The 2000/01 Surge of Yanert Glacier, Alaska

阿拉斯加中部山脉有许多涌浪型冰川，其中大部分位于德纳利断层之上。然而，由于重现时间很长，约为50-100年，而且只有三个冰川在该地区记录到重复涌浪，因此实际发生涌浪的情况很少见。其中之一是亚纳特海峡，据了解，它上一次出现激增是在1942年。这与阿拉斯加东南部的冰川非常不同，在那里，激流经常在不到20年的时间里重复出现。浪涌的确切原因和行为尚不清楚，因此，重要的是在出现浪涌时利用机会收集更多数据。不幸的是，很难预测增兵的确切年份或时间，也不可能提前计划充分的实地工作。亚纳特冰川位于阿拉斯加山脉中部，但人们对它知之甚少，除了它是一种涌动型冰川，并在1942年观察到了一次涌动。最近的激增始于1999/2000年冬末，但大部分都没有被注意到。2001年4月，它又重新启动，并发展成为一次大高潮。由于没有观察到持续时间超过两年的激增，亚纳特的激增可能会在今年夏天停止，明年冬天不会恢复。首席调查员将飞往亚纳特冰川的终点，并安装两台延时相机。人们将观察到目前距离冰川终点处约5公里的涌浪锋。它将被用来测量涌浪锋的前进速度，并确定前进停止的时间。第二个摄像头将被放置在冰川前面。预计这股洪流的结束将与一场大洪水同时发生。这台相机将记录洪水是否发生以及何时发生。首席调查员还将使用手持全球定位系统记录涌浪前沿的位置。在本季度结束时，他们将用机载测高系统拍摄冰川的轮廓，并取回延时相机。该剖面将被用来估计由于海浪激增而发生的冰的总质量传输。

ABSTRACT TrufferOPP-0126363There are a number of surge-type glaciers in the central Alaska Range and most of them overlying the Denali Fault . The actual occurrence of a surge, however, is rare because of the long recurrence time which is about 50-100 years and only three glaciers have been recorded to surge repeatedly in this region. One of these is the Yanert which is known to have last surged in 1942. This is very different from the glaciers in southeast Alaska where surges are often repeated in less than twenty years. The exact causes and the behavior of surges are not known, therefore, it is important to take advantage of opportunities for more data collection whenever it arises. Unfortunately, the exact year or time of a surge is very difficult to predict and it is impossible to plan for adequate field work in advance. The Yanert Glacier is located in the central Alaska Range, but little is known about it other than it is a surge-type glacier and a surge had been observed in 1942. The recent surge started in the late winter of 1999/2000, but most of it went unnoticed. In April 2001, it had restarted again and developed into a major surge . Because no surges have been observed to last more than two years, the Yanert surge is likely to stop this summer and not resume next winter. The Principal Investigators will fly to the terminus of Yanert Glacier and install two time lapse cameras. One will observe the surge front that is currently about five kilometers from the glacier terminus. It will be used to measure the rate of advance of the surge front and to establish the time when the advance stops. A second camera will be placed in front of the glacier. The end of the surge is expected to coincide with a big flood. This camera will record if and when the flood occurs. The Principal Investigators will also record the position of the surge front, using hand held GPS units. At the end of the season, they will fly a profile of the glacier with an airborne altimetry system and retrieve the time lapse cameras. The profile will be used to estimate the total mass transport of ice that occurred as a result of the surge.