Extremely dangerous, destructive and deadly M 6.6 earthquake hit western Sichuan, China

Magnitude 6.6 (USGS) shallow thrust earthquake hit Sichuan region in China on April 20, 2013 at 00:02 UTC. The epicenter was located 107 km (66 miles) NW (318°) from Leshan and 116 km (72 miles) WSW (252°) from Chengdu, Sichuan, China at coordinates 30.284°N, 102.956°E. The epicenter was close to southern end of aftershock zone of devastating M 7.9 that hit area in 2008. The depth of epicenter was 12.3 km (7.6 miles). EMSC recorded M 6.8 at depth of 20 km. Local agencies reported M 7.0.

More than 20 aftershocks from M3.6 to M5.1 hit the area after mainshock.

ER update 17:15 UTC – 161 people have been reported as killed so far (some are still missing which indicates that this number will further rise the coming hours. Max. delay to get people from below the rubble is approx. 72 hours. The weather conditions are favourable in Sichuan until tomorrow noon, after that the weather will be worsening (drizzle and rain for the next 3 days).

Update 16:35 UTC – This is an overview of the main points reiterated during the Press conference of the Sichuan governor earlier tonight (local time)
– More than 5,600 people were injured from whom 400 seriously. 140,000 people need to be relocated.
– It is one of the most destructive earthquakes in China in recent years. A 8.0-magnitude quake in Wenchuan county in Sichuan Province left 87,000 dead or missing (numbers vary depending the source) in May 12, 2008.
– Most of the old brick-wood houses were destroyed by the earthquake and parts of the brick-concrete houses were seriously damaged, according to Xinhua reporters at Gucheng village of Longmen township, the epicenter of the quake.
– Soldiers are racing against time in search of survivors in the debris in the village.
– Among some 7,000 houses in Longmen township, 5,000 collapsed in the quake.
– Hundred of tents have arrived at the village but the villagers still need 8,000 more tents.
– Ya’an (140 km from Chengdu) has a population of 1.53 million and is known as the hometown of the giant panda.
–  President Xi Jinping on Saturday ordered all-out measures to rescue victims and minimize casualties soon after the quake. He asked to strengthen seismic monitoring, take concrete steps to prevent secondary disasters, properly relocate people affected by the disaster, and maintain social stability of the quake zone.
–  The Communist Party of China Central Committee and Xi entrusted Premier Li Keqiang to direct the quake-relief work, who arrived at the quake-zone in the afternoon. Li took a helicopter to the epicenter and called a meeting at around 6 p.m. at the front-line headquarters in Longmen township. “Life is the most important thing and the top priority is saving lives, ” Li said. No minute or even second should be delayed during the “golden rescue period” in the first 72 hours after the quake.
Li urged rescuers to examine every house to ensure all the injured residents are saved amid continuous aftershocks. He also ordered the guarantee of accommodation, food and safe water for residents in the quake zone as well as measures against any epidemic situation.

– Emergency teams of ministries, armed forces and armed police are heading to the quake zone.
– Hardest-hit areas : townships of Longmen and Qingren.
– “Old houses in Gucheng village with a population of 3,000 completely collapsed. More than 95 percent of the houses in the village are inhabitable.
– Vehicles damaged by rolling rocks were seen in Lushan. Houses along a street in the Lushan county seat have also collapsed.
– Patients are receiving medical treatment on the ground in front of the Lushan County Hospital (they are treated in open space to avoid falling debris from possible aftershocks)
– The water and electricity supply in the county has been cut off due to the quake.
– Landslides have blocked traffic in many places across the county and two barrier lakes caused by the landslides are posing risks for the rescue efforts.
– Bifeng Gorge, a panda research base affiliated to the Wolong Giant Panda Protection and Research Center, is only 47 km from the epicenter. But there have no reports of human or panda casualties.
– About 3,870 armed police have arrived in Lushan county to assist with rescue efforts.
– More than 10,000 soldiers, including 8,000 field forces and 5,000 militia, have arrived at the disaster-hit areas by foot, trucks and helicopters.
– The soldiers will search for survivors household by household and distribute materials to the affected villages.
– Sadly, a military vehicle carrying 17 soldiers en route to the quake-hit area plummeted off a cliff around Saturday noon, killing one soldier and badly injured two.
– About 200 technicians from China Mobile (Sichuan branch) have been dispatched to disaster-hit areas to repair the telecommunications network.
– Infrastructures remain intact in Sichuan but are badly damaged and broken in the epicenter and nearby.
– The State Grid Corporation of China (electricity)  said the major lines in the province are operating smoothly, but those in the quake-hit area are severely damaged.
– In Lushan county, two transformer substations have halted service, with one of them unable to resume operation. Five hydropower stations in Ya’an are disconnected.
– According to the nation’s major telecommunications companies, as many as 279 telecommunication base stations have collapsed due to the quake (ER repeats over and over that also base stations should be earthquake resistant – Telecommunications base stations are collapsing all over the world, again and again …).
– The earthquake has also damaged 34 reservoirs or dams in Sichuan and affected the water supply for 303,000 people, according to the provincial water resources department.
– Sichuan has rich oil and gas resources, with many pipelines and refineries. Sinopec, Asia’s largest refiner, said no damage had been reported at its production facilities in the quake-hit regions.
Content and credit based on the Xinhua transcriptions after the press conference. (Read full update reports at Earthquake-report)

USGS PAGER issued YELLOW ALERT for estimated fatalities and RED ALERT for estimated economic losses. CCTV China reports that several buildings have collapsed and that landslides are making relief efforts and traffic to the quake hit zone very difficult. The epicenter area is completely blocked by debris and landslides. There are 7 million people living within a radius of 100 km from the epicenter.

Damage in epicenter area (Credit: Xa’an)

According to Earthquake Report,  The main tectonic plates colliding during this earthquake are the Indian plate and the Eurasian plate. The earthquake today follows a massive M7.8 earthquake earlier this week killing 41 in Pakistan and a M7.2 earthquake this morning in the Kuril Islands area.

Sources: USGS, EMSC, Earthquake-Report

Featured image: USGS Shake Map