Post by jonsdigs on Dec 2, 2006 10:53:54 GMT -5
The secrets of the Nerja Caves
Scientists can gauge the climate of the past by examining the stalagmites and stalactites in the Nerja Caves
José Luis López
Costa del Sol News
Formations in Nerja cave
IT may have looked as if Ali Baba and the forty thieves had invaded the Caves of Nerja last week, but this was certainly not the case. These were the pupils of a Malaga secondary school, there as part of the sixth Science Week to get to know at first hand the extraordinarily beautiful geological formations for which the caves have become world famous. Although it seems, at first sight, that the stalagmites and stalactites in the caves were formed over millennia by chance alone, the scientists now tell us that they are the result of climate changes over the centuries. They are, in fact, mineral deposits that scientists can use to determine temperatures at different periods of the distant past.
Prehistoric minerals
The stalagmites and stalactites do a lot more than make the caves beautiful. They are also climatic archives of the past, a kind of data-base of the weather that geologists and archaeologists can now examine as a means of knowing more about the climate of this part of Europe in prehistoric times, and researchers in the University of Granada are doing just that.
Research
“Scientists are now examining the isotopes of oxygen and carbon in certain stalactites and stalagmites in the caves to find out at what temperature these mineral deposits were formed. And as the average interior temperature of the caves coincides with the average outside temperature, we can make a fairly exact guess at the climate of the different periods,” says Cristina Liñán, a geological technician in the Nerja Caves Research Institute.
One might think that knowledge of the climate at different periods of the distant past would be quite unnecessary, but we must not forget that our predictions of the future are invariably based on our knowledge of the past.
Weatherwise, this is especially true. Studies carried out by the United Nations tell us that the sea level has risen by between ten and twenty centimetres over the 20th century, and that average temperatures worldwide will rise by between 1.6 and five grades over the next century.
The stalactites and stalagmites are thus crystal balls in the hands of the scientists. While some study the climate in the rocks, others study earthquakes of times past, all aimed at discovering if there is any risk of earthquakes in this region in the future.
Stalagmites
To find out more about earthquakes of the past, the scientists study stalagmites and stalactites that have broken as a result of earth tremors, in relation to those which have grown again on those broken.
The minerals on them are studied to determine age, and the different between the two reveals the dates in which earthquakes have taken place, and the frequency with which they have occurred.
Geological studies such as these have already taken place in Italian caves that are not open to the general public, but since the Nerja Caves are visited by large numbers of people each year, the scientists have some difficulty in establishing whether stalactites and stalagmites have been broken by earth movement as a result of earthquakes or by movement caused by human beings in more recent times.
Article
Scientists can gauge the climate of the past by examining the stalagmites and stalactites in the Nerja Caves
José Luis López
Costa del Sol News
Formations in Nerja cave
IT may have looked as if Ali Baba and the forty thieves had invaded the Caves of Nerja last week, but this was certainly not the case. These were the pupils of a Malaga secondary school, there as part of the sixth Science Week to get to know at first hand the extraordinarily beautiful geological formations for which the caves have become world famous. Although it seems, at first sight, that the stalagmites and stalactites in the caves were formed over millennia by chance alone, the scientists now tell us that they are the result of climate changes over the centuries. They are, in fact, mineral deposits that scientists can use to determine temperatures at different periods of the distant past.
Prehistoric minerals
The stalagmites and stalactites do a lot more than make the caves beautiful. They are also climatic archives of the past, a kind of data-base of the weather that geologists and archaeologists can now examine as a means of knowing more about the climate of this part of Europe in prehistoric times, and researchers in the University of Granada are doing just that.
Research
“Scientists are now examining the isotopes of oxygen and carbon in certain stalactites and stalagmites in the caves to find out at what temperature these mineral deposits were formed. And as the average interior temperature of the caves coincides with the average outside temperature, we can make a fairly exact guess at the climate of the different periods,” says Cristina Liñán, a geological technician in the Nerja Caves Research Institute.
One might think that knowledge of the climate at different periods of the distant past would be quite unnecessary, but we must not forget that our predictions of the future are invariably based on our knowledge of the past.
Weatherwise, this is especially true. Studies carried out by the United Nations tell us that the sea level has risen by between ten and twenty centimetres over the 20th century, and that average temperatures worldwide will rise by between 1.6 and five grades over the next century.
The stalactites and stalagmites are thus crystal balls in the hands of the scientists. While some study the climate in the rocks, others study earthquakes of times past, all aimed at discovering if there is any risk of earthquakes in this region in the future.
Stalagmites
To find out more about earthquakes of the past, the scientists study stalagmites and stalactites that have broken as a result of earth tremors, in relation to those which have grown again on those broken.
The minerals on them are studied to determine age, and the different between the two reveals the dates in which earthquakes have taken place, and the frequency with which they have occurred.
Geological studies such as these have already taken place in Italian caves that are not open to the general public, but since the Nerja Caves are visited by large numbers of people each year, the scientists have some difficulty in establishing whether stalactites and stalagmites have been broken by earth movement as a result of earthquakes or by movement caused by human beings in more recent times.
Article