New Evidence of Ice Age Comet Found in Ice Cores

• By Sid Perkins, Science News

A new study cites spikes of ammonium in Greenland ice cores as evidence for a giant comet impact at the end of the last ice age, and suggests that the collision may have caused a brief, final cold snap before the climate warmed up for good.

In the April Geology, researchers describe finding chemical similarities in the cores between a layer corresponding to 1908, when a 50,000-metric-ton extraterrestrial object exploded over Tunguska, Siberia, and a deeper stratum dating to 12,900 years ago. They argue that the similarity is evidence that an object weighing as much as 50 billion metric tons triggered the Younger Dryas, a millennium-long cold spell that began just as the ice age was loosing its grip (SN: 6/2/07, p. 339).

Precipitation that fell on Greenland during the winter after Tunguska contains a strong, sharp spike in ammonium ions that can’t be explained by other sources such as wildfires sparked by the fiery explosion, says study coauthor Adrian Melott, a physicist of the University of Kansas in Lawrence.

The presence of ammonium suggests that the Tunguska object was most likely a comet, rather than asteroids or meteoroids, Melott says. Any object slung into the Earth’s atmosphere from space typically moves fast enough to heat the surrounding air to about 100,000° Celsius, says Melott, so hot the nitrogen in the air splits and links up with oxygen to form nitrates. And indeed, nitrates are found in snow around the Tunguska blast. But ammonium, found along with the nitrates, contains hydrogen that most likely came from an incoming object rich in water — like an icy comet.

More than a century after the impact, scientists are still debating what kind of object blew up over Tunguska in 1908. They also disagree about whether an impact or some other climate event caused the Younger Dryas at the end of the ice age. But the presence of ammonium in Greenland ice cores at both times is accepted.

“There’s a remarkable peak of ammonium ions in ice cores from Greenland at the beginning of the Younger Dryas,” comments Paul Mayewski, a glaciologist at the University of Maine in Orono who was not involved in the new study. The new findings are “a compelling argument that a major extraterrestrial impact occurred then,” he notes.

Whenever a comet strikes Earth’s atmosphere, it leaves behind a fingerprint of ammonium, the researchers propose. Immense heat and pressure in the shock wave spark the creation of ammonia, or NH3, from nitrogen in the air and hydrogen in the comet. Some of the ammonium, or NH4+, ions generated during subsequent reactions fall back to Earth in snow and are preserved in ice cores, where they linger as signs of the cataclysmic event.

Although an impact big enough to trigger the Younger Dryas would have generated around a million times more atmospheric ammonia than the Tunguska blast did, the concentrations of ammonium ions in the Greenland ice of that age aren’t high enough.

But the relative dearth of ammonium in the ice might simply be a result of how the ice cores were sampled, Melott and his colleagues contend. Samples taken from those ice cores are spaced, on average, about 3.5 years apart, and ammonia could have been cleansed from the atmosphere so quickly that most of the sharp spike might fall between samples.

Image: Aftermath of the Tunguska event

Wired

Southern Sudan prepares for freedom – and puts dream of skyscrapers on hold

Southern Sudan rebels vow to go it alone despite little progress since peace accord

Xan Rice in Bor

In the early days of the war, with weapons supplies short and the odds of achieving independence impossibly long, the southern Sudanese rebels composed songs to keep up morale. Some were battle anthems, designed to inspire bravery against the Arab enemy from the north. Others, like the one sung to the women worried about losing their husbands in combat, reflected hopes of life in a time of peace.

"It said that whoever survived the struggle would be driving cars and living in skyscrapers," said Zalson Khor, an official with the Sudan People's Liberation Movement (SPLM), which led the rebellion then took on the task of building from scratch what is expected to become the world's newest nation next year.

Nowhere were the postwar expectations higher than in Bor, the capital of the largest state in Southern Sudan. It was in this Nile river town that the SPLM was born in 1983 when soldiers staged a mutiny against the government in Khartoum, kicking off one of Africa's longest civil wars.

Bor was also the home of the rebels' revered leader, John Garang, who signed the Comprehensive Peace Agreement with President Omar al-Bashir to end the conflict five years ago. The deal granted the south autonomy and mandated for the first time since Bashir seized power more than two decades ago that multiparty elections should be held, with the poll now scheduled for 11 April.

Most importantly, however, the agreement also offered southerners the chance to realise their dreams of secession from the north through a referendum in 2011. That vote, which is certain to be in favour of independence, is nine months away.

There are no skyscrapers in Bor. There is no electricity or clean water either. Navigating the dirt roads are some cars, mostly large four-wheel drives; they belong not to individuals, however, but UN peacekeepers, humanitarian organisations or the military.

There is a crumbling hospital built under British rule more than half a century ago, a makeshift high court that sits in a tumbledown house, a large covered market, and a police station and prison at the far end of town.

Arriving at Bor after a six-hour, 100-mile drive in a minibus taxi from the capital Juba, none of this seems much – until you realise what it was like when the war ended.

"There was almost nothing here," said Maker Thiong Maal, who assisted the mutinous soldiers in 1983 and is now an MP. "This was a helpless place".

That was true to an large extent even before the war – marginalisation by the authorities in the capital, Khartoum, was one of the main reasons for the rebellion, along with the imposition of an Arab-Muslim identity on people who were culturally sub-Saharan and held Christian or animist beliefs.

But what little there was had been run down or destroyed during the 21 years that Bor was a tightly controlled garrison town. The hospital was reserved for the northern military, the secondary school became an ammunitions store. The only "improvements" added were the shipping containers sunk into the ground to serve as foxholes.

Since the war ended the market, police station and prison have been built. Schools are overcrowded, but at least they are open.

A formerly one-street town now has intersections; hotels called Freedom and Liberty have sprung up. A power plant is under construction and a water treatment facility planned.

"Within a night you cannot meet the expectations of people," said Maal. "But things are changing gradually".

For Bor, read much of Southern Sudan. Even during the heyday of decolonisation in the 1960s few African countries started from such a low base, or with so few tools to do the job. Unlike some other liberation movements, the SPLM had never administered any real territory before taking power as an autonomous government in 2005. Many of the senior ministers under President Salva Kiir – who succeeded Garang after he died in a helicopter crash in July 2005, just months after the war ended – had spent most of the conflict as generals in the bush.

Short on skills and knowhow, the SPLM did at least have money flowing in. A key provision of the peace agreement stipulated that revenues from the lucrative oil fields situated in Southern Sudan be split equally between Khartoum and Juba, and this has worked remarkably smoothly, given the mistrust between the parties.

But even spending the cash carried practical challenges. There was no treasury in Southern Sudan, so ministers walked around with briefcases full of notes. Civil servant salaries were paid in brown paper bags. A lot of dollars disappeared – stolen or simply unaccounted for.

One of the urgent priorities was opening up transport links across the vast south. About 2,500 miles of dirt roads have been de-mined and repaired, helping 2 million people who were internally displaced or refugees to return home. But a large chunk of money spent by the government – more than 40% of the budget, by some measures – has gone to strengthening the 100,000-strong army. That angers aid workers but seems accepted by many southern Sudanese, who fear that President Bashir will try to block secession.

"It's impossible to talk of real development before the referendum," said Andrea Minalla, who runs the Juba office of IKV Pax Christi, a peacebuilding organisation. "The government's focus is military, military, and people have accepted that. They say 'Just take us there [to the referendum], and then we will decide what is to be done'".

The result is that most people's basic needs are still far from being met. Only a quarter of the population has access to primary healthcare – and NGOs provide 86% of those services. More than two-thirds of the population are illiterate; the figure rises to 90% for women. Southern Sudan has the highest rate of maternal mortality in the world. More than 4 million people require food aid.

Rising violence is another concern, particularly in Bor's Jonglei state. While cattle rustling among ethnic groups has gone on for generations, the raids in 2009 were the deadliest in years, with seven massacres – each leaving 100 people dead. The government is worried – it launched a big disarmament drive a few months back – and so are many ordinary citizens, but few share the view of some foreign observers that the clashes have the potential to threaten the overall stability of the south.

Indeed, despite the slow pace of change, and all the challenges that remain, it is hard to find any southern Sudanese who believe that staying united with the north would offer a better life than in an independent state.

"People are furious with our politicians for not doing more in five years," said Stephen Tut, editor of the South Sudan Post magazine, in Juba. "But the south is gone, and the north knows it. The only connection is the oil pipeline and political links. We have our own trade with east Africa, and our army".

And, even more importantly, a strong feeling of liberty, whose value for now remains greater than any number of skyscrapers. John Mac Acuek, a Bor native who served as a child soldier in the SPLM's "Red Army" before becoming a refugee and leaving for Australia, recently returned to Southern Sudan to set up a car business. What he noticed when coming back was "a sense of the ownership of the state, and the land".

"Before, people could not sit like this and breathe in the sweet air of the Nile," he said one evening. "That's freedom".

War and peace

• North Sudan and South Sudan were administered as separate regions by Britain until 1946 when they were merged.

• In 1955, a year before Sudan's independence, soldiers from the mostly Christian and animist south began an insurgency to protest at domination by the Arab-led north, with the conflict lasting until 1972.

• Just 11 years later the second Sudanese civil war began when the southern soldiers from the army's 105 Battalion staged an uprising in Bor. The war continued for more than two decades. More than 1.5 million people died as a result, with 4 million forced to flee their homes.

• The 2005 Comprehensive Peace Agreement ended the conflict and granted autonomy to Southern Sudan. Its people were also given the option of choosing independence in a referendum scheduled for January 2011.

The Guardian

Ethiopian Authorities Cover up Attempts of Genocide in Gambella

By Anyuak Media

The Ethiopian authorities in Addis Ababa attempt to cover up gross human rights violations and systematic genocide against Anywaa (or Anuak) either came too late or provides very little support in convincing the indigenous people, international community and organisations amid ample evidences in the contrary. In the last few weeks, information from the region indicates and reveals a continued effort by the Ethiopian authorities to force the indigenous people to sign a document covering up the action of the Ethiopian armed forces in the region and denying the allegations of genocide committed against the indigenous Anywaa community in 2003 in Gambella town and its surroundings.

It is to be recalled that the systematic genocide that reached its climax in 2003 was responsible for lost of innocent lives, displacement of civilians from their normal livelihood into other parts of the region and as refugees into exile. The council has rejected the secret document attributing blames and responsibility for political instability and conflicts in the region to activities of one of TPLF former ally, the Gambella Peoples Liberation Movement (GPLM). In serious discussions between the TPLF agents and members of the Gambella regional council, it become apparent that the TPLF accused GPLM of killing highland settlers at Okuna village, various conflicts between the GPLM and TPLF at Abol GPLM military camp, Gambella town and Dimma district.

The following are detail accounts of points of views of the regional council members regarding the claim that GPLM was responsible for political instability and conflicts in the region according to our sources:

• 
  
  The killing of highland settlers at Okuna village took place in 1991 immediately after the military regime collapsed and the GPLM armed forces have not yet arrived in Gambella town. Moreover, Okuna village is located miles away from the Gambella town, which could have made it very difficult for the GPLM army that came along the Openo River to cross into the heart land of Anywaa Kingdom and killed remaining highland settlers at that time. Thus, it became very remote that the GPLM had any responsibility over the killing of highland settlers in the region.
  
  
• 
  
  Abol was a military base for the GPLM army following the TPLF dominated government announcement that all armed forces in the country were to be stationed in one location. According to our sources, the TPLF army as it did to other liberation groups in the country were responsible for attacking the GPLM army position resulting in the lost of lives, displacement and destruction of the military base. However, the GPLM base was rebuild afterwards when normality returned to the region.
  
  
• 
  
  The conflict between the GPLM and TPLF in the Gambella town was because TPLF was looting and loading important machinery vital for reconstruction of the ravaged Gambella region’s economy and infrastructure. According to our source, it was made clear that the GPLM informed the TPLF on several occasions to stop irresponsible acts of looting Gambella properties that disrespect the principle of regional autonomy. Instead, the TPLF armed forces killed a GPLM member and that brought conflict between the two armed forces. Similar conflict over irresponsible act of the TPLF took place at Dimma district. As the case in the Gambella town incident, the TPLF shoot dead innocent civilians and GPLM army members resulting in deadly conflict between the two.
  
  
• 
  
  The blame that GPLM forces carried out the ambush of a vehicle belonging to Administration for Refugees and Returnees Affairs (ARRA), a counter part of UNHCR, was disputed on the ground that until today no member of GPLM army has been brought to justice regarding the ambush that led to the death of 8 government officials on the way to Odier- a proposed Sudanese refugees camp. Neither has any militant group had claimed responsibility for such attack. Instead, the army in collaboration with some highland settlers and government officials in the region went on rampaged to kill over 424 innocent Anywaa (or Anuak) civilians in the Gambella town. So far, the participants of the genocide remain at large without anyone of them brought to justice. Thus, the regional council rejected the unfounded government claim that there was no genocide against the Anywaa people in their own homeland and the responsibility lies on the activities of Gambella Peoples Liberation Movement.
  
  
  
  
  Yet, the Ethiopian authorities’ effort to make the cover up attempts a reality has been underway in the region following the failed attempt at the regional council meeting. The authorities after failing to secure any support from the regional council members have decided to force 350 young men and women from different locations of the region to sign a secret document the content of which they do not know on the meeting in Agricultural college in Gambella town. These young men and women are reported to have barely information about the history of conflict between the GPLM and TPLF. However, they would do so under duress and for fear of their lives and livelihood. Our sources indicate that so far the authorities have forced and secured 200 signatures out of the target of 2,500 under the senior military personnel supervision in the region.
  
  
  A young Nuer man on the meeting who expressed his opinion against the cover up attempt that there was no genocide against Anywaa (or Anuak) and GPLM was responsible for political instability and conflict in the region has been thrown out of the meeting and perhaps will be deprived of essential survival means if not put in jail because of his opinion.
  
  
  In another development, senior army officers have been conducting secret meetings in Gambella town the outcome of which, though not yet known will be devastating for the indigenous people. In the recent days, the army have been increasing their numbers in the town and for unknown reasons have relocated the military water tank at the centre of the Gambella town in front of the Ethiopian Evangelical Church Mekane Yesus (EECMY) where young Anywaa children are known to be playing during daylight and in the evenings.
  
  
  The complexity of human rights violations coupled with land grabbing issue that will destroy the indigenous people survival continued without limit. As previously indicated, Kwot Agole, son of late Dr David Owour Ojwato, remain in critical condition in the Gambella hospital.
  
  
  

  He awaits uncertain future upon being discharged from the hospital and these gross human rights violations and genocide campaign, a trend similar to the pre-2003 genocide campaign worry many indigenous people both in the country and in exile amid high ranking government and military officials secret meetings and land grabbing deals.
  
  
  One of the government militia official and his colleague has remained in Kaliti prison accused of not telling the truth in a court of law. Kwot Agid and Omot Obang went to Addis Ababa to witness against their fellow brothers; Obang Kut, Obang Thamriu and Omot Obang(Omot Wara-Achan) who remained in Ethiopian jails since they were detained across the international border in 2009. The two government officials appeared to the court of law on Monday 28th March 2010 but the court adjourned the hearing for Wednesday 31st March 2010.
  
  
  The international community and organisations concerned for monitoring human rights standards should be aware of the development in the Gambella region, southwestern part of Ethiopia. Without proper monitoring, the development in the region would overwhelm the international community and organisations in the future to come. Thus, there is a need to take notice of such serious developments in one of the remotest part of the country.
  
  
  Anyuak Media

An Exotic Look Into Colombia’s Drug Wars

By SIMON ROMERO

CALI, Colombia — Of all the animals that come to die under Ana Julia Torres’s samán trees, the ocelots are among the most numerous. There are eight of them here, seized from the estate of a murdered cocaine trafficker, who apparently collected them in the belief that any self-respecting drug lord should always have eight ocelots in his dominion.

Ms. Torres’s sanctuary houses hundreds of animals rescued largely from drug traffickers and paramilitary warlords, as well as from circuses and animal-smuggling rings, offering a strange window into the excesses and brutalities carried out in this country’s endless drug wars.

Ms. Torres looks after Dany, a Bengal tiger whose caretakers, employed by a paramilitary commander, said that he used to eat the flesh of death-squad victims; a lethargic African lion that had been fed a steady diet of illicit narcotics by its owner; and the ocelots that belonged to a drug lord with the nom-de-guerre Jabón, or Soap.

“Some of the cruelties I’ve seen make me ashamed to be a human being,” said Ms. Torres, 50, a school principal and animal-rights advocate who initially opened the sanctuary 16 years ago for animals, including a now deceased elephant, that had been discarded by traveling circuses around Colombia.

The creatures here, some 800 in all, range from the tiny kinkajou, a nocturnal mammal similar to a ferret found in Colombia’s rain forests, to baboons born across the Atlantic in Africa. Many of the former circus animals, including an old chimpanzee named Yoko, still find repose at Villa Lorena, as Ms. Torres’s sanctuary is called. Other animals, like a king vulture and a pygmy marmoset, one of the world’s smallest monkeys, were rescued in raids on wildlife smugglers who seek to profit from Colombia’s biodiversity.

But some of the most striking animals at Villa Lorena, located up a dirt road in the slum of Floralia, are the great cats that once belonged in the private zoos of drug traffickers, who still seem to find inspiration in the example of the dead cocaine baron Pablo Escobar.

Indeed, descendants of the hippos once owned by Mr. Escobar still roam the grounds of Hacienda Nápoles, his once luxurious retreat, where he amassed a private collection of exotic species, including rhinoceroses and kangaroos.

Ms. Torres’s sanctuary surpasses Mr. Escobar’s menagerie in its diversity. About 500 iguanas roam its trees and pathways near corrals for peccaries, flamingos, mountain goats and peacocks. Cages house toucans and spider monkeys. Ms. Torres closes the sanctuary to all but a handful of visitors.

“The animals here are not meant to be exhibited,” she said before leaning through cage bars to embrace and kiss on the lips a roaring lion named Jupiter, who was recovered from a circus where he had suffered from malnutrition. “They need to be protected, and have a right to live in peace”.

Some of the animals under her care found anything but peace before arriving at Villa Lorena. Several years ago, she nursed back to health a spider monkey called Yeyo, found by the police in a puddle of his own blood after being beaten by its owner. While Yeyo lost an eye from the abuse, he lived quietly at Villa Lorena until his death, she said.

Then there is the lion named Rumbero, rescued from a drug trafficker near the city of Manizales. Rumbero’s eyes have an empty, glazed look. Ms. Torres said he was forced to consume marijuana, ecstasy and other substances at bacchanals in Colombia’s backlands.

At almost every turn at Villa Lorena, animals display indignities suffered at the hands of man. A caiman with a severed limb stretches under the tropical sun. A macaw with a sawed-off beak flutters in its cage. Luís, a cougar who once belonged to a drug trafficker, limps around his cage, the result of having a front leg cut off.

Ms. Torres speaks of each case with passion, somewhere between outrage and desperation, bringing to mind the episode in Nietzsche’s life when he broke into tears and threw his arms around a horse on the streets of Turin while attempting to save it from a coachman’s whipping.

“We’ve received horses here, too, including one that a man in Cali tried to burn alive after dousing it with gasoline,” she said, motioning to Villa Lorena’s burial ground near the chimpanzee’s cage, where workmen bury all the animals that die at the sanctuary. “It didn’t make it”.

For others in animal-rights circles here, Ms. Torres’s sanctuary raises issues that are both philosophical and practical. “Animals are not like human beings, who can adjust to being in a wheelchair,” said Jorge Gardeazábal, a veterinary surgeon at Cali’s zoo.

Dr. Gardeazábal, citing the example of an ocelot with a severed leg, said that he preferred euthanasia in such cases, since the ocelot would be unable to carry out its genetic instinct to flee with quickness when it sensed fear. Still, he said he supported Ms. Torres’s sanctuary. “But it’s an activity that should be regulated by the authorities,” he said, to ensure the well-being of the animals and those who work with them.

While Ms. Torres receives help from Cali’s environmental police, who deliver rescued animals to her doorstep, she shuns government financing and other involvement with the authorities. She relies, instead, on private donations and food given to the sanctuary by grocery stores.

Eliécer Zorrilla, an official with Cali’s environmental police, said the hands of law enforcement were largely tied when it came to limiting the traffic in exotic animals, even those that were abused and ended up at Villa Lorena. Colombian law does not include prison terms for people found mistreating animals or owning a rare species, he said.

Mr. Zorrilla added that his officers could seize wild animals from their owners only when they were in the process of being transported or traded. “We have no idea how many other wild animals, from this continent or others, are being mistreated in captivity,” he said.

In an ironic twist, man’s clash with nature is also what sustains the animals in Villa Lorena. Roadkill, largely in the form of horses hit by cars, provides much of the meat for Ms. Torres’s carnivores. Workmen butcher the donated horse meat and toss it into cages, where it is quickly consumed.

Ms. Torres said that it took time for Dany, the man-eating Bengal tiger, to get used to his new diet. He roared with startling vigor one recent afternoon when it came time to eat; steel bars separated him from the laborer throwing him raw flesh. “Dany’s one of the few animals here that I cannot embrace,” said Ms. Torres. “At least not yet”.

Jenny Carolina González contributed reporting from Bogotá, Colombia

The New York Times

Chocolate 'can cut blood pressure and help heart'

Easter eggs and other chocolate can be good for you, as long as you eat only small amounts, latest research suggests.

The study of over 19,000 people, published in the European Heart Journal, found those who ate half a bar a week had lower blood pressure.

They also had a 39% lower risk of heart attacks and strokes.

Heart campaigners warned that too much chocolate is damaging because is has a lot of calories and saturated fat.

The study looked at the chocolate consumption of middle-aged men and women over eight years.

It compared the health of those who ate the most and least chocolate.

The difference between these two groups was just 6 grams a day, equivalent to one small square of chocolate a day.

The lead author, Dr Brian Buijsse, from the German Institute of Human Nutrition, Nuthetal said: "Our hypothesis was that because chocolate appears to have a pronounced effect on blood pressure, therefore chocolate consumption would lower the risk of strokes and heart attacks, with a stronger effect being seen for stroke".

This is, in fact, what the study found. Those who ate more chocolate cut their risk of heart attacks by around a quarter, and of stroke by nearly half, compared with those who ate the least.

Chocolate lovers dream

But Dr Buijsse warned that it was important people ensured that eating chocolate did not increase their overall intake of calories or reduce their consumption of healthy foods.

"Small amounts of chocolate may help to prevent heart disease, but only if it replaces other energy-dense food, such as snacks, in order to keep body weight stable," he said.

The researchers believe that flavanols in cocoa may be the reason why chocolate seems to be good for people's blood pressure and heart health.

And since there is more cocoa in dark chocolate, dark chocolate may have a greater effect.

Heart campaigners warned that chocolate is still bad for you if you eat too much.

Victoria Taylor, Senior Heart Health Dietician, at the British Heart Foundation said: "This sounds like a dream for chocolate lovers and just in time for Easter too, but it's important to read the small print with this study.

"The amounts consumed on average by even the highest consumers was about one square of chocolate a day or half a small chocolate Easter egg in a week, so the benefits were associated with a fairly small amount of chocolate.

"Some people will be tempted to eat more than one square, however, chocolate has high amounts of calories and saturated fat which are linked to weight gain and raised cholesterol levels. Two of the key risk factors for heart disease".

BBC News

Bulgaria PM Offers to Help Russia with Intelligence Information

Bulgaria’s Prime Minister Borisov had a telephone conversation with his Russian counterpart Vladimir Putin Tuesday night.

Borisov has expressed his condolences for the victims killed by two suicide bombers in the Moscow metro on Monday.

He has stated that Bulgaria condemns the attacks and has told his Russian counterpart Vladimir Putin that the Bulgarian intelligence services are ready to help their Russian colleagues by providing them with any available information that can aid the investigation.

A total of 38 people were killed in Monday’s bomb attacks in the Moscow subway.

Novinite