  .3  (,**.)
 -  +/-ῌ+/0 State of the Arc (SOTA) ,**- ῎ῌ῏῍   
Report of State of the Arc (SOTA) ,**Takashi SANOqC =- }? X!"  (5SX+
State of the Arc (SOTA) 

W YZ¡)¢(inop4X:;"<% <£ -  +  !"#$%  +¤Cq&[#¥¦ 3 m§X¨!" #YZO +331 '()*+,--./(0  , &Future directions and research objectives,*** 12(3(+405-6789:;""V + m§S©ª[ t§m$#«P¬< => ,***?% @&  - & ,**-  2 A +0B

X:;"<%,* C-D,EFG'/H4I Mt. Hood JKL Timberline Lodge =M +?  !"<% N O -D,EP Bill Leeman (Rice Univ.), Jon Davidson(Durham Univ.), Tobias Fischer (Univ. New Mexico),+% How can we better quantify thermal structure ofsubduction zones (SZs) ?
,% What are the mass and energy ﬂuxes in arcs, andhow do they inﬂuence arc structure?

Anita Grunder (Oregon State Univ.), Mark Reagan (Univ.

-% How do we di#erentiate steady state processes fromIowa), Martin Streck (Portland State Univ.)  -D

transient events in SZs, and how are these related to,E QR,) '()*+,- 12(3(+40SNTULVW 3* PXYZ[#:;"<% CVW \] ^ =_ `? >ab = c`? ]>=d efghi?  =jk`?  . X

YZ[<%tectonic forcing functions?
.% What is the composition of the mantle wedge, howdoes it melt, and what does it produce?
/% What are the e#ects of the ‘crustal ﬁlter’ in modifying mantle magmatic inputs and/or in producing theSOTA ,**- l(‘Energy and Mass Fluxes inVolcanic Arcs’  / minop4 =qh? Xrs!"<% tinop4, muvinop4VWwx!" tuvinop4

observed compositional spectrum of arc magmas?
0% How does the slab impart its signal (chemical/physical) to arc systems?

+ Pyz{|OX -* 

1% How can we reconcile the disparate time scales}~((*)(S:<q O:across the compositional spectrum from U-Th radioi-inop4l(<%Lm$# 0* }

X:;"X)+Q0 ,B- S[<SX!"# CPO[#$<% yz{|O ~(sotopes?
2% How can we better constrain the systematics ande#ects of degassing in the crust?
3% Whatdrives crystallization

(*)([#inop4/magmas?

2(S:#$<% + minop4 < SOTA ,**-  ¸.+1ῌ*2*+ j¹` -,/jk`fº»¼f
College of Environment and Disaster Research, Fuji
Tokoha University, -,/ Ohbuchi, Fuji .+1ῌ*2*+, Japan.
e-mail : sano@fuji-tokoha-u.ac.jp

and degassing in-D,E­®¯°±P²Xrs[<­®³´Xµ¶[# pre-conference trip [# 2 A +0 C Mt. St Helens S mid-conference trip [# 2 A +3 C Mt. Hood S post-conference trip [# 2 A ,+B,- C Oregon Cascade volcanoes S³
X·<%

State of the Arc (SOTA) ,**- @154

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I>?+;KO *P 3v4
TO^O#eTF63l.07 I lGNHkI
J4K Bill Leeman, Julie Morris $4L
16 MN? + NlOPM SrC3Q0O^O#RXYPS20 1
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SOTA,**- 4 Timberline Lodge.

Session #- : Chronologies and rates, mass contributions,and impacts of crustal level processes that,ῌ ῏῎ῐῑ῍inﬂuence arc magmatism 2  +1 +2 ,*  - f?$H3 Georg Zellmer 4]<  U-Th-Ra 9=>?056

P!7   ! "#$% $!&

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'()(*+,(-./ 0 123)*A¢3¥¦>?Q§ 1¨Y$O^OZ[© \V¡ 4Vª6]23f$©

Session #+ : Thermal structures of SZs.
Glenn Gaetani 4 petological constraints, Chris Kincaid)*$F38^ .$1¨«_ O^

4 geophysical constraints 056'()(*+,(-O«¬ `a$0M3E© [$4J!7 Gaetani 80 H, O  CO, 09$: h0 Mike Dungan LMN Jon Davidson 4¡ aX; <=> 1 =>?4@6s­P$b<RL<C3QY(53ABC+DE0FG4H3IJ

1 O^OL[j01¨«_O^O«¬4 Kincaid +;KLMNO *PQRST

®0cw¬76_I763J d<b<R3U0!& VW5 1LC3QH&¯6\V¡ aXTef23

XYP4Z3TEF[23U0\6 .$]O^OA(+0+;K_`

$056±g4./$H3.

ab!c"63 O^ObMd0#e3 (ﬂux melting vs. decompression melting)$056%&4'47 fg( , hiT
XYP$=jMkl)*D4+m,-4Hk no - hi$=>!d./-4H3J
originating below the MohoJohn Eiler 4]O^OA(+O o0 George Bergantz 4]1¨²R0c2
3=><0rLMN hXYP056 1Session #. : Energetics and dynamics of magma feeder

Session #, : Sources, processes, and rates of mass ﬂuxes

B9$¤VL[ 1¨«_ ¤V°

systemsij Kelly Russell 4O^OkR[.23j0./lr2mn056stu(! .

*P0c23< oj Jon Blundy IJ$H74 I s0p1q[r2stu( Simon Turner 4tu($7  Mt. St Helens O^OR³]#O *P$O^O3v450c23

0c23oE´IJ IJ0p23.

 1 ]#O *P46wxyz+;K_`4 $lq$ II$r a{|}~63I1q[rY(23 8^"#sk$H3 + ]634 ld78wxyz./-4

9#O*PQRS$#RO^O. Moho

 : : +;KO *P  av4;

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0v¸231¨¹3UO^O'wxº3

lk $ Simon Turner +;K_`3 U

$H3 , Moho 0tf7O^O`06

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H, O  +*155 #CJ KLM ;Q  bwtῌ      cd6J I- I#J!"#$

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=# I5DE

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Mt. St Helens- i ¢Q j6kl£m ¤6J ¢Q ¥c¦Qn

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St Helens kxl

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V0# 1N W24X 3COPQ=6J
 Tim Grove CJG#Y#) +** MPa.) GPaH, O 4)ῌ H, O)ῌX

Mt. St Helens "-6J©s FGH

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blast deposit µ¶1J ,

Mt. StH, O 

5!-678 9: Z*-#[;66 H, OJ

Session #/ : Origins, budgets, and inﬂuences of magmatic
volatiles* Bernard Marty \]T<^ 6J=_>] `a;bJKLcdef6J =_He T./>gh?S,9 /i He jf]  Q=BkR-l -Heῌ .He / =_m89 %6 

n@ op Gqr/ ]sABC
optuD V0 #CJ \] U6 E] v T<F? ]s T.
/1 GH :fw2  xy I#J K
L/2K*J z , ³´ +,,*** {X Mt. St Helens "-6J©s  Z·t¸
M John Pallister.

Paul Wallace > ] (H, O, CO,, SO,, Cl)

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(Mt. St Helens,6J  - )]

Mt. St Helens ῐ῎

Mt. St Helens \_Z 2  +/ _KLM KL^,

f=sQ` B a -¹B:s`"-¯o6J Mt. St Helens.

State of the Arc (SOTA) ,**- ¬¶#§156
Helens        !

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12*3 45#$%6789 Stop , :; Stop - <:=>?@5G45HI JK"9A#BCD E*FLMNO$PQRA

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Mt. St Helens D n(%o6*V, p -9-ῌ,Mt. Hood p .9 Mt. Hood l¬¶·9(w-%^_qrstuN 2 v +3  Mt. Hood XH(wt*xy459 z{ Stop +, , | Timberline Lodge:;}#~"9 Stop + V +./,*** n K-Ar l (wAp . Stop ,V;56(w 9Stop -  3 "p / Mt. Hood ?-%  (w"9 ${5O K-Ar +* nVW*  %6VW9 o5*"$o6-%VW=9 ^_Ml!
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V /"$h$ª«; ¬­¢,$9 ®¯ SOTA,**0 %&°±V²5%'³VW%9p /9 Mt. Hood ^_¸(459 o)¹*º·A#»¼45A=VW%9´µU (,***) State of the Arc (SOTA) ,**- (Ruapehu,New Zealand) ¬¶#§9 l ./ ++3ῌ+,,.