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左图拍摄于旧金山城区,图中居民楼外侧的梯子并非我们常见的楼梯,而是铁质的救生梯。谈及救生梯的来源,就得先从旧金山地震说起。旧金山位于环太平洋火山地震带上,地壳运动活跃,是美国本土地震活动较活跃的地区之一。1906年4月18日5时12分,旧金山发生了一次大地震,震级为里氏7.9级,持续75秒钟,造成3000多人遇难,30万人无家可归,是美国历史上主要城市所遭受的最严重的自然灾害。
The picture on the left is taken from the downtown area of San Francisco. The ladder on the outside of the residential building in the photo is not a common staircase but an iron ladder. Speaking of the source of the life-saving ladder, you have to start with the San Francisco earthquake. Located in the Pacific Rim volcanic belt, San Francisco is active in crustal movement and is one of the more active seismic areas in the United States. At 5:12 on April 18, 1906, a major earthquake hit San Francisco, with a magnitude of 7.9 on the Richter scale, lasting 75 seconds, killing more than 3,000 people and leaving 300,000 homeless. It is a major city in the history of the United States The worst natural disaster ever suffered.