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Z. Wang

Publications and source records attributed to Z. Wang.

At least 19 recordsLinked to original sources
USGS2019

Occurrence and sources of radium in groundwater associated with oil fields in the southern San Joaquin Valley, California

Geochemical data from 40 water wells were used to examine the occurrence and sources of radium (Ra) in groundwater associated with three oil fields in California (Fruitvale, Lost Hills, South Belridge). 226Ra+228Ra activities (range=0.010-0.51 Bq/L) exceeded the 0.185 Bq/L drinking-water standard in 18% of the wells (not drinking-water wells). Radium activities were correlated with TDS concentrations (p<0.001, ρ=0.90, range=145-15,900 mg/L), Mn+Fe concentrations (p<0.001, ρ=0.82, range=<0.005-18.5 mg/L), and pH (p<0.001, ρ=-0.67, range=6.2-9.2), indicating Ra in groundwater was influenced by salinity, redox, and pH. Ra-rich groundwater was mixed with up to 45% oil-field water at some locations, primarily infiltrating through unlined disposal ponds, based on Cl, Li, noble-gas, and other data. Yet 228Ra/226Ra ratios in pond-impacted groundwater (median=3.1) differed from those in oil-field water (median=0.51). PHREEQC mixing calculations and spatial geochemical variations suggest the Ra in oil-field water was removed by co-precipitation with secondary barite and adsorption on Mn-Fe precipitates in the near-pond environment. The saline, organic-rich oil-field water subsequently mobilized Ra from downgradient aquifer sediments via Ra-desorption and Mn/Fe-reduction processes. This study demonstrates that infiltration of oil-field water may leach Ra into groundwater by changing salinity and redox conditions in the subsurface rather than by mixing with a high-Ra source.

California↗
USGS2011

A short note on ground-motion recordings from the M 7.9 Wenchuan, China, earthquake and ground-motion prediction equations in the Central and Eastern United States

The 12 May 2008 Wenchuan earthquake (M 7.9) occurred along the western edge of the eastern China SCR and was well recorded by modern strong-motion instruments: 93 strong-motion stations within 1.4 to 300 km rupture distance recorded the main event. Preliminary comparisons show some similarities between ground-motion attenuation in the Wenchuan region and the central and eastern United States, suggesting that ground motions from the Wenchuan earthquake could be used as a database providing constraints for developing GMPEs for large earthquakes in the central and eastern United States.

Seismological Research Letters↗
USGS2010

Seismic hazard assessment: Issues and alternatives

Seismic hazard and risk are two very important concepts in engineering design and other policy considerations. Although seismic hazard and risk have often been used inter-changeably, they are fundamentally different. Furthermore, seismic risk is more important in engineering design and other policy considerations. Seismic hazard assessment is an effort by earth scientists to quantify seismic hazard and its associated uncertainty in time and space and to provide seismic hazard estimates for seismic risk assessment and other applications. Although seismic hazard assessment is more a scientific issue, it deserves special attention because of its significant implication to society. Two approaches, probabilistic seismic hazard analysis (PSHA) and deterministic seismic hazard analysis (DSHA), are commonly used for seismic hazard assessment. Although PSHA has been pro-claimed as the best approach for seismic hazard assessment, it is scientifically flawed (i.e., the physics and mathematics that PSHA is based on are not valid). Use of PSHA could lead to either unsafe or overly conservative engineering design or public policy, each of which has dire consequences to society. On the other hand, DSHA is a viable approach for seismic hazard assessment even though it has been labeled as unreliable. The biggest drawback of DSHA is that the temporal characteristics (i.e., earthquake frequency of occurrence and the associated uncertainty) are often neglected. An alternative, seismic hazard analysis (SHA), utilizes earthquake science and statistics directly and provides a seismic hazard estimate that can be readily used for seismic risk assessment and other applications. ?? 2010 Springer Basel AG.

Pure and Applied Geophysics↗
USGS2010

Three-dimensional long-period groundmotion simulations in the upper Mississippi embayment

We employed a 3D velocity model and 3D wave propagation code to simulate long-period ground motions in the upper Mississippi embayment. This region is at risk from large earthquakes in the New Madrid seismic zone (NMSZ) and observational data are sparse, making simulation a valuable tool for predicting the effects of large events. We undertook these simulations to estimate the magnitude of shaking likely to occur and to investigate the influence of the 3D embayment structure and finite-fault mechanics on ground motions. There exist three primary fault zones in the NMSZ, each of which was likely associated with one of the main shocks of the 1811-12 earthquake triplet. For this study, three simulations have been conducted on each major segment, exploring the impact of different epicentral locations and rupture directions on ground motions. The full wave field up to a frequency of 0.5 Hz is computed on a 200 ?? 200 ?? 50-km 3 volume using a staggered-grid finite-difference code. Peak horizontal velocity and bracketed durations were calculated at the free surface. The NMSZ simulations indicate that for the considered bandwidth, finite-fault mechanics such as fault proximity, directivity effect, and slip distribution exert the most control on ground motions. The 3D geologic structure of the upper Mississippi embayment also influences ground motion with indications that amplification is induced by the sharp velocity contrast at the basin edge.

Seismological Research Letters↗
USGS2009

Characteristics of ground motion at permafrost sites along the Qinghai-Tibet railway

Based on 14 typical drilling holes distributed in the permafrost areas along the Qinghai-Tibet railway, the distribution of wave velocities of soils in the permafrost regions were determined. Using results of dynamic triaxial tests, the results of dynamic triaxiality test and time histories of ground motion acceleration in this area, characteristics of ground motion response were analyzed for these permafrost sites for time histories of ground accelerations with three exceedance probabilities (63%, 10% and 2%). The influence of ground temperature on the seismic displacement, velocity, acceleration and response spectrum on the surface of permafrost were also studied. ?? 2008 Elsevier Ltd. All rights reserved.

Soil Dynamics and Earthquake Engineering↗
USGS2009

Earthquake hazards and lifelines in the Interstate 5 urban corridor: Woodburn, Oregon, to Centralia, Washington

The Interstate 5 highway (I-5) corridor, which stretches from Mexico to Canada, is both the main economic artery of the Pacific Northwest and home to the majority of Oregonians and Washingtonians. Accordingly, most regional utility and transportation systems have major components located within the I-5 corridor. For the purposes of this map, we refer to these essential systems as lifeline systems. The Pacific Northwest section of I-5, the I-5 urban corridor, extends from Eugene, Oregon, to the border of Canada. The population of this region is rapidly increasing with the bulk of growth and economic development centered in the cities of Eugene, Salem, and Portland, Oregon, and Olympia, Tacoma, Seattle, Everett, and Bellingham, Washington.

Oregon, Washington↗
USGS2009

Earthquake hazards and lifelines in the Interstate 5 urban corridor: Cottage Grove to Woodburn, Oregon

The Interstate 5 highway (I-5) corridor, which stretches from Mexico to Canada, is both the main economic artery of the Pacific Northwest and home to the majority of Oregonians and Washingtonians. Accordingly, most regional utility and transportation systems have major components located within the I-5 corridor. For the purposes of this map, we refer to these essential systems as lifeline systems. The Pacific Northwest section of I-5, the I-5 urban corridor, extends from Eugene, Oregon, to the border of Canada. The population of this region is rapidly increasing with the bulk of growth and economic development centered in the cities of Eugene, Salem, and Portland, Oregon, and Olympia, Tacoma, Seattle, Everett, and Bellingham, Washington.

Oregon↗
USGS2008

Trace element emissions from spontaneous combustion of gob piles in coal mines, Shanxi, China

The emissions of potentially hazardous trace elements from spontaneous combustion of gob piles from coal mining in Shanxi Province, China, have been studied. More than ninety samples of solid waste from gob piles in Shanxi were collected and the contents of twenty potentially hazardous trace elements (Be, F, V, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Sn, Sb, Hg, Tl, Pb, Th, and U) in these samples were determined. Trace element contents in solid waste samples showed wide ranges. As compared with the upper continental crust, the solid waste samples are significantly enriched in Se (20x) and Tl (12x) and are moderately enriched in F, As, Mo, Sn, Sb, Hg, Th, and U (2-5x). The solid waste samples are depleted in V, Cr, Mn, Co, Ni, Cu, and Zn. The solid waste samples are enriched in F, V, Mn, Cr, Co, Ni, Cu, Zn, Sb, Th, and U as compared with the Shanxi coals. Most trace elements are higher in the clinker than in the unburnt solid waste except F, Sn, and Hg. Trace element abundances are related to the ash content and composition of the samples. The content of F is negatively correlated with the ash content, while Pb is positively correlated with the ash. The concentrations of As, Mn, Zn, and Cd are highly positively correlated with Fe2O3 in the solid waste. The As content increases with increasing sulfur content in the solid waste. The trace element emissions are calculated for mass balance. The emission factors of trace elements during the spontaneous combustion of the gobs are determined and the trace element concentrations in the flue gas from the spontaneous combustion of solid waste are calculated. More than a half of F, Se, Hg and Pb are released to the atmosphere during spontaneous combustion. Some trace element concentrations in flue gas are higher than the national emission standards. Thus, gob piles from coal mining pose a serious environmental problem. ?? 2007 Elsevier B.V. All rights reserved.

International Journal of Coal Geology↗
USGS2008

The role of local soil-induced amplification in the 27 July 1980 northeastern Kentucky earthquake

Amplification of earthquake ground motions by near-surface soil deposits was believed to have occurred in Maysville, Kentucky, U.S.A. during the northeast Kentucky (Sharpsburg) earthquake (mb,Lg 5.3) of July 27, 1980. The city of Maysville, founded on approximately 30 m of Late Quaternary Ohio River flood plain alluvium, was 52 km from the epicenter, but experienced equivalent or higher Modified Mercalli Intensity (MMI) VII, compared with the epicentral area of the earthquake (i.e., MMI VI-VII). In this study, dynamic soil properties were obtained at 10 sites in Maysville using seismic P-wave and S-wave (SH-mode) refraction and reflection methods. Synthetically generated composite time histories and limited geotechnical information, along with the measured dynamic properties, were used to perform one-dimensional linear-equivalent amplification analyses. The results indicated the soils generated ground-motion amplification factors between 3.0 and 6.0 and at a frequency range between 2.0 and 5.0 Hz (0.2 to 0.5 s). The building damage in Maysville from the Sharpsburg earthquake was predominantly found in one- to three-story masonry structures. The estimated fundamental period for one- to three-story masonry buildings is approximately 0.11 to 0.26 s (3.8 to 9 Hz). These correlations suggest the elevated ground motion intensity in Maysville can be accounted for by near-surface soil-amplification effects and resonance of the ground motion by the buildings (i.e., double resonance).

Environmental & Engineering Geoscience↗
USGS2007

Comparison of the uptake of polycyclic aromatic hydrocarbons and organochlorine pesticides by semipermeable membrane devices and caged fish (Carassius carassius) in Taihu Lake, China

Uptake of polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs) by triolein-containing semipermeable membrane devices (SPMDs) and by crucian carp (Carassius carassius) was studied in Taihu Lake, a shallow, freshwater lake in China. Crucian carp and SPMDs were deployed side by side for 32 d. The first-order uptake rate constants of individual PAHs and OCPs for the two matrices were calculated and compared to relate the amounts of chemicals accumulated by the matrices to dissolved water concentrations. On a wet-weight basis, total concentrations of PAHs and OCPs in crucian carp fillets averaged 49.5 and 13.6 ng/g, respectively, after the 32-d exposure, whereas concentrations in whole SPMDs averaged 716.9 and 62.3 ng/g, respectively. The uptake rate constants of PAHs and OCPs by SPMDs averaged seven- and fivefold higher, respectively, than those for crucian carp; however, the patterns of uptake rate constants derived from test chemical concentrations in the crucian carp and SPMDs were similar. Although equilibrium was not reached for some PAHs and OCPs during the 32-d exposure period, a reasonably good correlation between the concentration factors (CFs) and octanol/water partition coefficient (K ow) values of PAHs and OCPs in SPMDs (r = 0.86, p < 0.001) was observed when potential sorption to dissolved organic carbon was taken into account. Similar efforts to correlate the CFs and Kow values of PAHs and OCPs in crucian carp (r = 0.75, p < 0.001) were less successful, likely because of PAH metabolism by finfish. Overall, the present results suggest that SPMDs may serve as a surrogate for contaminant monitoring with fish in freshwater lake environments. ?? 2007 SETAC.

Environmental Toxicology and Chemistry↗
USGS2007

Histological alternation and vitellogenin induction in adult rare minnow ( Gobiocypris rarus ) after exposure to ethynylestradiol and nonylphenol

Adult rare minnow ( Gobiocypris rarus ) were exposed to 0, 1, 5, and 25 ng/l (nominal concentrations) of 17α-ethynylestradiol (EE 2 ) and 3, 10, and 30 μg/l (nominal concentrations) of 4-nonylphenol (NP) under flow-through conditions for a period of 28 d. Low mortality was observed at 5 and 25 ng/l EE 2 and the growth of fish reduced significantly at 25 ng/l EE 2 compared to controls. However, the gonadosomatic indices (GSI) of male fish were significantly higher in 1 ng/l EE 2 treatments and in 10 and 30 μg/l NP treatments ( p < 0.05). Renal somatic indices (RSI) of male fish in EE 2 treatments were significantly higher than those in controls ( p < 0.05). In contrast, significantly decreased GSI and RSI of female fish could only be observed in 5 and 25 ng/l EE 2 treatments ( p < 0.05). Hepatosomatic indices (HSI) of male fish were significantly higher in 25 ng/l EE 2 treatments. However, significantly increased of HSI of female fish could only be observed in 1 ng/l EE 2 treatments. Plasma vitellogenin (VTG) induction could be observed in males after exposed to different concentrations of EE 2 and NP, and plasma VTG concentrations in females exposed to 5 and 25 ng/l EE 2 were also significantly higher than in controls ( p < 0.05). At level higher than 5 ng/l EE 2 or 30 μg/l NP, hepatic tissue and renal tissue impairment of males could be observed. The pathological male liver was associated with a hypertrophy of hepatocytes and damages to cellar structure and accumulated eosinophilic material. Renal tissue showed different pathological effects which was reflected by accumulated eosinophilic material, hemorrhages within the kidney tubules and hypertrophy of the tubular epithelia. Also at these levels of exposure, feminization of male fish could be noticed and parts of males manifested the testis-ova phenomenon. Ovaries of female rare minnow in 25 ng/l EE 2 treatment group were degenerated. Therefore when exposed to EE 2 and NP even at environmental observed concentrations, adverse effects could occur in the reproductive system of adult fishes. The observed hepatic tissue and renal tissue impairment should be due to the induction and accumulation of VTG in organs, especially in males.

Chemosphere↗
USGS2007

Seismic hazard and risk assessment in the intraplate environment: The New Madrid seismic zone of the central United States

Although the causes of large intraplate earthquakes are still not fully understood, they pose certain hazard and risk to societies. Estimating hazard and risk in these regions is difficult because of lack of earthquake records. The New Madrid seismic zone is one such region where large and rare intraplate earthquakes (M = 7.0 or greater) pose significant hazard and risk. Many different definitions of hazard and risk have been used, and the resulting estimates differ dramatically. In this paper, seismic hazard is defined as the natural phenomenon generated by earthquakes, such as ground motion, and is quantified by two parameters: a level of hazard and its occurrence frequency or mean recurrence interval; seismic risk is defined as the probability of occurrence of a specific level of seismic hazard over a certain time and is quantified by three parameters: probability, a level of hazard, and exposure time. Probabilistic seismic hazard analysis (PSHA), a commonly used method for estimating seismic hazard and risk, derives a relationship between a ground motion parameter and its return period (hazard curve). The return period is not an independent temporal parameter but a mathematical extrapolation of the recurrence interval of earthquakes and the uncertainty of ground motion. Therefore, it is difficult to understand and use PSHA. A new method is proposed and applied here for estimating seismic hazard in the New Madrid seismic zone. This method provides hazard estimates that are consistent with the state of our knowledge and can be easily applied to other intraplate regions. ?? 2007 The Geological Society of America.

Special Paper of the Geological Society of America↗
USGS2006

Recordings from the deepest borehole in the New Madrid Seismic Zone

The recordings at the deepest vertical strong-motion array (VSAS) from three small events, the 21 October 2004 Tiptonville, Tennessee, earthquake; the 10 February 2005 Arkansas earthquake; and the 2 June 2005 Ridgely, Tennessee, earthquake show some interesting wave-propagation phenomena through the soils: the S-wave is attenuated from 260 m to 30 m depth and amplified from 30 m to the surface. The S-wave arrival times from the three events yielded different shear-wave velocity estimates for the soils. These different estimates may be the result of different incident angles of the S-waves due to different epicentral distances. The epicentral distances are about 22 km, 110 km, and 47 km for the Tiptonville, Arkansas, and Ridgely earthquakes, respectively. These recordings show the usefulness of the borehole strong-motion array. The vertical strong-motion arrays operated by the University of Kentucky have started to accumulate recordings that will provide a database for scientists and engineers to study the effects of the near-surface soils on the strong ground motion in the New Madrid Seismic Zone. More information about the Kentucky Seismic and Strong-Motion Network can be found at www.uky.edu/KGS/geologichazards. The digital recordings are available at ftp://kgsweb.uky.edu.

Seismological Research Letters↗
USGS2005

Comment on "How can seismic hazard around the New Madrid seismic zone be similar to that in California?" by Arthur Frankel

A recent paper in the September/October 2004 issue of Seismological Research Letters, “How Can Seismic Hazard around the New Madrid Seismic Zone Be Similar to That in California?”, by Arthur Frankel, concludes “I have demonstrated how probabilistic seismic hazard for New Madrid can be greater than that at San Francisco at low probabilities for PGA and similar at low probabilities for 5 Hz S.A. By low probabilities, I mean annual probabilities less than the reciprocal of the return time of the New Madrid characteristic source, that is, 1/500. This is a consequence of the higher ground motions, for PGA and 5 Hz S.A. (and other high-frequency measures), expected for large New Madrid characteristic earthquakes compared to San Andreas earthquakes with similar magnitudes.” His conclusion is confusing and not necessarily true. The fundamental differences in assessing seismic hazard between San Francisco and the New Madrid seismic zone are the uncertainties, especially the uncertainties associated with the ground-motion attenuation relationship. The larger ground-motion uncertainties in both the median and its standard deviation derive a higher hazard in the New Madrid area. The larger standard deviation, in particular, derives a higher hazard at low annual probabilities of exceedance. Moreover, Frankel also equated the hazard (annual probability of exceedance) defined in probabilistic seismic hazard analysis (PSHA) with the average recurrence rate defined in engineering risk analysis. There is a fundamental difference in defining risk between PSHA and the engineering risk analysis. The risks—10%, 5%, and 2% probability of exceedance (PE) in 50 years—defined in PSHA are not interchangeable with those defined in engineering risk analysis. Hence, though Frankel's stated intention was to improve understanding of PSHA among nonpractitioners, the paper may cause more confusion and problems for users of the U.S. Geological Survey national seismic hazard maps.

Seismological Research Letters↗
USGS2005

Lifelines and earthquake hazards along the Interstate 5 Urban Corridor: Woodburn, Oregon to Centralia, Washington

The Interstate 5 highway corridor, stretching from Mexico to Canada, is not only the economic artery of the Pacific Northwest, but is also home to the majority of Oregonians and Washingtonians. Accordingly, most regional utility and transportation systems, such as railroads and electrical transmission lines, have major components in the I-5 corridor. The section of I-5 from Cottage Grove, Oregon, to Blaine, Washington, is rapidly urbanizing, with population growth and economic development centered around the cities of Eugene, Salem, Portland, Olympia, Tacoma, Seattle, Everett, and Bellingham. For the purposes of this map, we refer to this area as the I-5 Urban Corridor.

Oregon, Washington↗
USGS2005

Late paleozoic base and precious metal deposits, East Tianshan, Xinjiang, China: Characteristics and geodynamic setting

The East Tianshan is a remote Gobi area located in eastern Xinjiang, northwestern China. In the past several years, a number of gold, porphyry copper, and Fe(-Cu) and Cu-Ag-Pb-Zn skarn deposits have been discovered there and are attracting exploration interest. The East Tianshan is located between the Junggar block to the north and early Paleozoic terranes of the Middle Tianshan to the south. It is part of a Hercynian orogen with three distinct E-W-trending tectonic belts: the Devonian-Early Carboniferous Tousuquan-Dananhu island arc on the north and the Carboniferous Aqishan - Yamansu rift basin to the south, which are separated by rocks of the Kanggurtag shear zone. The porphyry deposits, dated at 322 Ma, are related to the late evolutionary stages of a subduction-related oceanic or continental margin arc. In contrast, the skarn, gold, and magmatic Ni-Cu deposits are associated with post-collisional tectonics at ca. 290-270 Ma. These Late Carboniferous - Early Permian deposits are associated with large-scale emplacement and eruption of magmas possibly caused by lithosphere delamination and rifting within the East Tianshan.

Episodes↗
USGS2004

Comparison of some sediment-hosted, stratiform barite deposits in China, the United States, and India

Shifts in world barite production since the 1980s have resulted in China becoming the world's largest barite-producing country followed by the US and India. Most barite produced for use in drilling fluids is derived from black shale- and chert-hosted, stratiform marine deposits. In China, Late Proterozoic to Early Cambrian marine barite deposits occur on the oceanic margins of the Yangtze platform, in the Qinling region in the north and the Jiangnan region in the south. Most US ore-grade deposits are in the Nevada barite belt; most commercial deposits occur in Ordovician and Devonian marine rocks along the western margin of the early Paleozoic North American continent. Production in India is predominantly from a single Middle Proterozoic deposit in a sedimentary basin located on Archean basement in Andrah Pradesh.The geologic and geochemical characteristics of the deposits are consistent with origins from a variety of sedimentary-exhalative processes, with biogenic processes contributing to the concentration of some seafloor barite. Linear distributions of clusters of lenticular deposits suggest a geographic relationship to syndepositional seafloor fault zones. Sulfur isotope data of the barite deposits range from values that are similar to coeval seawater sulfate to significantly higher ??34S values. Strontium isotope values of continental-margin-type deposits in Nevada and China are less radiogenic than those of cratonic-rift deposits (e.g. Meggen and Rammelsberg). Comparison of Lan/ Cen ratios of barite in the Qinling region of China with marine chert ratios suggests a relationship to hydrothermal fluids, whereas ratios from the Jiangnan region and Nevada can be interpreted as reflecting a biogenic influence.The California Borderland provides a potential modern analog where hydrothermal barium is being deposited on the seafloor in fault-block-bounded basins. Anoxic to dysaerobic conditions on some marine basin floors result from upwelling, nutrient-rich currents and high productivity in surface waters. In this setting, biogenic processes could contribute to the concentration of barium from hydrothermal sources. ?? 2003 Published by Elsevier B.V.

Ore Geology Reviews↗