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利用回声测声仪、3.5KHz反射剖面仪和旁侧声纳,在诺福克滨外海斯巴勒砂体西北端作了两次详细的调查。不对称砂波表明砂坝南翼的砂体向西北运移,而在坡度较陡的北翼,砂体向东南运移。其次,大型迭覆波痕可能比较清楚地体现了沉积物的运移,它证明存在着一个跨越砂坝的运动分量。在坝端西北和东南两翼的砂波之间,存在着一条对称砂波带。一般认为这说明物质的有效运移等于零,但在这种情况下,砂波槽中大型波痕的倾斜方向说明发生过平行于砂波脊的物质运移。这些情况表明砂体围绕砂坝运移并形成一个基本上闭合的循环的途径。沉积物结构参数证实了这样一种见解,即物质在砂坝两侧的底部受到淘洗,并由南向北以100％的有效搬运率运移至砂坝中段。根据对早至1886年的海图分析,尽管定位误差范围可以允许在过去的100年期间向东北移动0.25公里以上,但是该砂坝即使在此范围内也是稳定的。笔者建立了一种箱形模式来估计围绕砂坝尾部运动的流砂量,并从中得出对沉积时间和循环速率的影响。
Using echo sounder, 3.5KHz reflection profiler and side sonar, two detailed surveys were conducted on the northwestern tip of the Hesburle Sand Body off Norfolk Abbey. The asymmetrical sand wave indicates that the sand body in the southern wing of the sand bar migrates to the northwest, whereas in the steep northern wing, the sand body migrates to the southeast. Second, the large overlapping ripples may more clearly show the migration of sediments, which proves that there is a component of motion across the bar. There is a symmetrical sand wave band between the sand waves in the northwest and southeast wings of the dam. It is generally accepted that this indicates that the effective transport of material equals zero, but in this case the direction of tilt of the large scale marks in the sand trough indicates that material movement parallel to the sand ridge has occurred. These conditions indicate that the sand body migrates around the bar and forms a substantially closed cycle. Sediment structural parameters confirm the insight that material is panned at the bottom of both sides of the sand dam and transported from south to north at an effective transfer rate of 100% to the mid-section of the sand bar. According to the chart analysis up to 1886, even though the range of positioning errors could allow the movement of more than 0.25 km to the northeast over the past 100 years, the bar is stable even within this range. The author established a box-shaped model to estimate the amount of sand flowing around the tail of the sand dam and derived the effect on deposition time and circulation rate.