Nico is a Research Civil Engineer in the Earthquake Hazards Program.
Science and Products
Operational Earthquake Forecasting – Implementing a Real-Time System for California
It is well know that every earthquake can spawn others (e.g., as aftershocks), and that such triggered events can be large and damaging, as recently demonstrated by L’Aquila, Italy and Christchurch, New Zealand earthquakes. In spite of being an explicit USGS strategic-action priority (http://pubs.usgs.gov/of/2012/1088; page 32), the USGS currently lacks an automated system with which to forecast s...
Gridded earthquake ground motions for the 2023 AASHTO Design Specifications
For designing bridges to safely resist earthquakes, the 2023 editions of the AASHTO (1) Guide Specifications for LRFD Seismic Bridge Design, (2) LRFD Bridge Design Specifications, and (3) Guide Specifications for Seismic Isolation Design provide risk-targeted design ground motions via this data release and the corresponding USGS Seismic Design Web Services (listed below). The web services spatiall
Shakemap earthquake scenario: Building Seismic Safety Council 2014 Event Set (BSSC2014)
This is a catalog of earthquake scenarios, represented as ShakeMaps. A ShakeMap is a USGS product that facilitates communication of earthquake effects by portraying a map of the severity of shaking. Maps of shaking severity are provided in terms of macroseismic intensity, peak ground acceleration, peak ground velocity, and spectral accelerations (at 0.3, 1.0 and 3 sec oscillator periods).
Filter Total Items: 50
Evolution of design ground motions in California: NEHRP 2009 to 2020
The U.S. Geological Survey (USGS) National Seismic Hazard Model (NSHM) is used in construction codes, such as the National Earthquake Hazard Reduction Program (NEHRP) Provisions, to develop ground motions for structural and geotechnical design. When the NSHM is updated (e.g. changes to its earthquake rupture forecast or ground motion models), or the manner in which it is implemented in constructio
Earthquake early warning: Toward modeling optimal protective actions
Over the past few years early earthquake warning systems have been incorporated into earthquake preparation efforts in many locations around the globe. These systems provide an excellent opportunity for advanced warning of ground shaking and other hazards associated with earthquakes. This study aims to optimize this advanced warning for individuals inside a building when the alert is received. A c
Open-source resources help navigate new IM regulations
The revision of federal safety regulations for integrity management of gas transmission pipelines to require explicit consideration of seismicity increases the importance for operators to be actively identifying high-consequence areas (HCAs), evaluating seismic-related threats, and choosing a risk model to support risk management decisions. To ensure equal access to information by both operators a
Multi-period response spectra
Multi-period response spectra (MPRS) are incorporated in the development of seismic design ground motions in the 2020 edition of the NEHRP Recommended Seismic Provisions for New Buildings and Other Structures (2020 NEHRP Provisions) and are approved for adoption in the American Society of Civil Engineers (ASCE) Standard, Minimum Design Loads and Associated Criteria for Buildings and Other Structur
Earthquake risk of gas pipelines in the conterminous United States and its sources of uncertainty
Relatively little research has been conducted to systematically quantify the nationwide earthquake risk of gas pipelines in the US; simultaneously, national guidance is limited for operators across the country to consistently evaluate the earthquake risk of their assets. Furthermore, many challenges and uncertainties exist in a comprehensive seismic risk assessment of gas pipelines. As a first sta
Hazard-consistent seismic losses and collapse capacities for light-frame wood buildings in California and Cascadia
We evaluate the seismic performance of modern seismically designed wood light-frame (WLF) buildings, considering regional seismic hazard characteristics that influence ground motion duration and frequency content and, thus, seismic risk. Results show that WLF building response correlates strongly with ground motion spectral shape but weakly with duration. Due to the flatter spectral shape of groun
The seismic hazard implications of declustering and poisson assumptions inferred from a fully time‐dependent model
We use the Third Uniform California Earthquake Rupture Forecast (UCERF3) epidemic‐type aftershock sequence (ETAS) model (UCERF3‐ETAS) to evaluate the effects of declustering and Poisson assumptions on seismic hazard estimates. Although declustering is necessary to infer the long‐term spatial distribution of earthquake rates, the question is whether it is also necessary to honor the Poisson assumpt
The 2018 update of the US National Seismic Hazard Model: Ground motion models in the western US
The U.S. Geological Survey (USGS) National Seismic Hazard Model (NSHM) is the scientific foundation of seismic design regulations in the United States and is regularly updated to consider the best available science and data. The 2018 update of the conterminous U.S. NSHM includes significant changes to the underlying ground motion models (GMMs), most of which are necessary to enable the new multi-p
The 2018 update of the US National Seismic Hazard Model: Ground motion models in the central and eastern US
The United States Geological Survey (USGS) National Seismic Hazard Model (NSHM) is the scientific foundation of seismic design regulations in the United States and is regularly updated to consider the best available science and data. The 2018 update of the conterminous US NSHM includes major changes to the underlying ground motion models (GMMs). Most of the changes are motivated by the new multi-p
The 2018 update of the US National Seismic Hazard Model: Where, why, and how much probabilistic ground motion maps changed
The 2018 US Geological Survey National Seismic Hazard Model (NSHM) incorporates new data and updated science to improve the underlying earthquake and ground motion forecasts for the conterminous United States. The NSHM considers many new data and component input models: (1) new earthquakes between 2013 and 2017 and updated earthquake magnitudes for some earlier earthquakes; (2) two updated smoothe
A subset of CyberShake ground-motion time series for response-history analysis
This manuscript describes a subset of CyberShake numerically simulated ground motions that were selected and vetted for use in engineering response-history analyses. Ground motions were selected that have seismological properties and response spectra representative of conditions in the Los Angeles area, based on disaggregation of seismic hazard. Ground motions were selected from millions of availa
Tall building performance-based seismic design using SCEC broadband platform site-specific ground motion simulations
The scarcity of strong ground motion records presents a challenge for making reliable performance assessments of tall buildings whose seismic design is controlled by large-magnitude and close-distance earthquakes. This challenge can be addressed using broadband ground-motion simulation methods to generate records with site-specific characteristics of large-magnitude events. In this paper, simulate
Risk-Targeted Ground Motion Calculator
This web application can be used to calculate risk-targeted ground motion values in accordance with “Method 2” of 2010 ASCE 7 Standard Section 21.2.1.2.
Science and Products
- Science
Operational Earthquake Forecasting – Implementing a Real-Time System for California
It is well know that every earthquake can spawn others (e.g., as aftershocks), and that such triggered events can be large and damaging, as recently demonstrated by L’Aquila, Italy and Christchurch, New Zealand earthquakes. In spite of being an explicit USGS strategic-action priority (http://pubs.usgs.gov/of/2012/1088; page 32), the USGS currently lacks an automated system with which to forecast s... - Data
Gridded earthquake ground motions for the 2023 AASHTO Design Specifications
For designing bridges to safely resist earthquakes, the 2023 editions of the AASHTO (1) Guide Specifications for LRFD Seismic Bridge Design, (2) LRFD Bridge Design Specifications, and (3) Guide Specifications for Seismic Isolation Design provide risk-targeted design ground motions via this data release and the corresponding USGS Seismic Design Web Services (listed below). The web services spatiallShakemap earthquake scenario: Building Seismic Safety Council 2014 Event Set (BSSC2014)
This is a catalog of earthquake scenarios, represented as ShakeMaps. A ShakeMap is a USGS product that facilitates communication of earthquake effects by portraying a map of the severity of shaking. Maps of shaking severity are provided in terms of macroseismic intensity, peak ground acceleration, peak ground velocity, and spectral accelerations (at 0.3, 1.0 and 3 sec oscillator periods). - Publications
Filter Total Items: 50
Evolution of design ground motions in California: NEHRP 2009 to 2020
The U.S. Geological Survey (USGS) National Seismic Hazard Model (NSHM) is used in construction codes, such as the National Earthquake Hazard Reduction Program (NEHRP) Provisions, to develop ground motions for structural and geotechnical design. When the NSHM is updated (e.g. changes to its earthquake rupture forecast or ground motion models), or the manner in which it is implemented in constructioEarthquake early warning: Toward modeling optimal protective actions
Over the past few years early earthquake warning systems have been incorporated into earthquake preparation efforts in many locations around the globe. These systems provide an excellent opportunity for advanced warning of ground shaking and other hazards associated with earthquakes. This study aims to optimize this advanced warning for individuals inside a building when the alert is received. A cOpen-source resources help navigate new IM regulations
The revision of federal safety regulations for integrity management of gas transmission pipelines to require explicit consideration of seismicity increases the importance for operators to be actively identifying high-consequence areas (HCAs), evaluating seismic-related threats, and choosing a risk model to support risk management decisions. To ensure equal access to information by both operators aMulti-period response spectra
Multi-period response spectra (MPRS) are incorporated in the development of seismic design ground motions in the 2020 edition of the NEHRP Recommended Seismic Provisions for New Buildings and Other Structures (2020 NEHRP Provisions) and are approved for adoption in the American Society of Civil Engineers (ASCE) Standard, Minimum Design Loads and Associated Criteria for Buildings and Other StructurEarthquake risk of gas pipelines in the conterminous United States and its sources of uncertainty
Relatively little research has been conducted to systematically quantify the nationwide earthquake risk of gas pipelines in the US; simultaneously, national guidance is limited for operators across the country to consistently evaluate the earthquake risk of their assets. Furthermore, many challenges and uncertainties exist in a comprehensive seismic risk assessment of gas pipelines. As a first staHazard-consistent seismic losses and collapse capacities for light-frame wood buildings in California and Cascadia
We evaluate the seismic performance of modern seismically designed wood light-frame (WLF) buildings, considering regional seismic hazard characteristics that influence ground motion duration and frequency content and, thus, seismic risk. Results show that WLF building response correlates strongly with ground motion spectral shape but weakly with duration. Due to the flatter spectral shape of grounThe seismic hazard implications of declustering and poisson assumptions inferred from a fully time‐dependent model
We use the Third Uniform California Earthquake Rupture Forecast (UCERF3) epidemic‐type aftershock sequence (ETAS) model (UCERF3‐ETAS) to evaluate the effects of declustering and Poisson assumptions on seismic hazard estimates. Although declustering is necessary to infer the long‐term spatial distribution of earthquake rates, the question is whether it is also necessary to honor the Poisson assumptThe 2018 update of the US National Seismic Hazard Model: Ground motion models in the western US
The U.S. Geological Survey (USGS) National Seismic Hazard Model (NSHM) is the scientific foundation of seismic design regulations in the United States and is regularly updated to consider the best available science and data. The 2018 update of the conterminous U.S. NSHM includes significant changes to the underlying ground motion models (GMMs), most of which are necessary to enable the new multi-pThe 2018 update of the US National Seismic Hazard Model: Ground motion models in the central and eastern US
The United States Geological Survey (USGS) National Seismic Hazard Model (NSHM) is the scientific foundation of seismic design regulations in the United States and is regularly updated to consider the best available science and data. The 2018 update of the conterminous US NSHM includes major changes to the underlying ground motion models (GMMs). Most of the changes are motivated by the new multi-pThe 2018 update of the US National Seismic Hazard Model: Where, why, and how much probabilistic ground motion maps changed
The 2018 US Geological Survey National Seismic Hazard Model (NSHM) incorporates new data and updated science to improve the underlying earthquake and ground motion forecasts for the conterminous United States. The NSHM considers many new data and component input models: (1) new earthquakes between 2013 and 2017 and updated earthquake magnitudes for some earlier earthquakes; (2) two updated smootheA subset of CyberShake ground-motion time series for response-history analysis
This manuscript describes a subset of CyberShake numerically simulated ground motions that were selected and vetted for use in engineering response-history analyses. Ground motions were selected that have seismological properties and response spectra representative of conditions in the Los Angeles area, based on disaggregation of seismic hazard. Ground motions were selected from millions of availaTall building performance-based seismic design using SCEC broadband platform site-specific ground motion simulations
The scarcity of strong ground motion records presents a challenge for making reliable performance assessments of tall buildings whose seismic design is controlled by large-magnitude and close-distance earthquakes. This challenge can be addressed using broadband ground-motion simulation methods to generate records with site-specific characteristics of large-magnitude events. In this paper, simulate - Software
Risk-Targeted Ground Motion Calculator
This web application can be used to calculate risk-targeted ground motion values in accordance with “Method 2” of 2010 ASCE 7 Standard Section 21.2.1.2.