On this day, 52 years ago, on February 6, 1973 (January 4, 1973, the lunar calendar), a 7.9-magnitude earthquake occurred in the Garze Tibetan Autonomous Region of Sichuan Province. On February 6, 1973, a 7.9-pole earthquake occurred in Luhuo County in Ganzi Tibetan Autonomous Prefecture, Sichuan Province, causing varying degrees of damage to Ganzi, Daofu, Seda, Xinlong, Rangtang and other counties. The earthquake area is located in the middle reaches of Xianshui River in the southeast of the Qinghai-Tibet Plateau. Stratified landforms are developed in the area. Standing on the plateau, the Gongkala Mountain has a steep terrain and is more than 1000 meters higher than the Xianshui River Valley. There are second-order planation surfaces and eight-order terraces distributed in the earthquake area. There are low mountains and hills on both sides of the Xianshui River Valley. High-level land is missing on the left bank, and the width of low-level land is also smaller than that on the right bank. The rise on the southwest side is relatively large, and many alluvial fans are distributed in the shape of beads. The earthquake occurred on the Luhuo-Daofu fault zone in the Garzi-Aba fold-zou belt during the Indo-Chinese Period in western Sichuan. The fault zone is distributed in the direction of 50o north to the west, and there are intermediate and basic rocks invading along the fault zone, with deep fault characteristics. Neotectonic activity is very significant on the fault zone, and many strong earthquakes have occurred along this fault zone in history. The ground fissure zone formed by the earthquake is distributed intermittently in oblique rows or jagged shapes along the Xianshui River Valley in the direction of 50o to 60o to the north. It starts in the north and west near the east valley of Ganzi County, flows south to Zhuwei, Dandu, Xuxu and Laohekou, and ends in Renda, Luhuo County, with a total length of about 90 kilometers. The width of the ground fissures is 20-150 meters, and five or six ground fissures can be generally seen arranged in parallel. Ground fissure zones pass through different geomorphological units such as floodplains, terraces, cliffs, slopes and passes. Its distribution is obviously strictly controlled by the Luhuo-Daofu fault zone and inherits the sinistral twisting nature of the fault zone. In the extreme earthquake area, due to the weak and fractured lithology of the mountain, collapses and landslides of different scales occurred on the steep highway slopes, which had a serious impact on highway traffic. The houses and buildings in the earthquake area are mainly wooden structures, with significant national characteristics. In the extreme earthquake area, houses collapsed severely. Houses built on bedrock (such as near Dandu) generally have less damage, while houses built on high river floodplains and first-level terraces have more damage due to loose soil and high groundwater levels.