At 1:47 a.m. on September 21, 1999, Taiwan was slammed by its most powerful earthquake measuring 7.3 on the Richter scale in 100 years, struck central Taiwan near the small town of Chi-Chi, Pull Township just 6.9 km from the earth's surface near the epicenter. The shock source time function has a total duration of about 40-sec, the quake had caused over 10,000 casualties, including more than 2,000 deaths. Over 10,000 homes had collapsed. Roads throughout much of Taiwan were rendered impassable and rail traffic was disrupted. Rescue teams spent most weeks searching for survivors in the rubble, and towns across the island struggled to hold last rites and bury the victims.
At 1.47 am on September 21, 1999, an earthquake measuring 7.3 on the Richter scale rolled outwards from its epicenter 12.5 km from Sun Moon Lake in mountainous central Taiwan, Nantou County. It was only 10.0 km below the Earth surface. The slip distribution thus obtained is quite consistent with the field as an average of about 2–3 m slip along the fault and a maximum slip of about 7–8 m at about 40 km to the north of the epicenter. There were extensive surface ruptures for about 85 km along the Chelungpu faultwith vertical and left lateral strike-slip olivet. The maximum displacement of about 9.8 meters is among some of the largest fault movement ever measured.
While three major quakes in just over a month since August 1999, the world is hit by 18 earthquakes measuring 7.0 or greater every year on average. The three recent large quakes were all probably difference in nature, Taiwan's quake is classified as the "thrust-fault" type. Where one plate slides under another, while Turkey's was a case of two plates grinding against each other.
