@article{oai:nipr.repo.nii.ac.jp:00010749,
 author = {Marek Grad and Rolf Mjelde and Lech Krysiński and Wojciech Czuba and Audun Libak and Aleksander Guterch and IPY Project Group and Marek Grad and Rolf Mjelde and Lech Krysiński and Wojciech Czuba and Audun Libak and Aleksander Guterch and IPY Project Group},
 issue = {1},
 journal = {Polar Science, Polar Science},
 month = {Mar},
 note = {As a part of the large international panel “IPY Plate Tectonics and Polar Gateways” within the “4th International Polar Year” framework, extensive geophysical studies were performed in the area of southern Svalbard, between the Mid-Atlantic Ridge and the Barents Sea. Seismic investigations were performed along three refraction and wide-angle reflection seismic lines. Integrated with gravity data the seismic data were used to determine the structure of the oceanic crust, the transition between continent and ocean (COT), and the continental structures down to the lithosphere-asthenosphere system (LAB). We demonstrate how modeling of multiple water waves can be used to determine the sound velocity in oceanic water along a seismic refraction profile. Our 2D seismic and density models documents 4–9 km thick oceanic crust formed at the Knipovich Ridge, a distinct and narrow continent-ocean transition (COT), the Caledonian suture zone between Laurentia and Barentsia, and 30–35 km thick continental crust beneath the Barents Sea. The COT west of southern Spitsbergen expresses significant excess density (more than 0.1 g/cm3 in average), which is characteristic for mafic/ultramafic and high-grade metamorphic rocks. The results of the gravity modeling show relatively weak correlation of the density with seismic velocity in the upper mantle, which suggests that the horizontal differences between oceanic and continental mantle are dominated by mineralogical changes, although a thermal effect is also present. The seismic velocity change with depth suggests lherzolite composition of the uppermost oceanic mantle, and dunite composition beneath the continental crust., 第４回国際極年の枠組みにおける「プレートテクトニクスと極地への窓」という国際的研究グループの一部として、大西洋中央海嶺とバレンツ海の間の南スバールバール地域で大規模な地球物理探査が行われた。3測線で屈折・広角反射地震探査が行われ、重力・地震の統合データにより海洋性地殻、大陸-海洋遷移帯(COT)、リソスフェア-アセノスフェア深までの大陸地下構造が得られた。また水中多重反射波のモデリングから、測線下の海中音波速度が求められた。地震波・密度の2次元モデルからは、クニポビッチ海嶺で形成された4-9 km厚の海洋性地殻、明瞭かつ幅の狭いCOT、ローレンシアとバレンシア間のカレドニア縫合帯、及びバレンツ海の30-35 km厚の大陸地殻が得られた。重力モデルから上部マントルの密度と地震波速度に弱い相関が示されたが、海洋と大陸マントルの水平方向の差異は、熱的効果以上に鉱物相変化が支配的なことを示唆している。また地震波速度の深さ変化は、海洋マントル最上部におけるレルゾライト成分、及び大陸地殻下のダナイト成分の存在を示唆している。},
 pages = {168--183},
 title = {Geophysical investigations of the area between the Mid-Atlantic Ridge and the Barents Sea: From water to the lithosphere-asthenosphere system},
 volume = {9},
 year = {2015}
}