Rotational Motions in Seismology

Seismology is based primarily on the observation and modelling of three-component translational ground motions. Nevertheless, theoretical seismologists (e.g., Aki and Richards, 1980, 2002) have argued for decades that the rotational part of ground motions should also be recorded. It is well known that standard seismometers are sensitive to rotations (just like tiltmeters are sensitive to translations). The lack of observations of rotational motions was mainly due to the limited resolution of rotation sensors. However, in the past few years ring lasers, fibre-optic gyros, and other measurement devices have led to the first significant and consistent observations of rotational motions suggesting that complete six-component measurements may be possible in the near future. Accurate measurements of rotational motions may have implications for (1) recovering the complete displacement history from seismometer recordings; (2) further constraining rupture properties; (3) extracting subsurface properties; and (4) providing additional information to earthquake engineers. The goal of this session is to discuss measurement devices, observations, modelling, theoretical aspects and potential applications of rotational ground motions. The session will be accompanied by the installation of an International Working Group on Rotational Seismology that aims at promoting investigations of all aspects of rotational motions in seismology and their implications for related fields such as earthquake engineering, geodesy, strong-motion seismology, tectonics, etc., and to share experience, data, software, and results in an open web-based environment. Further information can be found at www.rotational-seismology.org.

Chairs

• H. Igel
• M. Todorovska
• W.H.K. Lee

Summary of Abstracts for Seismology Session S05

Ref. No (Status)	Authors	Title	Sec/ Sp.Ses	Poster Request	Type
13 (Submitted)	E Grekova M Kulesh G Herman I Shardakov	Modeling of the Propagation of Seismic Waves in Non-Classical Media: Reduced Cosserat Continuum	S/S05	Poster Request	C
166 (Submitted)	T Tobita S Sawada	Rotation Response of a Rigid Body Under Seismic Excitation	S/S05		C
1671 (Submitted)	Z Zembaty	Stochastic modeling of rocking seismic ground motion and respective structural load modeling	S/S05		C
2947 (Submitted)	V Graizer	Tilts in strong-ground motion	S/S05		I
3562 (Submitted)	B Huang C Liu C Lin C Wu W Lee	Measuring Mid- and Near-Field Rotational Ground Motions in Taiwan	S/S05	Poster Request	I
3620 (Submitted)	L Godinho A Tadeu F Sanchez-Sesma A Cadena-Isaza	Amplification of Ground Motion Rotations by Local Geology	S/S05		C
3818 (Submitted)	K Schreiber H Igel	Sagnac Interferometry for the Determination of Rotations in Seismology	S/S05		I
3985 (Submitted)	P Robert V Jean	Seismic Rotations Observed with Inertial Seismic Sensors	S/S05	Poster Request	C
6178 (Submitted)	R Nigbor J Evans T Hansen	Laboratory and Field Testing of two Rotational Seismometer Models	S/S05		I
7182 (Submitted)	H Igel U Schreiber A Cochard J Wassermann B Schuberth W Suryanto A Velikoseltsev	Broadband Rotational Ground Motions: Observations And Modelling	S/S05		C
7220 (Submitted)	S Lehndorfer W Suryanto N Dinh A Cochard J Wassermann H Igel U Schreiber	Observations Of Rotational Motions Around Vertical And Horizontal Axes: Comparison With Translations	S/S05		C
7250 (Submitted)	J Hautmann R Barsch J Wassermann H Igel A Velikoseltsev U Schreiber	Towards A Global Network Of Rotation Sensors	S/S05	Poster Request	C
7300 (Submitted)	N Dinh W Suryanto H Igel A Cochard A Velikoseltsev U Schreiber	Rotational Signals In The P Coda	S/S05		C
7327 (Submitted)	H Wang H Igel A Cochard M Ewald	Source- And Basin-Related Effects On Ground Rotational Motions: A Synthetic Study	S/S05		C
9384 (Submitted)	M Todorovska	Rotational Ground Motions Radiated by Vibrating Structures	S/S05		C
9570 (Submitted)	G Emore J Haase K Larson S Miyazaki	Sensitivity of Earthquake Fault Slip Reconstructions to Errors in Seismic Displacement Records	S/S05		C
9843 (Submitted)	J Fletcher P Spudich	Seismic Rotations and Strains at UPSAR from the September 28, 2004, M6 Parkfield Earthquake	S/S05	Poster Request	C
11108 (Submitted)	D Aldridge N Symons M Haney	3D Finite-Difference Numerical Simulations in Seismic Gradiometry	S/S05	Poster Request	C
11212 (Submitted)	R Boroschek	Engineering Implications of Rotational Sensitivity of Translational Accelerometers	S/S05		C
11216 (Submitted)	R Cowsik K Wagoner A Sircar	A New Instrument of Direct Observations of Torsional Normal Mode Oscillation of the Earth	S/S05		C
11615 (Submitted)	G Sasagawa T Hansen F Vernon U Schreiber H Igel A Velikoseltsev	The rotation sensor at Pinon Flat Observatory	S/S05	Poster Request	C