Aysén seismic swarm (January 2007) in southern Chile: analysis using Joint Hypocenter Determination     

Cindy Mora  Diana Comte  Ray Russo  Alejandro Gallego  Victor Mocanu 《Journal of Seismology》2010,14(4):683-691

A seismic swarm at the Aysén fjord started in January, 2007, reaching its highest activity between January and April, 2007. It was punctuated by the Mw5.3 23rd January event and the Mw6.2 21st April event which triggered a water-wave due to massive landslides; both with dextral strike slip focal mechanisms. More than 100 events were relocated with the Joint Hypocenter Determination method to study the depth distribution of the events of the swarm recorded by the Chile Ridge Subduction Project local network. The events are associated to a small area of approximately 7?×?7 km located in the Aysén fjord, on one of the main branches of the Liquiñe–Ofqui fault. Distribution in depth is located between 0 and 8 km and presents a west high dip with almost NS strike, consistent with the main trending of the Liquiñe–Ofqui fault and the published focal mechanisms. These characteristics, among others, suggest that the Liquiñe–Ofqui fault is active in this region and thus seismic risk has to be re-determined.  相似文献   

Crustal Architecture at the Collision Zone Between Rivera and North American Plates at the Jalisco Block: Tsujal Project     

Juanjo Dañobeitia  Rafael Bartolomé  Manel Prada  Francisco Nuñez-Cornú  Diego Córdoba  William L. Bandy  F. Estrada  Alejandra L. Cameselle  Diana Nuñez  Arturo Castellón  José Luis Alonso  Carlos Mortera  Modesto Ortiz 《Pure and Applied Geophysics》2016,173(10-11):3553-3573

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Cryptosporidium and Giardia in tropical recreational marine waters contaminated with domestic sewage: Estimation of bathing-associated disease risks     

Walter Q. Betancourt  Diana C. Duarte  Rosa C. Vásquez  Patrick L. Gurian 《Marine pollution bulletin》2014

Sewage is a major contributor to pollution problems involving human pathogens in tropical coastal areas. This study investigated the occurrence of intestinal protozoan parasites (Giardia and Cryptosporidium) in tropical recreational marine waters contaminated with sewage. The potential risks of Cryptosporidium and Giardia infection from recreational water exposure were estimated from the levels of viable (oo) cysts (DIC+, DAPI+, PI−) found in near-shore swimming areas using an exponential dose response model. A Monte Carlo uncertainty analysis was performed in order to determine the probability distribution of risks. Microbial indicators of recreational water quality (enterococci, Clostridium perfringens) and genetic markers of sewage pollution (human-specific Bacteroidales marker [HF183] and Clostridium coccoides) were simultaneously evaluated in order to estimate the extent of water quality deterioration associated with human wastes. The study revealed the potential risk of parasite infections via primary contact with tropical marine waters contaminated with sewage; higher risk estimates for Giardia than for Cryptosporidium were found. Mean risks estimated by Monte Carlo were below the U.S. EPA upper bound on recreational risk of 0.036 for cryptosporidiosis and giardiasis for both children and adults. However, 95th percentile estimates for giardiasis for children exceeded the 0.036 level. Environmental surveillance of microbial pathogens is crucial in order to control and eradicate the effects that increasing anthropogenic impacts have on marine ecosystems and human health.  相似文献   

Astrodynamical Space Test of Relativity Using Optical Devices I (ASTROD I)—A class-M fundamental physics mission proposal for Cosmic Vision 2015–2025     

Thierry Appourchaux  Raymond Burston  Yanbei Chen  Michael Cruise  Hansjörg Dittus  Bernard Foulon  Patrick Gill  Laurent Gizon  Hugh Klein  Sergei Klioner  Sergei Kopeikin  Hans Krüger  Claus Lämmerzahl  Alberto Lobo  Xinlian Luo  Helen Margolis  Wei-Tou Ni  Antonio Pulido Patón  Qiuhe Peng  Achim Peters  Ernst Rasel  Albrecht Rüdiger  Étienne Samain  Hanns Selig  Diana Shaul  Timothy Sumner  Stephan Theil  Pierre Touboul  Slava Turyshev  Haitao Wang  Li Wang  Linqing Wen  Andreas Wicht  Ji Wu  Xiaomin Zhang  Cheng Zhao 《Experimental Astronomy》2009,23(2):491-527

ASTROD I is a planned interplanetary space mission with multiple goals. The primary aims are: to test general relativity with an improvement in sensitivity of over three orders of magnitude, improving our understanding of gravity and aiding the development of a new quantum gravity theory; to measure key solar system parameters with increased accuracy, advancing solar physics and our knowledge of the solar system; and to measure the time rate of change of the gravitational constant with an order of magnitude improvement and the anomalous Pioneer acceleration, thereby probing dark matter and dark energy gravitationally. It is an international project, with major contributions from Europe and China and is envisaged as the first in a series of ASTROD missions. ASTROD I will consist of one spacecraft carrying a telescope, four lasers, two event timers and a clock. Two-way, two-wavelength laser pulse ranging will be used between the spacecraft in a solar orbit and deep space laser stations on Earth, to achieve the ASTROD I goals. A second mission, ASTROD (ASTROD II) is envisaged as a three-spacecraft mission which would test General Relativity to 1 ppb, enable detection of solar g-modes, measure the solar Lense–Thirring effect to 10 ppm, and probe gravitational waves at frequencies below the LISA bandwidth. In the third phase (ASTROD III or Super-ASTROD), larger orbits could be implemented to map the outer solar system and to probe primordial gravitational-waves at frequencies below the ASTROD II bandwidth.

Wei-Tou NiEmail:

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Transportation costs and the spatial distribution of land use in the Brazilian Amazon   总被引：1，自引：0，他引：1  

Diana Weinhold  Eustaquio Reis 《Global Environmental Change》2008,18(1):54-68

We examine the question of whether reducing transport costs in the Amazon has lead to increased land clearing. Data on land clearing, transport costs and other related variables from 1975 to 1995 is analyzed using econometric approaches that exploit the dynamic time series dimension of the data to control for possible omitted variables and endogeneity. Our results suggest that the impact of changes in transport costs on clearing depends greatly on the initial land use. Specifically, we find that in regions where a greater proportion of the land is already cleared, reducing transport costs can lessen the rate of future clearing. On the other hand, reducing transport costs through areas that have seen little human activity is more likely to increase deforestation.  相似文献   

Short-Term Response of a Downstream Marine System to the Partial Opening of a Tidal-River Causeway     

Travis G. Gerwing  Diana J. Hamilton  Myriam A. Barbeau  Katy Haralampides  Gordon Yamazaki 《Estuaries and Coasts》2017,40(3):717-725

The spillway gates of the Petitcodiac Causeway, a hydraulic structure ~35 km upstream of the mouth of the Petitcodiac River in New Brunswick, Canada, were permanently opened in April 2010. The short-term effect opening the spillway gates had on downstream intertidal mudflats of the upper Bay of Fundy was investigated. Specifically, a multivariate before-after-control-impact design was used to determine if opening the spillway gates affected the invertebrate community (crustaceans, polychaetes, and molluscs), abiotic sediment conditions (sediment water content, mean particle size, penetrability, and depth of the apparent redox potential discontinuity), or resource availability (sediment chlorophyll a concentration and organic matter content) of five intertidal mudflats (two impacted sites, three reference sites) spanning Chignecto Bay, the northern arm of the upper Bay of Fundy, up to 5 months post-opening. No biologically or statistically meaningful differences were detected between impacted and reference sites for any of the measured variables. This suggests that opening the causeway did not have a quantifiable impact on these intertidal mudflats, at least within half a year of the opening. This is likely a result of the macrotidal nature of the Bay of Fundy that overwhelmed any immediate changes to hydrodynamics that occurred after the opening of the causeway gates.  相似文献   

Thermo-hydro-mechanical response of a large piled raft equipped with energy piles: a parametric study     

Diana Salciarini  Federica Ronchi  Claudio Tamagnini 《Acta Geotechnica》2017,12(4):703-728

This paper presents the results of a parametric study in which a series of fully coupled, 3-dimensional thermo-hydro-mechanical Finite Element (FE) analyses has been conducted to investigate the effects of the thermal changes imposed by the regular performance of a GSHP system driven by energy piles on a very large piled raft. The FE simulation program has been focused mainly on the evaluation of the following crucial aspects of the energy system design: the assessment of the soil–pile–raft interaction effects during thermal loading conditions; the quantification of the influence of the thermal properties of the soil and of the geometrical layout of the energy piles on the soil–foundation system response, and the evaluation of the influence of the active pile spacing on the thermal performance of the GSHP–energy pile system. The results of the numerical simulations show that the soil–pile–raft interaction effects can be very important. In particular, the presence of a relatively rigid raft in direct contact with the soil is responsible for axial load variations in inactive piles of the same order of those experienced by the thermo-active piles, even when the latter are relatively far and temperature changes in inactive piles are small. As far as the effect of pile spacing is concerned, the numerical simulations show that placing a high number of energy piles in a large piled raft with relatively small pile spacings can lead to a significant reduction of the overall heat exchange from the piles to the soil, thus reducing the thermal efficiency of the system.  相似文献   

The influence of<Emphasis Type="Italic">Phragmites</Emphasis> (common reed) on the distribution,abundance, and potential prey of a resident marsh fish in the Hackensack Meadowlands,New Jersey     

Diana?L.?RaichelEmail author  Kenneth?W.?Able  Jean?Marie?Hartman 《Estuaries and Coasts》2003,26(2):511-521

This study investigates the influence ofPhragmites australis (common reed) invasion on the habitat of the resident marsh fish,Fundulus heteroclitus (mummichog) in the Hackensack Meadowlands, New Jersey. These abundant fish play an important role in the transfer of energy from the marsh surface to adjacent subtidal waters and thus estuarine food webs. The objectives of this 2-yr study (1999 and 2000) were to compare the distribution and abundance of the eggs, larvae, juveniles, and adults of mummichog and their invertebrate prey inhabitingSpartina alterniflora-dominated marshes withPhragmites-dominated marshes, and to experimentally investigate the influence of marsh surface microtoprography on larval fish abundance withinPhragmites-dominated marshes. In 2000, we verified that egg deposition does occur inPhragmites-dominated marshes. In both years, the abundance of larvae and small juveniles (4–20 mm TL) inS. alterniflora was significantly greater than inPhragmites-dominated marshes, while larger juveniles and adults (>20 mm TL) were similarly abundant in both habitat types. The overall abundance of larvae and small juveniles was significantly greater in experimentalPhragmites plots in which microtopography was manipulated to resemble that ofSpartina marshes than inPhragmites control plots. Major groups of invertebrate taxa differed between marsh types with potential prey for larval fish being significantly more abundant inS. alterniflora marshes.Phragmites-dominated marshes may not provide the most suitable habitat for the early life-history stages of the mummichog. The low abundance of larvae and small juveniles inPhragmites marshes is likely due to inadequate larval habitat and perhaps decreased prey availability for these early life history stages.  相似文献   

Magnetic fabric of bulgarian loess sediments derived by using various sampling techniques     

Neli Jordanova  Diana Jordanova  Vassil Karloukovski 《Studia Geophysica et Geodaetica》1996,40(1):36-49

Summary The anistropy of low field magnetic susceptibility has been studied for seven outcrops of loess sediments in North-Eastern Bulgaria. Different sampling methods were applied in order to choose the best technique for obtaining the primary magnetic fabric of such unconsolidated sediments. AMS results show significant changes in the petrofabric of samples collected by the first technique which disturbs the original sedimentary fabric. The second applied technique does not cause such a strong deformation but some disturbance of the magnetic fabric is probable. Typical sedimentary fabric is obtained from hand samples and it is therefore concluded that this represents the best method for obtaining reliable AMS results from soft sediments.  相似文献   

News from State Ground-Water Associations     

Diana Sarnovsky 《Ground water》1991,29(6):925-925

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