Assessment of ground motion variability and its effects on seismic hazard analysis : a case study for iceland
Probabilistic seismic hazard analysis (PSHA) generally relies on the basic assumption that ground motion prediction equations (GMPEs) developed for other similar tectonic regions can be adopted in the considered area. This implies that observed ground motion and its variability at considered sites c...
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ftustrathclyde:oai:strathprints.strath.ac.uk:53617 2024-04-28T08:25:45+00:00 Assessment of ground motion variability and its effects on seismic hazard analysis : a case study for iceland Ornthammarath, Teraphan Douglas, John Sigbjörnsson, Ragnar Lai, Carlo Giovanni 2011-08 https://strathprints.strath.ac.uk/53617/ https://doi.org/10.1007/s10518-011-9251-9 unknown Ornthammarath, Teraphan and Douglas, John <https://strathprints.strath.ac.uk/view/author/1027421.html> and Sigbjörnsson, Ragnar and Lai, Carlo Giovanni (2011 <https://strathprints.strath.ac.uk/view/year/2011.html>) Assessment of ground motion variability and its effects on seismic hazard analysis : a case study for iceland. Bulletin of Earthquake Engineering <https://strathprints.strath.ac.uk/view/publications/Bulletin_of_Earthquake_Engineering.html>, 9 (4). pp. 931-953. ISSN 1573-1456 Geology Engineering (General). Civil engineering (General) Article PeerReviewed 2011 ftustrathclyde https://doi.org/10.1007/s10518-011-9251-9 2024-04-10T01:04:35Z Probabilistic seismic hazard analysis (PSHA) generally relies on the basic assumption that ground motion prediction equations (GMPEs) developed for other similar tectonic regions can be adopted in the considered area. This implies that observed ground motion and its variability at considered sites could be modelled by the selected GMPEs. Until now ground-motion variability has been taken into account in PSHA by integrating over the standard deviation reported in GMPEs, which significantly affects estimated ground motions, especially at very low probabilities of exceedance. To provide insight on this issue, ground-motion variability in the South Iceland Seismic Zone (SISZ), where many ground-motion records are available, is assessed. Three statistical methods are applied to separate the aleatory variability into source (inter-event), site (inter-site) and residual (intra-event and intra-site) components. Furthermore, the current PSHA procedure that makes the ergodic assumption of equality between spatially and temporal variability is examined. In contrast to the ergodic assumption, several recent studies show that the observed ground-motion variability at an individual location is lower than that implied by the standard deviation of a GMPE. This could imply a mishandling of aleatory uncertainty in PSHA by ignoring spatial variability and by mixing aleatory and epistemic uncertainties in the computation of sigma. Station correction coefficients are introduced in order to capture site effects at different stations. The introduction of the non-ergodic assumption in PSHA leads to larger epistemic uncertainty, although this is not the same as traditional epistemic uncertainty modelled using different GMPEs. The epistemic uncertainty due to the site correction coefficients (i.e. mean residuals) could be better constrained for future events if more information regarding the characteristics of these seismic sources and path dependence could be obtained. Article in Journal/Newspaper Iceland University of Strathclyde Glasgow: Strathprints Bulletin of Earthquake Engineering 9 4 931 953 |
institution |
Open Polar |
collection |
University of Strathclyde Glasgow: Strathprints |
op_collection_id |
ftustrathclyde |
language |
unknown |
topic |
Geology Engineering (General). Civil engineering (General) |
spellingShingle |
Geology Engineering (General). Civil engineering (General) Ornthammarath, Teraphan Douglas, John Sigbjörnsson, Ragnar Lai, Carlo Giovanni Assessment of ground motion variability and its effects on seismic hazard analysis : a case study for iceland |
topic_facet |
Geology Engineering (General). Civil engineering (General) |
description |
Probabilistic seismic hazard analysis (PSHA) generally relies on the basic assumption that ground motion prediction equations (GMPEs) developed for other similar tectonic regions can be adopted in the considered area. This implies that observed ground motion and its variability at considered sites could be modelled by the selected GMPEs. Until now ground-motion variability has been taken into account in PSHA by integrating over the standard deviation reported in GMPEs, which significantly affects estimated ground motions, especially at very low probabilities of exceedance. To provide insight on this issue, ground-motion variability in the South Iceland Seismic Zone (SISZ), where many ground-motion records are available, is assessed. Three statistical methods are applied to separate the aleatory variability into source (inter-event), site (inter-site) and residual (intra-event and intra-site) components. Furthermore, the current PSHA procedure that makes the ergodic assumption of equality between spatially and temporal variability is examined. In contrast to the ergodic assumption, several recent studies show that the observed ground-motion variability at an individual location is lower than that implied by the standard deviation of a GMPE. This could imply a mishandling of aleatory uncertainty in PSHA by ignoring spatial variability and by mixing aleatory and epistemic uncertainties in the computation of sigma. Station correction coefficients are introduced in order to capture site effects at different stations. The introduction of the non-ergodic assumption in PSHA leads to larger epistemic uncertainty, although this is not the same as traditional epistemic uncertainty modelled using different GMPEs. The epistemic uncertainty due to the site correction coefficients (i.e. mean residuals) could be better constrained for future events if more information regarding the characteristics of these seismic sources and path dependence could be obtained. |
format |
Article in Journal/Newspaper |
author |
Ornthammarath, Teraphan Douglas, John Sigbjörnsson, Ragnar Lai, Carlo Giovanni |
author_facet |
Ornthammarath, Teraphan Douglas, John Sigbjörnsson, Ragnar Lai, Carlo Giovanni |
author_sort |
Ornthammarath, Teraphan |
title |
Assessment of ground motion variability and its effects on seismic hazard analysis : a case study for iceland |
title_short |
Assessment of ground motion variability and its effects on seismic hazard analysis : a case study for iceland |
title_full |
Assessment of ground motion variability and its effects on seismic hazard analysis : a case study for iceland |
title_fullStr |
Assessment of ground motion variability and its effects on seismic hazard analysis : a case study for iceland |
title_full_unstemmed |
Assessment of ground motion variability and its effects on seismic hazard analysis : a case study for iceland |
title_sort |
assessment of ground motion variability and its effects on seismic hazard analysis : a case study for iceland |
publishDate |
2011 |
url |
https://strathprints.strath.ac.uk/53617/ https://doi.org/10.1007/s10518-011-9251-9 |
genre |
Iceland |
genre_facet |
Iceland |
op_relation |
Ornthammarath, Teraphan and Douglas, John <https://strathprints.strath.ac.uk/view/author/1027421.html> and Sigbjörnsson, Ragnar and Lai, Carlo Giovanni (2011 <https://strathprints.strath.ac.uk/view/year/2011.html>) Assessment of ground motion variability and its effects on seismic hazard analysis : a case study for iceland. Bulletin of Earthquake Engineering <https://strathprints.strath.ac.uk/view/publications/Bulletin_of_Earthquake_Engineering.html>, 9 (4). pp. 931-953. ISSN 1573-1456 |
op_doi |
https://doi.org/10.1007/s10518-011-9251-9 |
container_title |
Bulletin of Earthquake Engineering |
container_volume |
9 |
container_issue |
4 |
container_start_page |
931 |
op_container_end_page |
953 |
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1797585442633154560 |