Seabed samples rewrite earthquake history near Istanbul
2015-03-30
(Press-News.org) SAN FRANCISCO--Located in the Marmara Sea, major earthquakes along the North Anatolian Fault (NAF) system have repeatedly struck what is current-day Istanbul and the surrounding region, but determining the recurrence rate has proven difficult since the faults are offshore. Cores of marine sediment reveal an earthquake history of the Cinarcik Segment, a main branch of NAF, and suggest a seismic gap where the next earthquake is likely to rupture, as detailed in a new study published in the Bulletin of the Seismological Society of America (BSSA).
The area has experienced several large earthquakes (>M6), and the scientific community has debated the exact location of the ruptures along the North Anatolian Fault, which extends nearly 750 miles across Northern Turkey and in the Aegean Sea. Most of the deformation on the fault is localized on the northern branch of the NAF, which crosses the Marmara Sea.
"The important part of this study is that it assigns past earthquakes to specific segments of the fault," said lead author Laureen Drab, a seismologist at the Ecole Normale Superieure in Paris, France. "Knowing which segment ruptured when has a big impact on the recurrence rate of earthquakes on the main fault segment that affects Istanbul."
Drab and her colleagues examined two cores of sediment deposits removed from the seabed to identify and date widespread quake-induced disturbances. Large earthquakes on submarine faults can cause underwater landslides, shaking up sediments that result in rapidly deposited layers, or turbidites, of silt and sand of jumbled grain sizes, minerals and specific geochemical properties. Radiocarbon dating and other tests of two core samples identified the age and timing of deposits.
Combining the historical catalogue and the new data from the core samples, Drab reconstructed the timing of earthquakes along NAF's main segment. The turbidites reveal six large earthquake-related events, from 136 to 1896 AD, along the Cinarcik Fault and reassigned the 1766 AD rupture previously thought to have occurred on the Cinarcik Fault to another segment.
"The combined records show three entire rupture sequences on the NAF, with the current sequence incomplete along the Cinarcik Fault," said Drab. "Based on this new data, we see that there is a seismic gap on the Cinarcik Segment, which, from my point of view, is where the next earthquake is likely to occur."
INFORMATION:
Drab's co-authors on the study include Aurelia Hubert-Ferrari, Sabine Schmidt, Philippe Martinez, Julie Carut and Meriam El Ouahabi. The paper will be published online March 30.
Media contact: Nan Broadbent
Seismological Society of America
408-431-9885, press@seismosoc.org
ELSE PRESS RELEASES FROM THIS DATE:
2015-03-30
Researchers have been fascinated for a long time by learning and memory formation, and many questions are still open. Bochum-based neuroscientists Prof Dr Denise Manahan-Vaughan and Dr Hardy Hagena have discovered a key building block for this complex process. A particular neurotransmitter receptor, namely the metabotropic glutamate receptor 5, is a switch for activating opposing forms of plasticity in the hippocampus, a brain region vital for memory forming. They reported in the current edition of "The Journal of Neuroscience".
Synapses between neurons process different ...
2015-03-30
While the body of evidence for feeding recommendations for children continues to evolve, one constant remains: Children do not eat enough vegetables. In fact, more than 90% of young children fail to meet vegetable recommendations, and these patterns often persist into adolescence and adulthood, making it important to understand the factors involved in establishing feeding patterns in early childhood. Are children not eating their vegetables because of texture, lack of role modeling, negative sensory experience, delayed introduction, bitter taste, infrequent exposure, rejection ...
2015-03-30
A new star rating system can help hockey players to know just how well each helmet on the market can protect them from suffering head injuries and concussions during the course of a season. The "Hockey STAR" (Summation of Tests for the Analysis of Risk) rating is an extension of a similar rating system developed for football helmets. It was developed by researchers from Virginia Tech in the US, led by Bethany Rowson, and reported on in Springer's journal Annals of Biomedical Engineering.
More ice hockey players suffer concussion while playing hockey than their counterparts ...
2015-03-30
Researchers at MIT and Northwestern University have developed a new peer-to-peer networking tool that enables sufferers of anxiety and depression to build online support communities and practice therapeutic techniques.
In a study involving 166 subjects who had exhibited symptoms of depression, the researchers compared their tool with an established technique known as expressive writing. The new tool yielded better outcomes across the board, but it had particular advantages in two areas: One was in training subjects to use a therapeutic technique called cognitive reappraisal, ...
2015-03-30
PHILADELPHIA -- Intensive care units across the United States vary widely in how they manage the care of patients who have set preexisting limits on life-sustaining therapies, such as authorizing do-not-resuscitate (DNR) orders and prohibiting interventions such as feeding tubes or dialysis, according to new research from the Perelman School of Medicine at the University of Pennsylvania. Their work is published in the current issue of JAMA Internal Medicine.
"We've long known that end-of-life and critical care varies across nations, regions and centers, whether from ...
2015-03-30
Bacteria have been discovered in the bladders of healthy women, discrediting the common belief that normal urine is sterile. This finding and its implications were addressed in an editorial published by researchers from Loyola University Chicago Stritch School of Medicine (SSOM) in the latest issue of European Urology.
"Clinicians previously equated the presence of bacteria in urine to infections. The discovery of bacteria in the urine of healthy females provides an opportunity to advance our understanding of bladder health and disease," said Alan Wolfe, PhD, lead author ...
2015-03-30
A key protein previously implicated in Lou Gehrig's disease and other neurological diseases plays an important role in the response to viral infection, according to a study led by scientists from the Icahn School of Medicine at Mount Sinai published today in Nature Immunology.
Neurological diseases have long been associated with inflammation, part of the body's response to injury or infection that occurs when immune cells home in to attack invaders like bacteria and viruses, and to drive healing, but the link between them has not been understood.
This new study result ...
2015-03-30
The body's immune system fights disease, infections and even cancer, acting like foot soldiers to protect against invaders and dissenters. But it turns out the immune system has traitors amongst their ranks. Dr. Karin de Visser and her team at the Netherlands Cancer Institute discovered that certain immune cells are persuaded by breast tumors to facilitate the spread of cancer cells. Their findings are published advanced online on March 30 in the journal Nature.
In Western countries about one in eight women will develop breast cancer. Of the women who die of this disease, ...
2015-03-30
Researchers at NYU Langone Medical Center have captured images of the underlying biological activity within brain cells and their tree-like extensions, or dendrites, in mice that show how their brains sort, store and make sense out of information during learning.
In a study to be published in the journal Nature online March 30, the NYU Langone neuroscientists tracked neuronal activity in dendritic nerve branches as the mice learned motor tasks such as how to run forward and backward on a small treadmill. They concluded that the generation of calcium ion spikes -- which ...
2015-03-30
A lower percentage of children are eating fast food on any given day and calories consumed by children from burger, pizza and chicken fast food restaurants also has dropped, according to an article published online by JAMA Pediatrics.
Colin D. Rehm, Ph.D., M.P.H., formerly of the University of Washington, Seattle, now of the Friedman School of Nutrition Science and Policy at Tufts University, Boston, and Adam Drewnowski, Ph.D., of the University of Washington, Seattle, analyzed data from the National Health and Nutrition Examination Survey from 2003 to 2010 to examine ...
LAST 30 PRESS RELEASES:
[Press-News.org] Seabed samples rewrite earthquake history near Istanbul
