A year-round halocline is a particular hydrographic structure in the upperArctic Ocean. On the basis of an analysis of the hydrographic data collected in the Arctic Ocean, itis found that a double-halocline structure ...A year-round halocline is a particular hydrographic structure in the upperArctic Ocean. On the basis of an analysis of the hydrographic data collected in the Arctic Ocean, itis found that a double-halocline structure exists in the upper layer of the southern Canada Basin,which is absolutely different from the Cold Halocline Layer (CHL) in the Eurasian Basin. ThePacific-origin water is the primary factor in the formation of the double-halocline structure. Theupper halocline lies between the summer modification and the winter modification of thePacific-origin water while the lower halocline results from the Pacific-origin water overlying uponthe Atlantic-origin water. Both haloclines are all the year-round although seasonal and interannualvariations have been detected in the historical data.展开更多
There is a long and wide continuous trough of deep mixed layers connecting the tropical western North Pacific Ocean with the offshore waters of the coast of California. Relatively warm water that is nearly uniform ver...There is a long and wide continuous trough of deep mixed layers connecting the tropical western North Pacific Ocean with the offshore waters of the coast of California. Relatively warm water that is nearly uniform vertically fills the trough, which is concluded here to be a northeastward flow joining the wide warm surface current at mid-latitudes off California documented earlier. Evi-dence for the trough comes from a North Pacific atlas based on very many indi-vidual mixed layer depth data points, taken over a 27-year period, compiled (av-eraged) in monthly mean charts with contours of constant mixed layer depth dis-played. BTs (bathythermographs) were used to record temperature versus depth continuously from which the mixed layer depths were determined. Centerline curves, connecting the deepest mixed layer depths, which approximate the mid-dle of the troughs, are constructed from the atlas and are presented for all twelve months. In going from west to east, these curves bend counterclockwise, gradu-ally most of the way then more markedly near California. The curves for the summer months come closer to California than any of the other ones do, suggest-ing that the warm current itself is nearest to California in summer. Confirmation of the prediction awaits future efforts.展开更多
1研究背景地震的孕育和发生通常伴随着应力场变化、地下流体迁移、地壳浅层破坏等事件的发生,从而导致地下介质物理性质(如波速)的变化。由于背景噪声监测方法的独特优势,背景噪声互相关函数在监测地震孕育过程中展现了巨大潜力(Brengui...1研究背景地震的孕育和发生通常伴随着应力场变化、地下流体迁移、地壳浅层破坏等事件的发生,从而导致地下介质物理性质(如波速)的变化。由于背景噪声监测方法的独特优势,背景噪声互相关函数在监测地震孕育过程中展现了巨大潜力(Brenguier et al,2008),也为地震预测预报工作提供了有用的参考信息。然而,噪声源季节性变化,对以背景噪声互相关方法测量的地震波速度的精度存在影响。因此,利用背景噪声监测地震波速度变化,必须对噪声源机制有清晰认识。展开更多
基金supported by the National Natural Science Foundation of China under contract Nos 40306005 and 40376007.
文摘A year-round halocline is a particular hydrographic structure in the upperArctic Ocean. On the basis of an analysis of the hydrographic data collected in the Arctic Ocean, itis found that a double-halocline structure exists in the upper layer of the southern Canada Basin,which is absolutely different from the Cold Halocline Layer (CHL) in the Eurasian Basin. ThePacific-origin water is the primary factor in the formation of the double-halocline structure. Theupper halocline lies between the summer modification and the winter modification of thePacific-origin water while the lower halocline results from the Pacific-origin water overlying uponthe Atlantic-origin water. Both haloclines are all the year-round although seasonal and interannualvariations have been detected in the historical data.
文摘There is a long and wide continuous trough of deep mixed layers connecting the tropical western North Pacific Ocean with the offshore waters of the coast of California. Relatively warm water that is nearly uniform vertically fills the trough, which is concluded here to be a northeastward flow joining the wide warm surface current at mid-latitudes off California documented earlier. Evi-dence for the trough comes from a North Pacific atlas based on very many indi-vidual mixed layer depth data points, taken over a 27-year period, compiled (av-eraged) in monthly mean charts with contours of constant mixed layer depth dis-played. BTs (bathythermographs) were used to record temperature versus depth continuously from which the mixed layer depths were determined. Centerline curves, connecting the deepest mixed layer depths, which approximate the mid-dle of the troughs, are constructed from the atlas and are presented for all twelve months. In going from west to east, these curves bend counterclockwise, gradu-ally most of the way then more markedly near California. The curves for the summer months come closer to California than any of the other ones do, suggest-ing that the warm current itself is nearest to California in summer. Confirmation of the prediction awaits future efforts.
文摘1研究背景地震的孕育和发生通常伴随着应力场变化、地下流体迁移、地壳浅层破坏等事件的发生,从而导致地下介质物理性质(如波速)的变化。由于背景噪声监测方法的独特优势,背景噪声互相关函数在监测地震孕育过程中展现了巨大潜力(Brenguier et al,2008),也为地震预测预报工作提供了有用的参考信息。然而,噪声源季节性变化,对以背景噪声互相关方法测量的地震波速度的精度存在影响。因此,利用背景噪声监测地震波速度变化,必须对噪声源机制有清晰认识。
