Saturday 31 December 2011

Acid spill from gold mine adds to Edith River's woes.

Heavy rainfall associated with Cyclone Grant (now downgraded to Tropical Storm Grant) has caused serious problems along the Edith River in Northern Territory, Australia. There has been widespread flooding, road and rail links have been cut, and a train derailment has lead to a spill of toxic copper concentrate. Now news has emerged that the rainfall has caused a retaining pond at the Mount Todd Gold Mine to fill up and overspill into the river.

The Stuart Highway near the Edith River.

There are typically two types of ponds at gold mines, settling tanks in which ore is deliberately mixed with chemicals that help extract the gold (typically cyanide and mercury compounds) and retaining ponds holding water drained from the mine. The pond affected appears to have been of the latter type, which would be less of a problem, but is still potentially nasty. A mine in the (high precipitation) Northern Territory is likely to produce a lot of water, which will have been contaminated by passing through metal rich deposits. The mine operators, Vista Gold, have conceded that the water is acidic, but have declined to release the results of tests on the water, saying this would 'confuse' the public.

The pond has a history of releasing sulphuric acid (H₂SO₄) and heavy metals into the river, leading to fish kills, and there is no reason to suspect that this spill will be very different. Sulphuric acid is common in wastewater from mines, formed when water reacts with sulphur compounds in the metal-bearing rocks. Retaining ponds containing sulphuric acid are commonly treated with calcium carbonate (CaCO₃; usually powdered limestone) in order to neutralize the acid. The nature of any metals in the water is less clear; iron and copper compounds are common in gold mine runoff, and aluminum, mercury, lead and cadmium are known at other mines.

On Thursday (28 December) the rate of water running out of the pond was estimated at 1700 m² per hour (1 700 000 liters per hour) and a spokesman from the company stated the water had a pH of 3-3.5 (roughly the equivalent of lemon juice or vinegar), though it was unclear if this figure related to the pool before the rains, the pool after the rains, or the river.

Toxicologist Barry Noller of the Centre for Mined Land Rehabilitation at the University of Queensland has observed that there is a danger of the released water reacting with copper concentrate spilt by a train derailment at the Edith River Crossing. The owners of the spilt material, OZ Minerals, have undertaken to clean up any material remaining at the sight, but admit that there is little they can do about any dissolved material entering the river system. The spill apparently contained copper metal, which is insoluble, copper sulphate, which is soluble, and iron sulphate, which is also soluble; all of these are toxic. Any copper and iron sulphate is likely to have been washed away already, copper could react with the dissolved sulphuric acid to form more copper sulphate, which would then be washed away.

There has been little official response from the authorities in the Northern Territory, which has been criticized by Opposition Minister for Natural Resources, Peter Chandler (Country Liberal), who has accused the Northern Territories Government of being unaccountable and helping the company to keep information from the public.

Friday 30 December 2011

Copper spill causes pollution alert on the Edith River in the Northern Territory, Australia.

On Tuesday 27 December 2011 as train carrying 1500 tonnes of copper concentrate was derailed when it attempted to cross a bridge over the Edith River. The bridge had apparently had its foundations washed away by flooding related to Cyclone Grant, and gave way as the train passed over it. Two members of the train crew were airlifted to hospital in Darwin. About 1200 tonnes of the copper concentrate are thought to have been lost.

The remains of the train at the Edith River Crossing. Picture by photographer Michael Franchi.

Copper concentrate is an early stage product of the copper extraction process. It is formed by taking copper ore, grinding it up, and then exposing it to chemicals that bind to copper and float (such as pine oil or long chain alcohols), so that the copper bearing minerals are separated from the rest of the medium. Typically the resultant mix contains about 25-35% copper, as well as a variety of copper and iron sulphides. It is greenish, slimy, toxic and valuable; the 1200 tonnes lost was probably worth about US$6 million (Au$5.9 million).

Copper compounds are extremely toxic, so this level of loss into a natural water system presents a serious threat to wildlife and agriculture. The Northern Territory's Environmental Protection Agency has launched an investigation of the spill, and has warned prosecutions may follow. The owner of the concentrate, mining company OZ Minerals, has stated that it will mount a cleanup operation once it is safe to work in the area. The company hopes that it should be able to recover any material remaining at the derailment sight, and that any material washed away will become to dilute to present a hazard. Copper compounds tend to be foul tasting as well as poisonous, so there is little danger of large animals drinking contaminated water, though there is a distinct danger to organisms that cannot avoid the chemicals, such as plants and aquatic invertebrates, which may then have an impact on animals higher in the food chain.

The prompt adoption of ownership for the situation by OZ Minerals does bode well for the cleanup. OZ Minerals has stated that the lost material is not significant compared to the size of the companies operations, and that it hopes to complete all shipments for export due in the first quarter of 2012 by March 31. Nevertheless the companies shares had fallen by 13¢ by 3pm on the 27th.

The materials were being transported from OZ Minerals' Prominent Hill mine in South Australia to the Port of Darwin in the Northern Territory for export, aboard a train operated by Genesee and Wyoming Australia. It appears that the operator erroneously believed the route was safe after Cyclone Grant was downgraded to a tropical storm. The closure of the line effectively cuts the Port of Darwin off from the rest of Australia, a major problem for exporters; Australia is unique among developed economies in that it is largely dependent on the export of raw materials. The Environment Centre Northern Territory (an environmental group) has expressed relief that the train was carrying copper concentrate, as trains from the Roxby Uranium Mine also use the route. The Chief Minister of the Northern Territory, Paul Henderson (Labor) has announced an official investigation into rail safety in the state, and has said he will accept any recommendations.

The rail link between Darwin and the rest of Australia.

Thursday 29 December 2011

Planets in the NY Virginis system.

NY Virginis is an eclipsing binary system roughly 2000 light years from the Earth in the constellation of Virgo. The name NY Virginis implies the 258th variable star in the constellation of Virgo. The system is also known as PG1336-018, where the PG stands for 'Palomar Green'; it was discovered during the Palomar Green survey.

The system is made up of two stars referred to as M₁ and M₂. M₁ has a mass of approximately 46% of that of our sun, but is over six times as hot (33 000 K as opposed to 5578 K for our sun). It is an 'Extreme Horizontal Branch' blue-white subdwarf-star, where the 'Extreme Horizontal Branch' refers to the position on a graph where colour/temperature is plotted against temperature. Stars of this type have run out of hydrogen in their core and expanded to form Red Giant stars, in which helium is fused in the core and hydrogen in the outer layers, then lost these outer layers for some reason (probably in this case interaction with M₂), exposing the helium-fusing core.

Orbiting this at a distance of slightly under 5 million km is M₂, a Red Dwarf star with 14% of the mass of our sun and a temperature of about 3000 K. Red Dwarfs are small, cool stars which do not get particularly hot due to their low mass, but subsequently burn for much longer than larger stars.

This month a study of the system by a team lead by SB Qian of the Yunnan Observatory was published in a paper on the arXiv database at Cornell University Library. Qian et al. combined data from an earlier study of the system by the South African Astronomical Observatory with new data collected by the Jorge Sahade Telescope in Argentina and the Yunnan Observatory.

This study was able to detect irregularities in the orbit of the two stars, which they used to calculate the existence of a planet with a mass of 2.3 times that of Jupiter, orbiting at a distance of 3.3 AU, that is to say 3.3 times the distance at which the Earth orbits the Sun, or twice the distance at which Mars orbits, every 2900 days. Qian et al. refer to this planet as M₃, but it is referred to elsewhere as NY Virginis b, or NY Vir b. This is inaccurate; using conventional numbering for the system M₁ would be NY Virginis A, M₂ would be NY Virginis B and M₃ would be NY Virginis c; since all bodies in the system are lettered, stars with a capitol and planets with a lower case letter.

The inclusion of M₃ in the model still does not completely resolve the irregularities in the two stars orbits. Qian et al. therefore infer a second planet, with a mass of about 2.5 times that of Jupiter, orbiting roughly once every 15 Earth years.

An artist's impression of a binary system with two planets. By scientific illustrator Mark A. Garlick.

Qian et al. also attempt to model the history of the NY Virginis system. As noted above, M₂ orbits M₁ at a distance of only 5 million km, but it cannot have been this close throughout the history of the system. Qian et al. calculate that if M₁ had originally had a mass the same as our sun (which is an arbitrary figure, but works for modeling the evolution of the system), then it would have grown till its radius was roughly 0.5 AU - half the radius of Earth's orbit, or slightly greater than the orbit of Mercury. In this model if M₂ had originally orbited M₁ at a distance of 0.8 AU (a slightly greater distance than that at which Venus orbits the sun) then once M₁ reached a radius of 0.5 AU, then M₂ would have started to tear away the outer atmosphere of M₁. This would have slowed down M₂ in its orbit, causing it to spiral inwards towards M₁, stabilizing in its current orbit once the outer atmosphere of M₁ was used up.

Eruptions from the Tompaluan Crater, Lokon-Empung, Sulawesi. December 2011.

Lokon-Empung is a double volcano located near the eastern tip of the northern arm of Sulawesi, Indonesia. It has two cone-shaped peaks, Lokon to the southwest and Empung 2.2 km to the northeast, with a saddle of volcanic rock separating the two. Of these Lokon is the larger, though it has not erupted in recorded history, whereas the slightly smaller Empung last erupted in the late eighteenth century. Situated on the saddle between the two summits is Tompaluan, a double crater that remains active to the current day.

Smoke rising from Tompaluan Crater. The Lokon summit is to the right, Empung to the left.

On 27 December 2011 the Pusat Vulkanologi Dan Mitigasi Becani Geologi (Indonesian Centre for Volcanology and Geological Hazard Mitigation) detected a series of seismic tremors beneath the mountain and imposed ban on traveling within 2.5 km of the crater. The following day the Jakarta Post reported a series of explosions from the crater.

Tompaluan is a very active volcano. In June-August 2011 a series of explosive eruptions and lava flows lead to over six thousand people being evacuated from around the mountain, with one fatality due to a heart attack during the evacuation process. Since then there have been smaller eruptions in October and November. There was also a small eruption in February this year. Prior to this year Tompaluan erupted in 2008, 2007, 2003, 2002, 2001, 2000, 1999, 1998, 1996, 1994, 1991, 1988, 1987, 1986, 1984, 1975, 1973, 1971, 1969, 1966, 1965, 1963, 1962, 196, 1958, 1951, 1949, 1942, 1930, 1893, and 1829. All eruptions prior to this appear to have been from the Empung crater.

The Lokon-Empung volcanic complex is located at the southern end of the Sangihe Volcanic arc, where an extension Molucca Sea Plate is being subducted beneath an extension of the Eurasian Plate, sometimes called the Sangihe Plate. As this happens part of the subducting plate is melted by the heat of the Earth's interior, and rises up through the overlying plate as liquid magma, forming volcanoes at the surface. 320(ish) km to the east the Molucca Plate is also being subducted beneath an extension of the Philippine Sea Plate, sometimes called the Halmahera Plate, producing a second chain of volcanoes in the Halmahera Islands. At some point in the future the Molucca Plate will vanish and the two volcanic arcs will meet.

The Molucca Sea, five million years ago (above) and today (bellow).

Wednesday 28 December 2011

Dutch court upholds fine against commodities giant Trafigura for illegally exporting toxic waste to Côte d'Ivoire.

On 23 December 2011 the Amsterdam Court of Appeal upheld a 2010 judgement by a Dutch court to the effect that multinational commodities trading company Trafigura had illegally exported hazardous waste to Abidjan, Côte d'Ivoire; waste that resulted in a number of deaths (up to 17, depending on the source of information) and tens of thousands of cases of poisoning (again exact figures are unclear, as different sources quote different figures).

The charge relates to a cargo of 400 tonnes of cleaning residue from oil tanks, which left the UK in June 2006 aboard the Greek registered ship Probo Koala; the cargo was shipped to Amsterdam, where it was due to be offloaded and processed by a Dutch company. However on 2 July 2006 the unloading in Amsterdam was cancelled after Trafigura discovered that the cost of processing would be 3000% of what they had originally expected. The ship was then redirected to Abidjan, where the cargo was unloaded and delivered to a local company for processing.

The Probo Koala.

The exact nature of the cargo is not clear, but the sudden increase in processing in Holland implies that the cargo was considerably more toxic than had been originally thought. Trafigura have constantly pointed out that residual waste of this kind is a common byproduct of the oil industry, and that it is commonly processed in a number of centers around the world, including Abidjan. However if an incorrect cleaning chemical had been used at some stage then a far more dangerous end-product would not be surprising. This would explain the higher costs required by the company in Holland, and the subsequent inability of the Ivorian company to handle the waste. The Dutch court accepted evidence from Côte d'Ivoire that the waste was caustic and caused burning to the skin (unsurprising in toxic cleaning residue); though a British court had early accepted that the waste would cause only 'flu-like symptoms' (though since the flu can kill you this isn't a great improvement).

An Ivorian man with burns allegedly caused by contact with waste from the Probo Koala.

Trafigura had already reached pre-trail settlements with the Ivorian government and a group of victims seeking compensation in the UK, by which they agreed to pay €152 million in Côte d'Ivoire and €33 million in the UK, in return for which they were able to avoid the matter coming before a court in either country. Unfortunately the stopover in Amsterdam meant that the shipment was also covered by Dutch law, enabling prosecutors there to bring charges against Trafigura. Since no settlement had been sought in Holland there was no way to prevent the matter coming to court. The Amsterdam Port Authorities were also charged for their part in the affair, but were acquitted. Trafigura were fined €1 million in July 2006, which both parties appealed; Trafigura wishing to have the conviction overturned and the prosecutor seeking to have the fine doubled to €2 million. Since Trafigura had already paid out a total of €185 million to avoid a judgement it is to be assumed that they were more concerned about being ruled liable than they were about the money.

The clean-up operation in Abidjan.

Trafigura also brought legal action against The Guardian newspaper in the UK in 2009, after the paper came into possession of documents relating to the shipment. The company was initially granted an injunction, but the documents then appeared on the Wikileaks website, then were raised in a parliamentary question by Labour MP Paul Farrelly, enabling The Guardian to claim the document was in the public domain, and publish anyway. Trafigura has consistently claimed that The Guardian's coverage of the story has been 'highly misleading' and 'a complete distortion of the facts'.

Major Earthquake in southwestern Siberia. 27 December 2011.

Slightly after 11.20 pm local time (slightly after 3.20 pm, GMT) on Tuesday 27 December 2011 a severe Earthquake shook a remote part the Kaa-Khem District of the Tuva Republic, southwestern Siberia, close to the Mongolian border, roughly 96 km to the east of Kyzyl, the capitol of the Tuva Republic. The quake was measured as having a magnitude of 6.6 on the Richter Scale and occurring at a depth of 6.9 km by the United States Geological Survey, and as having a magnitude of 6.5 on the Richter Scale and having a depth of 10 km by the Russian Academy of Sciences, which is slightly less severe but still pretty bad; the larger the magnitude and the shallower the depth, the more severe any effects felt at the surface will be. There have been at least three aftershocks, with magnitudes of 4.7-4.8.

Population exposure map from the United States Geological Survey, showing the epicenter of the quake (black star), the intensity of the shaking at the surface (coloured lines, yellow more severe than green), and local population centers (grey writing)

The quake has also been described as a magnitude 9.5 quake in some Russian press releases; this is a Medvedev-Sponheuer-Karnic (MSK) scale number; the MSK scale is an intensity measure used by Russian seismologists, it is an indication of the likely damage caused by a quake rather than the actual energy released as in the Richter Scale. A magnitude 9.5 quake on the MSK scale is considered to be Destructive to Devastating, with general panic, people thrown to the ground, severe damage to non-earthquake proofed buildings, damage to earthquake proofed buildings, and the potential of massive landslides and flooding.

The quake was felt in Kyzyl, where there are reports of minor damage to buildings but no casualties, but not as yet from the area where the quake was centered. The area is sparsely populated, with the majority of homes in the area being holiday homes owned by Russian city dwellers, which are unlikely to have been in use in mid-winter, but it is still thought highly likely that there will have been casualties, as buildings in the area are not generally Earthquake-proofed, and people forced to leave their homes abruptly in the middle of the night during the Siberian winter are deemed to be at extreme risk of hypothermia; temperatures are likely to have been between -20°C and -30°C in the area at the time of the quake. Emergency teams have been dispatched to the area, and a state of emergency declared by authorities in the Tuva Republic.

Major Earthquakes in southwestern Siberia are rare, the most recent was a quake in the neighboring Altai Republic in September 2003 that measured 7.2 on the Richter Scale, prior to which there had been no major quakes in the region for over 70 years. These quakes are a product of India pushing into the Eurasian Plate far to the south, which causes the eastern part of the Eurasian Plate to rotate clockwise, provoking pressure to build up in Central Asian rocks and eventually faulting within the mountains of southwestern Siberia.

Tuesday 27 December 2011

Wasp-19b: a Highly Irradiated Hot Jupiter.

Wasp-19b is an exoplanet slightly larger than Jupiter (1.1 times the mass, 1.31 times the radius) orbiting a G-type star 815 light years from the Earth in the constellation of Vela. It was discovered in 2009 by the WASP-South Telescope near Sutherland in Northern Cape Province, South Africa, and its discovery reported in a paper in The Astrophysical Journal by a team lead by Leslie Hebb of the School of Physics and Astronomy at the University of St. Andrews in Scotland.

Wasp-19b has the shortest year of any known planet, orbiting its star in slightly under 19 hours, at a distance of 1.65% of that at which the Earth orbits the Sun. This comfortably places Wasp-19b in the 'Hot Jupiter' category of planets, large planets orbiting close to their stars. But Wasp-19b is hot even for a Hot Jupiter, since the star it orbits is not a cool Red Dwarf, like most Hot Jupiters, but a G-type star with a mass 95% of that of the Sun, a radius 93% of that of the Sun (which is 7.15 times that of Wasp-19b), and a luminosity 71% of that of the Sun. Wasp-19b has an almost circular orbit, with an eccentricity of just 6000 km (that is to say when it is at its closest to its star it is only 6000 km closer than when it is at its furthest).

A simple model of the Wasp-19 system.

This month a team lead by David Anderson of the Astrophysics Group at Keele University published a paper on the arXiv online Database at Cornell University Library detailing the results of a spectrographic study of the atmosphere of Wasp-19b using the Spitzer Space Telescope; this paper has also been accepted for publication in the Monthly Notices of the Royal Astronomical Society.

Most Hot Jupiters appear dark due to Titanium and Vanadium Oxides (TiO and VO) trapped it warm layers of the upper stratosphere, but Wasp-19b appears bright, suggesting that it lacks these dark-molecule trapping layers. The most likely explanation for that is that it lacks a stratified atmosphere due to the high energy input it receives from it's star. Thus it is likely to have both Titanium and Vanadium Oxide in its atmosphere, just not trapped in a discreet layer where they can act as a dark layer.

The precise makeup of the atmosphere of Wasp-19b could not be determined by this study, but the team were able to narrow it down to two possible models. The first, the 'carbon rich' model has an atmosphere comprised primarily of Carbon Monoxide (CO) and Methane (CH₄); the second, or 'oxygen rich', model has an atmosphere composed mostly of Carbon Monoxide, Carbon Dioxide (CO₂) and Water (H₂O).

See also The Atmosphere of GJ1214b, TrES-2b, the black planet and Exoplanets on Sciency Thoughts YouTube.

Monday 26 December 2011

Oklahoma shaken by Earthquake on Christmas Day.

At 8.10 am local time (2.10 pm GMT) on the morning of 25 December 2011 the small town of Cromwell in Seminole County, Oklahoma, was shaken by a small Earthquake. The quake measured 3.3 on the Richter Scale, which is fairly small, but occurred at a depth of only 10.4 km, directly beneath the town, enough to give the town quite a jolt, though there are no reports of any injuries or serious damage.

Earthquake location map from the United States Geological Survey.

Oklahoma is a long way from any major tectonic boundaries, but it does have a number of fault systems, and small Earthquakes are not unusual. Up until 2009 Oklahoma averaged about 50 Earthquakes a year, but in each of the two years 2010 and 2011 Oklahoma suffered over 1000 quakes, which requires an explanation.

Map of the geological fault lines of Oklahoma, from the Bureau of Economic Geology at the University of Texas at Austin.

This is major increase in seismic activity over a short period of time, and requires an explanation. In the absence of any known natural phenomenon that could have caused this (such as the appearance of a volcano in central Oklahoma), many residents have started to question whether the state's hydrocarbon industry could be to blame. Oklahoma has long been a producer of both natural gas and oil, but as reserves have shrunk producers have increasingly turned to Hydraulic Fractionation (Fracking) as a means of maintaining production levels.

Fracking is a process by which water and chemicals are forced into buried strata in high pressure blasts in order to produce shock waves, which will hopefully cause the release of hydrocarbons. Shock waves in buried strata are, in layman's terms, Earthquakes, so an increase in Earthquakes in areas where Fracking is being practiced is not surprising. The Fracking industry have always maintained that their aim is to provoke quakes with magnitudes of less than 1.0 on the Richter Scale, but in Oklahoma, as in other places the practice has been linked with much larger quakes, often in excess of 3.0; which is more than a hundred times as large (the Richter Scale is logarithmic, 2.0 is ten times as large as 1.0, 3.0 is ten times as large as 2.0 and one hundred times as large as 1.0), something the industry disputes, refusing to accept responsibility for such large quakes without further evidence, even though they cannot offer an alternative explanation for the increase in quake activity.

The American National Academy of Sciences is currently looking into the subject, and is expected to produce a detailed report on Fracking and Earthquakes sometime in 2012, but in the meantime the Oklahoma Geological Survey commissioned a report from Austin Holland, a tectonics expert at the Department of Geosciences, University of Arizona, into the conetection between a fracking operation at the Eola Field in Garvin County, to the southwest of Seminole.

Holland came to the conclusion that 'The strong correlation in time and space as well as a reasonable fit to a physical model suggest that there is a possibility these earthquakes were induced by hydraulic-fracturing. However, the uncertainties in the data make it impossible to say with a high degree of certainty whether or not these earthquakes were triggered by natural means or by the nearby hydraulic-fracturing operation'. This has been widely reported in the press as 'uncertainties in the data make it impossible to say with a high degree of certainty whether or not these earthquakes were triggered by natural means or by the nearby hydraulic-fracturing operation', or even 'Seismologist Cannot Link Drilling To Oklahoma Earthquakes', which is a long way from what Holland actually reports.

Holland examines seven criteria which need to be met in order to establish that the quakes are the responsibility of the Fracking operation in Garvin County. Five of these can be met, and the remaining two cannot be answered either way given the evidence available when making the report, which had not been gathered with the specific intention of answering these questions.

1. Are these events the first known earthquakes of this character in the region?
Unknown. Oklahoma does not have a long history, and earthquake monitoring has never been a priority as the state has never suffered a seriously debilitating quake. Therefore it is impossible to say with confidence that quakes on this scale have never occurred, merely that they have never been recorded.

2. Is there a clear correlation between injection and seismicity?

Yes. There was a clear correlation in time and space between deep fracking operations at Eola Field and earthquakes, but not between shallow operations and any quakes.

3. Are the epicenters near wells (within 5 km)?

Yes. Nearly all the earthquakes have epicenters (the point on the surface directly above the centre of the quake) within 5 km of a well, and the majority much closer.

4. Do some earthquakes occur at or near injection depths?

Yes. Most of the earthquakes occur near injection depths.

5. If not, are there known geologic structures that may channel flow to sites of earthquakes?

Yes. There are numerous vertical block faults within the Eola Field, which have excellent potential for channeling flow.

6. Are changes in fluid pressure at well bottoms sufficient to encourage seismicity?

Yes. If this was not the case then hydraulic fractionation would not work in these rocks.

7. Are changer in fluid pressure at hypocentral locations sufficient to encourage seismicity?

Unknown. The study was conducted using data that was collected for other purposes; it would simply not be possible to say from this data if this criteria was correct.

Map from Holland's report showing the extent of the Eola Field (cross-hatched area), pre-existing geological faults (green lines), the site of the well where Hydraulic Fractionation is taking place (black hexagon), an the location and depth of known quakes that have taken place since fractionation began (coloured circles, key to depths bottom right).

Thus when Holland states that 'The strong correlation in time and space as well as a reasonable fit to a physical model suggest that there is a possibility these earthquakes were induced by hydraulic-fracturing. However, the uncertainties in the data make it impossible to say with a high degree of certainty whether or not these earthquakes were triggered by natural means or by the nearby hydraulic-fracturing operation' he means just that; he is saying that using the data available, which was not gathered for the purpose of this study, it is not possible to be 100% certain that the quakes are being caused by the fracking, but this is still quite likely. In legal terms the balance of probability is that fracking is causing earthquakes, but that this cannot be proven beyond all reasonable doubt. Unfortunately Holland states this with dry scientific reserve rather with a salesman's hyperbole, which has enabled a degree of (sometimes willful) misinterpretation.

Sunday 25 December 2011

Russian satellite crashes into house.

On Friday 23 December 2011 Russian Andrei Krivoruchenko was at home with his wife in the village of Vagaitsevo, in Ordynsk District, Novosibirsk, Siberia, when he heard a large crash. Investigation revealed a large hole in his roof, caused by a 50 cm titanium sphere which had apparently fallen out of the sky. This turned out to be a fuel tank from a Russian Meridian communications satellite, which had been launched in Plesetsk, Northern Russia, minutes before.
The hole in Andrei Krivoruchenko's roof.

The satellite was part of a communications network designed cover Siberia and the Russian Arctic and Far East. It was launched on a Soyez-2.1b rocket launched at the Plesetsk Cosmodrome which broke up seven minutes after takeoff, apparently due to a third stage rocket failure. Most of the debris is likely to have burned up in the atmosphere, but several pieces of landed in Ordynsk District, including the titanium sphere, an essentially cannon-ball shaped fuel tank.

The flight path of the doomed satellite.

It has been a particularly bad year for Roscosmos, the Russian space agency, who have lost string of satellites and probes to failed launches.

On 4 December 2010 a Proton Rocket carrying three Glonass-M navigation satellites (a Russian rival to the American GPS system) launched from the Baikonur Cosmodrome in Kazakhstan on the wrong flight path, failed to reach orbit, and eventually crashed into the Pacific 1500 km northwest of Honalulu.
The Glonass Satellite, as it should have looked.

On 1 February a Rokot/Briz-KM booster carrying the Kosmos 2470 Satellite, designed for creating detailed three dimensional maps and studying plate tectonics, was launched from the Plesetsk Cosmodrome failed to reach its correct orbit after a second stage ignition failure. Roscosmos were unable to establish contact with the satellite. A month later a second system failure caused the satellite to move out of alignment with the sun, causing its solar power system to fail.

On 15 August 2011 another Proton Rocket from Baikonur carrying the Express-AM4 communications satellite, designed to cover Russia and Central Europe, failed to reach its correct orbit after the final stage failed to separate properly. The satellite reached orbit, but not in the correct position; it was apparently unable to deploy its solar panels with the final stage still attached, and communication was lost a few days later when its batteries failed.

The Express-AM4 on the launch-pad.

On 24 August a Soyuz U rocket carrying a Progress 44 supply vessel for the International Space Station, blasted of from Baikonur, but developed a booster problem 325 seconds after launch, causing the rocket to shut down and the satellite to fall back to Earth. This was a serious problem for the Space Station, as since the end of NASA's Space Shuttle program, the Soyuz rockets are the only ones capable of reaching the Station.

On 9 November the Fobos-Grunt interplanetary probe, intended to land on the Martian moon Phobos, blasted off from Baikonur, but suffered another booster failure and became trapped in low-Earth orbit. It is thought likely that the probe will fall back to Earth in February 2012.
The Fobos-Grunt Probe, as it was intended.

Saturday 24 December 2011

Oil spill off the coast of Nigeria.

On 20 December 2011 a routine transfer between a floating oil production, storage and off-loading vessel and a waiting oil tanker in the Bonga Field, off the coast of Nigeria, developed a problem resulting in the discharge of a large amount of oil into the sea. The operators, The Shell Exploration and Production Company (SNEPCo), a local subsidiary of the Shell global oil group, estimated the loss at under 40 000 barrels, roughly one-fifth of the Bonga Field's daily output, and the worst offshore oil spill in the Bight of Benin since 1998. SNEPCo has responded by closing down production at the Bonga Field, and deploying five ships and two aircraft to spray the spill with dispersants, chemicals which break down oil in seawater.

Satellite image of the oil spill released by the environmental group SkyTruth.

Oil spreads very thinly over the surface of the water very thinly, so a spill of 40 000 barrels ought to cover about 600 km² of ocean. However satellite images taken by the European Space Agency Envisat Satellite and released by the SkyTruth environmental group on 21 December appear to show a slick covering about 923 km², suggesting that Shell may have lost slightly more oil than they thought, and Peter Ibador of Nigeria's National National Oil Spill Detection and Response Agency (NOSDRA)has suggested that the spill could be three times as large as Shell has admitted, presenting a severe threat to wildlife and the local population. Senator Bukola Saraki, chairman of the Nigerian Senate Committee on Environment and Ecology expressed concern that NOSDRA lacks the equipment and manpower to monitor the situation, let alone combat a spill on this scale, making Nigeria dependent on the 'grace and benevolence' of the oil companies to deal with incidents of this nature.

Nevertheless by the 24th Shell appeared to be confident that they had dispersed about 50% of the oil, without calling on assistance from waiting Nigerian Navy vessels, and have been inviting senior Nigerian government officials to visit the area.

Shell has been the biggest player in the Nigerian oil industry since the 1950s, but has long suffered from a poor reputation in the area, both for weak environmental management and links to several military regimes with bad records on human rights. In August this year the United Nations Environment Program produced a detailed report into oil pollution in the Ogoniland area of the Niger Delta, as a result of which traditional leaders of the Ogoni People have lodged a court action against Shell in the US, seeking a billion dollars in compensation for past environmental damage.

The structure of Vesta.

NASA's Dawn Probe moved into orbit around the asteroid Vesta on 16 July this year (2011) and has been beaming information back to Earth ever since. A picture has emerged of an oblate spheroid (squashed ball-shaped) world measuring 578 × 458 km, with a surface dominated by a large crater 460 km in diameter (Rheasilvia) at the southern pole; a series of grooves around the centre of the asteroid appear to be stress structures caused by the Rheasilvia impact.

A false-colour image of the surface of Vesta, centered on the Rheasilvia Crater.

This month NASA scientists attending the Fall Meeting of the American Geophysical Union report the discovery of of a metallic core and magnetic field in Vesta. This allows some interesting inferences about the history of Vesta to be made. In order to have assumed a spherical shape with a differentiated metal core Vesta must have taken a considerable time to cool, far longer than can be explained by its current size. The most likely explanation for this is that Vesta lost an appreciable amount of it's mass as a result of the Rheasilvia impact.

Vesta is currently designated as an Asteroid, rather than a Dwarf Planet, a body large enough to assume a spherical structure due to its own gravity, as it was not thought to be massive enough to achieve this, but Vesta is clearly roughly spherical, so either our theories on how massive a body must be to assume a spherical shape are wrong, or Vesta has lost some mass since it formed, something which the Rheasilvia impact can explain. It is likely that Vesta will be redesignated as a Dwarf Planet in the near future.

A map of the magnetic field of Vesta; like the surface this clearly shows the effects of the Rheasilvia impact.

The Dawn Probe is due to leave Vesta in July 2012 and move on to Ceres, which it will reach in February 2015. Ceres was formerly considered to be the largest asteroid in the Solar System; though since the introduction of the Dwarf Planet classification it has been considered the smallest Dwarf Planet, with Vesta, formerly the second largest asteroid promoted to largest asteroid.

The Ediacaran Fauna; not animals after all?

Most modern animal groups appear abruptly at, or very shortly after, the beginning of the Cambrian period, 542 million years ago. The Cambrian starts abruptly with a layer of small shelly fossils that are hard to assign to any group, which are then replaced abruptly by fossils belonging to more familiar groups; arthropods, molluscs, brachiopods, etc., which then persist throughout the fossil record till the present day (albeit with considerable evolutionary improvements). At the same time there are abrupt fluctuations in the isotopic ratios of Carbon, Strontium and Sulphur, which are equally hard to explain.

This is how the origin of animal life is recorded in the fossil record, something many palaeontologists have found less than satisfactory for a long time, particularly as DNA evidence suggests that the major animal groups diverged from one-another at least 200 million years before the beginning of the Cambrian (the 'DNA-clock' works by measuring the rate of mutation in non-coding, or 'junk' DNA; since this DNA does not affect the organism it is not subject to natural selection and ought to mutate at a steady rate). This has lead to a great deal of interest in any animal fossils that might pre-date the beginning of the Cambrian.

The earliest single celled fossils are about 3500 million years old, with chemical indicators of life being even older in the sedimentary record. The earliest eukaryotic cells (cells with nucleuses) are about 1000 million years old, the first fossils we can identify as belonging to identifiable animal groups are just under 542 million years old; but the intervening period is not devoid of interesting fossils.

The Ediacaran 'Fauna' appear in the fossil record about 585 million years ago and persist till the start of the Cambrian, when they vanish abruptly. The fossils are clearly of multicellular organisms with pre-defined structures (like animals) but do not closely resemble any known post-Ediacaran group, living or fossil. No Ediacaran organism seems to have produced any mineralized tissue, such as bone or shell. These fossils are rare, but have attracted a great deal of attention. The have been found in England, Nova Scotia, Mexico, Namibia, Australia, Russia and China, amongst other places.

Charnia is a typical member of the Ediacaran Fauna; it has a clear structure, has been found in many parts of the world, but does not resemble any known organism.

The period of time between 635 and 542 million years ago has been formerly named the Ediacaran. The Ediacaran Period precedes the Cambrian and follows the Cryogenian, which ran from 850 to 635 million years ago, and was marked by several severe glaciations (Ice Ages) of near global extent. This makes for a plausible (if unverifiable) story for the origin of animal life. The vast glaciations of the Cryogenian somehow caused single celled animals to form organized colonies, which grew more sophisticated during the Ediacaran, then started to produce mineralized tissues at the beginning of the Cambrian as a result of some change in seawater chemistry. Biomineralization probably started as a way of secreting unwanted chemicals, but was rapidly co-opted for other purposes, provoking a radical restructuring of the bodies of those animals that adopted it.

The 23 December edition of the journal Science contains a paper by a team lead by Therese Huldtgren of the Department of Palaeozoology at the Swedish Museum of Natural History, which examines a number of globular Early Ediacaran fossils from the Doushantuo Formation of Guizhou Province in China, that have been considered to be embryonic Ediacarans. Based upon this analysis, Huldtgren et al. conclude that the 'embryos' show patterns of cell division incompatible with the embryonic development of animals, and that the organisms that produced it cannot therefore be closely related to animals.

The Doushantou 'Embryos'.

The fossils from Doushantuo are all microscopic, and come from early in the Ediacaran Period (635-551 million years ago). In addition to the 'embryos' there are achritarchs (a form of algae), ciliates, seaweeds and what may be sponges and soft corals as well as a possible planktic larvae that has been named Vernanimalcula. Since the only known large organisms at during the period are the Ediacarans, it is fairly obvious to conclude that the embryos are those of Ediacarans. However, this is t best a guess; there is no actual evidence to link the embryos to the Ediacaran Fauna, so they may represent a part of the life-cycle of some as yet unknown organism, which co-existed with, or even predated the Ediacaran Fauna.

Based upon this there is no real evidence to suggest that the Ediacarans either were, or were not, true animals. They remain a mystery.

Friday 23 December 2011

Christchurch shaken by another Earthquake. 23 December 2011.

Slightly before 3.20 pm on Friday 23 December 2011 the city of Christchurch in New Zealand was struck by an Earthquake with a magnitude of 5.9 on the Richter Scale, which occurred at a depth of 4.9 km, 15 km northeast of the city. This was followed by a series of aftershocks, the largest of which had a magnitude of 5.0 on the Richter Scale, and occurred 21 km southeast of the city at a depth of 7.6 km, 9 hours after the initial quake. There are no reports of any serious injuries or damage, but a number of buildings had to be closed temporarily, including shopping malls during their busiest weekend of the year, there was localized flooding.

Flooding in the Parklands District of Christchurch. Earthquakes can cause flooding by squeezing water out of soil, as well as by damaging water mains and sewers.

Christchurch has always been prone to Earthquakes, but since September last year (2010) the city has been repeatedly shaken by large quakes. The largest of these quakes, on 22 February this year, killed 188 people and damaged a number of the cities prominent buildings. Nobody is quite sure what the cause of this increased activity is.

New Zealand lies on the boundary between the Australian and Pacific Plates. Beneath the islands the Pacific Plate is being subducted beneath the Australian and is sinking into the planet's interior. As the Pacific Plate passes underneath the Australian friction causes earthquakes. These are most likely to be felt in the east of the country, where the boundary between the planets is shallowest. To the west the boundary zone is much deeper, so that quakes directly caused by inter-plate friction are seldom felt at the surface, but heating of the underlying Pacific Plate by the Earth's interior causes it to partially melt; as this happens lighter minerals rise up through the overlying Australian Plate, causing volcanoes - which can themselves cause Earthquakes.

The positions of the Australian and Pacific Plates beneath New Zealand.

Mysterious object falls from the sky in Namibia.

News has emerged today of a mysterious object that fell out of the sky about 750 km north of Windhoek in November this year. The object is a metal sphere, about 35 cm in diameter, 110 cm in circumference and weighing 6 kg, apparently made of two metal hemispheres welded together. There is nothing mysterious about the materials used, and the object is definitely something that could be made with human technology. Nevertheless nobody seems to know quite what the object is, or who made it. The Namibian authorities have been in contact with both NASA and the European Space Agency, but neither have been able to identify the object.

The mysterious object.

Actually, as mysterious objects go, this one is not very mysterious. It is clearly a part of a satellite, intended to hold some sort of liquid, probably fuel for an instrument. Fuel tanks on satellites tend to by spherical and very solid, as this is the best structure for coping with a liquid sloshing about in changing gravity fields with zero pressure on the outside. It is also an excellent shape for surviving re-entry through the Earth's atmosphere, enabling the tanks to survive re-entry when the rest of the satellite burns up. This is not the first mysterious sphere to fall from the sky, previous examples have been recorded in Australia, Brazil and the US. Many more probably fall into the sea, remote locations where they are never found, or in countries that will not publicize the find.

See also Space Age Archaeology.

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Thursday 22 December 2011

Eruption in the Zubair Archiapelago, in the southern Red Sea.

On 19 December 2011 fishermen on the Red Sea reported seeing an eruption on Saba Island about 60 km to the southeast of Jebel Zubair Island, with lava fountains rising 20-30 m above the island. The same day the Ozone Monitoring Instrument (OMI) on the Aura satellite recorded a rise in Sulphur Dioxide (SO₂) levels above the southern Red Sea. The next day (20 December) the Moderate Resolution Spectroradiometer on the EOS Satellites detected a volcanic plume rising from a submarine eruption roughly 1.5 km southwest of Haycock Island, or 12 km northeast of Jebel Zubair. This is the first eruption in the Zubair Archipelago since at least 1846.

Satellite image of the plume near Jebel Zubair.

The Zubair Archipelago are a group of volcanic islands off the southwest coast of Yemen; they are essentially a shield volcano on the Red Sea Rift with a number of vents. A shield volcano is a broad, low profile volcano made up of successive layers of lava; it lacks the cone shape of a stratovolcano, but can grow far larger. The Hawaiian Islands are massive shield volcanoes, as are the vast volcanoes of Mars.

The Red Sea Rift is a spreading boundary between two tectonic plates, the African Plate and the Arabian, where new oceanic crust is being formed. Arabia was formerly part of the African Plate, but split away about 30 million years ago. The Great Rift Valley of Africa is a continuation of this rift, that is slowly splitting Africa in two from the north to the south.

Diagram showing a cross section through the rocks beneath the Red Sea.

The same rift system is also responsible for the nearby Jabal al-Tair volcanic island, which erupted unexpectedly in 2007, after 124 years of inactivity, killing 8 people, as well as the volcanoes of the Afar Triagle in Eritrea and Ethiopia and the volcanic fields of southern Yemen and Saudi Arabia.

See also Eruptions on Mount Nymuragira, Eruptions on Mount Ebro and Volcanoes on Sciency Thoughts YouTube.

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A Titanosaur from the Antarctic.

Titanosaurs were the largest animals ever to roam on land; they were sauropod dinosaurs that survived to the end of the Cretaceous (most sauropods went extinct at the end of the Jurassic, certainly all non-Titanosaurian Sauropods were extinct by the Mid Cretaceous), and grew to sizes far in excess of their earlier relatives, which were big animals even by dinosaur standards. The biggest Titanosaur for which we can estimate a size, Argentinosaurus, grew up to 35 m in length and weighed 80-100 tonnes; it is quite possible that other Titanosaurs grew bigger, but most are only known from highly fragmented remains; in order to be fossilized efficiently an animal needs to be buried quickly, not easy for a creature as large as a Titanosaur.

Titanosaurs were first discovered in South America, where they seem to have originated and reached the peak of their diversity, and have subsequently been discovered in Africa, Europe, Asia, Australia and, most recently, North America. This month a team lead by Ignacio Cerda of Consejo Nacional de Investigaciones Científicas y Tecnológicas - INIBIOMA and the Museo de Geología y Paleontología at the Universidad Nacional del Comahue in Buenos Aeries published a paper in the German journal Naturwissenschaften in which they describe the discovery of a Titanosaur on James Ross Island, Antarctica.

The location of the Titanosaur find.

The discovery comprises only a part of a single vertebra; this is large and distinctive enough that it could not come from anything other than a Titanosaur, though Cerda et al. have not attempted any more detailed classification due to the limited nature of the material. The sedimentary beds in which the vertebra was found are thought to be of Upper Campanian age, between roughly 75 and 70 million years old.

The James Ross Island vertebra; (a & d) front view, (b & e) side view, (c & f) rear view.

Dinosaurs are not very well known from Antarctica, not so much because they were absent as because they are hard to find there now. Much of the continent is covered in snow and ice, and what is exposed has been scoured repeatedly by glaciation. Thus it is unsurprising that this is the first Titanosaur, and only the second Sauropod, found in Antarctica. Titanosaurs arose in South America and dispersed during the Early Cretaceous. Since they are known to have been present in Australia and New Zealand, areas that were still connected to Antarctica during the Early Cretaceous but not to any other land mass, then Titanosaurs must have been present in Antarctica at that time. It is possible that the new Titanosaur is descended from Titanosaurs that moved to Antarctica during this initial dispersal, but it is also possible that it is more closely related to the Titanosaurs present in South America during the Late Cretaceous, as South America and Antarctica were still connected till quite late in the Period (how late is still a matter of conjecture among geologists.

A reconstruction of the position of the continents during the Late Cretaceous.

See also An American Titanosaur and Dinosaurs on Sciency Thoughts YouTube.

Wednesday 21 December 2011

Kepler discovers two Cthonian Planets orbiting a subdwarf star.

KIC 05787616 (Kepler Input Catalogue 05787616) is a Hot B-type subdwarf star, 3850 light years from the Earth. A Hot B-type subdwarf is a Red Giant star that has lost it's outer layers prematurely, before it begins to fuse helium; thus when they do start to fuse helium they do it unshielded by the cooler, darker outer layers of the Red Giant, making them some of the hottest, brightest objects in the sky. The precise cause of this loss of outer layers is unclear, and it is doubtful that all Hot B-type subdwarfs have formed in the same way.

As a former Red Giant KIC 05787616 was an unlikely candidate for a planetary system, particularly one close enough in to the star to be detected easily, but it was in the Kepler field of view (Kepler stares constantly at the same bit of space), so Kepler was gathering data on it, it is an unusual and interesting object, and telescope time is a precious resource to astronomers, so the data gathered was bound to be used.

This week a team lead by Stephane Charpinet of the Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse publish a paper in the journal Nature detailing the (highly unexpected) discovery of a pair of small planets orbiting KIC 05787616. These two roughly Earth-sized objects orbit the star at 0.60% and 0.76% of the distance between the Earth and the Sun, and were, unusually, detected not by the dimming of the star as they passed in front of it, but by the heat and light they were emitting. Many planets have been found orbiting close to their stars in the past (such planets are the easiest to detect), but typically around small, cool, Red Dwarf type stars, not anything as hot as KIC 05787616 (a B-type subdwarf has a surface temperature of between 20 000 and 40 000 K, compared to 5778 K for our sun). Consequently these planets are far hotter than anything previously discovered, with estimated surface temperatures of between 8000 and 9000K; i.e. the planets themselves are considerably hotter than the surface of our sun. This causes the planets to emit a considerable amount of light. The two planets orbit the star every 5.76 and 8.23 hours respectively.

These planets must, somehow, have survived the star passing through a Red Giant phase, something that scientists were not certain was possible prior to this discovery (and which they shall probably argue about for some time to come). The most likely explanation is that they were formerly large, gas giant type planets further out in the system, and that they were swallowed by the star in its expansive phase, had their outer layers stripped away and fell towards the star as friction with the gas giant's corona slowed them down (orbiting planets are in a dynamic relationship with their star, held in place by a combination of centrifugal force and gravity; if they are for some reason slowed down they fall towards the star, if they speed up they move away). Somehow this process caused the star to shed it's outer layers, leaving the B-type subdwarf at the centre, being orbited by the two reduced planets. Gas giants that have lost their outer layers are called Cthonian Planets; these also were only a theory until the discovery of the KIC 05787616 system (two previously discovered planets, COROT-7b and Kepler-10b are considered possible Cthonian Planets, the new planets differ in that we have no other explanation for them).

A model of the evolution of the KIC 05787616 system.