Central Surface Elevation, Ice Thickness And Digital Terrain Model Of The Antarctic Bottom Lambert Glacier Basin Construction And Analysis

The midland of Lambert glacial basin of Amery ice shelf system, the largestice-floating system and the ice sheet-ice shelf-marine material balance system of themost importance is taken as the object of study. Based on ArcGIS software platformand by making use of the data of PCMEGA investigation plan, the thesis integratesthe data of ICEatGLAS laser altimeter. Meanwhile, the thesis makes correspondinganalysis on the construction of surface altitude and ice thickness for the midland ofLambert glacial basin and the digital model of the bottom configuration. Maincontents and conclusions are as follows:(1) The method of digital data interpolating has been studied systematically.Three most typical interpolation methods, respectively Inverse Distance Weighting,Radial Basis Function Interpolation and Kriging Interpolation are contrasted andverified. And contrasts are made on advantages and disadvantages of the threeinterpolations methods in constructing the digital models for ice altitude of theAntarctic Pole, ice thickness and bottom configuration by means of cross-validationmethod.(2) Ordinary Kriging interpolation is selected by means of cross validationmethod as the best interpolation method. The surface altitude, ice thickness and thedigital model for bottom configurations of500m500m grid resolution are obtainedvia this interpolation method. Moreover, contrasts are made with the surfacealtitude, ice thickness and the digital model for bottom configurations generatedfrom BEDMAP data base and errors between two of them are analyzed.(3) Lambert glacial basin displays a descending trend from the south to thenorth in terms of its surface altitude. The surface altitude reaches the highest in thesouthwest end, with the altitude value of3039.37m in the place. In the convergingplace of Lambert glacial basin, Mellor glacial basin and Fisher glacial basin, thealtitude value is relatively low, where there is the lowest altitude value, that is,122.31m. The average altitude value of the researched area is higher than seal level.(4) The ice thickness in the midland of Lambert glacial basin is gradually reducing with the ice-floating directions of Lambert glacier, Mellor glacier and Fisherglacier. In the convergence of three glaciers of Lambert glacier, Mellor glacier andFisher glacier, the thickness is gradually grows. The thickness is also very low inMountain Gambrustev, Mountain Prince Charles and nearby as well as both sides ofLambet graben. The ice thickness of the research areas displays a reducing trendfrom the inland to periphery, with higher thickness in the inland areas, lowerthickness in the edges. The largest thickness occurred at the northwest end and itreaches3452.73m while smallest thickness occurred in the mort peripheral place ofLambert glacier, with average thickness of1976m in this area. The higher values ofice thickness concentrate on the west part of the research area, and extensions in thenorth side display a trend of NW-SE while the south side is in a direction of N-S. Theups and downs of the distribution of ice thickness clearly shows a cross-like shape,along with which there is thicker ices in this areas while the ice is not so thick inother areas. Generally speaking, the thickness displays a reducing trend.(5) The bottom terrains of inland area of Lambert glacial basin display mostobvious ups and downs, with distinct geographical features of glacial actions. Riftvalleys are deeply cutting the surface, with obvious through valleys and branchvalleys and they reach the deepest in the convergence of Mellor, Fisher and Lambert.The height of bed rock is lower than200m, with the lowest point which is2300mlower than the sea level（67°10′E,73°9′S）. The valley is rather abrupt and thebrae is straight and abrupt. The bottom is relatively smooth and wide and itsperpendicular throw with valley shoulders is almost1300m at the maximum. In theinland areas, the altitude of the terrain is relatively high, which is related with themountain range at the bottom of Gamburtsev.