RSS

Continental breakup and UHP rock exhumation in action: GPS results from the Woodlark Rift, Papua New Guinea

Abstract

We show results from a network of campaign Global Positioning System (GPS) sites in the Woodlark Rift, southeastern Papua New Guinea, in a transition from seafloor spreading to continental rifting. GPS velocities indicate anticlockwise rotation (at 2-2.7 º/Myr, relative to Australia) of crustal blocks north of the rift, producing 10-15 mm/yr of extension in the continental rift, increasing to 20-40 mm/yr of seafloor spreading at the Woodlark Spreading Center. Extension in the continental rift is distributed among multiple structures. These data demonstrate that low-angle normal faults in the continents, such as the Mai'iu Fault, can slip at high rates nearing 10 mm/yr. Extensional deformation observed in the D'Entrecasteaux Islands, the site of the world's only actively exhuming Ultra-High Pressure (UHP) rock terrane, supports the idea that extensional processes play a critical role in UHP rock exhumation. GPS data do not require significant interseismic coupling on faults in the region, suggesting that much of the deformation may be aseismic. Westward transfer of deformation from the Woodlark Spreading Center to the main plate boundary fault in the continental rift (the Mai'iu fault) is accommodated by clockwise rotation of a tectonic block beneath Goodenough Bay, and by dextral strike-slip on transfer faults within (and surrounding) Normanby Island. Contemporary extension rates in the Woodlark Spreading Center are 30-50% slower than those from seafloor spreading-derived magnetic anomalies. The 0.5 Ma-present seafloor spreading estimates for the Woodlark Basin may be overestimated, and a re-evaluation of these data in the context of the GPS rates is warranted.

 
Comments Off

Posted by on October 23, 2014 in Blog

 

Some scientists share better than others

Some scientists share better than others. While astronomers and geneticists embrace the concept, the culture of ecology still has a ways to go. New research explores the paradox that although ecologists share findings via scientific journals, they do not share the data on which the studies are built, said a co-author of the paper.
 
Comments Off

Posted by on October 22, 2014 in Blog

 

Karakoram glacier anomaly resolved, a cold case of climate science

Researchers may have hit upon an answer to a climate-change puzzle that has eluded scientists for years, namely why glaciers in the Karakoram range of the Himalayas have remained stable and even increased in mass while glaciers nearby and worldwide have been receding. Understanding the 'Karakoram anomaly' could help gauge the future availability of water for hundreds of millions of people.
 
Comments Off

Posted by on October 22, 2014 in Blog

 

A ‘Star Wars’ laser bullet — this is what it really looks like

Action-packed science-fiction movies often feature colourful laser bolts. But what would a real laser missile look like during flight, if we could only make it out? How would it illuminate its surroundings?
 
Comments Off

Posted by on October 22, 2014 in Blog

 

Global consumption an increasingly significant driver of tropical deforestation

International trade with agricultural and wood products is an increasingly important driver of tropical deforestation. More than a third of recent deforestation can be tied to production of beef, soy, palm oil and timber. 'The trend is clear: the drivers of deforestation have been globalized and commercialized,' says one expert.
 
Comments Off

Posted by on October 22, 2014 in Blog

 

New devices based on metamaterials

Researchers have designed and manufactured new devices based on metamaterials (artificial materials with properties not found in nature). They achieved the first experimental demonstration ever with epsilon-near-zero metamaterials. “These materials have surprising characteristics, such as the fact that a wave traveling within them can do so at almost infinite speed and, thus, can be transmitted from one place to another without hardly any loss of energy, no matter how unusual or complicated the shape of the material," according to a researcher.
 
Comments Off

Posted by on October 22, 2014 in Blog

 

New window on the early Universe

Scientists see good times approaching for astrophysicists after hatching a new observational strategy to distill detailed information from  galaxies at the edge of the Universe. Using two world-class supercomputers, the researchers were able to demonstrate the effectiveness of their approach by simulating the formation of a massive galaxy at the dawn of cosmic time. The ALMA radio telescope – which stands at an elevation of 5,000 meters in the Atacama Desert of Chile, one of the driest places on earth – was then used to forge observations of the galaxy, showing how their method improves upon previous efforts.
 
Comments Off

Posted by on October 22, 2014 in Blog

 

Special microscope captures defects in nanotubes

Chemists have devised a way to see the internal structures of electronic waves trapped in carbon nanotubes by external electrostatic charges. Carbon nanotubes have been touted as exceptional materials with unique properties that allow for extremely efficient charge and energy transport, with the potential to open the way for new, more efficient types of electronic and photovoltaic devices. However, these traps, or defects, in ultra-thin nanotubes can compromise their effectiveness.
 
Comments Off

Posted by on October 21, 2014 in Blog

 

Scientists disprove theory that reconstructed boron surface is metallic

Scientific inquiry is a hit and miss proposition, subject to constant checking and rechecking. Recently, a new class of materials was discovered called topological insulators—nonmetallic materials with a metallic surface capable of conducting electrons. The effect, based on relativity theory, exists only in special materials -— those with heavy elements —- and has the potential to revolutionize electronics.
 
Comments Off

Posted by on October 21, 2014 in Blog

 

Two vessels from WWII convoy battle off North Carolina discovered: German U-boat 576 and freighter Bluefields found within 240 yards

Scientists have discovered two significant vessels from World War II's Battle of the Atlantic. The German U-boat 576 and the freighter Bluefields were found approximately 30 miles off the coast of North Carolina. Lost for more than 70 years, the discovery of the two vessels, in an area known as the Graveyard of the Atlantic, is a rare window into a historic military battle and the underwater battlefield landscape of WWII.
 
Comments Off

Posted by on October 21, 2014 in Blog