1
- 2005- 2005 1 1 5 1 6 7 8 10 4 2 2006 Far- Eastern Russia- Japan Seismic Network Seismic station operating O  IRIS Broad band Operating station Planning station Sapporo Center 1 IRS 6-10 1 2005 WS84
2 2006 1
STS LS- 7000XT G    STRECKEI SEN AG L- 4C- 3D lHz LS7000XL F LS- 7000XT
90 GPS 12V80Ah AC LAN LS- 7000XL WndowsXP EP SONY VAO POG kha 2005 6 akh TYM  8
TER
1 kha 1 F F 2006 2 3 IRIS 4 MDJ YSS KHA ar  Ter 3 4 2006 2005 3 2006 2 2005 5 2006  7 2 2005 AO2 I FREE ( 1)   P 5 (2) S-P (3) S ( 4) ( 5) ( 1) P P PP- P I SC ap, JI SNET, SPANET, SKI PPY, LDG 26, 500 PP- P IRIS P PP PP PP-P o 500 PP- P 64 × 32 PP-P 2 VFEP2 Fukaoet al., 2001 I SC 700 I SC VFP2 fukao et  al., 2001 500km 3 660km WPP2 660km 2 3 WEPP2 ( 2 S-P Vp/Vs Vp, Vs Vp/Vs Vp/Vs S-P preliminary Vp/Vs Vp/Vs S-P Vp/Vs 1Hz 2Hz Vp^s
(Ts-Tp)o Vp/Vs dlp, dls, P/S (Vp/Vs)o
S-P
[Fukao et. al., 2001] Vp=Vp° Vp/Vs-(Vp/Vs)o
Prel i mnary  Vp/Vs Vp/Vs R=dlnVs/dlnVp
R P Vs
Vp/Vs S 2100km Vp/Vs (3) S Fukao et al. 1992, JGR; Fukao et al. 2001, Rev. of Geophys.   , . , 670 km , 670 km (Takeuchi & Kobayashi 2004, GJI). (Direct Solution Method; Takeuchi et al. 2000, PEPI ) 200 , Degree-18 (degree-2 ) ( 4) H - net Hri (2001) H - net H - net ScS2 sScS2 ScS, sScS, ScS Ando( 1984) ,   Fukao( 1984) NWSSE ScS H - net ScS Vl adi vost ock( 02/06/28, №6. 7, 566km), Kuri l    02/11/17, M 7. 3, 459km  , Sakhal i n( 03/07/27, Nb6. 7, 481km) H - net ScS, sScS, ScS2, sScS2 Kuri l V adi vost ock ScS2 NWSSE 1 Q 75 ScS sScS ScS sScS V adi vost ock NEN 1. O Kuri l NE 1. O Sakhal i n   NW   1. 8 S radiation pattern Sakhal i n S ScS correl at i on NW NE (5) 12 Tynask Khabarovsk Corney Terney 5 nini - SEED STS- 2 f ul l - SEED I D
I D
10
2008 KRO5-14 12 11 3 ) 1 18 （ 2 1999 CMG- 3T, 360s- 50Hz) (Guralp 1 4 (T07,T08,T12,T15) ) ( （  2006 11 A02 P Fukao et al., 2004 Ichiki et al, 2005 (1) (2) (3) LOBEM Karato (1993) cDρ² a kT (1) D r k c P P D Hae et al., 2005 0.3 wt% Koyama et al., 2005 P P OBEM AQ 1.
SPEED- 1500, SPEED- MkII
SPring- 8 SPring- 8 GRC ISEI GRC 2 SPring 8 CCD 2 X SPring- 8 SPEED- MkII SPring- 8 X GRC EBSD FE- SEM GRC 3 x 18GPa, 1700K 2 P-V-T X P-V-T MgSiO3 P- V- T superhyrdours phase B Griggs
Ge
4 X SPring- 8 X
MORB
X X 2 SPring-8    BL04B1 SPEED-1500 SPEED-MkII Ringwoodite post-spinel perovskite
Pyrolite post-garnet post-spinel 2 wt.% -0.5MPa/K Katsura et al. (2004), Fei et al. (2005)   Mg2SiO4 2 wt.% post-spinel -2MPa/K Ringwoodite Ringwoodite Post-spinel 2wt.%H2O Olivine-wadsleyite,  wadsleyite-ringwoodite MORB post-garnet post-garnet 24GPa,1000 K post-spinel post-garnet 1000K H2O
B A B 1.5~2GPa A 2wt.% MORB 2wt.% post-garnet 1.Liitasov, K., and Ohtani, E., Stability of hydrous phases in CMAS-pyrolite-H2O system up to 25 GPa. Phys. Chem. Mineral., 30: 147-156, 2003.2.Litasov, K. and Ohtani, E., Hydrous lower mantle: The water source for wet plumes, 8th International Kimberlite Conference long abstract, 2004. 3. Litasov, K.D., Ohtani, E., Suzuki, A., Kawazoe, T., Funakoshi, K., Absence of density crossover between basalt and peridotite in the cold slabs passing through 660 km discontinuity, Geophys. Res. Lett., 31, L24607, doi:10.1029/2004GL21306, 2004.4. Litasov, K.D. and Ohtani, E., Phase relation in hydrous MORB at 18-28 GPa: Implications for heterogeneity of the lower mantle. Phys. Earth Planet. Inter., 150, 239-263, 2005. 5. Litasov, K.D., Ohtani, E., Suzuki, A., Kawazoe, T., Funakoshi, K., Absence of density crossover between basalt and peridotite in the cold slabs passing through 660 km discontinuity, Geophysical Research Letters, 2004GL021306R in press, 2005. 6. Litaasov, K.D., E. Ohtani, A. Sano, A. Suzuki, and K. Funakoshi (2005a) In situ X-ray diffraction study of post-spinel transformation in a peridotite mantle: Implication to the 660-km discontinuity, Earth Planet. Sci. Lett. (in press).7. Litasov, K.D. E. Ohtani, A. Sano, A. Suzuki, and K. Funakoshi (2005b) Wet subduction versus cold subduction, Geophys. Res. Lett., 32, L13312, doi:10.1029/2005GL022921. wt.%H2O wadsleyite FTIR nol - 1)  / RIJ D f = 1.0 x 10 5 exp [- 128 (kJ 1200 Nernst-Einstein =Dcq²/kT Ω 3 Ω 5 vt. % Ohtani  and Meda,  2001 Takahashi et al., 1998 2000 Chtani  and Meda 2001 2vt % 8w MRB wt. % MRB Ohtani  and Meda,  2001 Si Q 2 47.68vt. % A 2 Q 2 14.67, FeO 9.17, NgO 7.23, CaO 10.75, Na2O 2 5Q HgO 8 0 (Sakanaki et al., Nature 2005) 20GPa 2200 vt 3 59g/cm 7. 82cm²/nol 8wt % 8vt 1650 PREM(Dzi evonski  and Aderson,   1981) 5. 3vt 27GPa Si, O Si o LH-DAC 139GPa,3000K post-perovskite PF post-perovskite 18.3 atm% (6.3wt.%) o 6.6atm%(4.0wt.%) Si O,Si 67 D” ABO3 200km D" 50km D" 100km MgSiO3 (Mg0.9Fe0.1)2SiO4 (Mg0.5Fe0.5)SiO3 Mg3Al2Si3O12 KLB-1 MORB MORB D" MgO MgSiO3 119GPa   2500K D" ABO3 ABO3 titanate germanate MgSiO3 MgGeO3   MnGeO3   CaIrO3 CdGeO3 320GPa   2000K SiO2 270GPa   2000K 1988 200GPa 200GPa Si 6 MgSiO3 BL10XU SP8 PF 300GPa 140GPa   3000 K nm X
% % 1
H O
6XPa ``choke poi nt [Kavanoto et  al., 1996] [ Honda and  Yoshi da,   2005) A 2003 B van der H l st  and Seno [ 2003] 660km (B) ( A) (B) 2 3 2
6  18   6  23Gyr
2
12pWkg 12pWkg 6  79   7. 83Gyr 660km 660km 3 660km 3 internittent 600km 750km 40 i nt ernit t ent 3) 3 3 4 5 4 3 4 2 Busse et al., 1993 (    ) 4 2 3 2 3 2 A04 660 km 3 3 3 3 1 km 10 (=10 ) 1 km 3 3 9 3 3 + + 5 ) 13.4 ( 1024×1024×256 2 1 ( ) ( ) "phase function" ( ) 0.2 1 ( ) ( –4.3 MPa/K) ( ) 3000 km 18000 km 3 ) &si m 62.5 K 3 3 2 2 ( ) 3 2 ( ） ( GMRES m ) Uacc u o um-1 ( 2 ) Uacc up um l ( GMRES(m)    ) GMRES (Residual Cutting Method) 660 km 125 K ( m m ( ( m 10 2 ( 10 4 106 ) 1 3 Christensen (1996) Cizkova et al. (2002) ( ) ( 2) 2 410 km +3 MPa/K 660 km –3 MPa/K 660 km 660 km 660 km (Yoshida et al., 2001) (Moresi and Gurnis, 1996) Christensen, U. R., 1996. The influence of trench migration on slab penetration into the lower mantle. Earth Planet. Sci. Lett. 140, 27-39. Cizkova, H., van Hunen, J., van den Berg, A. P., Vlaar, N. J., 2002. The influence of rheological weakening and yield stress on the interaction of slab with the 670 km discontinuity. Earth Planet. Sci. Lett. 199, 447-457. Moresi, L., Gurnis, M., 1996. Constraints on the lateral strength of slabs from three-dimensional dynamic flow models. Earth Planet. Sci. Lett.  138, 15-28. Yoshida, M., Honda, S., Kido, M., Iwase, Y., 2001. Numerical simulation for the prediction of the plate motions: Effects of lateral viscosity variations in the lithosphere. Earth Planets Space 53, 709-721. 100 1 1000 10 MT 100 5m 10km ( ) / ( ) 660km - = 4 W m ¹ K ¹ （  1 cal m¹K¹ ) = 10 cm²s ¹ (SI   10 9 ( ) 1 ( ) 10 GPa 20 GPa( 600 km ) 1500  （     400-600km ) 1100K 8GPa 3％ 4％ klb 1 PREM 2700km MgSi Q D D PREM 1% klb 1 2200km 2500km 2800km 2500km 2700- 2800km 1%
ゲラーロバート・冨士延章・河合研志（東大・理）実体波の読み取られた到達時刻をデータとして用いる走時トモグラフィの出発点は、70年代の後半に発表された一連の画期的な論文(Sengupta & Toksoz, GRL, 2 84-86, 1976; Aki et al. JGR, 82 277-296, 1977)だったと言える。当時のモデルの解像度は荒いものであったが、それ以来全世界の研究者の努力の積み重ねによって解像度は向上され、走時トモグラフィは地球内部の構造およびダイナミクスの解明に大きく貢献してきた。一方で、走時だけをデータとすることでの限界も指摘されつつあり、波形そのものをデータとした内部構造推定、すなわち波形インバージョンによって、より詳細かつ正確な内部構造推定が可能となる公算が大きいであろう。しかしながら、波形インバージョンの実用化のためには幾つかの技術的な課題も残っており、我々はその解決に取り組んでいる。ここでは、その研究を要約する。本研究は今年度から特定領域研究として採択されたもので、当座の目的は波形インバージョンによる西太平洋下の上部マントルおよび遷移層の微細構造推定である。すでに広帯域波形データを用いた局所的な波形インバージョンは、中南米下のD"層のS波速度構造推定(Kawai et al., AGU, 2003)で先がけて行われており、本研究はその拡張である。現在、局所的な1次元モデルに対してフォワードモデリングを行い、波形データセットを集めている。これらはインバージョン実行のための下準備となる。まず、西太平洋下をサンプルするMw≥6.0かつ震源の深さ400km以上の1995年から2005年までのイベントのレコードをF-net,  IRIS,  OHP等から取得し、SN比がよい波形をデータセットとして選別した。震源関数の影響（Half durationが大きくなりすぎる）を考察し、Mw≤6.5のデータを使った方が良いと判断した。次に、Kawai et al. (2006, GJI, in press) の波形計算ソフト（ソフトは以下のサイトで公開中：http://www-solid.eps.s.u-tokyo.ac.jp/~dsm/）を用いて局所的な遷移層の３つのモデルに対してフォワードモデリングを行った。anisotropic  PREM, AZ41, ak135の深さ600kmの震源に対するプロフィールを掲載している（図）。不連続面の数などの影響から、三重合が見られる場合と見られない場合がある。西太平洋の局所的１次元モデルの研究は、現在に至るまで数多く発表されており、微細構造の推定手段の一つとして現在においても有効であると考える。ところが、それらは主に実体波を用いたフォワードモデリングによって行われており、定量的かつ客観的な見積もりが困難であった。そこで、本研究は波形インバージョンにより遷移層の微細構造を局所的に推定してゆくことで、遷移層のイメージを具体化することを目指している。波形インバージョンには、効率よくモデルパラメータに対する偏微分係数を計算するスキーム（Geller & Hara, GJI 1993）を用いる予定である。また、将来的に3次元で解くためのアプローチとしての最適化演算子を用いた差分法のコードの開発も進めている（Hirabayashi et al., GJI, submitted）。局所的な波形インバージョンは今始まったばかりであり、それが３０年前の走時トモグラフィのように急成長することを期待したい。の遷移層モデル(anisotropic PREM, AZ41, ak135)の深さ600kmの第浅形プロフィール(왕去百姓10° -40° ) 10s主で計算した.不津誌面の深さや数のMARGINS Subduction Factory MARGINS InterRidge InterRidge 17 18 Douglas A. Wiens Wiens Conder Douglas A. Wiens, Nobukazu Seama, and James Conder, Mantle Structure and Flow Patterns Beneath Active Back-Arc Basins Inferred from Passive Seismic and Electromagnetic Methods, Ridge 2000 - InterRidge AGU Monograph, Interactions among Physical, Chemical, Biological, and Geological Processes in Back-arc Spreading Systems, accepted. MB 11 ML O 690 km 1998] [Taj i na  and  Grand,   1995, ML O MB 11 MB 11 ML o broadeni ng P SV- P Ho reflectivity M3.11, M2.0 MB 11, ML 0 [Li et al., 1998] Baba et al., in press.; Evans et al., 2005 Hirth & Kohlstedt, 1996 Kohlstedt & Mackwell, 1998; Wang et al., 1996; Woods & Mackwell, 1998; Woods et al., 2000 Mainprice et al., 2000 Ichiki et al, in press. bulk b: a: 15 60 Ma 1 3 1 1 Ki ckof f 2004 Ki chof f 2004 1 20-21 I FREE B NA Grai g 2 11 2005 10 11 2 10 89 11 94 2 1 15 500 660 660 660 0.5MPa/K± 0.3 1 1 Ismail-Zadeh
DEM
DEM 2 2 1 Fe
28
3 CMB 3 10 8 1.0MPa/K 2 Kick-off 3 Kick-off 2006 7
5th Biennial Workshop on Subduction Processes emphasizing the Japan-Kurile-Kamchatka-Aleutian Arcs (JKASP-5) and International Volcanological Field School for Graduate Students --Linkages among tectonics, magma genesis, and eruption in the northern Pacific arc-- @ Hokkaido University International Congress Hall, Sapporo, Hokkaido, Japan July 9-14, 2006 [July 9-19 for the International Volcanological Field School] FIRST CIRCULAR CALL FOR PARTICIPANTS and ABSTRACTS Graduate School of Science, Hokkaido University Geological Survey of Hokkaido REGISTRATION DEADLINE: 31 MARCH 2006 EXPECTED ABSTRACT DEADLINE: 30 APRIL 2006 Updating info: http://tomura.eos.hokudai.ac.jp/jkasp2006/
Objective
This continuous and mature workshop has been widely covering subduction processes emphasizing the active Japan-Kurile-Kamchatka-Aleutian volcanic arcs, containing regional and local tectonics, seismic activity, deep and shallow subsurface structure, magma genesis, magma evolution, eruption mechanisms, volcano seismology, geochemistry, geodynamics and volcano and earthquake hazard mitigation. These segmentalized scientific objectives have automatically desired organic linkage with each other to understand the nature of geodynamic system. International geoscience community in the North Pacific has taken a step to overcome the obstacles which had disturbed scientific work in this region. This fact implies 5 th meeting will be able to build vital and fruitful relationship not only for scientific output but also meaningful future collaboration between neighbor residents. One of the special emphases of the forthcoming meeting will be to report progress on imaging the stagnant slab beneath northern Pacific region and its linkage to the volcanic phenomena, deep-to-shallow focus earthquakes and plate dynamics. This understanding will allow the fundamental further development of models for whole subduction zone processes. Another highlight of this workshop is the International Volcanological Field School for Graduate Students, which has been fully funded by Initiative for Attractive Education Program of Hokkaido University. This school will offer the opportunities to make productive international relationship between graduate students. Field excursion to the volcano Tokachi will be held after the scientific sessions, which will provide a clue to understand the pre- and post- caldera process of island arc volcano.
International Volcanological Field School
(Sunday, July 15 - Saturday, July 21) Volcanological Field School for students from Japan and other countries will be held after the workshop. This is one of the geological studies field course for graduate students of Hokkaido University. International students are welcome to join the course. In this course students will learn about a wide variety of volcanoes and eruptive products in Hokkaido Island, where is a junction of two arcs, Northeast Japan and Kuril Arcs. We will expect less than 20 students. All costs during Hokkaido staying will be supported by Hokkaido University and LOC.
Steering Committee:
Minoru Kasahara and Mitsuhiro Nakagawa, Sapporo, Japan Evgenii Gordeev and Victor Chebrov, Petropavlovsk-Kamchatsky, Russia John Eichelberger and Jon Dehn, Fairbanks, AK, USA
Local Organizing Committee:
Hokkaido University: Minoru Kasahara (chairman), Mitsuhiro Nakagawa (vice-chairman), Hiroaki Takahashi, Mitsuhiro Yoshimoto, Takahiro Maeda Geological Survey of Hokkaido: Noritoshi Okazaki
Form of Workshop:
Speakers who hope oral presentation are asked to talk for 15 minutes including discussions, and are able to use a fixed windows PC with digital projector but no overhead projector (OHP). Poster presentations are also welcome, and will be available throughout the dates of workshop. Presenters are not able to submit more than two presentations as first author.
Meeting Venue
Scientific sessions will be held at International Congress Hall of Hokkaido University, locating near Hotels, Sapporo station, and central Sapporo city.
Language of the meeting
The official language of the workshop is English.
Travel and Accommodation
Travel arrangements up to New-Chitose/Sapporo airport should be made individually. But there are little direct flights from abroad to New-Chitose. LOC recommend US and EU participants will come to Sapporo via Osaka/Kansai or Nagoya/Chubu airport where have many direct flights from/to US and EU, and easy to transfer to the Sapporo/Chitose flights. Tokyo/Narita airport requests 2-3 hours moving to the Tokyo/Haneda domestic airport by bus and/or JR line. For Russian participants, Niigata airport is one of potential transfer route to Sapporo. For Sakhalin participants, Sapporo/Chitose and Hakodate airports have direct flight in Monday, Wednesday and Friday. After arriving at New-Chitose airport, get on JR-line for Sapporo JR Station. During Sapporo staying, "Sapporo Aspen Hotel" and "Sapporo Mets Hotel" are potentially preserved. Both are within an easy walking distance to the meeting place and Sapporo station. Fundamentally, hotel reservation will be handled by LOC but individual accommodation bookings in Sapporo via internet are approval. We anticipate that costs for food and lodging will average about $150/day in Sapporo. Accommodations during excursion will be lumped by LOC.
Weather
Beginning of July in Sapporo is generally sunny and daytime temperatures averaging +20°C. However, there is always a possibility of rain and cold air, especially in field trip.
Pre-Registration and Abstract Submissions
Participants wishing to make oral/poster presentations are requested to fill registration form with tentative titles and submit it until March 31, 2006. People who want to attend this workshop but non-presentation also need to make registration. Students who hope to join the International Volcanological School are also requested to submit a registration form until above deadline. Expected deadline of abstracts is April 30, 2006. LOC will inform concrete deadline and formatting in 2 nd circular which will be issued immediately. Please check updating info at http://tomura.eos.hokudai.ac.jp/jkasp2006/.
Expected Registration Fee and Field Trip Costs
There will also be a registration fee of approximately $250 to cover group events. Field trips are expected to cost about $400 each including accommodations and meals. Costs for students who will join the International Volcanological Field School will be fully supported except for trip fee from your country to Sapporo. Please fill out the attached registration form with expected title of your presentation and return it to the Hiroaki Takahashi (hiroaki@eos.hokudai.ac.jp) until the deadline, 31 March 2006. All conference attendees are requested to pay in cash by US dollars or Japanese Yen at the registration desk.
Contact
If you are interested in receiving subsequent circulars regarding this meeting, please contact the following members, Sapporo LOC member: Minoru Kasahara ( mkasa@eos.hokudai.ac.jp ), Mitsuhiro Nakagawa (nakagawa@ep.sci.hokudai.ac.jp), Hiroaki Takahashi (hiroaki@eos.hokudai.ac.jp). US participation will be coordinated by UAF/GI through Jon Dehn (jdehn@gi.alaska.edu) and Pavel Izbekov (pavel@gi.alaska.edu) Russian participation will be coordinated through IVS by Evgenii Gordeev (gordeev@kcs.iks.ru)
Sponsorship:
This meeting will be sponsored by the Institute of Seismology and Volcanology, and Division of Natural History of Hokkaido University, Stagnant Slab Projected of Grand-in-Aid for Scientific Research of MEXT of Japanese Government, Initiatives for Attractive Education of Graduate Schools at Hokkaido University funded by MEXT of Japanese Government, and Geological Survey of Hokkaido.
Sunday, July 9 15:00 - 18:00 Registration and Check-in 18:00 - 20:00 Icebreaking reception @Scientific Sessions Monday, July 10 Introduction and welcome Imaging stagnant slab and upper mantle structure beneath north-western Pacific region. Seismological and geological tectonics, geodynamics, subdcution-related seismology. Tuesday, July 11 Magma genesis, geochemistry, volcanic eruptions, and monitoring. Volcano and earthquake hazard mitigation Discussion on international collaboration for research and education. Evening discussion at Sapporo Beer Garden with ram B.B.Q. @Field excursions at Central Volcanic Zone of Hokkaido Island Wednesday, July 12 Moving from Sapporo to the base of the Tokachi volcano by chartered bus. Geological short reconnaissance of Tokachi volcanic group. Open discussions at open-air hot spring bath in hotel. Thursday, July 13 Climbing up to the active craters of Tokachi volcano (2041m) by walk about 6-7 hours for round trip. Geological and petrological discussions will be made during the way. Athletic shoes or light climbing boots are recommended. Participants who will not able to climb up can visit volcano monitoring stations, volcano hazard mitigation facilities, and taking hot spring bathes. Open discussion: Summary of meeting, future collaborations, and time and place of next workshop. Friday, July 14 Back to Sapporo by chartered bus until evening. Participants should be taking accommodation at Sapporo because of lack of night flight. @International Volcanological Field School Sunday, July 15-Thirsday, 19 Geological field trip will be held after above field excursion. Costs of this course will be fully founded by Initiatives for Attractive Education Program of Hokkaido University. Dec. 2004 P. 22 14 km  3 km  ³ 13 1010 10'0 P.23 Ra= Ra= = 113-0032 Phone: 03-5841-5701 Fax: 03-3812-9417 1-1-1