The theme for this week's Photo Hunt is Water. This is the local river, the River Rom. Just before it joins the River Ravensbourne to form the River Beam it is let out of its culverts and allowed to be a proper river again. Okay it's not much of a river but it is Romford's river!
Tethys is a mid-sized satellite with a density close to that of pure ice. But a large valley system visible today must have formed when the crust was being heated and under great strain according to a presentation at the 39th Lunar and Planetary Science Conference in Houston.
Calculations by Erinna Chen and Francis Nimmo, from the University of California, Santa Cruz, show that tidal interactions were the only viable way of providing the amount of heat associated with the formation of Ithaca Chasma. They propose that Tethys' orbit around Saturn was once perturbed by gravitational interactions with another moon - Dione - which made Tethys' orbit more "eccentric". The resulting tidal forces caused frictional heating of Tethys' interior. But at some point, the orbital interaction between Tethys and Dione was broken, and Tethys fell back into a less eccentric orbit. As it did so, it began to cool. Freezing of a liquid ocean would have generated sufficient stresses in the crust to form Ithaca Chasma, the researchers said.
"We have a large rift system that brought water to the surface, so it seems likely that this happened," Ms Chen explained. She said that there was no way of knowing exactly how deep the ocean was, but speculated that it could have been 100km deep at some point in Tethys' past.
Tethys joins Europa and possibly Callisto in a small club of icy Solar System bodies thought either to have a subsurface ocean today, or to have had one in the distant past. Some researchers also think Saturn's moon Enceladus could harbour liquid water beneath the surface, although this idea has been called into question recently.
A couple of days ago I posted on the possible discovery of a fiant underground lake in the Darfur region of Sudan. Acording to scientist Alain Gachet, however, the lake may have actually dried up millennia ago
In his view the area received too little rain and had the wrong rock types for water storage. On Wednesday, Boston University's Farouk El-Baz said he had received the backing of Sudan's government to begin drilling for water in the newly-discovered lake, in North Darfur. He said radar studies had revealed a depression the size of Lake Erie in North America. But Mr Gachet, who has worked on mineral and water exploration in Africa for 20 years, said the depression identified by the Boston researchers was probably full of water 5,000 to 25,000 years ago.
"This lake was at the bottom of a broad watershed feeding the Nile above Khartoum," Gachet said "This watershed is completely dry today on the southern border of Egypt, Libya and north-western border of Sudan - one of the worst areas in the world." However he said that there was a substantial source of water further south in Darfur where he was he was helping a UN-backed project to drill for water. "There is enough water within these aquifers to bring peace in Darfur... and even more - enough to reconstruct the economy of Darfur."
An increasingly obsolete degree in Physiology and Biochemistry did not give O'Donnell a knowledge of geology so I have no idea who is right here. But if either Gachet or El-Baz is right then there is a faint possibility of eliminating one of the main sources of conflict in Darfur. Sadly the cynic does not hold its breath.
"Much of the unrest in Darfur and the misery is due to water shortages," said geologist Farouk El-Baz, director of the Boston University Centre for Remote Sensing, told the Associated Press. By studying satellite and radar images, Mr Baz and other Boston University researchers identified possible streams running from a 5,000-year-old lake that is now obscured by the sands of northern Darfur. The lake occupied an area of nearly 12,000.
Scientists plan to identify the best location for drilling the first wells. Egypt has pledged to drill the first 20, and the UN mission in Sudan also plans to drill several more for use by its peacekeeping forces, the university said. In a recent article for the Washington Post, the UN secretary general, Ban Ki-Moon, cited the lack of water as one of the reasons behind the conflict. Camel herders replenished themselves at the farmers' wells and grazed on their lands. The farmers responded by erecting fences amid fears that their land would be ruined by passing herds.
Darfur activists warned, however, that the discovery of water would not relieve victims of "the politics of a genocidal regime".Eric Reeves, a professor at Smith College in Massachusetts, told the Boston Globe: "What you see is not simply a competition for the scarce resources of Darfur. If we want to look at the violence in Darfur, we don't look underground, we look at the political realities that exist today."
Given the rate of climate change across the world, access to water will become a source of conflict, especially in more unstable regions. It is not inconceivable that Israel’s next war with Syria and Jordan could be over access to the River Jordan. I don’t hold out too much hope that peace will come to Darfur anytime soon but it is worth a try.
