Using tiny bone fragments from fossilized fish, scientists have traced the roots of the climate phenomenon known as El Niño, the intermittent warming of ocean waters off the coast of Peru that can affect weather worldwide. According to a report published in the current issue of the journal Science, modern El Niño conditions arose around 5,000 years ago.
Image: Courtesy of C. Fred T. Andrus
Previous research based on fossilized mollusk remains had suggested that El Niño conditions did not exist thousands of years ago, but those findings were preliminary. In the current study, C. Fred T. Andrus of the University of Georgia and colleagues analyzed isotopes of oxygen present in the ear stones, or otoliths (see micrograph at right), of a species of catfish that lives off the coast of Peru and does not migrate. Like tree rings, otoliths grow concentrically and incorporate elements indicative of the environment in which they formed. "By looking at the entire otolith," co-author Douglas E. Crowe of the University of Georgia explains, "we can reconstruct the water temperature history throughout the life of the fish, from season to season and year to year."
In this case, the researchers focused on the amount of oxygen isotope 18 in the otoliths--an indicator of the water temperature in which the fish lived. The team examined fossils recovered from two Peruvian archaeological sites approximately 6,000 years old and found that ocean temperatures then were on average three to four degrees Celsius warmer and less variable than current sea temperatures are.
Sarah Graham | Scientific American
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More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
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The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
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