美国东海岸发生5.8级地震

A magnitude-5.8 earthquake has rattled¹ the east coast of the United States.

一场5.8级的地震刚刚袭击了美国东海岸。

The quake centred on the state of Virginia but was felt in Washington, where the Pentagon and US Capitol were evacuated², as well as in New York.

The National Cathedral was damaged and the Washington Monument closed. There were no immediate³ reports of injuries.

Federal officials said two nuclear reactors⁴ had been taken offline near the epicentre of the quake but that no damage had been reported.

A total of 12 nuclear plants declared "unusual events" after the quake.

The quake struck some 84 miles (135km) from south-west of Washington, at a depth of 3.7 miles (6km), the US Geological Survey (USGS) said.

Its epicentre was about 8km (five miles) from the town of Mineral, in the state of Virginia.

An initial measurement of 5.8 was later upgraded to 5.9, but later amended⁵ back to 5.8 by the USGS.

The quake was one of the most powerful on the east coast of the US since 1897, according to USGS records, matching the strength of a tremor⁶ in the state of New York in 1944.

Three aftershocks were recorded during Tuesday, the USGS said, the first two measuring 2.8 and 2.2. The third shock, at 20:04 local time (00:04 GMT on Wednesday), was a magnitude-4.8 tremor.

Flights held

The main earthquake shook Washington DC for about 30 seconds at 13:51 on Monday (17:51 GMT), causing office buildings to sway（摇摆） and houses to shake.

The streets of the city filled with evacuated workers minutes after the quake, and police moved swiftly to cordon⁷ off（隔离） key government institutions, restricting access to federal buildings on Capitol Hill.

Television monitors and lights swayed for about 30 seconds as the quake rumbled⁸ away, and the mobile phone network showed intermittent⁹（间歇的） service for some time afterwards.

"When it started, it felt like someone was moving furniture next door," Peter Walker told the BBC from Washington.

"Things began to shake even more and so everyone rushed out into the corridor.

"The alarm went off and the building was evacuated. After an hour we were all sent home.

"There are traffic jams all over the city. The metro¹⁰ is really crowded and so some people are walking or cycling home."

President Barack Obama, on vacation in Martha's Vineyard, Massachusetts, was briefed on the quake by his senior national security and emergency management staff, the White House said, but told that no emergency assistance had been requested.