An earthquake, also known as a quake, tremor or temblor, is the result of a sudden release of energy in the Earth's crust that creates seismic waves. The seismicity, seismism or seismic activity of an area refers to the frequency, type and size of earthquakes experienced over a period of time.
At the Earth's surface, earthquakes manifest themselves by shaking and sometimes displacement of the ground. When the epicenter of a large earthquake is located offshore, the seabed may be displaced sufficiently to cause a tsunami. Earthquakes can also trigger landslides, and occasionally volcanic activity.
Yunnan authorities say accurate earthquake forecast ‘broke the law’
Yunnan authorities said a private agency which accurately predicted the 5.0 magnitude earthquake in the region on Wednesday “broke the law”.
Zhang Junwei, a spokesman for Yunnan Earthquake Administration, said any earthquake predictions by private parties or agencies were violating the law. “All earthquake forecasts must comply with relevant laws,” he said on Thursday. Zhang was responding to a successful private prediction of a 5.0 magnitude earthquake which hit Yunnan’s Dali district on Wednesday night.
The earthquake demolished 493 houses and injured 14, a report by Xinhua said. It affected nearly 130,000 people from 12 nearby towns.
The forecast, which was made public three days prior to the earthquake, said: “It is estimated that regions within Yunnan would experience strong tremors within 72 hours. Preliminary predictions indicate it would be a 5.0 magnitude thermal activity.” The post was published on China’s twitter-like microblog service under the alias, “Forecast Centre”. A map was attached to the post. Three regions were circled and it was forecast that the earthquake would strike there.
The post also urged provincial newspaper and rescue institution to be on high alert for “abnormal seismic activity”.
Initially, the post did not get much attention. It was reposted only 300 times - a relatively small amount for China’s most popular social networking platform. But it went viral after people discovered the earthquake occurred as predicted - in the same region, with same magnitude and in a similar time frame.
One user responded to the post, saying: “I have to pay close attention to this microblog account. I take a look at it everyday before I go to bed to be the best.”
The person behind the blog, who refused to be identified, told Yunnan Information Daily he produced the forecast based on information published by the government’s online seismological data centre. He said analysing the information required professional knowledge, but not much equipment.
Zhang Junwei said he always welcomed ideas from private institutions or individuals. But he stressed that unofficial predictions could not be relied on. “We are concerned these predictions could have a negative impact on society,” Zhang explained.
Some bloggers were not impressed by Zhang’s comments. One online comment said: “If such an accurate prediction was ‘breaking the law’, then what was the 'lawful' earthquake administration doing. It should hire this man [who made the accurate prediction] to be its manager.”