East longitude 1 18. 1 degree, north latitude 39.6 degrees, deep in the earth's crust 16 kilometers from the ground, a strong earthquake with a magnitude of 7.8 suddenly occurred in Fengnan District, Tangshan City, Hebei Province, China. Twenty-three seconds later, Tangshan was reduced to ruins, with 656 137 civil buildings. The direct economic losses amounted to more than 3 billion yuan. The scene of the earthquake victims is extremely tragic and rare in the world.

Beijing, the capital of China, is shaking, and the tall beams and columns of Tiananmen Gate are convulsively "quacking". From Bohai Bay to Inner Mongolia and Ningxia, and from the south of Heilongjiang to the north of the Yangtze River, people in this land of China feel abnormal shock and fear. The collapse, shaking and vibration of buildings in Tianjin awakened former Australian Prime Minister Whitlam who was visiting this city!

A shocking alarm sounded at the Palmer Observatory in Alaska, USA, and the major news agencies in the world announced the disaster news to the whole world that day-the Hawaiian Seismic Station announced that an earthquake of magnitude 8. 1 occurred in China, with its epicenter near Beijing.

Extended data1After July 28th, 976, the aftershock of Tangshan earthquake continued, with an earthquake of magnitude 7. 1 occurred in Luanxian on the same day 18:45. On may 28th, 20 12 10:22, an earthquake of magnitude 4.8 occurred at the junction of Tangshan city and Luanxian county, which experts called the normal aftershock activity of Tangshan earthquake more than 30 years ago.

During1811-1812, the "New Madrid Earthquake" occurred in the New Madrid seismic belt in the south and midwest of the United States. So far, the activity in this seismic belt is still active, and the law of seismic activity conforms to an important law of aftershocks-"Omori's Law", so the earthquake that occurred in this area is still the aftershock of the "New Madrid Earthquake".

Aftershocks are earthquakes whose magnitude is weaker than the main shock. After a major earthquake, aftershocks may occur at any time, most of which are microseisms that humans can't feel, but there are also major earthquakes with great destructive power. Aftershocks are often called "ghosts after earthquakes" because of their unpredictability and easy to cause great losses of people and property.