2. It was a catastrophic earthquake and is also the deadliest earthquake on record, killing approximately 830,000 people. It happened on the 23 rd of January 1556 More than 97 counties were affected A 840-kilometre-wide (520 mi) area was destroyed The Shaanxi earthquake's centre was in the Wei River Valley in Shaanxi Province In certain areas, 20-metre (66 ft) deep crevices opened in the earth

3. Earthquakes are usually caused when rock underground suddenly breaks because something has gone wrong. This sudden release of energy causes the seismic waves that make the ground shake. When two blocks of rock or two plates are rubbing against each other, they stick a little. They don't just slide smoothly, the rocks catch on each other. The rocks are still pushing against each other but not moving. After a while, the rocks break because of all the pressure that's built up. When the rocks break, the earthquake happens. During the earthquake and afterward blocks of rock start moving and they continue to move until they get stuck again. The spot underground where the rock breaks is called the focus of the earthquake. The place above the focus (on top of the ground) is called the epicentre of the earthquake.

4. Millions of people at the time lived in artificial Loess caves on high cliffs in the area of the Loess Plateau. The soft loess clay had formed over thousands of years because of wind blowing silt into the area from the Gobi Desert. Loess is a highly erosion-prone soil that is vulnerable to the forces of wind and water. The Loess Plateau and its dusty soil cover almost all of Shanxi, Shaanxi, and Gansu. Much of the population lived in dwellings called yaodongs in these cliffs. This was the major contributing factor to the huge death toll. The earthquake caused landslides, which destroyed the caves. Killed or injured an estimated 830,000 people. This massive death toll is thought to have reduced the population by about 60 %

5. The impact on the environment This particular quake led the people in the region affected to search for ways to minimize the damage caused by the earthquake. Many of the people in the quake were people who had been crushed by falling buildings. Therefore, in the aftermath of the 1556 quake, many of the stone buildings that had been high were replaced with buildings made of softer, more earthquake-resistant materials, such as bamboo and wood.