1. Deep Structure Research of the Earth after the International Geophysical Year (Geotraverse Project and InterMARGINS)
A.G.Rodnikov, N.A.Sergeyeva, L.P.Zabarinskaya
Geophysical Center, Russian Academy of Sciences
Moscow, Russia

2. First International Polar Year (1882-1883)
Austro-Hungarian navy officer, Arctic explorer who discovered Franz Josef Land, an archipelago north of Russia, and who advanced a successful scheme for international cooperation in polar scientific investigations but died before it first occurred in
Karl Weyprecht
( )

3. The International Geophysical Year 1957 – 1958
inspired by the IPY and occurred 75 years after the first IPY
The Bureau of the special IGY Committee in Brussels in M. Nikolet (Belgium), General Secretary of the Committee, ( in the center); to the left of him: L. Berkner (USA), Vice-President, V. V. Beloussov (USSR), Bureau member and later Vice-President, and to the right of him J. Kulon (France) Bureau member, C. Chapman (Great Britain), Committee President

4. Emblem of IGY

5. The International Geophysical Year 1957 – 1958
Academician I. P. Bardin, Chairman of the Soviet Committee for IGY,
Vice-President of the USSR Academy of Sciences informs on the conference for press that
the Soviet Union intends to launch the artificial satellite of the Earth during
the International Geophysical Year (IGY).
Barcelona, 1955.
В 1955 г. на заседании комитета по проведению Международного геофизического года (1957—1958 гг.) в Барселоне академик И.П.Бардин и, несколько позже, на астронавтическом конгрессе в Копенгагене, академик Л.И.Седов заявили о намерении Советского Союза запустить искусственные спутники Земли в рамках геофизического года. В 1955 г. на заседании комитета по проведению Международного геофизического года (1957—1958 гг.) в Барселоне академик И.П.Бардин и, несколько позже, на астронавтическом конгрессе в Копенгагене, академик Л.И.Седов заявили о намерении Советского Союза запустить искусственные спутники Земли в рамках геофизического года. В 1955 г. на заседании комитета по проведению Международного геофизического года (1957—1958 гг.) в Барселоне академик И.П.Бардин и, несколько позже, на астронавтическом конгрессе в Копенгагене, академик Л.И.Седов заявили о намерении Советского Союза запустить искусственные спутники Земли в рамках геофизического года. В 1955 г. на заседании комитета по проведению Международного геофизического года (1957—1958 гг.) в Барселоне академик И.П.Бардин и, несколько позже, на астронавтическом конгрессе в Копенгагене, академик Л.И.Седов заявили о намерении Советского Союза запустить искусственные спутники Земли в рамках геофизического года.

6. NP" stations carry out the program of complex year-round research
in the fields of oceanology, ice studies, meteorology, aerology,
geophysics, hydrochemistry, hydrophysics, as well as in the field of marine biology.
Немагнитная шхуна «Заря» — единственное в мире немагнитное научное судно.
Построено в Финляндии на верфи «Лайватеоллисуус» в 1952 году по заказу
АН СССР. Это парусно-моторная трехмачтовая шхуна с гафельным вооружением.
В 1955 г. на заседании комитета по проведению Международного геофизического года (1957—1958 гг.) в Барселоне академик И.П.Бардин и, несколько позже, на астронавтическом конгрессе в Копенгагене, академик Л.И.Седов заявили о намерении Советского Союза запустить искусственные спутники Земли в рамках геофизического года
San Andreas Fault
A major geologic fault located in California. It runs from San Francisco
to near San Diego and has been the source of serious earthquakes.
(See also under “Earth Sciences.”)

7. Non-magnetic schooner “Zarja”
Russian non-magnetic oceanographic research vessel ZARJA (or ZARYA).
Built 1952 in Finland, 333grt, wood auxiliary three-masted schooner.

8. North Pole Drifting Station SP-7
Drifting station SP-7* conducting observations in the Arctic regions from April 23, till April 11, 1959, Distance = 3520 km
*Soviet and now Russian drifting ice stations are named "Severnyy polyus“
(Russian: «Северный полюс»; English: "North Pole") and are abbreviated SP
(Russian: «СП»; English: "NP"). Each station is assigned an ordinal number.

9. Soviet and American Researches in the South Pole

10. Results of IGY
Press-conference on IGY results. Professor V. V. Beloussov is
speaking.
From left to right
A. D. Powsner,
N. V. Shebalin,
N. V. Pushkov and V. A. Magnitsky.
Moscow, 1963.

11. After the International Geophysical Year
1957 – 1958
New Projects
Ocean Margins
Ocean Margins

12. Gulf of California (San Andreas Fault Observatory at Depth)
Drilling the San Andreas Fault at Depth
The first of these drilling projects is making a borehole next to the San Andreas fault
near Parkfield, California, at a depth of about 3 kilometers. Drilling began in 2004 with a vertical hole going down 1500 meters, then curving toward the fault zone.
The 2005 work season extends this slanting hole all the way across the fault, and is being followed by two
years of monitoring.

13. Project “CRISP” (Costa Rica Seismogenesis Project) InterMARGINS, Newsletter No 4, 2004
CRISP is a project to understand the initiation of large earthquakes and seismic rupture by drilling on either side of the updip limit of seismogenesis. The shallow dip of the subduction zone off southern Costa Rica and relatively high subducting plate temperature cause this seismogenic environment to rise to drilling depth.
Materials, temperature, lithification, fluid flow and chemical changes that occur down the subduction zone are hypothesized to cause the transition from stable to unstable slip that ultimately results in great earthquakes. Along the erosional convergent margin of Costa Rica the seismogenic plate interface is surrounded by eroded debris rather than by trench sediment.

14. CRISP is structured in 2 programs that
systematically lead to deep riser drilling of the seismogenic zone. The non-riser drill Program A will provide cores
to characterize lower plate igneous basement rock and its hydrology. Paleo-depth indicators will allow a first
estimation of eroded debris and trench sediment thickness input by the subduction channel into the seismogenic
zone. Instruments will be deployed in the holes to record microseismicity and monitor fluid pressure. Program B
involves 3.5-km and 6.0-km-deep holes that are engineered from results of Program A. Program B riser drilling
samples the subduction channel along the plate interface and characterizes conditions in the zone of stable slip and
then conditions in the zone of unstable slip. This provides observations to determine physical and mineralogical
transformations and dynamic changes causing unstable slip. The riser-drilling sites are in 500m and 1000m deep
water and in an area of optimum operating conditions nearly year around. Osa Peninsula provides the opportunity
to expand investigation farther down the seismogenic zone with land drilling to ~7km should that become
attractive in the future. With a low sediment supply, fast convergence rate, abundant seismicity, subduction
erosion, and a change in subducting plate relief along strike, CRISP offers excellent opportunities to learn causes
of earthquake nucleation and rupture propagation. It complements other deep fault drilling (SAFOD and
NantroSeize) and investigates the first order seismogenic processes common to most faults and those unique to
erosional margins.
IODP Proposal Cover Sheet
New Revised Addendum
Above For Official Use Only X

15. New
Subduction
Zone in the Japan Sea

16.
Geophysical Center of the Russian Academy of Sciences took part in the fundamental researches on the deep cross-sections of the lithosphere through the marginal seas in a transition zone from Asian continent to the Pacific Ocean investigated under the Geotraverse International Project and InterMARGINS

17. Area of Research
The deep structure of the Eurasia-Pacific transition zone was investigated under the Geotraverse Project and InterMARGINS along the deep sections of the tectonosphere, including the lithosphere and the asthenosphere. The first geotraverse, was preparated in cooperation with Japanese geoscientists, crossed the region of the Japan Sea. The second geotraverse, carried out in cooperation with Japanese and Chinese geoscientists, crossed the region of the Philippine Sea and the North China Plain. The third geotraverse crossed the region of the Okhotsk Sea.

18. Seismicity
The Eurasia-Pacific
Transition Zone

19. Distribution of Heat flow
The Eurasia-Pacific
Transition Zone

20. The Japan Sea Geotraverse

21. Seismic Profile along the Philippine Sea Geotraverse

22. The North China Plain-Philippine Sea Geotraverse
There are correction between asthenosphere and formation of deep basins. Under Paleogine West Philippine Basin the asthenosphere lies at the depth of km. Under the Neogene Parece Vela basin the asthenosphere lies at the depth of 30 km. Under the Mariana Trough the asthenosphere reaches the crust causing active tectonic and magmatic processes.

23. The Okhotsk Sea Geotraverse

24. Area of Research
Bathymetry contour chart for the Sea of Okhotsk showing location of major sedimentary basins: North Sakhalin Basin, Deryugin Basin, TINRO Basin, Kuril Basin. Map prepared using 2-minute digital gridded topography data (Modified after Smith and Sandwell, 1997).

25. Tectonic Scheme Compiled from the data of Maruyama et al
Tectonic Scheme Compiled from the data of Maruyama et al., 1997; Cruise ..., 2000; Zonenshain et al., 1990; Kiratzi and Papazachos, 1996; Rodnikov et al., 2001
The Okhotsk Sea region is a large Lithospheric plate of the transition zone from Asian continent to the Pacific. It is located in the contact zone of three Lithospheric plates : Eurasian, North American and the Pacific. Arrows show plate movement direction.

26. Deep Structure of Deryugin Basin and North Sakhalin Basin (Sea of Okhotsk)
The Deryugin Basin was formed in the Cenozoic at the site of the ancient deep trench after the subduction of the Okhotsk Sea Plate under Sakhalin had been completed in the Early Paleogene. The North Sakhalin oil and gas basin was formed at the site of the Late Cretaceous bark-arc basin. The Deryugin basin is located above a hot plume in the mantle that is asthenospheric diapir of partial melting revealed at a depth of 25 km. The west side is bounded by ophiolite belt of ultramafic magmatic rocks, which confine an ancient (K2-Pg) paleosubduction zone separating Deryugin Basin from North Sakhalin basin.

27. The Upper Mantle for the Sea of Okhotsk
Seismic tomography model of the upper mantle in the Okhotsk Sea (Bijwaard, 1998). There are two subduction zones: ancient (Triassic-Cretaceous), the subduction Okhotsk Sea plate under Asian Continent and recent, the subduction Pacific plate under Kamchatka.

28. Asthenosphere and Moho beneath the Sea of OkhotskC
The Model of the of the Lithosphere structure of the Sea of Okhotsk.
A-the Okhotsk Sea floor relief. B - Moho. C - asthenosphere. The asthenosphere in the upper mantle of the Sea of Okhotsk is located at a depth of km and beneath the Northwestern Pacific basin it is revealed at a depth of 100 km. Diapirs of partial melting come off the asthenosphere, reaching a depth of km beneath the Tatar Strait Trough, Deryugin Basin and Kuril Basin and causing an active tectonic regime manifested in volcanic, seismic and hydrothermal activity. Red color shows the area of magma formation.

29. The Okhotsk Sea Geotraverse
The Okhotsk Sea Geotraverse crosses the Sikhote Alin, Sakhalin, Kuril Basin, Kuril Island Arc and Pacific. The thickness of the crust varies from km under Sakhalin and the Kuril Islands to 8-10 km under the Kuril Basin. In the Cenozoic, the large part of the sedimentary basins was formed. The asthenosphere in the upper mantle is separated mostly from geothermal data. The upper surface of the asthenosphere is an isotherm 1000-1200C, the temperature of partial melting. The asthenosphere is located in the upper mantle of the Sea of Okhotsk at a depth of km. From the asthenosphere the diapirs go off that reach a depth of km beneath the sedimentary trough of Tatar Strait and Kuiril Basin, causing an active tectonic regime.

30. Conclusions
A distinctive feature of the transitional zone between the Eurasian continent and the Pacific Ocean is the presence of an asthenosphere in the upper mantle.
The tectonically active regions, such as the island arcs and the rifts of the marginal seas, correlate with a thick, magma-generating asthenosphere. The asthenospheric diapirss are marked on the surface by rift formations and mainly tholeiitic magma eruption.
The asthenosphere resides in a depth of 50-80 km under the old Paleogene deep basins of the marginal seas, at about 30 km under the Neogene basins, and at a depth of  km under the Pliocene-Quaternary and recent inter-arc basins, causing the breaks of the lithosphere, the formation of rifts, basalt lava eruptions, and hydrothermal activity
Rifts in the marginal seas and island arcs may by accompanied by intense mineralization. The combination of high heat flow, volcanicity and hydrothermal activity in these structures, in the past and at present, can lead to the formation of sulfides and non-metalliferous mineral deposits.
The formation of the sedimentary basins is associated with recent and ancient subduction zones. The sedimentary basins are characterized by:
- rift structures or spreading centers at their basement;
- active magmatism at the initial stage of formation;
- hydrothermal processes associated with sulphides formation;
- high density of heat flow caused by the uplift of the asthenosphere to the crust;
- localization of asthenosphere diapirs in the upper mantle;
- asthenospheric diapirs are channels, along which hot mantle fluids from the asthenosphere penetrate into the sedimentary basins and other units transition zone.