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
Six-decade-old space mystery solved with shoebox-sized satellite called a CubeSat
15.12.2017 | National Science Foundation
NSF-funded researchers find that ice sheet is dynamic and has repeatedly grown and shrunk
15.12.2017 | National Science Foundation
DNA molecules that follow specific instructions could offer more precise molecular control of synthetic chemical systems, a discovery that opens the door for engineers to create molecular machines with new and complex behaviors.
Researchers have created chemical amplifiers and a chemical oscillator using a systematic method that has the potential to embed sophisticated circuit...
MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.
Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...
Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...
Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.
To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
11.12.2017 | Event News
08.12.2017 | Event News
07.12.2017 | Event News
15.12.2017 | Power and Electrical Engineering
15.12.2017 | Materials Sciences
15.12.2017 | Life Sciences