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RSS feed for Figshare Profile John DouglasNomogram for the minimum usable period of earthquake strong ground motions accounting for base slab averaging at strong-motion stations
https://figshare.com/articles/figure/Nomogram_for_the_minimum_usable_period_of_earthquake_strong_ground_motions_using_the_equations_of_Stewart_2000_for_soil_structure_interaction_at_strong-motion_stations/14095669
Stewart (Earthquake Spectra, 2000) presents an equation (equation 4) to estimate the minimum spectral period that would not be affected from soil-structure interaction effects (base slab averaging) at strong-motion stations of equivalent radius, r, with an incoherence parameter for the incoming waves, kappa. The empirical relationship of Kim and Stewart (Journal of Geotechnical and Geoenvironmental Engineering, 2003) between kappa and Vs has been used here to allow this equation to be evaluated knowing only Vs. This equation is represented here as a Type 4 nomogram using the software pynomo.An example is shown using an isopleth for Vs=400m/s and r=5m which gives a minimum usable period of 0.1s.Seismology and Seismic Exploration, Earthquake Engineering2021-02-23 09:52:02Animation of the history of ground motion prediction equations
https://figshare.com/articles/figure/Animation_of_the_history_of_ground_motion_prediction_equations/5058493
Animation showing the rough location for which published ground motion prediction equations were derived against time (each dot corresponds to a single model). Also shown are the cumulative total of models and a list of some of the key publications (last updated: 14 January 2021).Seismology and Seismic Exploration, Earthquake Engineering2021-01-14 15:31:47Graph of ground motion predictions versus publication date
https://figshare.com/articles/figure/Graph_of_ground_motion_predictions_versus_publication_date/5058340
Graph showing the number of ground motion prediction equations published in each year (columns) and the cumulative total of equations (lines). It is also shown on www.gmpe.org.uk. Last updated: 14 January 2021Seismology and Seismic Exploration, Earthquake Engineering2021-01-14 15:30:34Cost-benefit analysis for Operational Earthquake Forecasting using probabilistic seismic hazard assessment for circular area using Excel
https://figshare.com/articles/dataset/Cost-benefit_analysis_for_Operational_Earthquake_Forecasting_using_probabilistic_seismic_hazard_assessment_for_circular_area_using_Excel/12961664
This is a Microsoft Excel spreadsheet to under cost-benefit analyses for operational earthquake forecasting actions based on the probabilistic
seismic hazard for a circular area of uniform seismicity characterised by a
Gutenberg-Richter relation and using a simple ground motion prediction
equation (Cauzzi and Faccoli, 2008). The circular area is split into 10 annuli to integrate over the area.
The hazard curve is computed as well as various associated parameters (e.g.
mean disaggregated scenario).The numbers in yellow can be changed to assess the benefit-to-cost ratio for different actions.
It is an extension of my spreadsheet for PSHA for a circular source, which
is also available here.For more details please see the article by Douglas and Azarbakht (2020).Seismology and Seismic Exploration, Decision Making, Earthquake Engineering2020-09-16 08:40:10Nomogram for cost-benefit analysis of Operational Earthquake Forecasting
https://figshare.com/articles/figure/Nomogram_for_cost-benefit_analysis_of_Operational_Earthquake_Forecasting/12961634
The nomogram developed for cost–benefit analysis of Operational Earthquake Forecasting actions. An isopleth (red dotted line) is shown for an example application for a threshold PGA of 0.05 g (left-most axis), a daily probability of an earthquake of magnitude ≥ 4 of 4%, a week-long (7 days) OEF action and a L/C ratio of 1000 leading to R = 3.5 (right-most axis).It was drawn using a type 3 nomogram and the software Pynomo. See open-access article by Douglas and Azarbakht (2020) for more details.Seismology and Seismic Exploration, Decision Making, Earthquake Engineering2020-09-16 08:26:03Example nomogram for earthquake vulnerability and damage assessment using vulnerability index approach
https://figshare.com/articles/figure/Example_nomogram_for_earthquake_vulnerability_and_damage_assessment_using_vulnerability_index_approach/11882598
An example nomogram for use firstly (left-hand side of the diagram) to assess the vulnerability of a masonry building to earthquake ground motions using the RISK-UE level 1 approach (only some of the vulnerability modifiers are included) and then to use the assessed vulnerability index and the expected earthquake macroseismic intensity to estimate the expected damage distribution in terms of the EMS98 damage scale. Details of the Level 1 approach are given in Milutinovic and Trendafiloski (2003).An example is shown using an isopleth (dashed blue line) for a medium height M3.2 type building (Masonry vaults) that is badly maintained undergoing an earthquake of macroseismic intensity (EMS98) VII (7). The distribution of damage states is shown by the column of the stacked bar-chart on the right-hand side that is intersected by the vertical blue dashed line.The left-hand side of the diagram is a type 3 nomogram produced using the pynomo software, whereas the right-hand side is a normal graph underlaid by a binomial distribution.Seismology and Seismic Exploration, Earthquake Engineering2020-02-21 16:37:00Probabilistic seismic hazard assessment for circular area using Excel
https://figshare.com/articles/dataset/Probabilistic_seismic_hazard_assessment_for_circular_area_using_Excel/11726631
This is a Microsoft Excel spreadsheet to compute the probabilistic seismic hazard for a circular area of uniform seismicity characterised by a Gutenberg-Richter relation and using a simple ground motion prediction equation. The circular area is split into 10 annuli to integrate over the area. The hazard curve is computed as well as various associated parameters (e.g. mean disaggregated scenario).It is an extension of my spreadsheet for PSHA for a point source, which is also available here.Probability, Seismology and Seismic Exploration, Earthquake Engineering2020-01-26 10:57:45Probabilistic Seismic Hazard Assessment by Excel
https://figshare.com/articles/dataset/Probabilistic_Seismic_Hazard_Assessment_by_Excel/5053936
This is a simple Excel spreadsheet that computes the seismic hazard curve for a point source and an untruncated Gutenberg-Richter magnitude-frequency relation.Updated on 24th January 2020 to include calculation of the magnitude of the disaggregated mean scenario and addition of some extra informationProbability, Seismology and Seismic Exploration, Earthquake Engineering2020-01-24 17:05:49Excel spreadsheet alternative to the nomogram to help explain probabilistic seismic hazard
https://figshare.com/articles/dataset/Excel_spreadsheet_alternative_to_the_nomogram_to_help_explain_probabilistic_seismic_hazard/10274078
An alternative in the form of an Excel spreadsheet to the nomogram to help explain probabilistic seismic hazard, which is also available on figshare. See the description of that nomogram for details and the associated journal article: https://link.springer.com/article/10.1007/s10950-019-09885-4.Seismology and Seismic Exploration, Earthquake Engineering, Visual Communication Design (incl. Graphic Design)2019-11-08 14:19:49Nomogram to help explain probabilistic seismic hazard
https://figshare.com/articles/figure/Nomogram_to_help_explain_probabilistic_seismic_hazard/10274021
Nomogram summarising the results of simple probabilistic seismic hazard assessments (PSHAs) for peak ground acceleration and elastic response spectral acceleration for a structural period of 1s and return periods from 100 to 2500 years, where the effects of the activity rate and the slope of the Gutenberg-Richter relation are captured.To read the nomogram, connect two of the variables (e.g. N(M0 = 4.5) and return period) with a straight line and where it crosses the axis for the third variable that is its value (e.g. PGA). Example calculations are shown using red lines for a return period of 475 years and an activity rate of N(M0 = 4.5) = 0.1 (a moderate seismicity zone).It is a Type 10 nomogram drawn using the pynomo program.For details see the Open Access article: https://link.springer.com/article/10.1007/s10950-019-09885-4 where this nomogram is presented.An alternate to this nomogram in the form of an Excel spreadsheet is also available on figshare. Seismology and Seismic Exploration, Earthquake Engineering, Visual Communication Design (incl. Graphic Design)2019-11-08 14:09:54Nomogram to estimate the impact of epistemic uncertainty in the median earthquake ground motion on the hazard curve
https://figshare.com/articles/figure/Nomogram_to_estimate_the_impact_of_epistemic_uncertainty_in_the_median_earthquake_ground_motion_on_the_hazard_curve/9825047
Nomogram showing the effect of epistemic uncertainty in the earthquake ground motion model on the seismic hazard. The nomogram is developed using the approximate result of Toro (2006) connecting R, the ratio of the mean to median ground motion (e.g. peak ground acceleration) for a given annual frequency of exceedance, k, the slope of the hazard curve in log-log space, and sigma_mu, the lognormal epistemic uncertainty in the median ground motion (expressed as the standard deviation of the predicted median ground motions for a given magnitude and distance).The isopleths show two example calculations using this graph by connecting with straight lines choices of k and sigma_mu and reading off the value of R.See Douglas (Capturing Geographically-Varying Uncertainty in Earthquake Ground Motion Models or What We Think We Know May Change, doi: 10.1007/978-3-319-75741-4_6, 2018) for more details. The equation captured in this nomogram is Equation 6.1 of this paper (also see Table 6.1 of the same paper).This nomogram was produced using Pynomo using a Type 2 equation.Seismology and Seismic Exploration, Earthquake Engineering2019-09-13 15:11:26Nomogram of use for risk-targeting in the context of seismic design
https://figshare.com/articles/figure/Nomogram_of_use_for_risk-targeting_in_the_context_of_seismic_design/8099903
Nomogram showing the sensitivity of the ratio lambda_ref/lambda_c to the values of X, beta and k1 within the context of risk-targeted seismic design. The isopleths show two example calculations using this graph by connecting with straight lines choices of lambda_ref/lambda_c and X and reading off the value of k1.Where:lambda_ref is the mean annual frequency of exceedance of S_a^reflambda_c is the mean annual frequency of collapseX is the probability of collapsebeta is Standard deviation of S_a^ck1 is the slope of the seismic hazard curve in log-log spaceS_a^c is the pseudo-spectral acceleration at collapseS_a^ref is the pseudo-spectral acceleration corresponding to refSee Gkimprixis et al. (Comparison of methods to develop risk-targeted seismic design maps, doi: 10.1007/s10518-019-00629-w, 2019) for more details. This figure is Figure 11 of that open-access paper.This nomogram was produced using Pynomo using Type 10 equations for three values of beta.Seismology and Seismic Exploration, Earthquake Engineering2019-05-09 08:37:12Results of backbone scaling surveys
https://figshare.com/articles/journal_contribution/Results_of_backbone_scaling_survey_at_16ECEE/6587699
Results of online surveys conducted at the 16th European Conference on Earthquake Engineering and the Journées Luxembourgeoises de Géodynamique
2019/SERA meeting on the backbone scaling factors to be used.Seismology and Seismic Exploration, Earthquake Engineering2019-03-28 09:52:14Nomogram for the Gutenberg-Richter earthquake occurence relation
https://figshare.com/articles/figure/Nomogram_for_the_Gutenberg-Richter_earthquake_occurence_relation/7844750
A nomogram for the Gutenberg-Richter relation: log N=a-b M, where N is the number of earthquakes, M is the magnitude and a and b are empirical coefficients (b is generally around 1 for most regions and datasets).Draw a straight line from one axis and when it hits the diagonal axis for the required 'a' value travel perpendicular until the intersection with the other axis. For example, if you want to see how many magnitude 6 earthquakes there are assuming a=4 and b=1, go vertically from M=6 on the x axis until the intersection with the a=4 diagonal line and then read across to find N=0.01. Created using pynomo using a type 5 nomogram.Geophysics, Seismology and Seismic Exploration2019-03-14 14:39:21Nomogram connecting fundamental period of a single soil layer, the depth of the layer and the shear-wave velocity of the layer
https://figshare.com/articles/dataset/Nomogram_connecting_fundamental_period_of_a_single_soil_layer_the_depth_of_the_layer_and_the_shear-wave_velocity_of_the_layer/7825037
A nomogram connecting the fundamental period, T, of a soil layer of shear-wave velocity, Vs, and depth, H, using the formula T=4H/Vs. Also given is the fundamental frequency, f, (1/T) and the shear-modulus assuming a density (rho) of 2000kg/m^3, i.e. G=rho Vs^2 (results would be similar for the normal range of density, about 1800 to 2500kg/m^3).Connect up two axes and where the line crosses the third axis is the result. An example line is shown for a fundamental period of 0.5s and a depth of 30m, which gives a shear-wave velocity of 240m/s.Created using pynomo using a type 1 nomogram with type 8 nomograms for each of the principal axesGeophysics, Seismology and Seismic Exploration, Earthquake Engineering2019-03-11 11:56:01Nomogram connecting source radius, stress drop, corner frequency, and seismic moment/magnitude
https://figshare.com/articles/dataset/Nomogram_connecting_source_radius_stress_drop_corner_frequency_and_seismic_moment_magnitude/7820126
A nomogram similar to that published by M. Mahdyiar (1987) connecting source radius, stress drop, corner frequency, and seismic moment/magnitude assuming the Brune (1970, 1971) source model and a shear-wave velocity at the source of 3.5km/s (the results would be similar for the normal range of shear-wave velocity, about 3 to 4km/s).Connect up two axes and where the line crosses the third axis is the result. An example line is shown for a stress drop (delta sigma) of 10bars and a moment magnitude (M) of 6, which gives a corner frequency (f0) of about 0.15Hz and a source radius (r) of 8km.Created using pynomo using a type 1 nomogram with type 8 nomograms for each of the principal axesGeophysics, Seismology and Seismic Exploration2019-03-11 11:44:57Nomogram for the rock GMPE of Ambraseys et al. (1996)
https://figshare.com/articles/figure/Nomogram_for_the_rock_PGA_GMPE_of_Ambraseys_et_al_1996_/7111535
A nomogram to evaluate the ground motion prediction equation of Ambraseys et al. (1996) for the peak ground acceleration (PGA) and response spectral acceleration (SA) at 1s on rock. Connect any two variables with a straight line (e.g. magnitude and distance) to find the third (e.g. PGA or SA). Blue values give the 16% percentile PGA or SA (-1 sigma/standard deviation), red values give the median PGA or SA and black values give the 84% percentile PGA or SA (+1 sigma/standard deviation).The use of this nomogram is illustrated for a magnitude (Ms) 6.5 earthquake at a Joyner-Boore distance of 20km by the dashed black line.Because of slight differences in the pseudo-depth coefficient for the equations for PGA and SA(1s) the SA estimates for very short distances (<5km) are slightly incorrect.Not that the GMPE of Ambraseys et al. (1996) is used for illustration purposes only and because it can be shown on a simple nomogram. There are many more modern GMPEs that could be preferred for actual seismic hazard assessments.Seismology and Seismic Exploration, Earthquake Engineering, Civil Engineering not elsewhere classified2018-09-26 16:17:32Presentation of 16ECEE Theme Lecture
https://figshare.com/articles/presentation/Presentation_of_16ECEE_Theme_Lecture/6668309
The Powerpoint presentation used for my Theme Lecture at the 16th European Conference on Earthquake Engineering in Thessaloniki, Greece, on 18th June 2018. For more information please refer to the publications below.Seismology and Seismic Exploration, Earthquake Engineering2018-06-25 10:26:06Explanation of partially non-ergodic probabilistic seismic hazard assessment
https://figshare.com/articles/presentation/Explanation_of_partially_non-ergodic_probabilistic_seismic_hazard_assessment/6449807
A set of three slides to explain partially non-ergodic probabilistic seismic hazard assessment. I have used them on various occassions over the past few years. Seismology and Seismic Exploration, Earthquake Engineering, Civil Engineering not elsewhere classified2018-06-06 10:27:30Have strong-motion data a nationality?
https://figshare.com/articles/presentation/Have_strong-motion_data_a_nationality_/6449798
A slide used to pose the question of regional dependency in strong-motion data and hence for empiricial ground-motion prediction. I have used in on various occassions over the past decade.Seismology and Seismic Exploration, Earthquake Engineering, Civil Engineering not elsewhere classified2018-06-06 10:20:06Method to create risk-targeted seismic design maps
https://figshare.com/articles/presentation/Method_to_create_risk-targeted_seismic_design_maps/6449792
An animated slide explaining the steps to create risk-targeted seismic design maps by combining seismic hazard and fragility curves. I have used this slide on various occassions to explain this technique. For more details see the recent review article by Douglas and Gkimprixis (2018) Seismology and Seismic Exploration, Earthquake Engineering, Civil Engineering not elsewhere classified2018-06-06 10:11:48Distribution of strong-motion data in Europe and GMPE development
https://figshare.com/articles/presentation/Distribution_of_strong-motion_data_in_Europe_and_GMPE_development/5132053
Animated slide showing the distribution of strong-motion data in Europe (from the RESORCE database), the areas of high and low hazard (0.1g PGA at 475-year return period) and the possibility of GMPE development using local data. This slide was first show at the symposium in London in memory of Prof. Ambraseys and it has been shown a number of time since.Seismology and Seismic Exploration, Natural Hazards, Earthquake Engineering2017-06-21 08:00:11Transfer of aleatory to epistemic uncertainty within earthquake ground motion prediction
https://figshare.com/articles/presentation/Transfer_of_aleatory_to_epistemic_uncertainty_within_earthquake_ground_motion_prediction/5121916
Animated slide showing how aleatory variability transfers to epistemic uncertainty for increasingly sophisticated procedures for earthquake ground motion prediction. This slide was originally developed for my theme lecture but I have shown it since in various presentations:Douglas, J. (2014), Fifty years of ground-motion models, Second European Conference on Earthquake Engineering and Seismology, Istanbul, Turkey, 24th–29th August.Seismology and Seismic Exploration, Natural Hazards, Earthquake Engineering2017-06-21 07:52:32Explanation of earthquake response spectra
https://figshare.com/articles/presentation/Explanation_of_earthquake_response_spectra/5121913
This is a set of five slides explaining how earthquake response spectra are derived from strong-motion records and simple models of structures and their purpose within seismic design and assessment. It dates from about 2002 and I have used it in various introductory lectures on engineering seismology.Seismology and Seismic Exploration, Earthquake Engineering2017-06-20 09:56:49Probabilistic seismic hazard assessment "Cake"
https://figshare.com/articles/presentation/Probabilistic_seismic_hazard_assessment_Cake_/5053945
This slide explains the different ways that the results of a probabilistic seismic hazard assessment can be presented. The diagram was developed in SHARE but never published.Seismology and Seismic Exploration, Earthquake Engineering2017-05-31 16:18:48Time-Dependent_Risk_Assessment
https://figshare.com/articles/presentation/Time-Dependent_Risk_Assessment/5053933
This is a slide showing the idea behind risk-dependent risk assessment for earthquakes. It was created in 2010 for the REAKT project proposal but it was never official published.Seismology and Seismic Exploration, Earthquake Engineering2017-05-31 16:06:18Introduction_to_Engineering_Seismology_Earthquake_Engineering.pptx
https://figshare.com/articles/presentation/Introduction_to_Engineering_Seismology_Earthquake_Engineering_pptx/5047876
Introductory slide to how seismic risk is calculated. It shows how it requires a combination of engineering seismology and earthquake engineering.Geology, Geophysics, Seismology and Seismic Exploration, Natural Hazards, Civil Geotechnical Engineering, Earthquake Engineering2017-05-29 09:51:13