French researchers have looked into data mining to develop a method for extracting information on the vulnerability of cities in regions of moderate risk, creating a proxy for assessing the probable resilience of buildings and infrastructure despite incomplete seismic inventories of buildings. The research exposes significant vulnerability in regions that have experienced an "explosion of urbanization."
"Considering that the seismic hazard is stable in time, we observe that the seismic risk comes from the rapid development of urbanization, which places at the same site goods and people exposed to hazard" said Philippe Gueguen, co-author and senior researcher at Université Joseph Fourier in Grenoble, France. The paper appears today in the journal Seismological Research Letters (SRL).
Local authorities rely on seismic vulnerability assessments to estimate the probable damage on an overall scale (such as a country, region or town) and identify the most vulnerable building categories that need reinforcement. These assessments are costly and require detailed understanding of how buildings will respond to ground motion.
Old structures, designed before current seismic building codes, abound in France, and there is insufficient information about how they will respond during an earthquake, say authors. The last major earthquake in France, which is considered to have moderate seismic hazard, was the 1909 magnitude 6 Lambesc earthquake, which killed 42 people and caused millions of euros of losses in the southeastern region.
The authors relied on the French national census for basic descriptions of buildings in Grenoble, a city of moderate seismic hazard, to create a vulnerability proxy, which they validated in Nice and later tested for the historic Lambesc earthquake.
The research exposed the effects of the urbanization and urban concentrations in areas prone to seismic hazard.
"In seismicity regions similar to France, seismic events are rare and are of low probability. With urbanization, the consequences of characteristic events, such as Lambesc, can be significant in terms of structural damage and fatalities," said Gueguen. "These consequences are all the more significant because of the moderate seismicity that reduces the perception of risk by local authorities."
If the 1909 Lambesc earthquake were to happen now, write the authors, the region would suffer serious consequences, including damage to more than 15,000 buildings. They equate the likely devastation to that observed after recent earthquakes of similar sizes in L'Aquila, Italy and Christchurch, New Zealand.
Nan Broadbent | EurekAlert!
Global study of world's beaches shows threat to protected areas
19.07.2018 | NASA/Goddard Space Flight Center
NSF-supported researchers to present new results on hurricanes and other extreme events
19.07.2018 | National Science Foundation
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
20.07.2018 | Power and Electrical Engineering
20.07.2018 | Information Technology
20.07.2018 | Materials Sciences