Short answers, pulled from the story.
The 1556 Shaanxi earthquake claimed more than 100,000 lives, yet the true death toll may have reached 730,000 when accounting for the subsequent emigration, plague, and famine that followed. This disaster was not merely a geological event but a societal collapse triggered by the destruction of yaodongs, the dwellings carved into loess hillsides that housed the region's population.
The 1960 Chilean earthquake on the 22nd of May 1960 stands as the largest earthquake ever recorded on a seismograph, reaching a magnitude of 9.5. The energy released by this event was approximately twice that of the next most powerful earthquake, the Good Friday earthquake of 1964 in Alaska.
The 1976 Tangshan earthquake in China killed between 240,000 and 655,000 people, making it the deadliest earthquake of the 20th century. This disaster was not only a result of the magnitude of the quake but also of its proximity to heavily populated areas and the lack of seismic building codes.
Most of the world's seismic activity occurs along tectonic plate boundaries, particularly within the Pacific Ring Fire, a horseshoe-shaped zone that encircles the Pacific Ocean. This area accounts for 90 percent of the world's earthquakes and 81 percent of the largest ones, making it the most dangerous place on the planet for anyone living near a fault line.
Despite considerable research efforts by seismologists, scientifically reproducible predictions cannot yet be made to a specific day or month. Earthquake forecasting is concerned with the probabilistic assessment of general earthquake hazards, including the frequency and magnitude of damaging earthquakes in a given area over years or decades.