G

CAVE’S MYSTERY NOW CRYSTAL CLEAR

Following extensive analysis, a team of geologists from Mexico and Spain believe they can explain how giant selenite gypsum crystals in Mexico’s Cueva de los Cristales in the Naica mine complex, 150 kilometres southeast of Chihuahua, were formed. The crystals are among the largest ever found, weighing as much as 55 tonnes and measuring up to 11 metres in length. Analysis of tiny pockets of fl uid found inside the crystals revealed the exact chemical composition and temperature of the water in which they formed, allowing the scientists to deduce that they grew within a narrow temperature range – around 58°C – submerged in mineral-rich water. The scientists now think it’s likely that there are more giant crystals elsewhere in the mine system. The Naica mines yield large quantities of lead, zinc and silver, and the chambers containing the crystals would be submerged by water were it not for the mining activities. “I’ve recommended to the mining company that they try to preserve them and I would like to see UNESCO get involved,” said Professor Juan Manuel Garcia-Ruiz of the University of Granada.

North Sea fl oor was once desirable residence

New images of the North Sea fl oor have revealed a landscape that was once criss-crossed by river valleys and dotted with freshwater lakes and rounded hills, described by one archaeologist as “the best-preserved prehistoric landscape, certainly in the whole of Europe and possibly the world.” The team of archaeologists from the University of Birmingham recreated the landscape by piecing together three-dimensional seismic records collected during the past two years by oil-prospecting vessels across a 23,000square-kilometre area. Based on the fi ndings, the scientists have suggested that the North Sea fl oor would once have supported a wealth of

fauna and fl ora, making it an ideal home for hunter-gatherers – rather than just a bridge between northern Europe and Great Britain, as was previously thought. “This was probably a heartland of population at the time,” said Professor Vince Gaff ney, director of the university’s Institute of Archaeology and Antiquity. In a scenario that bears some resemblance to the current predicted threat from global warming, the area was, said Gaff ney, inundated between 9,000 and 20,000 years ago in a relatively short space of time due to a warming climate. “The area we have mapped was wiped out in the space of 4,000 years,” he said.

COMING SOON: ENCYCLOPAEDIA OF LIFE

A monumental eff ort is being made by several scientifi c institutions to record every plant, animal and other species on Earth in an online encyclopaedia. The estimated 1.8 million species will be entered onto a multimedia website by several institutions, including the USA’s Field Museum, Harvard University and Smithsonian Institution, over the next ten years. The website, www.eol.org, will be accessible to all, and will initially present text, photographs, videos and distribution maps for animals, plants and fungi, with microbial life to follow later. “The Encyclopaedia of Life will provide valuable biodiversity and conservation information to anyone, anywhere, anytime,” said Dr James Edwards, executive director of the project.

8 www.geographical.co.uk JULY 2007

Javier Trueba/MSF/Science Photo Library; HP VISTA (U niversity of Bi rm ingham)
WORLDWATCH

©ARC Centre of Excellence; Everest Rescue Trust

REEF EXPOSURE REVEALS CORAL COLONISATION

Large swathes of coral reef that died after being lifted to the surface following an earthquake off the west coast of Sumatra, Indonesia, in 2005, are providing scientists with an opportunity to witness reef recovery and colonisation in action. Scientists from the Wildlife Conservation Society Indonesia Program (WCSIP) and the Australian Research Council Centre of Excellence for Coral Reef Studies (ARCCECRS) headed to the area to investigate the condition of the reefs on and

around the Indonesian island of Simeulue following the quake. They found that the March 2005 earthquake, which measured 8.9 on the Richter scale and caused 839 fatalities, elevated an estimated 400 kilometres of coastline by between 80 and 120 centimetres, exposing extensive areas of coral to the air. “This is a story of mass mortality on a scale rarely observed,” said Stuart Campbell from the WCSIP. “In contrast to other threats, such as coral bleaching, none of the corals

uplifted by the earthquake have survived.” On a positive note, however, the team found that areas previously too deep for coral and associated organisms were now being colonised by those species worst aff ected by the quake. “This is a unique opportunity to document a process that occurs maybe once a century and promises to provide new insights into coral-recovery processes that, until now, we could only explore on fossil reefs,” said Dr Andrew Baird of ARCCECRS.

Remote-controlled rescue chopper for Everest

A helicopter manufacturer in New Zealand has conceived plans for an unmanned rescue helicopter that will be capable of plucking mountaineers in distress from the summit of the world’s highest mountain. The result of six years of research and development, TGR Helicorp’s Alpine Wasp is designed to reach altitudes of up to 9,000 metres – nearly twice as high as existing helicopters – and will be summoned at the touch of a button by climbers carrying special transponders. The Alpine Wasp has been constructed using lightweight composite materials, has a specially designed diesel engine and rotor blades that can work in the oxygen-depleted atmosphere found at high altitude – most helicopters are restricted to an altitude of 4,300 metres. Climbers would be clipped to the helicopter’s harness and pulley and would then be instructed and monitored from a base station via video cameras and microphones.

Following extensive testing in New Zealand’s Southern Alps, the designers hope to have the Alpine Wasp stationed in a specially designed hanger at 3,440-metre Namche Bazaar – the gateway to Mount Everest – by spring next year. The news has raised concerns from within the mountaineering community that the presence of a rescue helicopter could encourage even greater numbers of inexperienced climbers to attempt to climb Everest.

IN BRIEF UK The Millennium Seed Bank Project has just banked its billionth seed.

Part of the Royal Botanic Gardens, Kew, the bank contains the seeds of

more than 18,000 wild plant species from 126 countries.

TAIWAN Traffi c on a busy stretch of

motorway in Taiwan was brought to a standstill earlier this year by a swarm

of butterfl ies. Taiwanese authorities halted motorists on a 600-metre

section of Freeway Three to allow hundreds of thousands of milkweed

butterfl ies to continue their annual migration north to breed.

CHINA The Tibetan meteorological

offi ce has announced that it has successfully seeded clouds to trigger

snowfall over the Tibetan plateau. Chinese offi cials regularly seed

clouds with silver iodide, which encourages the formation of

water droplets, as a way of clearing pollution – especially before public

holidays – but this is the fi rst time snow has been ‘created’.

JULY 2007 www.geographical.co.uk 9