How many major earthquakes occurred during the Tang Tianbao period?

There was only one earthquake in Tangshan. 17.8 earthquake occurred in Tangshan at 3: 42: 53 on July 28th, 976. The epicentre of the earthquake was located in Jixiang Road, lunan district, Tangshan, with a latitude of 39 degrees 38' north and a longitude of 1 18 degrees 1' east, and the epicenter intensity reached 165438+. On that day 18: 45, an earthquake of magnitude 7 occurred. An earthquake with a magnitude of 1 6 occurred in Luanxian county. 9 occurred in Ninghe River on 1 15 in the same year. The aftershocks after the main earthquake further aggravated the earthquake disaster. Tangshan earthquake has no obvious foreshock, the aftershock lasts for a long time, and the attenuation process fluctuates greatly. Aftershocks have not subsided for more than 20 years. There was no small-scale foreshock in the Tangshan earthquake, which occurred in the early morning when people were asleep, causing 242,769 deaths and164,000 serious injuries, ranking third in the world earthquake history in the 20th century, second only to the Haiyuan earthquake. Tangshan earthquake 14 provinces, municipalities and autonomous regions felt the earthquake, among which Beijing and Tianjin were severely affected, and the energy generated by strong earthquakes was equivalent to 400 Hiroshima atomic bombs. The whole city of Tangshan was razed to the ground in an instant, and the city's transportation, communication, water supply and power supply were interrupted. After the Tangshan earthquake, 96% of the houses in the city collapsed, and those that did not collapsed were also seriously damaged. Facing the ruins, it took more than four years to discuss, investigate and clean up the ruins. Until 1980, the disaster relief task basically ended and Tangshan officially began to rebuild. At that time, the country was in difficulties and there was a shortage of funds, and there was no foreign aid for Tangshan reconstruction. The reconstruction funds of Tangshan city are all borne by the state. Ten years after the earthquake, 20.9 million square meters of various buildings were built in Tangshan, including 68 residential buildings 1, 2 1, 800 square meters and 68 designed residential quarters 1. Among them, there are 59 in lubei district, 32 in lunan district, 58 in guye district, 9 in Fengrun District 10 and Kaiping District. In the first 10 year after the earthquake, the people of Tangshan won a great victory in earthquake relief and reconstruction under extremely difficult circumstances. After another 10 year, the national economy has been fully revitalized; 10 entered a new stage of rapid and healthy economic and social development in the third year. Baidu encyclopedia -7? 28 Tangshan earthquake