What would happen on Earth if a meteorite would crash again such as the one that exterminated dinosaurs 65 million years ago? In order to answer this question a team of researchers of the University of Granada is working since 1989 on the analysis of the trace left by this impact in the planet. In our country, extraterrestrial materials have been found mainly in the deposits of sediments of the Betica Mountain Range such as in Agost (Alicante) and Caravaca (Murcia), and of the Basque-Cantabrian basin.
This team has the financing of the Ministry of Education and Science through different projects of the National Plan I+D+I. The Andalusian Council ahs contributed too through the research group RNM179, coordinated by professor Miguel Ortega Huertas, and international programs like IMPACT, of the European Science Foundation, and the “Ocean Drilling Program”. The research works have been developed in collaboration with different prestigious universities and centres such as the University of París VI in France, the universities of Rome and Bari in Italy, the ETH-Zentrum of Zürich in Switzerland and the Universities of San Diego and Stanford in the United States.
Traces under the ocean
In order to find out what happened on Earth 65 million years ago, besides analysing the samples found in the deposits of the Betica Mountain Range and the Basque-Cantabrian basin, this group has carried out research works on other locations of this period in Tunisia and Italy, has taken part in an ocean drilling campaign of the “Ocean Drilling Program” in the Northwest Atlantic and at present participates in the “International Continental Drilling Program” through research works on samples from drillings carried out in the Peninsula of the Yucatan, where you can find the crater of the meteorite that exterminated life in the Cretacic, a data that can now be confirmed thanks to all the proofs contributed by the studies carried out in the area. The research works on the materials extracted in the area have completed those carried out in the Northwest Atlantic in the area of the peninsula of Florida (close to the impact structure of Chicxulub, Peninsula of Yucatan, Mexico).
Although the analysis of the samples from drillings in the Peninsula of Yucatan is being carried out at present, previous results point out the main effects produced by this impact. In this sense, the supervisor of the research work points out the climatic change and ocean productivity as two of the most important consequences. «There was an Earth global warming as a consequence of the extinction of sea plankton, which acts as a CO2 drain. Therefore, that CO2 passed to the atmosphere, provoking an acid rain and the consequent greenhouse effect. It involved an important chemical alteration in the oceans too, which affected seriously sea biologic productivity and, finally, exterminated life”.
Planet warming
According to Martínez, it would happen too if a similar meteorite would crash again on Earth in future, although she says that, considering the difference between the geological and the human scale, “there are few probabilities that it happens again all through human history. However, as regards smaller meteorites and minor consequences, there are more probabilities”.
As regards the possibility that in future science could deflect or alter the orbit of a meteorite to avoid the impact, professor Martínez says that “it would be really difficult” and she adds that “it would be improbable to be able to stop a catastrophic event of the dimensions of the one that exterminated dinosaurs million years ago”.
Reference
Professor Francisca Martínez Ruiz
Andalusian Institute of Earth Sciences
Tel. 958 246 228 / 243 158. Mobile 630 880 511. E-mail. fmruiz@ugr.es
