tH,$lB~ CPL82MwF&(GwߌJSPahd`T{E qtm,1s#s+STE !FQm4-֕iS#l|1ᤅLULŎw7ŜoQ*OzSȫ1 ڵ=FH,alv'pCU !YgeQkI-_U]I7R:pF0"cE2@ JC0渿rgYe饯}?ダKOaH@Du }NOcV4whԥkً{w9Ƣ L"cYTxԝǮ yR.a\AISR^K*ǿkM1)9ᣏL֒Dg;[~ Fjz$iKi#۶,Y/"x(АПRXekq"C|PLk:Q9vnlAIQ2*ؠH緡GZ*c56٤髠~ -ʎllyߌXSf0V)dYn}TcвKW RsŞT^3$AcQ&*c!&  XZ*4c5E {A)[,a_ŗԢu,az0K$%Z<_=Eq c5i1H '1O|SeM|_AYOR֧ւaWg8u$fJ&VǦ+0WS[?R^SJsiko~pR0WW},Ε#F](hdAĒ_M fY]M3"j;[p`NI>^5 U3JIq-7hYzx(ePEI;X %]I.#K0-l*ZG@< =q LͪdSIaz{b͊k1FH"]Iku`y犕+4C:`34WU)Y# IէY̦!VUtA4q8Z*i! dVkUԭ]k(,6s)y&VFi sJiL4Ro آ]GO5AaWYJ"Cs& W1Rhۜ )~,qKsGaJ%2fbXK:,ċkb5NOJGW%#V-qs隩"* lMG}jX`}<no>@3FNii."IX\H߃ &@+r4:TY…bT 47*IJYLJaU,9]w'Lʹk,ԑDG X&xbOUA L4:}۞rCT<:y`l/rF fCJ+@fuT]7*%P2Rs7>I?e~A"dyE!hÿ1A;Kfe:\g F|_F&9GU\SƾQ $>, ktdYb3N!THkvÿjs_jf音p$Mg~aԦ/Ej)[c^~e&SE/ټc?y-6ļu6;MtxrL;:$ &xuY`Y5=sM-=M-Dn*n6pICF֡i+Gmj^o>W jՖ/+xȵW ?+̠e)/U3T􃏳;[n?JmR2G^L"~W|j HEm}~W5+vl{oחeUYP+S7?}+s`fU(lHr?yuɞbe"UQ@&i4vkX.'no|sn)4ezŘW6w{Ƣ٢ G I77۝;Yt0 ~+[qF3RLe2ڱ+JV ݱ`|0HK4i] oVW/ *U`} X%-5TpSLB k|RJ f.{ݸpe=:00$`>[a)iVTPz`yo Z%=GZi"[;NL5[ LG'^xtAQ I&,cv7LJ%W0Jpu ܋~LJ|}MJʑC%Dc[X^6pZ4BVK*ǐo57VYC{;:ě84ɘR! wv6q~(ZjSJ]Z~}#j:YQJidƒpCmzSMO7YJy5@J &ZArw>5<,J%t5V,.gv6ԣS8+!z%rdY{C+D-WL2/#PP[~*2u!beE^w=5 "0uP9A- k,yϕ\){|%L4 h HX3S}tiHU:ST,}c9'邼OƢWٿ6r .A@A@A$O vQ#ƂxS X'}  Fhd,T: whKPKx(%1fZ1 X9NTQZb"}SSC'CU9U2075o1b8^ZB9.-]&9/LCrust/Mantle Boundary
The boundary between the crust and the mantle is defined by a seismic discontinuity named the Moho. As seismic waves pass the Moho, they enter the mantle, which has a higher seismic velocity than the overlying crust. Seismic waves travel significantly faster in the upper mantle than they do in the lower crust, and this creates a seismic boundary.
*Mantle velocities: Click the "Earthquake" button in the figure and watch the seismic rays as they travel through the crust and the mantle from the earthquake hypocenter (a seismic ray is just a single path of a seismic wave as it travels through the earth; there are an infinite number of rays for any given seismic wave). Notice that the waves that travel through the mantle arrive at the right side of the figure before the rays that travel through the crust, even though the route through the mantle is longer. The reason is that the seismic waves travel faster in the mantle than in the crust.
*Curved ray paths: But why do the seismic rays travel along curved paths instead of straight ones? Isn't the quickest route between two points a straight line? Push the earthquake button again to see that the deeper, curved ray paths are traveling faster than the shallower, straighter paths. Yes, the quicker path is a straight line, but only if both travel paths have the same velocity. In your car, it may be shorter to drive straight through downtown to get to the other side of a big city, but it will generally take less time to bypass the city congestion by going around it on the freeway that has four lanes in each direction and no traffic signals. Similarly, the part of the seismic wave that travels deeper through the mantle and crust (where pressure is higher and the rocks are more dense) travels faster than the rays that travel through shallower (slower) rocks, and so the fastest path for an earthquake wave is nearly always a deeper, curved path through the earth. scroll_rootNONNOqJFIF22" ?R xm䟕F9! vqUdI F O`=)V"3OAkGj@RᶳFsbQ`w%6瞴ئTR"]4[ ǵe}PHuQ!&Urq>r_;}A<;-}V3'梋{_!m AO utM8>~1^[;0u2 nM f{4{vR@U99NX1vϗQ3`-ڃ}ؖVf\@0?k"e?2UBY@Pp87sW%.%TQVIg8JKsteA*kAh3͞ޡF!g ܞ UK$Tf49EB6(>߀M`TF u>ӓנINOAO!d,EU8=H5;[VZ,2(t"r~e1?;sL$rI|HOܛΊ)!Tkͱ'zE"eQp:QEٿ=l]\%%@,I, D,tsx@2] Id܅t`N/  f3̙ff3 333ff3̙ ̙@̇2 ԮnT3jofnT3jof#f f3̙f(f3=Qff3f̙~̙@f e@@@4!4 E3f@\!\ - Db%3!3jof Db%3!3joff33B=d苭lH2B #t`rMɮZ^P~wOIqmv׾p.H,i*32e8Mgsגl=pa7$9cCsߡODn5,u K8pbwJie r,~5!˪;\p26%ƺ)}5|{phcL9[BQԯӦM8#%XD9e I.J0aCIRw "f21m#'Z8HZ{K= XF΄e95 jF*ux oHGsN4  AQ1@6vD$GV\?LE񼀮7~bдa9*R+i[ 2&J;-Uz6JtRx/oL=gzHTfXB뙨vhq̧2.㭇-̊\,t4;F. 7nOmvn;!Uiwt=2l@6?{ 16oA~߶@(} } 5ukj=oP~n^+@5v: ڶ1" 4#Zvc!QSf؀]uN4|t Ϫ?xpN6#(Y~:zLPCq2_,fڿl zvy%sX5C4췇=l%)I]mgvFk k*+G1+;zQFGl`(!sP/H2l@˒%sp@XF53&eCۤ(({. pwtD,@4)mQzR(fhu)ވSnpݑ(ˆ;hS b9ǩPƲb/ al`-5mQKc %Be -j&a,uxc׀ ZN;mxc- vj(Y Ő[^iXŒ[^jYE[^kY-ׅ^?m`}siis,"!`.; BLݵn Q1BRZҟw1)0>招wtrS>keiv> mil>(yT+ _3rTʂ+0ຖ9o@<:9TdډʼAQ}T?QY0r6rYK m-Gmhom;i,B mPyX`,4do7%mYomY'!Բ`amD<Ӗzh*;o;!aX SB-GmpodǡY+rC[}b--t7 ySdŷ"-Ame5,S[VBKP-+rXMXw inU߼ҏ6'+ ~-6| %k+VX0|-p7%-@zo2hbб "@ Ar̋(TY\e"%@,` ( "@ L爲YYk k l@Y(%G4J d>~,vB꠲ӭ0~[?Dx0| ("%%jߜK Y-东;DQ%)0 -տ;9 qB7Ztd لie I.JLf01`^BiHi[H喎-1VBV;@il RA; Pgߓ;,a~x4  "Co!mQC Ro ['Eh%nD[#{34Ef#.BaDPK/#m/? ]pc1=~{]vim;kh?8v~kN=[mZm|DvH|io{B  ]1Ƙ}ϑN[@zG ǜ e:\jb!dioR/.VVAFR%Ҋ;ϭ2$gm'"~-emȢ:a>{NcW ꥦD,òN\W&54#kEvGaq\ ;FC;gYuZDu^,J<$!ir<=ہʖ@f3%rk &cc׏XҤ]Zz\׀ Xĕ%\ j@(+y)k+=Wk+!Kk+)GA݅Vv׏WR+CzWOnנWV YjdS9$v$H;]m m`$=[\!<{$]Of33%};*<OCJ/ }3"n7LwbF e뢈x3f(- .96 U5A' 'pp'Lqc0F@6 `x8 m+y- `P>yD-\fd *v5v5$JH?L7Ӕk Umb!CS34D+F}"g Q~}Sy)JvX lZ3ZuaZD`P-UCEEXutT" џH%T_1iToe8RJ Ѕ P|B=%#}2EPy l-d.+]+լvS; uaZD`ucZP0S-Ҧ/t!vT/`IH_c̑TBD[)KY oooo5kJ Ѕ P|B=%'U3Pe`*]nUvS; uͣZP0udvP0n-ғqsV34tcޝ/`I*OZ K+52VXNxUG~V]:pJ NnfdNcw6R%ẙBMhNOdq}kDFq=v{}_VqL udvP0uevP0Y-Ҧ/t!vT/JNYC:kBuJ%[u[uZi3J Ѕ P|B.φ5Hl#J:'^oonk uͅvP0uצvO~-ҕqQtTt54/VD)?KW/Bk4R z+Žs8:QD"+HݵmPw@ >63m5[u */_Qy޽C Qfn=/ 2e6};dE6PjϞ)RkUqޗ.SgN?7?M Zl u׆vOuקvYx-JP廔HנR.zP|z~D3B 5~#QM.eB`cb$&P{^0rdUw*:Rʻm*/_RC|P H<!z_8=lQ騦ПH IWP/=zsW9]m\m uקvYxuקvYx`-JЂ˯P|R H !Uv܏BkEy;i%w]wήU6Q|*/_B o.]BK5#HO"T( a*PH^W*e( uקvYxuקvYx]-JЂ˯P|R H !s %R'm$k79ʵJ/*/_B o.]BK5#HO"T( aT$[#&lc=VS)LvvަS:ŘVtccVrHi@1Ndgqp" `#  4TURV ە@$!`-H& x jaM|ޤ޼oY""` %#x jI!޸ȼoM#l_]BE<%< 8aK ORrԦ?Y;e Q?mw͇3 $D ?6ݝi@ m@ =i@@ Ρ2ci@$@ ȣK⌭ki@@ 6d?i@H@ P|V˰Ai@@ ̜$b3i@l@ ̵«2F@@F  k @r@8@UU@q@9@@@@Fk@@33@L@ff@@@3@@f@Fk@@33@L@ff@@@3@@f@Fk&@@33@L@ff@@@3@@f@Fk0@@33@L@ff@@@3@@f@Fk:@@33@L@ff@@@3@@f@FkD@@33@L@ff@@@3@@f@FkN@@33@L@ff@@@3@@f@FkX@@33@L@ff@@@3@@f@Fkb@@33@L@ff@@@3@@f@Fkl@@33@L@ff@@@3@@f@Fkv@@33@L@ff@@@3@@f@Fk@33@ff@@@?FkhY  +2 !"#@ %D  U.LLLN{LOM} M LD LE @' ,(;JvaҐ$T@M%Ź8D'E&h P "@H}Ȳk ke kYYDôÔÈ}&@M??+_rootsidescrollsidetextLithosphere / Asthenosphere
The crust and the mantle are defined by chemical composition. The crust is made up of felsic and mafic rock, whereas the mantle is made up of ultramafic rock. However, there is another way to define the outer layers of the earth based on physical properties.
*Crunchy outer part: According to this model, the outermost layer, or lithosphere, is defined as the portion of the earth that behaves in a "rigid" fashion - primarily bending and faulting under stress but not flowing in a plastic fashion. The lithosphere includes the crust and the uppermost part of the mantle and extends to a depth of about 100 kilometers (a little deeper where it is cold and shallower in hot areas, such as ocean ridges).
*Chewy middle: Below the lithosphere is the asthenosphere, a zone of the mantle that behaves in a plastic fashion - "plastic" means that it is a solid rock but that it is capable of "flowing" by means of crystal deformation. This flowing is what commonly happens in metamorphic rocks, too, and in glacial ice. This weak, plastic asthenosphere layer is part of the upper mantle that extends from 100 kilometers to about 350 kilometers.
*Low velocity zone: In general, the seismic velocity of rocks in the mantle increase downward as the pressure increases (giving us the curved ray paths discussed previously). However, the rocks of the asthenosphere are so close to the melting temperature that there is a small amount of partial melting in this zone (about 1% of the rock is actually molten). This is not enough melt to stop S-waves from traveling through the asthenosphere, but it is enough to slow the average velocity of the P- and S-waves through this zone. The graph on the right side of the figure shows the slower velocities (as low as 7 km/second) in the zone of the mantle we call the asthenosphere. Thus seismic waves help us define the extent of the asthenosphere in the mantle. scroll_rootNONNO'l]\%%@,I, D,tsx@2] Id܅t`N/  f3̙ff3 333ff3̙ ̙@̇2 ԮnT3jofnT3jof#f f3̙f(f3=Qff3f̙~̙@f e@@@4!4 E3f@\!\ - Db%3!3jof Db%3!3joff3f33B=d苭lH2B #t`rMɮZ^P~wOIqmv׾p.H,i*32e8Mgsגl=pa7$9cCsߡODn5,u K8pbwJie r,~ܘe%+lKt STj+v'>0ѶNIW-só,p_MpFKа r2ra# r\Xa|&%s &# LgDeFcJFO,qhz* sK`k`@ԌT+!c:ސUni "A! b[2lJ Mqua:og`(q慧5 IR[J%M)2QjhsѵS={z`!m?@ݮ§[u;AnIuZDu^,J<$!ir<=ҟ([P (_Tv ~UAp1&@LץZņvZ.OsVհ-G5iz`;̡[  ~ xì" kMDWu@W,05 gYPK *b9TL;hi@)J]K_֧AοNTڣvv>6#(Y~:zLPCq2_,fڿl zvy%sX5C4췇=l%)I]mgvFk k*+G1+;zFb9׮ eMT$䩙;Ol`(+cxݫ Fp~C0T =A렡칸%<4٭Q,m 4lN7ވvq  L綀A *Ymͷ: muhE/ %Le ZնMyc- h K}@Lwxc-j*폛^i^j m^k+ׅ^?mCore
The core is primarily a mixture of iron (Fe) and nickel (Ni) metals, with a little sulfur (S) and other trace elements. The inner core is a crystalline solid with this composition, whereas the outer core is a liquid.
How do we know? We can't visit the center of the earth, so we have to find other ways to tell us what the core is really like. But don't worry; scientists are a creative bunch. The composition of the core is strongly based in both theory and observation.
1) Mass balancing: Astronomers have long known the total mass of the earth from calculations of the earth's orbit around the sun and its orbital interaction with the moon. Knowing also the size of the earth, simple division yields the average density of the earth's materials. Because we have observations and experimental laboratory data that tell us the average density of crust and mantle rocks, we can compare these with the whole earth density and find that the earth is too light! There must be a very heavy component deep inside the earth, and a core made of iron and nickel is just right for balancing the mass of the earth.
2) Seismic waves: Earthquake data regarding the velocity of seismic waves inside the core fit nicely with experimental laboratory data regarding the velocity of seismic waves in iron-nickel alloys under extremely high temperatures and pressures. Seismic waves also tell us that the core exists in the first place (because of the very strong change in seismic wave velocity that occurs at the core/mantle boundary).
3) Meteorites, Part I: Because we have much data suggesting that our solar system and the meteorites, asteroids, and planets within it all formed at the same time (about 4.55 billion years ago), we can get a good idea of the average composition of the entire earth by careful analysis of the sun (from a distance) and of meteorites (up close). Data from many meteorites suggest that the earth should be significantly richer in iron than the composition of our crust and mantle allow. Therefore, there should be a very iron-rich component deep inside the earth, and a core made of iron and nickel is just right for balancing the iron composition of the earth.
4) Meteorites, Part II: One common type of meteorite is the "iron" meteorite, which consists of metallic iron, with a minor amount of nickel and other trace elements. A picture of an iron meteorite with its distinctive crystal pattern is shown on the right side of the accompanying diagram. These crystals do not form in our laboratory experiments, and careful analysis and comparison with other crystals suggests that such crystals can only occur when the iron is very slowly cooled, under tremendous pressures, to the point at which these slow-growing crystals can appear. Geologists hypothesize that iron meteorites represent rocks from the solid core of a (now missing) planet.
5) Orbital considerations: Also from astronomers come measurements that tell of earth's angular momentum. In a nutshell, these measurements tell us that the earth cannot consist of rocks that have a homogeneous density throughout - rather, the earth must have lighter rocks in the mantle and core and much more dense materials in the core. Experimental work with iron-nickel alloys shows that this iron-rich composition is just right for balancing earth's angular momentum.scroll_rootNONNORJ8:@S: G3JFIFHHC   %# , #&')*)-0-(0%()(C   (((((((((((((((((((((((((((((((((((((((((((((((((((1"K !1A"Qa2qB#R$34Cbrst56%u#!1QAa"2q ?W!tABl{m5C("\Bo6Ux*t=R$fKMJ$X3 3K4}q~J+' ZXskw6 R9ܐO"b:`J2(LS؛qc7gOSƥBG̀6VaG/'z54_3OQ,PRJUXJ\[`{JDͫfj;KW4y߅7iggvVS'{s4h$;ƫX kN6x/9i \ jqЍ%]Pkr܋r;_ z@Y^$OQGyV bIR:+]XXqoCD\Ƣ/ð;yZOG"׵ UeXf!mOWECYG'THQl[[DPE4t憦J3FcУr,q$ͪX˪M},TۍbE TE- ZGd6IAĵ f)Qimx 9ՕҋRe&ݓA#J ھI৊:Fe}h$]J Jikf,@6/rAOn V{T5JT2MTuSmk-OUW7F8s8h]:=6;9Yk&v]le:y[^xU5GHidI66b6\Zh/ `LyKd+J|&bzajWkFof`ٲkՌ?X^=׶  RST aSJPm۰xƩP& ^xd{H4mZȠjI̖衖3$h׎YamMN2d%[}~Ziw?N0ُw#zl y<L#$^x}':@]&yAέ$m8Mi<(N̠}~fmDyx;׆ji)+QQըDp券=IUQTu*_ }jvc'+FS6ͼoe+ׇU)،fSMd1+rn3 E4Km:KTEKA$!Dj57Qŷ<펗K]eRƚ6+ `;6bE 7r3/j`G[q؃s` ž"ij:I-(zw0م.7)y%6t#ʞU421p\#7>blF6O=4Z9`Nҩ:M,.6?9%oja hӻI6,BͥT94&1k]Yqi*:!_2 j`s,js8@[SLqLs)lQSԏ@|vx MVw[_ S,K,񴡔*6pIűм&-ɥy^x()s)kЍS"Ƚ6~Sp*:^)e17B2H>YXDo b\XC:xQ[U8zjYT43$nF-=o6[ er4fP_V0;n\IO4XDڻ w% 14s25ŁlMz/L$f"C}$ࡆ[o@@zi=ZN$\…' іX>s`d0 e,܃.5Q;"kÅĺCVU(NӢs Sq[V_{p.-9}$Ҥj [r.oqksS$aV.nMzƕ9x5{.%`,{^۞aN5Dc,Q+4jH.#=q!xjs}ǜJj-NUYQ u mhRtXYMbyÌ',OOt <ֽx .uXs !0FebPP<#ii<7+dZX(n:} a|m$UUQSZ4b\. 6cu 1m X檅(0U0nr;1s j)_(@:"7VQ w=pwq4 F u#ORGu) p47'P$TAqr{c[Od$ֆj<(/y:p] <+|E.mͱbsU_+T4P6?pĵuWRp"L eD6cP$;S>xH!m{`Jvt}_ >YuR4uEċcŮ6:Grj?xp͓ISѨZc+/7m$yteš_}m;b߂en GxïORg+G|iD3UF]Q$O{Z}tr<I\*joUOh"=5CSjZ:1nv6 >TTfp64M#R7DRCms f\je ]|?㟡]JSG/g"21`o.Ih!+$ٶ~57i|>FDޯ$/"bN^=9qn׮1†ɸw:Y R. B=ONTMQ „SRBxoq0W'Ƞ2zaDl ͉6h,iQE-T"XjXAk}\oߴZ ~={bSK)k(3Y#ȫ$k) AX c12/gG0h-emvhkQxECum%m,8=V=HWZ4ZTAj)X敆l.O-w SPW 0rV1<[۱c6<(& ?k9nc㈲چE#!v`w[av*3 u%_REn;X[Oٵ_׵Q$Y'}Dof k x0Sf٬5r3 Aۋs(̐1;X;)Tبn8`b=ʩQ@kv>04QTC2γ3 r XSuRjॖ(<3e牫*娯ٿ4$^oſ/\SyMKOP151G2GŶPo޽2ɡ-*TآH76۝s|5U稨5tǦNK06>n8y,ɿi6]%l`b齍ů]aHj:1-Q%#,oqܑ]J̙sPfT@[ZpT(b@R4fAM#0Jj9iiC4z,FDjQ#N[CԎak[n JA-$)e[}?`W1mb H>C~6{-IbS{_S5SC ,B%©m>sW,uљ ^m# ~Fs g[  _lesXIyhg꼕^Sf]21k4+5鹹Qǘ(JT14NY`M4pkf|&[;VGD!s~}7@a0vy,aQXηJ\ 8=aj$-#X(tʑ12_!Т'hf!3!HR=vգjxi7}C4. VU 7kufM2@eYJ۽ƺ➲K2!Kq‘HiTR$YZ^~pV0~-xoUMPXKTev)m۾9>IW(s:)dae ů~l0e}5b=Dh] Tp7]EA]#L׉jZsI28xefW_ sMGYMM C$R:Ȯ5Ym]N`a7TQFjBUq. S/EBIIFֿrw9lq *䚜zX麑:GnG-F:戍_ X{_m–o&bC"JyYP/pnFvV*Ѝq4>J?cvt5HBUe5M5$rSjuix7 #x)\S-]@2;muTJXJ/PFzS;xM[8Fmf^IQˤXkoZlGfseQkJ8vfQ7jsFe-7pcs+8ݞ-En5u""u{tftTxOUd3@SvyFxƟs[[AEPY95_Itj+,S l]HEcr:N)l,Cx{.)"W W[{i[:)L·2w̳u2ӓ q16QrʅVRXC$Y7|Dձhk bԌޢ'D6 ,[a5t[q1(hPGPRc MC("~i$OյD;ilGbh da}|6$oI[k|!)`'EC,#dȑ2e{l,ҝ-_c gcb h ۾<\.1TOpNAeh $l.f5uu2B6`ssͯ]j1*"BquU[bSlA WjQO_ $+$)΄/X N.euU:76@ bWoϾe+*b` 1/0@mk0YfsRP:U׿b9vꊣP** ,6`EabduYԲ.ۋIF>(\5n#,6`/7R~aeʕfoSOUHdY0A0#h# YPf3#F-N1Y`Nǃ ]fHslFf(bC6z4M-CJU4^4uQ-M>fkY"ݬoߞ/"Ib2=4PX_p=|EUѮxD 5Ž60h (Κ:cH>koԪ3dYJ=>]& /y5\Ƕ+JȺ$I^2<>OO*:0*bh9dV[vdt4lHPC WGqqJi[,ؑ{ Z;]LqGTӔ*լopWer †E'XA,} x.%uMU\o,U9VLv%np*4|>g2aI$˻[`^/K6T|$%Y_ 72Weq[__L#}?݊YQxٛFu\ol0`*"V[郵 pu:I5/j9>$RTw?߃vaBNP7rGom:Ar"f@@'H6$\-3Tm#aȷ+(Ui#̧PE/!7v?݆ڊzJWuz匐AܕE= (UF ԟ k(MVqŗʩ(T84D>QsncU%$PMEYgM!Ftl@b\|i騣QcSebCn=l *ktY.;0ݶ>"#X#kRqclKϜiGa!ZuP{6><`?6 4SuigH,P~7!Ԕ5ULbe"0;aYQ,seG.ĵ8鄢 "JJLhB*tӭ9imۋpHkd)dlK r<7>m*ss `JV0yW9{ =:u? Fj;ߍ(X7QJAǍj*|#J,/`wclѡ%$QOSrtXEe }2`G(}.+E~ʩJ K,nnwGѴ)裓XG A}_Ɲ8$R~&6@ojZtPu:G."+4H\ᾘYy#;2?{*C8AU u~|vŶe>M!>b;sqnpE_ GDmnaX,f-fhA$oc0Vƥ̫᪪ъ#p@~_~xfRU?dJTNz3SWefyl hZ؎ 8VSeQTV̝fpޛc.OѥvEO$J!ʤBi ~ نءEEtu@%<4 kQ*n醜0irh3&qýwAI2ÙeuVi`C0t`N@"a3h^zjR$3U|on-qͷLx'_$jAŷx&4e !|?2m͇ {ۜ!2骘"%n`w-S)yX6o-LI;3|ty|Ya}Vc X'}6:@:Yx[[_j6SƋ #̠u%ȹ.[TNѻH|Z4ȷ,o{ZieFx"VexmrX s3v]%ClbJp7%-*ʂ(4r#Pʩ,6ۨ@>ۜVT3eTtD#Jo5'#6˥h)gJ1!Ъ 0ā{ka;=nj|^*jQd qn{ ƵQ<Ҥ=5L) ܀sYYAU&C 9u:H&iP/~ sj+S%J )$nV޷&IRS$#Aeo}6bf1WKY"yc4U QW. W1dl,jf$ZS|0J)fhP$F8ԑlYɹ)!(KCPqH]i㉴:F#iצ8sH(bԨnE*,IPQ,miUIRM-zW,qM>}UqlHXs'R< 4I2H&4DgU83J˰-lZjrOwդ kocyi1PPL9BصeVgs\14IyQ$Ec?UdS01 cHNEJ~q4f B (-(mz:X`ˢ DBKJ7녜ֆF@Sہyh$ZI;Y┫F8 RmLơ*i:bYPZ8(}9&X"IRIn߁>RUDHn};n24NZ 7ƳZb5E05Kg wf ͨSGE]-MD7;}=1r,~ըL)O$!6W7zqXex:ѭ8iPjyY5nm kGE e\shDLq5؝kIU̫*IMUdhХ1ĀžCmGO:L'TXo,԰re@u[%2ߴW.$ߕ**]h.v ͮZӢ Ti۷hE)O P F^ewcLok\[`y$ :Yj>K4b˾,]=D@mel;bsC1-F+΢?olA<ԴbHb)~,:0 Ʋԩ*P0m{znqIaEzdؽQ T#kGaoN< F!|:3[U?-eҚU )GQ`o⁥ f7ZB٣ز-^^9WQ8Uarǂ:e|2AI?e> iG]{cY="@Voʏx4p\-S.*cWsK+ X(~̣!|ʲ6|(q"R|;c)e2KJ@RZ>&?g>4BpL'"85PRAOSQ;lGf1SA(-xJ¡uw G>[)dR86"ې;N4pѵ,YHH6'UdD|] ze?QaV :{`6}qh$B#J̤n{__A>L/ط.AbExώkC Hz xr*+t,f )]gOᏫgM!v|L1}*$ "#Lǟx`GS "YF/Na \5V -ȶN;D(ZJ,?|de> &NC?&D|U5;K A&׾.?\}b:tbm5͏>o3Κ[ U5PQ9 qPnw -%,jIcDv*R潸aICTh'aQbƲ$ՅV0PY>f'Nݶ.=/2CKM3@Tvo>!zW,)6CR!e[?tb? PJ TUFDÒG13NcPRA)n+;?P^/fIf]J 2n;O۷`ڱdyP)v ʣz1 E%UA?O1&w4uӢ xo`.hO1O}7N)EDZ2WOVD qÒdC l.=bFG]#|\jrfw)<(<&39j"5YP-cbikH}iR[i)vAHc"|T$ r쑩`} 5K 82g X<u<꩒M߽؛qUUёO!~Gl)Cc'r쳥bHd `/a'Wske$zSK~{a.0*dy^n$>I1i)&I2$X5{qlK{)$򷔨NAhz[3aWMk( uma o 6 En_)U?b^E};9c1՟#юa'1lZ꾧c1db<{?xf>߂?G1h[n3ؽT_݇Z f3 y#c1AHٿ4pA@A3@@O vQ#Ƃx@(!5drB AFdYe=H T:vSǀ)Gez kŋMqIU7!( qJ{t짏S(8ˌpeqpy$"8bxU4,5` P Fh eȼdȴxdIȴxV5,6`<( P Fh XdȤȈȴxdIȴxW6I7h j XoĜ i!oިޘެoQ eM̅޸Ĝo̅X7*8h "@Y,Y Y83"9Xr P "@Is 9@RSUVWXY??' _rootsidescrollsidetextHow do we know the outer core is liquid?
Early seismologists discovered that seismic waves point unambiguously toward the presence of a liquid core inside the earth. But how did they figure that out? Click on the P-wave button to start the animation of an earthquake near the top of our planet and watch as a P-wave front moves (blue) through the mantle and the core. Notice the curved ray paths of the P-wave - again, this happens because both the mantle and core each have faster seismic velocities in their deeper portions than in their shallower portions. Click on the S-wave button to start the animation of an earthquake near the top of our planet and watch as an S-wave front moves (red) through the mantle and into the core. Notice that the S-wave moves through the mantle more slowly than does the P-wave (S-waves are slower in all rocks). Also notice the curved ray paths of the S-wave - again, this happens because both the mantle and core each have faster seismic velocities in their deeper portions than in their shallower portions.
*Shadow zones - S-waves: Most important, notice that S-waves do not pass through the mantle. Instead, S-waves are absorbed by liquid in the outer core. We know this because seismometers on the far side of the earth from an earthquake typically record only a P-wave and no corresponding S-wave. We call the far side of the earth from any large earthquake the "S-wave shadow zone" (shown in gray on the earth model when the S-waves stop running). Remember that you learned earlier about the fact that S-waves cannot travel through liquids or gases; thus the simplest interpretation is that the core is a liquid. Experimental data regarding the properties of a liquid iron core at those depths confirm that the iron-nickel mixture should indeed be molten at the core. Thus the absence of S-wave data on the far side of the earth gives us strong evidence for a liquid core in the middle.
*Shadow zones - P-waves: There is also a P-wave shadow zone, with a different shape from the S-wave shadow. Because the liquid outer core has a slower seismic velocity than the mantle above it, P-waves are bent, or refracted, as they pass into the core. When they come out again, the ray paths follow a different course, and this leaves a shadow zone where no P-waves reach the earth's surface. If the outer core were solid, a P-wave shadow zone (if there were one at all) would have a very different shape.scroll_rootNONNO?0spinner<thisstandalone0O?)$_root.main.coreclip.labels@0#6amainCMk:pVr  P "@(TYLY(Y\øYkØYlk}YH}YYȲY`äYäY<:@??_rootsidescrollsidetextHow do we know the inner core is solid?
Here's a puzzler! If the outer core is clearly a liquid iron-nickel mixture, then shouldn't the inner core of the earth be liquid, too? The inner core should be hotter, and therefore it should be a liquid, too, right?
*No: Actually, the pressure is so high in the inner core that an iron-nickel mixture is not stable as a liquid and instead crystallizes into a solid form, probably much like the meteorite sample with large crystals. So even though the inner core is hotter than the outer core, it is a solid, not a liquid.
*How do we know? An extra set of P-waves. Danish geophysicist Inge Lehman discovered this in the 1930s by painstaking observations of and attention to data that other geophysicists just ignored as "noise". Until this time, geophysicists thought that the entire core was a liquid. However, she found a second, very weak, P-wave following after the first one when looking at seismic waves that had passed nearly straight through the earth's center. She concluded that the core has an inner, solid part where S-waves can exist and that her weak P-waves represented a complex seismic wave that was part P-wave and part S-wave. Her proposed ray path consists of a P-wave from the hypocenter of the earthquake that traveled first through the mantle and outer core, then traveled as a slower S-wave within the solid inner core, and then emerged as a P-wave again through the outer core, mantle, and crust to the seismometer on the other side of the earth. Some influential geophysicists thought this was too subtle a dataset to be meaningful (that's what they considered "noise" in the data, like static in a radio signal). But several others agreed with Lehman, and by the late 1930s her work defining the presence of a solid inner core was widely accepted. She published a paper with her conclusions in 1936 that was titled " P' " (pronounced, "P Prime"), which is one of the shortest titles on record for a scientific paper. (Note: P' is the geophysicists' shorthand for the seismic boundary between the outer and inner core.)scroll_rootNONNO:;p @fwSs@ txߋ'2x͉M;'<u.ja55DŽ>4=nKUfDffƛ (̙3} 3f32VcձصMU-VBf$x-!JΙp1v"՜Z?J8C .d -/*X\6mK<%h&;mPŨ_rVA7Lv-O=9T2;Poe*U;;KUk)X+ttص0Z^V+>`  M[2e `(T@4?X^ !yIeOd:@XG ]AXG ]BXG ]oVoCXG ]oVoDX G ]oVoEXG ]oVoFXG ]ooNGhrpq y 1FT$78=S|78!d> !od #xD0LHXj\ xAc$FLH#S$@@<<1 pb<IXj ̙#S$@@<<1 pb+J`)H  m rP@ A6u&KX `fLnѺ)[<*L`&H  H- x) %MX T f狛2VNX@ TGdEd4OX k΀ `2RP@e,  Pn [\%'e,fP4f@ЙҏkZo[nLKit*Eirmq3W?0,cxD|6+@JrzWDg b va[{ l߫ceNmQP f PRPf (SPg (TPg (UP&g ZVP&f ^WP&f d,@cXne$ff _$0rdڻ qo~ly뉫ѓ;M(YZLbSgGBi|EY䴌DSمR]J.R-OYmr;b6IjRz'ѡD}/`Pa-iJ͉y?PJ[)KGzt ~(%.nWntx䅕KziQDm#@ SBBR)_NzQ\&@>O{tb@ @x8?z@ }AꀊBbC퀊 Dn E Fu G7z选 H JIpԐJ>怊KG^LAt>MKtN$ OA~XP%DQE;iRYnSonTUnVnWsX%DY+aZkـ [ !\0F"]+#^$@N_SyLdphs4i`pr 0 P "@'TYLY(Y\øYkØYXYôØ}YH}YYȲYxոìYY<`@