A 'South American' Marsupial from the early Eocene of Australia.

Modern Australian Marsupials are generally held to be a distinct evolutionary lineage, distinct from South American Marsupials. All modern Australian and New Guinean Marsupials are placed in a single group, the Eomarsupialia. These, along with a single South American species, the Monito del Monte (Dromiciops gliroides), are placed in the Australidelphia, one of two Marsupial Superorders, the second being the Ameridelphia, which includes all other Marsupials (and which is probably paraphyletic). Marsupials are thought to have originated in the Americas, and spread to Australia via Antarctica in the Late Cretaceous or Paleocene, probably in a single event, with all Eomarsupials descending from a single Australidelphian species that made the journey.

In a paper published in the journal Naturwissenschaften on 5 August 2012, Robin Beck of the School of Biological, Earth and Environmental Sciences at the University of New South Wales and the Department of Mammalogy at the American Museum of Natural History, describes a single calceneus (heal bone) from the Tingamarra Local Fauna of Queensland, which he interprets as being from a Ameridelphian Marsupial.

The Tingamarra calceneus in (a) dorsal, (b) distsal and (c) oblique views. Beck (2012).

Beck suggests that if this interpretation is correct then it suggests that Marsupials did not reach Australia in a single event, but that there may have been some degree of exchange between Australian and South American faunas before the breakup of Gondwana between 28 and 41 million years ago.

See also New species of Ground Opossum from eastern Bolivia, What killed the Australian Thylacine, Walking with Giant Wombats and Mammals on Sciency Thoughts YouTube.

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Collision leads to oil spill on swollen Mississippi.

A 6 km section of the Mississippi River was closed by the US Coast Guard after a towing vessel collided with a fleet of docked barges at Alton, Illinois, at about 1.00 am local time (6.00 am GMT) on Friday 3 May 2013, causing fourteen of them to break away from their moorings. This in turn led to an a series of further collisions, including one in which a barge being loaded with crude was struck, leading to around 1100 liters of oil being lost into the river. This is the second major breakaway barge incident in the area in two weeks, 114 barges broke away from their moorings in an incident on 20 April, causing damage to a number of facilities along the river.

The location of the Alton barge incident. Google Maps.

The Mississippi has always had a reputation for being a temperamental river, and has become increasingly prone to flooding events recently, due to higher precipitation in the American and Canadian Mid-West, caused by sustained higher temperatures over the Atlantic. This has lead to persistently high waters and a raised water table, which can quickly turn into floods when  additional water enters the system.

Residents building a flood-wall at Carksville Missouri on 21 April 2013. Reuters/Office of Missouri Governor Jay Nixon.

The swollen river means that there is little that can be done about oil spilled into the river, other than to hope the turbulent waters disperse it quickly.

See also Plains Midstream Canada charged over April 2011 Alberta oil spill, Oil spill in Bayelsa State, Nigeria, Exxon Mobil fined $1.7 million for Yellowstone River oil spill, Willard Bay State Park, Utah, closed by oil spill and Dutch court fines Shell over pollution in ther Niger Delta.

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Explosion at oil facility in Louisiana.

A storage tank at a crude oil facility at Denham Springs in Livingston Parish, Louisiana, exploded at about 10.30 pm on Thursday 2 May 2013 (3.30 am on Friday 3 May, GM), prompting local authorities to evacuate 30 homes in the vicinity. The facility belongs to Denbury Resources and has two storage tanks with a combined capacity of 2300 barrels. It receives oil from the Lockhart Crossing Oil Field via a pipeline that is reportedly undamaged. 

Fire teams surveying the burning oil facility at Denham Springs. Livingston Parish Sheriff's Office.

One of the storage tanks at the site is reported to have ruptured, though it is unclear if this was the cause of the explosion or a result of it, the other is intact, but has been described as 'bulging slightly from the heat' by a representative of the Office of Homeland Security and Emergency Preparedness in Livingston Parish. There were reportedly delays in fighting the fire as firefighters had wait for the delivery of fire retardant foam; with water being used to attempt to keep the surviving tank cool. 

The location of the Denham Springs storage facility. Google Maps.

See also Double pipeline explosion in northeast Libya, Homes evacuated after Arkansas oil leak, Gas pipeline explosion in West Virginia, Two feared dead after explosion on oil rig in Gulf of Mexico and Massive sinkhole opens up in Assumption Parish, Louisiana.

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Over 60 feared dead in Darfur gold mine collapse.

It is feared that more than 60 miners have lost their lives in a mine collapse in the remote Darfur region of northwest Sudan. The incident happened at the Jebel Amir mine in the north of the region on Monday 29 April 2013, but news of the incident only reached Khartoum on Thursday 3 May. The mine has a central shaft descending 60 m from the surface, with a number of side gantries. At the time of the incident 66 miners were officially working in the mine, but the real number present is likely to have been somewhat larger. Another 10 miners apparently descended into the pit to attempt to rescue their colleagues and were also trapped.

The approximate location of the Jebel Amir mine. Google Maps.

Gold has become Sudan's principle earner of foreign currency since the independence of South Sudan in 2011, which cut the country's oil revenues by 75%. This has provoked a goldrush in northern Darfur, where dozens of mines produce around 15 tonnes of gold per year. Despite the economic importance of the industry it is almost totally unregulated, with very little safety precautions in the mines and frequent fighting between rival ethnic groups. In January and February 2013 around 400 people were killed in ethnic clashes around Jebel Amir, with around 10 000 more being displaced by the fighting.

See also Miner killed by gas on Mindanao Island, Chilean court suspends work at the Pascua-Lama Gold Mine over entironmental concerns, Uranium mining to begin in Tanzania, Two Sierra Leonean artisanal miners killed by soil cave-in and 83 feared dead after Tibetan landslip.

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Total eclipse of the Sun visible from Australia, Papua New Guinea and the Solomon Islands, 9 May 2013.

A total eclipse will be visible from parts of the Southern Hemisphere on 9-10 May 2013. The eclipse will be visible across parts of the Northern Territory and Queensland on 9 May, before moving across the southeastern tip of Papua New Guinea, the D'Entrecasteaux Islands group and the central part of the Solomon Islands, before crossing the international dateline and ending in 10 May over the Pacific Ocean.

The path of the 9-10 May 2013 Solar Eclipse. The total eclipse will be visible along the central dark grey path. A partial eclipse will be visible from the shaded areas; in the lighters area the full eclipse will not be visible as it will have started before dawn (west) or will continue after sunset (east). The red lines are the equator and the international dateline. HM Nautical Almanac Office.

Solar eclipses occur as a result of the Moon passing in front of the Sun as seen from Earth. The Sun and Moon appear roughly the same size from Earth, though this is coincidental, the Moon being considerably smaller and closer than the Sun. 

The relative positions of the Sun, Moon and Earth during a Solar eclipse. Starry Night.

The Moon orbits the Earth every 28 days, but does not cause a Solar eclipse every month. This is because the orbit of the Moon is inclined to the orbit of the Earth about the Sun. Thus when the Moon is in the same part of the sky as the Sun it is usually either above or below it from our perspective (though it is effectively invisible at these times, since the Moon only 'shines' with reflected light from the Sun), with eclipses only occurring at those points in the cycle where the two orbital plains intersect.

How the differing inclinations of the Earth and Moon's orbits prevent us having an eclipse every 28 days. Starry Skies.

See also The Earth approaches its perihelion, The Southern Solstice, The Earth reaches its aphelion and NASA's Solar Dynamic Observatory observes the transit of Venus.

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At least two people killed by Kashmir Earthquake.

Slightly before 12.30 pm local time (slightly before 7.00 am, GMT) on Wednesday 1 May 2013, eastern Kashmir was shaken by a Magnitude 5.4 Earthquake at a depth of 9.8 km, roughly 100 km northeast of Jammu and 120 km southeast of Srinagar, according to the United States Geological Survey. This is a moderately large Earthquake and dangerous in a mountainous area, and local press are reporting that at least two people have been killed and over 70 injured.

The location of the 1 May 2013 Earthquake. Google Maps.

Kashmir is in the Himalayas, on the boundary between the Indian and Eurasian Plates. India is pushing northwards into the Eurasian Plate at a rate of about 5 cm per year, causing folding and uplift along the boundary, which has created the Himalayas, Tibetan Plateau and mountain ranges of Central Asia. This is not a smooth motion, the rocks of the boundary resist the movement, then give way as the pressure builds up, leading to frequent Earthquakes.

Damage to a house following the 1 May 2013 Earthquake. Earthquake Report.

See also A least 12 fatalities after a Magnitude 5.6 Earthquake in eastern Afghanistan, 83 feared dead after Tibetan landslip, Earthquake in Baghlan Province, Afghanistan, Earthquake rattles Assam, northeast India and Earthquakes on Sciency Thoughts YouTube.

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Miner killed by gas on Mindanao Island.

A miner reportedly died as a result of a gas leak in a small goldmine in Pantukan Municipality on Mindanao Island in the Philippines at around 6.00 pm local time (10.00 am GMT). The miner, named by local police as Jun Lope (24) of Lorento had been working in a shaft 15 m below the surface, ventilated by a blower pumping air to the workface through a hose, but failed to emerge after 30 minutes. A second miner entered the shaft to search for him, but was overcome by noxious fumes, although he managed to raise the alarm by pulling on the air hose, prompting a rescue. Mine gas is more usually associated with coal pits, where it is produced by compression of the coal, driving of volatile organic compounds, but can affect other forms of mine. The incident is being investigated by police in Pantunkan.

The Pantunkan area has a large number of small scale artisanal mines, which are unregulated and seldom have any form of health and safety procedure. Accidents are frequent in these mines, as are environmental problems, particularly as the gold metal is separated from the ore using cyanide and mercury. In 2011 a landslide killed 26 workers at a mine in Pantunkan.

A small scale mine in Pantunkan. The ground up ore is mixed with mercury in the settling pools to separate the gold. Golden Means.

The Philippine government has tried to regulate or close these mines in recent years, but has met with widespread opposition, as the mines are a source of income for many poor families. The small mines are more popular than large mining operations, which are often owned by foreign companies. These larger mines pay revenue to the central government, but often provide less employment in local communities, and frequently have a patchy record on environmental and safety issues.

See also Two Sierra Leonean artisanal miners killed by soil cave-in, Seven workers killed by mine explosion in Hunan Province, China, Human Rights Watch reports on mining in India, Nine killed at illegal rare-earth mine in Guangxi Zhuang Autonomous Region, southern China and Operations ceased at Padcal Mine following flooding. 

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