eprintid: 1443 rev_number: 15 eprint_status: archive userid: 2 dir: disk0/00/00/14/43 datestamp: 2015-02-17 07:39:25 lastmod: 2017-02-08 12:21:32 status_changed: 2015-04-27 12:10:54 type: article metadata_visibility: show creators_name: Bommer, Julian J. creators_name: Abrahamson, Norman A. creators_name: Strasser, Fleur O. creators_name: Pecker, Alain creators_name: Bard, Pierre-Yves creators_name: Bungum, Hilmar creators_name: Cotton, Fabrice creators_name: Fah, Donat creators_name: Sabetta, Fabio creators_name: Scherbaum, Frank creators_name: Studer, Jost corp_creators: Civil and Environmental Engineering Imperial College London, UK corp_creators: Pacific Gas and Electricity Company Geosciences Department, USA corp_creators: Civil and Environmental Engineering Imperial College London, UK corp_creators: Geodynamique et Structure, France corp_creators: Division MSRGI Grenoble, France corp_creators: NORSAR, Norway corp_creators: LGIT, Université Joseph Fourier, France corp_creators: Institut für Geophysik, Switzerland corp_creators: Servizio Sismico Nazionale, Italy corp_creators: Inst. fur Geowissenschaften Universität Potsdam, Germany corp_creators: Studer Engineering, Switzerland title: The Challenge of Defining Upper Bounds on Earthquake Ground Motions ispublished: pub subjects: MP3_2 divisions: EPOS-P full_text_status: none abstract: Recent studies to assess very long-term seismic hazard in the United States and in Europe have brought the issue of upper limits on earthquake ground motions into the arena of problems requiring attention from the engineering seismological community. Few engineering projects are considered sufficiently critical to warrant the use of annual frequencies of exceedance so low that ground-motion estimates may become unphysical if limiting factors are not considered, but for nuclear waste repositories, for example, the issue is of great importance. The definition of upper bounds on earthquake ground motions also presents an exciting challenge for researchers in the area of seismic hazard assessment. This paper looks briefly at historical work on maximum values of ground-motion amplitudes before illustrating why this is an important issue for hazard assessments at very long return periods. The paper then discusses the factors that control the extreme values of motion, both in terms of generating higheramplitude bedrock motions and of limiting the values of motion at the ground surface. Possible channels of research that could be explored in the quest to define maximum possible ground motions are also discussed. date: 2004 date_type: published publication: Seismological Research Letters volume: 75 number: 1 publisher: Seismological Society of America pagerange: 82-95 id_number: doi:10.1785/gssrl.75.1.82 refereed: TRUE issn: 0895-0695 official_url: http://dx.doi.org/10.1785/gssrl.75.1.82 access_IS-EPOS: limited owner: Publisher citation: Bommer, Julian J. and Abrahamson, Norman A. and Strasser, Fleur O. and Pecker, Alain and Bard, Pierre-Yves and Bungum, Hilmar and Cotton, Fabrice and Fah, Donat and Sabetta, Fabio and Scherbaum, Frank and Studer, Jost (2004) The Challenge of Defining Upper Bounds on Earthquake Ground Motions. Seismological Research Letters, 75 (1). pp. 82-95. DOI: https://doi.org/10.1785/gssrl.75.1.82