东南极Amery冰架与陆地冰分界线的重新划定及验证

Re-definition and Validation of the Grounding Line of Amery Ice Shelf,East Antarctica

  • 摘要: 根据无线电回波测厚(RES)数据对东南极Amery冰架与陆地冰分界线进行了重新划定,指出该冰架的接地线位置最南一直向内陆延伸到73.2°S处,距冰架末端最远距离约500km。并在该流域选取了两条具有代表性的剖面,分别用水面以下的冰厚度与总的冰厚度的比值、流体静力学平衡理论等进行了验证。同时对该地区所在的整个冰流系统用5km ERS-1/DEM数据和1km RAMP/DEM数据,GPS实地测量值等对这一结论进行了验证。最后按流体静力学平衡条件对该流域的漂浮冰部分重新进行了标定。

     

    Abstract: This paper re-defines the grounding line(GL) of Amery Ice Shelf(AIS),East Antarctica,utilizing radio echo sounding(RES) data.It was indicated that the GL southmostly extended to 73.2°S,about 500 km away from the ice front.Two representative profiles are selected to validate the above preliminary conclusion,by ratio of bed depth to ice thickness,and height divergence between the measured height and the calculated value according to ice thickness by hydrostatic equilibrium theory.Moreover,the conclusion is further validated by ERS-1 digital elevation model(DEM) gridded 5 km and RADARSAT Antarctic mapping project(RAMP) 1km-gridded DEM,and tidal noise detected by in situ GPS measurements.Finally,the floating ice region of the whole ice stream is illustrated according to the hydrostatic equilibrium theory.

     

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