Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

BSSA special issue on rotational seismology

28.04.2009
A special May issue of the Bulletin of the Seismological Society of America (BSSA) focuses on the emerging field of rotational seismology and its applications to engineering.

The special issue will feature seismological research on all aspects of rotational ground motions (including theory, instrumentation, observation, and interpretation) and on rotations in structural response.

Rotational seismology is of interest to a wide range of disciplines, including various branches of seismology, earthquake engineering, and geodesy, as well as to physicists using Earth-based observatories for detecting gravitational waves generated by astronomical sources as predicted by Einstein in 1916.

Seismology and earthquake engineering have been based on the observation and modeling of translational ground and structural motions. Although rotational effects from earthquakes have been observed for centuries, rotational ground motion has been ignored due to a widespread belief that rotation is insignificant and practical difficulties in measuring it. Theoretical work in modern rotational seismology began in the 1970s, and attempts to deduce rotational motion from accelerometer arrays began in the 1980s. However, modern direct measurements of rotational ground motions began only about a decade ago when affordable angular sensors became sensitive enough (capable of measuring an angle of less than ten thousandth of a degree) to detect rotations from small earthquakes, while large ring laser gyros (intended for studying the Earth's rotation) became capable of detecting even smaller rotations from distant earthquakes.

Ring laser observations at Wettzell, Germany and at Piñon Flat, California demonstrated consistent measurements of rotational ground motions in the far field. The high cost of present high-precision ring laser gyros (costing $1 million or more) makes widespread deployment unlikely. Less expensive and/or less sensitive alternatives are now being pursued by five academic groups. At present, only Taiwan has a modest program to monitor both translational and rotational ground motions from regional earthquakes at several free-field sites, as well as two arrays equipped with both accelerometers and rotational seismometers in a building and a nearby site.

Based on the developments described in the BSSA special issue, observation, analysis, and interpretations of both rotational and translational ground motions will soon play a significant role in seismology and earthquake engineering.

The lead guest editor William H. K. Lee is Scientist Emeritus at the U.S. Geological Survey in Menlo Park, California. He can be reached at lee@usgs.gov.

Nan Broadbent | EurekAlert!
Further information:
http://www.seismosoc.org
http://www.usgs.gov

More articles from Earth Sciences:

nachricht Predicting unpredictability: Information theory offers new way to read ice cores
07.12.2016 | Santa Fe Institute

nachricht Sea ice hit record lows in November
07.12.2016 | University of Colorado at Boulder

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Electron highway inside crystal

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...

Im Focus: Significantly more productivity in USP lasers

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:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

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...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

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...

Im Focus: Quantum Particles Form Droplets

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...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>