Seismologists rely on written accounts, mostly local newspaper articles, to judge how strongly the ground shook during earthquakes that predate the use of current instrumentation. Those news accounts have proven to be misleading, say scientists, and reliance upon them must be tempered when evaluating the size of past earthquakes.
By focusing on the most dramatic damage and other effects of an earthquake, news stories can provide an unbalanced view of a disaster. For historical earthquakes it is difficult to estimate the effects of this bias. However, a recently deadly earthquake--the M7.6 Bhuj, India earthquake of 2001--provided an unprecedented opportunity to compare the media accounts with the results of an exhaustive, ground-based survey of damage.
"This study isn’t about the media," says Susan E. Hough, co-author of the paper and a seismologist at the U. S. Geological Survey in Pasadena, California. "It isn’t the job of the media to provide a detailed survey of the effects of an earthquake. It’s the seismologist’s job to evaluate media and other written accounts. We need to do careful, balanced assessments of accounts of past earthquakes to understand the hazard from future earthquakes. Media accounts have a built-in bias that is natural to telling any story – whether by a journalist or by an eyewitness."
The severity of an earthquake can be expressed in terms of intensity, which is based on observations by eyewitnesses to the ground motion and the shaking of buildings, trees, and anything in the surrounding area. The perceived intensity varies within the affected zone, depending upon the location of the witness to the epicenter.
In "Quantifying the ‘Media Bias" in Intensity Surveys: Lessons from the 2001 Bhuj, India, Earthquake," Hough and co-author Prabhas Pande, Ph.D, Director, Earthquake Geology Division Geological Survey of India, studied the effects of the 7.6 Bhuj earthquake that occurred on 26 January 2001. This quake was felt across much of the Indian subcontinent, and official government figures cited 13,800 fatalities and 166,000 injuries.
Two independent intensity surveys evaluated the earthquake: one based on extensive news articles written in the early aftermath of the earthquake and the other based on direct surveys and interviews conducted by the Geological Survey of India. The comparison yielded important information for seismologists who interpret past events for which only written accounts are available.
"The research confirmed the tendency of written accounts to focus on the most dramatic, rather than representative effects in their accounts," write the authors. Further, the authors conclude that the media bias "can be significant, and is most severe at the strongest shaking levels."
Nan Broadbent | EurekAlert!
Predicting unpredictability: Information theory offers new way to read ice cores
07.12.2016 | Santa Fe Institute
Sea ice hit record lows in November
07.12.2016 | University of Colorado at Boulder
Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.
Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
09.12.2016 | Life Sciences
09.12.2016 | Ecology, The Environment and Conservation
09.12.2016 | Health and Medicine