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At least 469 records · Page 26Linked to original sources

USGS2011

Meeting CCS communication challenges head-on: Integrating communications, planning, risk assessment, and project management

The Midwest Geological Sequestration Consortium, Schlumberger Carbon Services, and Archer Daniels Midland has implemented a comprehensive communications plan at the Illinois Basin–Decatur Project (IBDP), a one million metric tonne Carbon Capture and Storage project in Decatur, IL, USA funded by the U.S. Department of Energy’s National Energy Technology Laboratory. The IBDP Communication Plan includes consortium information, funding and disclaimer citations, description of target audiences, media communications guidelines, paper and presentations guidelines, site visit information, crisis communication, on-site photography regulations, and other components. The creation, development, and implementation processes for the IBDP Communication Plan (the Plan) are shared in this paper. New communications challenges, such as how to address add-on research requests, data sharing and management, scope increase, and contract agreements have arisen since the Plan was completed in January 2009, resulting in development of new policies and procedures by project management. Integrating communications planning, risk assessment, and project management ensured that consistent, factual information was developed and incorporated into project planning, and constitutes the basis of public communications. Successful integration has allowed the IBDP to benefit from early identification and mitigation of the potential project risks, which allows more time to effectively deal with unknown and unidentified risks that may arise. Project risks and risks associated with public perception can be managed through careful planning and integration of communication strategies into project management and risk mitigation.

Illinois↗

USGS2009

Cross-comparison of the IRS-P6 AWiFS sensor with the L5 TM, L7 ETM+, & Terra MODIS sensors

As scientists and decision makers increasingly rely on multiple Earth-observing satellites to address urgent global issues, it is imperative that they can rely on the accuracy of Earth-observing data products. This paper focuses on the crosscomparison of the Indian Remote Sensing (IRS-P6) Advanced Wide Field Sensor (AWiFS) with the Landsat 5 (L5) Thematic Mapper (TM), Landsat 7 (L7) Enhanced Thematic Mapper Plus (ETM+), and Terra Moderate Resolution Imaging Spectroradiometer (MODIS) sensors. The cross-comparison was performed using image statistics based on large common areas observed by the sensors within 30 minutes. Because of the limited availability of simultaneous observations between the AWiFS and the Landsat and MODIS sensors, only a few images were analyzed. These initial results are presented. Regression curves and coefficients of determination for the top-of-atmosphere (TOA) trends from these sensors were generated to quantify the uncertainty in these relationships and to provide an assessment of the calibration differences between these sensors. ?? 2009 SPIE.

Conference Paper↗

USGS2012

Expanding biological data standards development processes for US IOOS: visual line transect observing community for mammal, bird, and turtle data

The US Integrated Ocean Observing System (IOOS) has recently adopted standards for biological core variables in collaboration with the US Geological Survey/Ocean Biogeographic Information System (USGS/OBIS-USA) and other federal and non-federal partners. In this Community White Paper (CWP) we provide a process to bring into IOOS a rich new source of biological observing data, visual line transect surveys, and to establish quality data standards for visual line transect observations, an important source of at-sea bird, turtle and marine mammal observation data. The processes developed through this exercise will be useful for other similar biogeographic observing efforts, such as passive acoustic point and line transect observations, tagged animal data, and mark-recapture (photo-identification) methods. Furthermore, we suggest that the processes developed through this exercise will serve as a catalyst for broadening involvement by the larger marine biological data community within the goals and processes of IOOS.

Conference Paper↗

USGS1994

Strontium isotope geochemistry of soil and playa deposits near Yucca Mountain, Nevada

The isotopic composition of strontium contained in the carbonate fractions of soils provides an excellent tracer which can be used to test models for their origin. This paper reports data on surface coatings and cements, eolian sediments, playas and alluvial fan soils which help to constrain a model for formation of the extensive calcretes and fault infillings in the Yucca Mountain region. The playas contain carbonate with a wide range of strontium compositions; further work will be required to fully understand their possible contributions to the pedogenic carbonate system. Soils from an alluvial fan to the west of Yucca Mountain show that only small amounts of strontium are derived from a fan draining a carbonate terrane have strontium component. Although much evidence points to an eolian source for at least some of the strontium in the pedogenic carbonates near Yucca Mountain, an additional component or past variation of strontium composition in the eolian source is required to model the pedogenic carbonate system

Nevada↗

USGS2012

Real-time seismic monitoring of the integrated cape girardeau bridge array and recorded earthquake response

This paper introduces the state of the art, real-time and broad-band seismic monitoring network implemented for the 1206 m [3956 ft] long, cable-stayed Bill Emerson Memorial Bridge in Cape Girardeau (MO), a new Mississippi River crossing, approximately 80 km from the epicentral region of the 1811-1812 New Madrid earthquakes. The bridge was designed for a strong earthquake (magnitude 7.5 or greater) during the design life of the bridge. The monitoring network comprises a total of 84 channels of accelerometers deployed on the superstructure, pier foundations and at surface and downhole free-field arrays of the bridge. The paper also presents the high quality response data obtained from the network. Such data is aimed to be used by the owner, researchers and engineers to assess the performance of the bridge, to check design parameters, including the comparison of dynamic characteristics with actual response, and to better design future similar bridges. Preliminary analyses of ambient and low amplitude small earthquake data reveal specific response characteristics of the bridge and the free-field. There is evidence of coherent tower, cable, deck interaction that sometimes results in amplified ambient motions. Motions at the lowest tri-axial downhole accelerometers on both MO and IL sides are practically free from any feedback from the bridge. Motions at the mid-level and surface downhole accelerometers are influenced significantly by feedback due to amplified ambient motions of the bridge. Copyright ASCE 2006.

Conference Paper↗

USGS1986

PERFORMANCE OF AN EARTHQUAKE EXCITED ROOF DIAPHRAGM.

The objective of this paper is to study the earthquake performance of the roof diaphragm of the West Valley College gymnasium in Saratoga, California through a complete set of acceleration records obtained during the 24 April 1984 Morgan Hill Earthquake (M equals 6. 1). The roof diaphragm of the 112 ft. multiplied by 144 ft. rectangular, symmetric gymnasium consists of 3/8 in. plywood over tongue-and-groove sheathing attached to steel trusses supported by reinforced concrete columns and walls. Three sensors placed in the direction of each of the axes of the diaphragm facilitate the evaluation of in-plane deformation of the diaphragm. Other sensors placed at ground level measure vertical and horizontal motion of the building floor, and consequently allow the calculation of the relative motion of the diaphragm with respect to the ground level.

Conference Paper↗

USGS2005

Probabilistic liquefaction triggering based on the cone penetration test

Performance-based earthquake engineering requires a probabilistic treatment of potential failure modes in order to accurately quantify the overall stability of the system. This paper is a summary of the application portions of the probabilistic liquefaction triggering correlations proposed recently proposed by Moss and co-workers. To enable probabilistic treatment of liquefaction triggering, the variables comprising the seismic load and the liquefaction resistance were treated as inherently uncertain. Supporting data from an extensive Cone Penetration Test (CPT)-based liquefaction case history database were used to develop a probabilistic correlation. The methods used to measure the uncertainty of the load and resistance variables, how the interactions of these variables were treated using Bayesian updating, and how reliability analysis was applied to produce curves of equal probability of liquefaction are presented. The normalization for effective overburden stress, the magnitude correlated duration weighting factor, and the non-linear shear mass participation factor used are also discussed.

Conference Paper↗

USGS1993

Simulation of changes in storm-runoff characteristics, Perris Valley, California

The population of Perris Valley, California, has increased from about 20,000 in 1970 to more than 130,000 in 1992. Increased urbanization in Perris Valley since 1970 has produced appreciable changes in storm-runoff characteristics. Additional impervious area has resulted in increased storm-runoff volumes and peak discharges. Few studies have documented the effect of urbanization on runoff characteristics in the Perris Valley area. A study of runoff characteristics under the current level of development in Perris Valley was begun in 1989 to determine how recent urbanization changed runoff characteristics from 1970-75, a period for which rainfall and runoff data are available. This paper briefly describes the methods being used in a study to determine the effects of urbanization in Perris Valley and presents a few results of that study. Rainfall and runoff data collected in a previous study (1970-75) were used to calibrate a rainfall-runoff model. This model will be used to simulate the runoff in Perris Valley during the early development of the basin. Rainfall and runoff data currently (1990-93) being collected in Perris Valley will be used to calibrate and verify a rainfall-runoff model simulating the current runoff conditions. Two simulations of a long-term time series of runoff will be done using the rainfall-runoff models and historical rainfall. A duration analysis of the simulated runoff will be used to compare the storm-runoff characteristics of the two urban conditions.

Conference Paper↗

USGS2015

Operational considerations for implementing regional sediment management plans in the northern Gulf of Mexico

Development of a comprehensive and stakeholder-driven Regional Sediment Management plan can provide the basis for long-term sustainable resource use and protection. This paper highlights three operational components that can positively influence sediment management at a regional scale, including (1) integration of an operational sediment budget, (2) development of a monitoring and adaptive management plan, and (3) development of a regional sediment availability and allocation program. These components seek to incorporate science and adaptive management through implementation of an organized and well-documented decision making process. They represent a coordinated framework that could serve as a guide for unifying financial investments in regional sediment management plans. Collectively, they establish an integrated process for addressing uncertainties about future system change in light of shrinking federal and state budgets, competing demands for sediment resources within riverine and marine waters, and policy considerations related to sediment/water use (e.g., navigation and commerce versus environmental management).

Conference Paper↗

USGS2008

Application of high-resolution linear Radon transform for Rayleigh-wave dispersive energy imaging and mode separating

Multichannel Analysis of Surface Waves (MASW) analysis is an efficient tool to obtain the vertical shear-wave profile. One of the key steps in the MASW method is to generate an image of dispersive energy in the frequency-velocity domain, so dispersion curves can be determined by picking peaks of dispersion energy. In this paper, we image Rayleigh-wave dispersive energy and separate multimodes from a multichannel record by high-resolution linear Radon transform (LRT). We first introduce Rayleigh-wave dispersive energy imaging by high-resolution LRT. We then show the process of Rayleigh-wave mode separation. Results of synthetic and real-world examples demonstrate that (1) compared with slant stacking algorithm, high-resolution LRT can improve the resolution of images of dispersion energy by more than 50% (2) high-resolution LRT can successfully separate multimode dispersive energy of Rayleigh waves with high resolution; and (3) multimode separation and reconstruction expand frequency ranges of higher mode dispersive energy, which not only increases the investigation depth but also provides a means to accurately determine cut-off frequencies.

Conference Paper↗

USGS2016

Learning from the recent Taiwan Meinong Earthquake

This paper highlights the lessons learned following a reconnaissance trip to Tainan, Taiwan two weeks after the February 2016 earthquake. The reconnaissance was conducted by Gilsanz, Murray Steficek engineers (GMS) and an earthquake engineer from the United States Geological Survey (USGS), in collaboration with the Earthquake Engineering Research Institute (EERI), the Applied Technical Council (ATC) and the National Center for Research in Earthquake Engineering (NCREE) of Taiwan. Observations were made of damages, success of base-isolated high-rise and retrofitted school buildings, site effects and ground failures as well as the response of both city agencies and building owners to the earthquake. The motivation for engineers and the public for such a mission is to learn from the observations to be better prepared for the next earthquake.

Meinong↗

USGS2005

Real-time seismic monitoring and functionality assessment of a building

This paper presents recent developments and approaches (using GPS technology and real-time double-integration) to obtain displacements and, in turn, drift ratios, in real-time or near real-time to meet the needs of the engineering and user community in seismic monitoring and assessing the functionality and damage condition of structures. Drift ratios computed in near real-time allow technical assessment of the damage condition of a building. Relevant parameters, such as the type of connections and story structural characteristics (including geometry) are used in computing drifts corresponding to several pre-selected threshold stages of damage. Thus, drift ratios determined from real-time monitoring can be compared to pre-computed threshold drift ratios. The approaches described herein can be used for performance evaluation of structures and can be considered as building health-monitoring applications.

Conference Paper↗

USGS2019

Probabilistic seismic hazard analysis using stochastic simulated ground motions

: In recent years, ground motion models used in probabilistic seismic hazard analyses (PSHA) have evolved from the traditional approach of using ground motion prediction equations (GMPEs) to using ground motion time series models. The purpose of this paper is to develop an approach to perform a probabilistic seismic hazard analysis using stochastic site-based simulation techniques. These techniques consist of empirical stochastic models that simulate both near-fault and far-field ground motion time series. The near-fault models consider directivity pulses, which can impose large seismic demands. The proposed approach was applied to a site located in Los Angeles Downtown and the corresponding hazard curves were developed. The results were compared to hazard curves derived for the same site from CyberShake, which uses a physics-based simulation approach, and from a traditional GMPE approach. The comparison indicated that the proposed methodology accurately describes the seismic hazard at the site at high hazard levels. The proposed approach is computationally efficient compared to the use of physics-based simulations like CyberShake.

Conference Paper↗

USGS2005

Recent advances to obtain real - Time displacements for engineering applications

Conference Paper↗

USGS2002

Model Performance of Water-Current Meters

The measurement of discharge in natural streams requires hydrographers to use accurate water-current meters that have consistent performance among meters of the same model. This paper presents the results of an investigation into the performance of four models of current meters - Price type-AA, Price pygmy, Marsh McBirney 2000 and Swoffer 2100. Tests for consistency and accuracy for six meters of each model are summarized. Variation of meter performance within a model is used as an indicator of consistency, and percent velocity error that is computed from a measured reference velocity is used as an indicator of meter accuracy. Velocities measured by each meter are also compared to the manufacturer's published or advertised accuracy limits. For the meters tested, the Price models werer found to be more accurate and consistent over the range of test velocities compared to the other models. The Marsh McBirney model usually measured within its accuracy specification. The Swoffer meters did not meet the stringent Swoffer accuracy limits for all the velocities tested.

Conference Paper↗

USGS2020

Scale-specific metrics for adaptive generalization and geomorphic classification of stream features

The Richardson plot has been used to illustrate fractal dimension of naturally occurring landscape features that are sensitive to changes in scale or resolution, such as coastlines and river channels. The Richardson method estimates the length of a path by traversing (i.e., “walking”) the path with a specific stride length. Fractal dimension is determined as the slope of the Richardson plot, which shows path length over a range of stride lengths graphed on log-log axes. This paper describes a variant of the Richardson plot referred to as the Scale-Specific Sinuosity (S 3 ) plot. S 3 is defined as negative one times the slope of the Richardson plot for a given stride length. A plot of S 3 against stride length offers a frequency distribution whose area under the curve reflects total sinuosity, and whose points mark the amount of sinuosity contributed to the total sinuosity at each stride length. Mathematical relations of S 3 with fractal dimension and sinuosity for linear features are described. The S 3 metric is demonstrated and discussed for several linear stream features distributed over the conterminous United States. The S 3 metric can help guide the preservation of stream feature sinuosity during cartographic generalization and may assist automated geomorphic classification of river systems.

Conference Paper↗

USGS2004

Analysis of summer 2002 melt extent on the Greenland ice sheet using MODIS and SSM/I data

Previous work has shown that the summer of 2002 had the greatest area of snow melt extent on the Greenland ice sheet ever recorded using passive-microwave data. In this paper, we compare the 0?? isotherm derived from the Moderate-Resolution Imaging Spectroradiometer (MODIS) instrument, with Special Sensor Microwave/Imager (SSM/I)-derived melt, at the time of the maximum melt extent in 2002. To validate the MODIS-derived land-surface temperatures (LSTs), we compared the MODIS LSTs with air temperatures from nine stations (using 11 different data points) and found that they agreed to within 2.3??2.09??C, with station temperatures consistently lower than the MODIS LSTs. According to the MODIS LST, the maximum surface melt extended to ???2300 m in southern Greenland; while the SSM/I measurements showed that the maximum melt extended to nearly 2700 m in southeastern Greenland. The MODIS and SSM/I data are complementary in providing detailed information about the progression of surface and near-surface melt on the Greenland ice sheet.

Conference Paper↗

USGS2014

Optimally managing water resources in large river basins for an uncertain future

Managers of large river basins face conflicting needs for water resources such as wildlife habitat, water supply, wastewater assimilative capacity, flood control, hydroelectricity, and recreation. The Savannah River Basin for example, has experienced three major droughts since 2000 that resulted in record low water levels in its reservoirs, impacting local economies for years. The Savannah River Basin’s coastal area contains municipal water intakes and the ecologically sensitive freshwater tidal marshes of the Savannah National Wildlife Refuge. The Port of Savannah is the fourth busiest in the United States, and modifications to the harbor have caused saltwater to migrate upstream, reducing the freshwater marsh’s acreage more than 50 percent since the 1970s. There is a planned deepening of the harbor that includes flow-alteration features to minimize further migration of salinity. The effectiveness of the flow-alteration features will only be known after they are constructed. One of the challenges of basin management is the optimization of water use through ongoing regional economic development, droughts, and climate change. This paper describes a model of the Savannah River Basin designed to continuously optimize regulated flow to meet prioritized objectives set by resource managers and stakeholders. The model was developed from historical data by using machine learning, making it more accurate and adaptable to changing conditions than traditional models. The model is coupled to an optimization routine that computes the daily flow needed to most efficiently meet the water-resource management objectives. The model and optimization routine are packaged in a decision support system that makes it easy for managers and stakeholders to use. Simulation results show that flow can be regulated to substantially reduce salinity intrusions in the Savannah National Wildlife Refuge while conserving more water in the reservoirs. A method for using the model to assess the effectiveness of the flow-alteration features after the deepening also is demonstrated.

Georgia, South Carolina↗