Magnitude 6.6 Earthquake in western Xinjiang Province, China.

The United States Geological Survey recorded a Magnitude 6.6 Earthquake at a depth of 12.6 km in the Pamir Mountains of western Xinjiang Province, China, slightly before 10.25 pm local time (slightly before 2.25 pm GMT) on Friday 25 November 2016. At least one person has died following this event and over three hundered buildings have been damaged or destroyed. The Earthquake was felt as far away as Tashkent in Uzbekistan and Islamabad in Pakistan.

Rescue workers removing personal items from a home damaged by the 25 November 2016. Xinhua.

The Pamir Mountains lie to the north of the boundary between the Indian and Eurasian tectonic plates, which runs through northern Afghanistan. The Indian Plate is moving northward relative to the Eurasian Plate, causing folding and uplift along this boundary, which has led to the formation of the Hindu Kush Mountains of Afghanistan, The Pamirs in Tajikistan, the Himalayas and the other mountain ranges of Central Asia., and which makes the nations in this boundary zone prone to Earthquakes.

 The approximate location of the 25 November 2016 Pamir Mountains Earthquake. Google.

Witness accounts of Earthquakes can help geologists to understand these events, and the structures that cause them. The international non-profit organization Earthquake Report is interested in hearing from people who may have felt this event; if you felt this quake then you can report it to Earthquake Report here.

 

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Evacuations after ammonia spill in Corcoran, California.

Part of the city of Corcoran in King County, California, was evacuated for about five hours after a tanker spilled around 11 000 litres of anhydrous ammonia on Monday 28 November 2016. The spill occurred after the vehicle overturned in a road-traffic accident, though the cause of this initial incident is unclear. About 120 people were evacuated from buildings close to the accident, due to the extremely toxic nature of the chemical.

Clouds of ammonia mist in Corcoran, California, on 28 November 2016. ABC30.

Ammonia is used in a wide variety of industries, but usually in a diluted form. Anhydrous ammonia (ammonia without any water) is both toxic and corrosive, though injuries from ammonia are rare even in incidents such as this where large volumes are spilled, as ammonia has a strong and extremely unpleasant smell that people tend to retreat from rapidly (to the extent that people are more often injured trying to escape the smell than directly by the ammonia.

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Porttrombidium gedanense: A Mite from Baltic Amber.

Baltic amber is the preserved resin of Eocene coniferous trees that formed huge forests covering much of Scandinavia and Northern Europe. This amber is noted for the production of large numbers of Arthropod fossils, particularly Insects and Arachnids. After the True Flies (Diptera), Mites (Acari) are thought to be the second most abundant group in this amber, making up about 20% all preserved animals, though they are relatively understudied with many undescribed specimens residing in collections.

In a paper published in the journal PalZ on 30 May 2016, Marta Konikiewicz of the Department of Invertebrate Systematics and Ecology at Wroclaw University of Environmental and Life Sciences, Elżbieta Sontag of the Museum of Amber Inclusions at the University of Gdańsk and Joanna Mąkol, also of the Department of Invertebrate Systematics and Ecology at Wroclaw University of Environmental and Life Sciences, describe a new species of Mite from Baltic amber from the Gulf of Gdańsk.

The new species is placed in the genus Porttrombidium, and given the specific name gedanense, meaning 'from Gdańsk'. It is described from a single, juvenile specimen.

Porttrombidium gedanense, juvenile specimen. Konikiewicz et al. (2016).

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Nesolinoceras laluzbrillante: A new species of Ichneumon Wasp from the Dominican Republic.

Ichneumons are a widespread, numerous and diverse group of Wasps noted for their parasitoid reproductive strategy, which involves the adult female Wasp injecting an egg into a living host, with the emerging larva eating this host alive from the inside. Each species of Ichneumon Wasp typically targets a single host species, with the most common victims being Beetles, Butterflies, Spiders and other Wasps (including other Ichneumons). The genus Nesolinoceras contains a single species, Nesolinoceras ornatipennis, from Cuba, which targets the larvae of the Citrus-borer Beetle, Elaphidion cayamae, the female wasp drilling her ovipositor through the bark of the tree to lay her eggs on Beetle Grubs beneath.

In a paper published in the American Museum Novitates on 11 May 2016, Bernardo Santos of the Division of Invertebrate Zoology and Richard Gilder Graduate School at the American Museum of Natural History, describes a second species of Nesolinoceras from the Dominican Republic.

The new species is named Nesolinoceras laluzbrillante, where 'laluzbrillante' derives from the Spanish 'la luz brillante' meaning 'the bright light', in reference to the bright climate of the Dominican Republic and the glossy wings of the Wasp; this name having been chosen by students of the Washington Heights Expeditionary Learning School, in New York City. The species is described from five specimens, two females and three males, trapped in a recently cleared forest margin at the Punta Cana Ecological Foundation. These have a distinct black-and white colouration, and the females are slightly larger than the males, having a forewing length of 8.8-9.0 mm, while the forewing of the males measures 7.2-8.0 mm. The life-cycle of the species and host of the young is unknown.

Nesolinoceras laluzbrillante, female specimen. Santos (2016).

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Magnitude 7.0 Earthquake off the coast of El Salvador.

The United States Geological Survey recorded a Magnitude 7.0 Earthquake at a depth of 10.3 km, roughly 149 km offshore of the municipality of Puerto El Triunfo in Usulután Department, El Salvador, slightly before 6.45 pm local time on Thursday 24 November 2016 (slightly before 0.45 am on Friday 25 November, GMT). The quake was felt across much of Central America, from Guatemala to Costa Rica, though there are no reports of any major damage or injuries. A tsunami warning was initially issued, but later withdrawn.

The approximate location of the 24 November 2016 Central American Earthquake. Google.

El Salvador and the other countries of Central America are located on the southern part of the Caribbean Plate, close to its boundary with the Cocos Plate, which underlies part of the east Pacific. The Cocos Plate is being pushed northwards by expansion of the crust along the East Pacific Rise, and is subducted beneath the Caribbean Plate along the Middle American Trench, which runs parallel to the south coast of Central America, passing under the peninsula  as it sinks into the Earth's interior. This is not a smooth process, the plates tend to stick together, breaking apart again once the pressure from the northward movement of the Cocos Plate builds up to much, triggering Earthquakes. 

Earthquakes along subductive margins are particularly prone to causing tsunamis, since these often occur when the overlying plate has stuck to the underlying plate, being pulled out of shape by its movement.. Eventually the pressure builds up to far and the overlying plate snaps back, causing an Earthquake and a tsunami. 

Simplified graphic showing tsunami generation along a convergent margin.NASA/JPL/CalTech.

Witness accounts of Earthquakes can help geologists to understand these events, and the structures that cause them. The international non-profit organisation Earthquake Report is interested in hearing from people who may have felt this event; if you felt this quake then you can report it to Earthquake Report here.

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Asteroid 2016 WH passes the Earth.

Asteroid 2016 WH passed by the Earth at a distance of 900 100 km (2.34 times the average distance between the Earth and the Moon, 0.60% of the average distance between the Earth and the Sun), at about 0.05 am GMT on Monday 21 November 2016. There was no danger of the asteroid hitting us, though had it done so it would have presented no threat. 2016 WH has an estimated equivalent diameter of 7-24 m (i.e. it is estimated that a spherical object with the same volume would be 7-24 m in diameter), and an object of this size would be expected to explode in an airburst (an explosion caused by superheating from friction with the Earth's atmosphere, which is greater than that caused by simply falling, due to the orbital momentum of the asteroid) in the atmosphere between 37 and 20 km above the ground, with only fragmentary material reaching the Earth's surface. 

The calculated orbit of 2016 WH. Minor Planet Center.

2016 WH was discovered on 19 November 2016 (two days before its closest approach to the Earth) by the University of Arizona's Mt. Lemmon Survey at the Steward Observatory on Mount Lemmon in the Catalina Mountains north of Tucson. The designation 2016 WH implies that the asteroid was the eigtht object (object H) discovered in the second half of November 2016 (period 2016 W).

2016 WH is calculated to have a 741 day orbital period and an elliptical orbit tilted at an angle of 2.74° to the plain of the Solar System that takes it from 0.84 AU from the Sun (i.e. 84% of the average distance at which the Earth orbits the Sun) to 2.36 AU from the Sun (i.e. 236% of the average distance at which the Earth orbits the Sun, more than the distance at which the planet Mars orbits the Sun). It is therefore classed as an Apollo Group Asteroid (an asteroid that is on average further from the Sun than the Earth, but which does get closer). This means that it has occassional close encounters with the Earth, with the last having occured in November 2014.

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Sinkhole traps coach in South London.

About a hundred tourists including about 30 children had to be rescued after a coach became trapped in a sinkhole that opened up in a road in Lewisham, South London, on Saturday 26 November 2016. The passengers were helped off the vehicle by members of the London Fire Brigade and were provided with food by a local Lidl supermarket before being taken to a temporary shelter.

Coach trapped in a sinkhole in Lewisham, South London, on 26 November 2016. ITV News.

Sinkholes are generally caused by water eroding soft limestone or unconsolidated deposits from beneath, causing a hole that works its way upwards and eventually opening spectacularly at the surface. Where there are unconsolidated deposits at the surface they can infill from the sides, apparently swallowing objects at the surface, including people, without trace.

 Coach trapped in a sinkhole in Lewisham, South London, on 26 November 2016. ITV News.

On this occasion the sinkhole is believed to have been caused by a burst water main which washed away sediments beneath the road until it collapsed. The incident has been accompanied by flooding of several roads in the area, which has been closed to traffic by the Metropolitan Police. 

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