Super-deep seismic reflection study in growth of continental crust beneath the Hidaka Collision Zone, Hokkaido

北海道日高碰撞带下方大陆地壳生长的超深地震反射研究

• 批准号: 12304027
• 负责人: ITO Tanio
• 金额: $ 28.68万
• 依托单位: Chiba University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12304027/
• 关键词: Hidaka Collision Zone; delamination; Pacific plate; seismic reflection study; growth of continental crust

In order to detect the 3-D geometrical relationship between the descending Kuril arc delaminated at the middle lower crust and the upper surface of subducting Pacific plate, the super-deep seismic reflection experiment, Super-Deep Hidaka 2000, was conducted in the low noise-level area, Samani Town, southern part of the Hidaka Collision Zone. The target of this experiment is located down to 50 km deep. Seismic lines were set up in two directions, NW-SE (parallel to the Pacific plate subduction) and NE-SW (neally paralle to the Kuril arc collision). Total length of the lines reached 32 km long. Main specifications were as follows : Shot at about 300 m interval with 30 Sweeps in average(6-30 Hz, 24 sec) by 5 vibrators, 9 pick-ups / receiving point at 50 m interval. The basic processing produces fairly excellent profiles which is successful in exhibiting both the deeper part of the HMT (Hidaka Main Thrust) and the subducting Pacific plate. The image of descending Kuril arc is still unclear. Further processing will improve the present profiles and provide the new powerful data on the geometrical relationship between the descending Kuril arc and the subducting Pacific plate.

为了探测下地壳中拆沉的千岛弧下降与俯冲太平洋板块上表面的三维几何关系，在日高碰撞带南部萨马尼镇低噪声区进行了超深日高2000地震反射实验。这次实验的目标位于50公里深处。地震线设置在两个方向，NW-SE（平行于太平洋板块俯冲）和NE-SW（几乎平行于千岛弧碰撞）。铁路总长达32公里。主要规格如下：间隔约300米，平均30次扫描（6-30赫兹，24秒），5个振动器，9个拾音器/接收点间隔50米。基本处理过程产生了相当出色的剖面，成功地展示了HMT （Hidaka主逆冲）的较深部分和俯冲的太平洋板块。千岛弧下降的图像仍然不清楚。进一步的处理将改进现有剖面，并为千岛弧下降与太平洋板块俯冲之间的几何关系提供新的有力资料。

项目成果

Iwasaki, T., Yoshii, T., Hirata, N., Sato, H.: "New features of island arc crust inferred from seismic refraction/wide-angle reflection expeditions in Japan""seismotectonics in Cnvergent Plate Boundary" (Y.Fujinawa et al., eds.), Terra Pub.. 57-70 (2002)

Iwasaki, T., Yoshii, T., Hirata, N., Sato, H.：“日本地震折射/广角反射考察推断岛弧地壳的新特征”“趋同板块边界的地震构造”（Y.

Ito, T.: "Active faulting, lower crustal delamination and ongoing Hidaka arc-arc collision, Hokkaido, Japan""Seismotectonics in Cnvergent Plate Boundary" (Y. Fujinawa, et al., eds. ), Terra Pub.. 219-224 (2002)

Ito, T.：“活动断层、下地壳分层和正在进行的日高弧-弧碰撞，日本北海道”“聚合板块边界中的地震构造”（Y. Fujinawa 等人编辑），Terra Pub.. 219-

Ito, T.: "Active faulting, lower crustal delamination and ongoing Hidaka arc-arc collision, Hokkaido, Japan""Seismotectonics in Cnvergent Plate Boundary" (Y.Fujinawa et al., eds.), Terra Pub.. 219-224 (2002)

Ito, T.：“活动断层、下地壳分层和正在进行的日高弧-弧碰撞，日本北海道”“聚合板块边界中的地震构造”（Y.Fujinawa 等人编辑），Terra Pub.. 219-224

Karp B., Karnaukh V., N.Isezaki: "Acoustic basement and sedimentary layer of the Japan Sea. In : Geol and mineral resourses of Russian shelf areas"GEOS. (in press). (2002)

Karp B.、Karnaukh V.、N.Isezaki：“日本海的声学基底和沉积层。见：俄罗斯陆架地区的地质和矿产资源”GEOS。

Karp B., Karnaukh V., N.Isezaki: "Acoustic basement and sedimentary layer of the Japan Sea.In:Geology and mineral resourses of Russian shelf areas"GEOS. (In press). (2002)

Karp B.、Karnaukh V.、N.Isezaki：“日本海的声学基底和沉积层。见：俄罗斯陆架地区的地质和矿产资源”GEOS。