relation: https://episodesplatform.eu/eprints/1437/ title: Recalculated probability ofM≥ 7 earthquakes beneath the Sea of Marmara, Turkey creator: Parsons, Tom subject: Method and procesing description: New earthquake probability calculations are made for the Sea of Marmara region and the city of Istanbul, providing a revised forecast and an evaluation of time-dependent interaction techniques. Calculations incorporate newly obtained bathymetric images of the North Anatolian fault beneath the Sea of Marmara [Le Pichon et al., 2001; Armijo et al., 2002]. Newly interpreted fault segmentation enables an improved regional A.D. 1500–2000 earthquake catalog and interevent model, which form the basis for time-dependent probability estimates. Calculations presented here also employ detailed models of coseismic and postseismic slip associated with the 17 August 1999 M = 7.4 Izmit earthquake to investigate effects of stress transfer on seismic hazard. Probability changes caused by the 1999 shock depend on Marmara Sea fault-stressing rates, which are calculated with a new finite element model. The combined 2004–2034 regional Poisson probability of M ≥ 7 earthquakes is ∼38%, the regional time-dependent probability is 44 ± 18%, and incorporation of stress transfer raises it to 53 ± 18%. The most important effect of adding time dependence and stress transfer to the calculations is an increase in the 30 year probability of a M ≥ 7 earthquake affecting Istanbul. The 30 year Poisson probability at Istanbul is 21%, and the addition of time dependence and stress transfer raises it to 41 ± 14%. The ranges given on probability values are sensitivities of the calculations to input parameters determined by Monte Carlo analysis; 1000 calculations are made using parameters drawn at random from distributions. Sensitivities are large relative to mean probability values and enhancements caused by stress transfer, reflecting a poor understanding of large-earthquake aperiodicity. publisher: American Geophysical Union date: 2004-05-22 type: Article type: PeerReviewed identifier: Parsons, Tom (2004) Recalculated probability ofM≥ 7 earthquakes beneath the Sea of Marmara, Turkey. Journal of Geophysical Research, 109 (B5). pp. 1-21. DOI: https://doi.org/10.1029/2003JB002667 relation: http://dx.doi.org/10.1029/2003JB002667 relation: doi:10.1029/2003JB002667