Probabilistic Seismic and Liquefaction Hazard Analysis of the Mississippi Embayment Incorporating Nonlinear Effects

Research Article| December 13, 2017 Probabilistic Seismic and Liquefaction Hazard Analysis of the Mississippi Embayment Incorporating Nonlinear Effects Mahesh Singh Dhar; Mahesh Singh Dhar aCenter for Earthquake Research and Information, University of Memphis, Memphis, Tennessee 38152‐3050 U.S.A., msdhar@memphis.educcramer@memphis.edu Search for other works by this author on: GSW Google Scholar Chris H. Cramer Chris H. Cramer aCenter for Earthquake Research and Information, University of Memphis, Memphis, Tennessee 38152‐3050 U.S.A., msdhar@memphis.educcramer@memphis.edu Search for other works by this author on: GSW Google Scholar Author and Article Information Mahesh Singh Dhar aCenter for Earthquake Research and Information, University of Memphis, Memphis, Tennessee 38152‐3050 U.S.A., msdhar@memphis.educcramer@memphis.edu Chris H. Cramer aCenter for Earthquake Research and Information, University of Memphis, Memphis, Tennessee 38152‐3050 U.S.A., msdhar@memphis.educcramer@memphis.edu Publisher: Seismological Society of America First Online: 13 Dec 2017 Online Issn: 1938-2057 Print Issn: 0895-0695 © Seismological Society of America Seismological Research Letters (2018) 89 (1): 253–267. https://doi.org/10.1785/0220170141 Article history First Online: 13 Dec 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Mahesh Singh Dhar, Chris H. Cramer; Probabilistic Seismic and Liquefaction Hazard Analysis of the Mississippi Embayment Incorporating Nonlinear Effects. Seismological Research Letters 2017;; 89 (1): 253–267. doi: https://doi.org/10.1785/0220170141 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietySeismological Research Letters Search Advanced Search ABSTRACT The influence of deep sediment deposits of the Mississippi embayment (ME) on the propagation of seismic waves is poorly understood and remains a major source of uncertainty for site‐response analysis. In this study, we used updated and newly available resources for seismic and liquefaction hazard analyses of the ME. We developed an improved 3D geological model. Additionally, we used surface geological maps to prepare liquefaction hazard maps. Both equivalent linear and nonlinear site‐response codes were used to develop site amplification distributions for use in generating hazard maps. The site amplification distributions are created using the Monte Carlo approach on a 0.1° grid. The 2014 national seismic hazard model and attenuation relations are used to prepare seismic hazard maps. Then, liquefaction hazard maps are generated using available liquefaction probability curves. Equivalent linear response (with increased precision and restricted nonlinear behavior with depth) shows similar hazard for the ME compared with nonlinear analysis (without pore pressure) results. At short periods, nonlinear deamplification dominates the hazard, but at long periods resonance amplification dominates. The liquefaction hazard tends to be high in Holocene and late Pleistocene lowland sediments, even with lowered groundwater levels, and low in Pleistocene loess of the uplands. Considering pore‐pressure effects in nonlinear site‐response analysis at a test site on the lowlands shows amplification of ground motion at short periods. Peak ground acceleration (PGA) estimates from ME liquefaction and modified Mercalli intensity (MMI) observations are in the 0.25g–0.4g range. Our estimated M 7.5 PGA hazard within ∼10 km of the fault can exceed this. Ground‐motion observations from liquefaction sites in New Zealand and Japan support PGAs below 0.4g⁠, except at sites within 20 km exhibiting pore‐pressure‐induced acceleration spikes due to cyclic mobility where PGA ranges from 0.5g to 1.5g⁠. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.