Expectations for international MARGINS' collaborations from the point of view of an
"active margin" country
Gaku KIMURAThe University of Tokyo
iFREE JAMSTEC
One Day Suddenly!
2004 Sumatra Tsunami1944 Tonankai Earthquake Mie Prefecture
Top 12 since 20C
1906 Equador1923 Kamchatka1938 Banda1950 Tibet1952 Kamchatka1957 Alaska1960 Chile 1963 Kuril1964 Alaska1965 Rat Alaska2004 Sumatra2005 N.Sumatra
Nankai Trough: Longest Historical Record
Ide et al., 2007
Obana & Kodaira, 2009
国土地理院/世界最稠密 GPS南海トラフ
Recent Great Discoveries
Obara, Science 2002, Ito et al., Science 2007, Ide et al., Nature 2007
Plate boundary depth contour
Rupture AreaRupture Area
Rupture Area
Deep Low Frequency TremorDeep ultra-low Frequency TremorSlow slip
Shallow ultra Low Frequency Tremor
Soon: Direct observation within fault zone bore hole
Recent Great Discoveries : far field observation
Deep LFT
Shallow LFT
Chikyu
Moore et al., 2009
Splay Fault
Oceanic Crust Decollement
3D Nankai accretionary wedge
Moore et al., 2007, 2009
The splay Fault from the bottom
Many landslides around active portion of the splay fault
Horizontal slice at -2910m
Clear deformation ofyoung (<0.5My) slope sediments
南海トラフ海底地形・断面図
フィリピン海プレート
Splay Fault
10cm
X-rayCT
Drilling Result of the splay fault Kinoshita, Tobin et al., 2009
1944 Tonankai!Disturbed mud is a key
Analyzed byYamaguchi et al.
Conclusion1. Nankai Trough SEIZE is a quite successful on-
going international collaboration through individual PIs, IODP frame, Margins program and others.
2. International collaboration is strongly expected from “active margin” countries because natural geo-hazard issues are so serious and urgent.
3. A new frame of international MARGINs is expected in each country.