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

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Smallest transistor worldwide switches current with a single atom in solid electrolyte

17.08.2018 | Physics and Astronomy

Robots as Tools and Partners in Rehabilitation

17.08.2018 | Information Technology

Climate Impact Research in Hannover: Small Plants against Large Waves

17.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>