The earthquake had a magnitude of 8.0 Ms and 7.9 Mw. The epicenter was in Wenchuan County, Ngawa Tibetan and Qiang Autonomous Prefecture, 80 km (50 mi) west/northwest of the provincial capital of Chengdu, with its main tremor occurring at 14:28:01.42 China Standard Time (06:28:01.42 UTC), on May 12, 2008, lasting for around two minutes; in the quake, almost 80% of buildings were destroyed.
Tremors were felt approximately three minutes after the quake.
Tremors were felt approximately three minutes after the quake, continuing for about half a minute. This was also the most distant earthquake known ever to be felt in Hong Kong. The intensity reached MM III in Hong Kong.
It took about eight minutes for the quake to reach Taiwan, where the tremors continued for one to two minutes; no damage or injuries were reported. The intensity was MM III in Taipei.
Tremors were felt approximately eight minutes after the earthquake in parts of Mongolia.
Tremors were felt approximately five minutes after the earthquake in northern parts of Vietnam. The intensity was MM III in Hanoi.
In parts of Thailand, tremors were felt six minutes after the quake. Office buildings in Bangkok swayed for the next several minutes.
Tremors were felt in Tuva, no casualties reported.
Tremors were felt eight and a half minutes after the quake in all parts of Bangladesh.
Tremors were felt approximately nine minutes after the earthquake in parts of India.
In parts of Northern Pakistan tremors were felt ten minutes after the quake.
Persistent heavy rain and landslides in Wenchuan County and the nearby area badly affected rescue efforts. At the start of rescue operations on May 12, 20 helicopters were deployed for the delivery of food, water, and emergency aid, and also the evacuation of the injured and reconnaissance of quake-stricken areas.
By 17:37 on May 13, a total of over 15,600 troops and militia reservists from the Chengdu Military Region had joined the rescue force in the heavily affected areas.
Many rescue teams, including that of the Taipei Fire Department from Taiwan, were reported ready to join the rescue effort in Sichuan as early as Wednesday. However, the Red Cross Society of China said that (on May 13) "it was inconvenient currently due to the traffic problem to the hardest-hit areas closest to the epicenter".
Beijing accepted the aid of the Tzu Chi Foundation from Taiwan late on May 13. Tzu Chi was the first force from outside the People's Republic of China to join the rescue effort.
By 12:17 CST, May 14, 2008, communication in the seat of Wenchuan was partly revived.
By May 14, the Ministry of Civil Affairs stated that 10.7 billion yuan (approximately US$1.5 billion at that time) had been donated by the Chinese public.
On the afternoon of May 14, 15 Special Operations Troops, along with relief supplies and communications gear, parachuted into inaccessible Mao County, northeast of Wenchuan.
Because of the magnitude of the quake, and the media attention on China, foreign nations and organizations immediately responded to the disaster by offering condolences and assistance. On May 14, UNICEF reported that China formally requested the support of the international community to respond to the needs of affected families.
A direct chartered cargo flight was made by China Airlines from Taiwan Taoyuan International Airport to Chengdu Shuangliu International Airport sending some 100 tons of relief supplies donated by the Tzu Chi Foundation and the Red Cross Society of Taiwan to the affected areas. Approval from mainland Chinese authorities was sought, and the chartered flight departed Taipei at 17:00 CST, May 15 and arrived in Chengdu by 20:30 CST.
By May 15, Premier Wen Jiabao ordered the deployment of an additional 90 helicopters, of which 60 were to be provided by the PLAAF, and 30 were to be provided by the civil aviation industry, bringing the total number of aircraft deployed in relief operations by the air force, army, and civil aviation to over 150, resulting in the largest non-combat airlifting operation in People's Liberation Army history.
A rescue team from the Red Cross in Taiwan was also scheduled to depart Taipei on a Mandarin Airlines direct chartered flight to Chengdu at 15:00 CST on May 16.
On May 16, rescue groups from South Korea, Japan, Singapore, Russia, and Taiwan arrived to join the rescue effort.
On May 16, China stated it had also received $457 million in donated money and goods for rescue efforts so far, including $83 million from 19 countries and four international organizations.
Saudi Arabia was the largest aid donor to China, providing close to €40,000,000 in financial assistance, and an additional €8,000,000 worth of relief materials.
Rescue efforts performed by the Chinese government were praised by western media, especially in comparison with Myanmar's blockage of foreign aid during Cyclone Nargis, as well as China's previous performance during the 1976 Tangshan earthquake. China's openness during the media coverage of the Sichuan earthquake led a professor at Peking University to say, "This is the first time [that] the Chinese media has lived up to international standards". Los Angeles Times praised China's media coverage of the quake as being "democratic".
On the evening of May 18, CCTV-1 hosted a special four-hour program called The Giving of Love, hosted by regulars from the CCTV New Year's Gala and round-the-clock coverage anchor Bai Yansong. It was attended by a wide range of entertainment, literary, business, and political figures from mainland China, Hong Kong, Singapore, and Taiwan. Donations of the evening totaled 1.5 billion Chinese Yuan (~US$208 million). Of the donations, CCTV gave the biggest corporate contribution at ¥50 million.
At 14:28 CST on May 19, 2008, a week after the earthquake, the Chinese public held a moment of silence. People stood silent for three minutes while air defense, police and fire sirens, and the horns of vehicles, vessels, and trains sounded. Cars and trucks on Beijing's roads also came to a halt.
The State Council declared a three-day period of national mourning for the quake victims starting from May 19, 2008; the PRC's National Flag and Regional Flags of Hong Kong and Macau Special Administrative Regions flown at half-mast. It was the first time that a national mourning period had been declared for something other than the death of a state leader, and many have called it the biggest display of mourning since the death of Mao Zedong.
Strong aftershocks continued to strike even months after the main quake. On May 25, an aftershock of 6.0 Mw (6.4 Ms according to CEA) hit northeast of the original earthquake's epicenter, in Qingchuan County, Sichuan.
On May 27, two aftershocks, one 5.2 Mw in Qingchuan County and one 5.7 Mw in Ningqiang County, Shaanxi, led to the collapse of more than 420,000 homes and injured 63 people.
As a result of the earthquake and the many strong aftershocks, many rivers became blocked by large landslides, which resulted in the formation of "quake lakes" behind the blockages; these massive amounts of water were pooling up at a very high rate behind the natural landslide dams and it was feared that the blockages would eventually crumble under the weight of the ever-increasing water mass, potentially endangering the lives of millions of people living downstream. As of May 27, 2008, 34 lakes had formed due to earthquake debris blocking and damming rivers, and it was estimated that 28 of them were still of potential danger to the local people. Entire villages had to be evacuated because of the resultant flooding.
On May 29, 2008, government officials began inspecting the ruins of thousands of schools that collapsed, searching for clues about why they crumbled.
Rescue efforts also came from Jet Li's One Foundation which saw the martial arts actor Wu Jing assisting in the efforts.
The Artistes 512 Fund Raising Campaign, an 8-hour fundraising marathon, was held on June 1 in Hong Kong; it was attended by some 200 Sinosphere musicians and celebrities.
On Children's Day, June 1, 2008, many parents went to the rubble of schools to mourn for their children. The surviving children, who were mostly living in relief centers, performed ceremonies marking the special day, but also acknowledging the earthquake.
In June, Hong Kong actor Jackie Chan, who donated $1.57 million to the victims, made a music video alongside other artists entitled "Promise"; the song was composed by Andy Lau.
In the aftermath of the quake, many local governments promised to formally investigate the school collapses, but as of July 17, 2008, across Sichuan, parents of children lost in collapsed schools complained they had yet to receive any reports.
The same area suffered two more aftershocks of 5.6 and 6.0 Ms (5.8 and 5.5 Mw , respectively, according to USGS) on July 23, resulting in 1 death, 6 serious injuries, the collapse of hundreds of homes, and damaging kilometers of highways.
Pingwu County and Beichuan County, Sichuan, also northeast of Wenchuan and close to the epicenter of a 7.2 Ms earthquake in 1976, suffered a 6.1 Ms aftershock (5.7 Mw according to USGS) on August 1; it caused 2 deaths, 345 injuries, the collapse of 707 homes, damage to over 1,000 homes, and blocked 25 kilometers (16 mi) of country roads.
As late as August 5, yet another aftershock of 6.1 Ms (6.2 Mw according to USGS) hit Qingchuan, Sichuan, causing 1 death, 32 injuries, telecommunication interruptions, and widespread hill slides blocking roads in the area including a national highway.
Executive vice-governor Wei Hong confirmed on November 21, 2008, that more than 90,000 people in total were dead or missing in the earthquake.
He stated that 200,000 homes had been rebuilt, and 685,000 were under reconstruction, but 1.94 million households were still without permanent shelter. 1,300 schools had been reconstructed, with initial relocation of 25 townships, including Beichuan and Wenchuan, two of the most devastated areas. The government spent $441 billion on relief and reconstruction efforts.
On May 12, 2009, China marked the first anniversary of the quake with a moment of silence as people across the nation remembered the dead. The government also opened access to the sealed ruins of the Beichuan county seat for three days, after which it will be frozen in time as a state earthquake relic museum, to remind people of the terrible disaster. There were also several concerts across the country to raise money for the survivors of the quake.