The Alaska earthquake of July 10, 1958: Movement on the Fairweather fault and field investigation of southern epicentral region
The Alaska earthquake of July 10, 1958: Movement on the Fairweather fault and field investigation of southern epicentral region
复制标题
1958年7月10日阿拉斯加地震：费尔韦瑟断层的运动及震中南部地区的实地调查
DOI：
--
复制
发表时间：
1960
期刊：
影响因子：
--
通讯作者：
D. Tocher
中科院分区：
文献类型：
--
作者：
D. Tocher
费尔韦瑟断层是一个可识别的地质和地貌特征，从东南部的帕尔马湾到雅库塔特湾以东的冰原岛峡湾，沿地表轨迹沿着200公里。1958年7月10日的地震是由断层的大部分或全部运动引起的：在帕尔马湾发生了10英尺或更大的右侧偏移，那里的地表走向在海洋下向东南方向延伸，在冰原岛峡湾的南海岸形成了新的陡坎。在克里隆湖北端以东的断层上的一个点上测量到西南侧相对西北移动了21 1/2英尺，向上移动了3 1/2英尺。帕尔马湾和冰原岛峡湾之间断裂的连续性无法得到肯定的证明，因为冰和水掩盖了断层带沿着约80%的地面。在费尔韦瑟断层两侧的平坦地区，观察到克里隆湖中心以东基岩中广泛的小断层。这些小断层系统在总体上与这次地震和1899年雅库塔特湾地震中在冰原岛峰峡湾形成的小断层系统相似。在从斯宾塞角到圣伊莱亚斯山的太平洋沿岸沿着，人们观察到了除断层作用以外的各种地质效应。其中包括地球和岩石雪崩，雪和冰雪崩，地球滑坡，地球倾斜，以及来自火山口和裂缝的沙尘暴。
ABSTRACT The Fairweather fault is recognizable as a geologic and geomorphic feature from Palma Bay on the southeast at least as far northwest as Nunatak Fiord east of Yakutat Bay, a distance of 200 kilometers along the surface trace. The earthquake of July 10, 1958, was caused by movement on much or all of that segment of the fault: a 10-foot or larger right-lateral offset occurred at Palma Bay where the surface trace trends southeastward under the ocean, and fresh scarps were formed on the south shore of Nunatak Fiord. A displacement in which the southwest side moved relatively northwest 21 1/2 feet and up 3 1/2 feet was measured at one point on the fault just east of the north end of Crillon Lake. Continuity of breakage between Palma Bay and Nunatak Fiord cannot be demonstrated positively because ice and water conceal the ground surface in the fault zone along about 80 per cent of that distance. Extensive minor faulting in bedrock east of the center of Crillon Lake was observed on flat areas on both sides of the Fairweather fault. These systems of minor faults were similar in general appearance to those formed on the Nunatak at Nunatak Fiord both in this earthquake and in the Yakutat Bay earthquakes of 1899. A wide variety of geological effects other than faulting was observed throughout a broad area along the Pacific coast from Cape Spencer to Mount St. Elias. Among these were earth and rock avalanches, snow and ice avalanches, earth slumps, earth lurches, and sandblows from craterlets and fissures.