Two powerful earthquakes have struck China's north-west Gansu province, killing at least 75 people and leaving more than 400 others injured. The first earthquake near Dingxi city had a magnitude of5.9 and was shallow, with a depth of just 9.8 km (6 miles), the US Geological Survey said. Just over an hour later, a magnitude 5.6 quake hit the same area, it added. In 2008, an earthquake in Sichuan province left up to 90,000 people dead and millions homeless. A factory worker in Minxian county told AFP that he felt "violent shaking" and "ran to the yard of the [factory] plant immediately. Our factory is only one floor. When I came to the yard, I saw an 18-storey building, the tallest in our county, shaking ferociously, especially the 18th floor," he said. The area has been hit by 371 aftershocks, according to the Earthquake Administration of Gansu province. Tremors were felt in the provincial capital, Lanzhou, and as far away as Xian, 400km (250 miles) to the east.

At least 5,600 houses in the province's Zhangxian County are seriously damaged and 380 have collapsed, while some areas suffered from power cuts or mobile communications being disrupted, the earthquake administration added. "Many have been injured by collapsed houses," a doctor based in Minxian County was quoted by Reuters news agency as saying. "Many villagers have gone to local hospitals along the roads." The earthquake has caused a direct economic loss of 198 million Yuan ($32m; £21m), the Dingxi government said on its micro-blog. The closer to the surface an earthquake strikes, the more damage it can cause, our correspondent adds. The earthquake reportedly triggered a series of mudslides and landslides, making it difficult for rescuers to access some areas hit by the quake. The Gansu military police have deployed 500 soldiers, including 120 specialist rescuers, while 500 emergency tents and 2,000 quilts are also being transported to affected areas, Xinhua added. Officials from the civil affairs, transportation and earthquake departments were also visiting local towns to assess the damage, a statement on the Dingxi party website said. - BBC

A powerful earthquake has hit China's north-west Gansu province, killing at least 11 people and seriously injuring at least 81 more, officials say.

The earthquake near Dingxi city had a magnitude of 5.98 and was shallow with a depth of just 9.8 km (6 miles), according to the US Geological Survey.

Dingxi local authorities say several houses have collapsed in the quake. In 2008, an earthquake in Sichuan province left up to 90,000 people dead and millions homeless.

Officials from the civil affairs, transportation and earthquake departments are visiting local towns to assess the damage, a statement on the Dingxi party website said.

Crews of fire fighters and rescue dogs have already arrived at the scene, the BBC's Celia Hatton in Beijing reports. The closer to the surface an earthquake strikes, the more damage it can cause, our correspondent adds.

"You could see the chandeliers wobble and the windows vibrating and making noise, but there aren't any cracks in the walls," AFP quoted a clerk at Wuyang Hotel, about 40 km (25 miles) from the epicentre, as saying.

"Shop assistants all poured out onto the streets when the shaking began," the clerk said.

Event Time
2013-07-21 05:09:31 UTC
2013-07-21 17:09:31 UTC+12:00 at epicenter

Location
41.713°S 174.443°E depth=14.0km (8.7mi)

Nearby Cities
46km (29mi) ESE of Blenheim, New Zealand
53km (33mi) SSW of Karori, New Zealand
54km (34mi) SSW of Wellington, New Zealand
67km (42mi) SW of Lower Hutt, New Zealand
72km (45mi) SSW of Porirua, New Zealand

A 4.3 quake hit the east coast of New Zealand tonight, following a 4.5 magnitude quake in central New Zealand this afternoon, and a 5.7 earthquake that rattled people in Wellington and Blenheim this morning. Geonet reported tonight's quake was 20 km east of Te Araroa, a settlement on the east coast of the north island, near the southern edge of the Bay of Plenty. The quake was 62 km deep and hit at 11.42pm. GeoNet reported this afternoon's was of a "strong" intensity, 35 km east of Seddon, at a depth of 15 km. The quake hit at 3.21pm.

The first quake struck at 9.06 am and was centered 30km east of Seddon, south of Blenheim, at a depth of 8 km. Rated as severe, it turned Wellington office workers white-knuckled as it swayed high-rises in the capital, with buildings also being rocked in Blenheim. The shallow tremor was felt as far away as Christchurch and New Plymouth. In Wellington it was felt as one jolt, gradually picking up in intensity, while those in Blenheim felt two shakes. GeoNet said it received more than 6000 reports after the jolt. It said the fact it struck off the South Island spared the region from its full force, though there were a few reports that it had a damaging intensity.

People screamed, dived under desks and sheltered in doorways as a "severe" magnitude 5.7 earthquake rocked Wellington this morning.

There have been no reports of damage so far, but workers in the central city have described multi-storey office buildings swaying for at least 30 seconds as the quake hit at 9.06am.

GeoNet said the "severe" quake struck 30km east of Seddon, in Marlborough, at a depth of 8km.

There has been a flurry of smaller shocks since the initial magnitude 5.7 quake, the strongest recorded as magnitude 3.8 at 9.38am.

At least 10 other shocks were recorded in the Marlborough area by 9.45am.

A Fire Service central communications spokeswoman said there were no reports of damage in the Wellington region so far, although an alarm activation may have been caused by the quake.

The quake shook the emergency services communications centre on the seventh floor of the police station on Victoria St in central Wellington for a good 30 seconds, she said.

There have also been no reports of damage in the upper South Island, a Fire Service southern communications spokesman said.

Event Time
2013-07-17 02:37:42 UTC
2013-07-16 21:37:42 UTC-05:00 at epicenter

Location
15.635°S 71.773°W depth=6.6km (4.1mi)

Nearby Cities
18km (11mi) W of Chivay, Peru
88km (55mi) NNW of Arequipa, Peru
148km (92mi) NE of Camana, Peru
151km (94mi) WSW of Ayaviri, Peru
399km (248mi) WNW of La Paz, Bolivia

Technical Details

Event Time
2013-07-16 09:35:54 UTC
2013-07-16 19:35:54 UTC+10:00 at epicenter

Location
6.309°S 154.782°E depth=44.3km (27.5mi)

Nearby Cities
77km (48mi) W of Panguna, Papua New Guinea
84km (52mi) W of Arawa, Papua New Guinea
353km (219mi) SE of Kokopo, Papua New Guinea
520km (323mi) E of Kimbe, Papua New Guinea
666km (414mi) WNW of Honiara, Solomon Islands

Technical Survey

A 7.3 magnitude earthquake has struck south of Bristol Island in the South Sandwich Islands. No tsunami alert exists, however. The massive 7.3 magnitude earthquake began today July 15, 2013 far out to sea, far from Argentina and Chile's coast, officials tell news. It was initially reported as a 6.8 magnitude quake before being upgraded. The large earthquake today began moments ago. It erupted at 12:03 pm local time, officials tell news. It also posted a moderate depth. USGS indicates to news that the quake starting twenty miles below sea level. But the quake was far from land when it began. Officials tell news that the quake was closest only to one island.

The quake began one hundred thirty miles southeast of Bristol Island in the South Sandwich Islands. The quake was thereafter a great distance from other nations. The quake was one thousand six hundred miles at least from Ushuaia, Argentina. It was roughly one thousand seven hundred miles from Rio Gallegos in Argentina as well. Reps tell news that the quake was about one thousand seven hundred miles from Punta Arenas, Chile and about one thousand three hundred mils from Stanley in the Falkland Islands. The National Weather Service says that no tsunami danger exists currently for the U.S, Gulf of Mexico, Puerto Rico and Virgin Islands. But officials. Both the Alaska Tsunami Warning Center and the Pacific Tsunami Warning Center confirm that no tsunami threat is in place. - LA Late News

USGS data

Two new studies of earthquakes near injection wells have seismologists using words rarely heard these days in earthquake science: prediction and warning. The research has also renewed calls for better seismic monitoring and reporting in regions experiencing man-made earthquakes.

"Shale gas operations have completely changed our energy policy and people are injecting in places they've never injected before. If we're going to do this safely, we need to address the environmental issues, including protecting water supplies and earthquake risk," said Cliff Frohlich, a seismologist at the University of Texas Institute for Geophysics who was not involved in the new studies.The two reports appear in today's (July 11) issue of the journal Science.
Links between injection and earthquakes

In the Midwest, researchers discovered a warning signal that moderate-sized earthquakes may strike near injection wells, where mining companies dispose of waste fluids. At three sites in Oklahoma, Colorado and Texas, passing seismic waves from faraway earthquakes - the recent massive temblors in Japan, Sumatra and Chile - triggered swarms of small earthquakes. The seismic activity continued until magnitude-4 and magnitude-5 earthquakes struck, such as the large earthquakes near Prague, Okla., in November 2011.

In last few years, Himachal Pradesh (HP) is witnessing increased frequency of earthquakes up to 5 magnitude on the Richter scale, which has led to the fear of bigger quakes hitting the state in future. While experts are claiming low intensity quakes release seismic energy to avoid bigger earthquakes, unplanned constructions, even on steep hills, has led to fear of widespread destruction if a high magnitude earthquake hits the state. In the past 90 years, 250 quakes of magnitude 4 and more than 60 with a reading of 5 on the Richter scale have rocked HP and adjoining states of Jammu and Kashmir (J&K) and Uttarakhand. On Tuesday, a low intensity earthquake of magnitude 5 had hit Kullu, Chamba and Lahaul-Spiti districts and its epicenter was between J&K and HP.

Last month, between June 4 and 6, four low intensity earthquakes had hit the state and epicenter of all the quakes was between Chamba and Lahaul-Spiti. The areas falling in districts Chamba, Kangra, Mandi, Kullu, Hamirpur and Bilaspur are very sensitive as they fall in the very high damage risk seismic zone (Zone V), whereas the rest of the areas falls in high damage risk zone (Zone IV). According to D D Sharma of Himachal Pradesh University, frequent occurrences of low intensity earthquakes are good because they help in releasing the seismic energy and does not allow accumulation of energy, which later results in earthquakes of bigger magnitude and intensity. "It is said that a big earthquake revisits after a gap of 50 years and in Kangra district for last 110 years no major earthquake has occurred.