Earth Sciences

Many studies reported the chlorite dissolution kinetics in acidic pH-resulting in the development of chlorite dissolution rate law covering the pH and temperature dependence-but they rarely discussed how various intrinsic factors, including chlorite types, structural complexity, and surface roughness (refers specifically to the ratio between Brunauer-Emmett-Teller surface area, BET SA, and geometric surface area, GSA, in this paper), influenced the chlorite dissolution rate or the mechanism for dissolution congruency. In this study, results obtained from mixed-flow reactor experiments performed on a Mg-rich chlorite, over a pH range of 2-6 at 25 • C and 95 • C, indicated that pH and temperature control not only the chlorite dissolution rate but also the congruency of element release. Low pH facilitated the dissolution of Fe from chlorite interlayers and caused incongruent element release rates at 25 • C, while higher temperature experiments at the same pH overcame the differences in surface reactivity between the interlayer and the tetrahedral-octahedral-tetrahedral (TOT) layer, and finally evolved into congruent dissolution. The lower pH also made chlorite dissolution more resistant to varying flow rates. A dissolution rate constant of 10 -10.51 mol/m 2 /s, a reaction order of 0.32, and activation energy of 42.03 kJ/mol were determined for the Mg-rich chlorite dissolution kinetics at 25 • C, in an acidenhanced mechanism. Longer-term reactive transport modeling (RTM) on the chlorite dissolution demonstrated that low pH and large specific surface area (SSA) decreased the chlorite percentage, bulk surface area, and saturation index quicker, and in a non-linear fashion. Chlorite with higher SSA lost more bulk surface area (BSA) than that with lower SSA, when the same mass of chlorite was dissolved. Through tabulating and recalculating a series of data from the literature, the combined effects of intrinsic and extrinsic factors-including chlorite type, BET SA/GSA ratio, and temperature-were explored. Fe-rich chlorite dissolves faster than Mg-rich chlorite in acid and neutral pH, due to the oxidative dissolution mechanism. The chlorite dissolution rate constant is linearly and positively correlated to BET SA/GSA for the same type of chlorite (Fe-rich and Mg-rich). Higher temperatures help reduce the effects of extrinsic and intrinsic factors on chlorite dissolution rates.

Many studies reported the chlorite dissolution kinetics in acidic pH-resulting in the development of chlorite dissolution rate law covering the pH and temperature dependence-but they rarely discussed how various intrinsic factors, including chlorite types, structural complexity, and surface roughness (refers specifically to the ratio between Brunauer-Emmett-Teller surface area, BET SA, and geometric surface area, GSA, in this paper), influenced the chlorite dissolution rate or the mechanism for dissolution congruency. In this study, results obtained from mixed-flow reactor experiments performed on a Mg-rich chlorite, over a pH range of 2-6 at 25 • C and 95 • C, indicated that pH and temperature control not only the chlorite dissolution rate but also the congruency of element release. Low pH facilitated the dissolution of Fe from chlorite interlayers and caused incongruent element release rates at 25 • C, while higher temperature experiments at the same pH overcame the differences in surface reactivity between the interlayer and the tetrahedral-octahedral-tetrahedral (TOT) layer, and finally evolved into congruent dissolution. The lower pH also made chlorite dissolution more resistant to varying flow rates. A dissolution rate constant of 10 -10.51 mol/m 2 /s, a reaction order of 0.32, and activation energy of 42.03 kJ/mol were determined for the Mg-rich chlorite dissolution kinetics at 25 • C, in an acidenhanced mechanism. Longer-term reactive transport modeling (RTM) on the chlorite dissolution demonstrated that low pH and large specific surface area (SSA) decreased the chlorite percentage, bulk surface area, and saturation index quicker, and in a non-linear fashion. Chlorite with higher SSA lost more bulk surface area (BSA) than that with lower SSA, when the same mass of chlorite was dissolved. Through tabulating and recalculating a series of data from the literature, the combined effects of intrinsic and extrinsic factors-including chlorite type, BET SA/GSA ratio, and temperature-were explored. Fe-rich chlorite dissolves faster than Mg-rich chlorite in acid and neutral pH, due to the oxidative dissolution mechanism. The chlorite dissolution rate constant is linearly and positively correlated to BET SA/GSA for the same type of chlorite (Fe-rich and Mg-rich). Higher temperatures help reduce the effects of extrinsic and intrinsic factors on chlorite dissolution rates.

Frozen volatiles make up an important volume fraction of the low-density moons of the outer solar system. Understanding the tectonic history of the surfaces of these moons, as well as the evolution of their interiors, requires knowledge of the mechanical strength of these icy materials under the appropriate planetary conditions (temperature, hydrostatic pressure, swain rate). We are conducting ongoing laboratory research to measure mechanical properties of several different ices under conditions that faithfully reproduce conditions both at the moons' surfaces (generally low temperature, to about 100 K, and low pressures) and in the deep interiors (wanner temperatures, pressures to thousands of atmospheres). We report here recent progress in two different phases of our work: rheology of ices in the NH3-H20 system at temperatures and strain rates lower than we have ever before explored, with application to the ammonia-rich moons of Saturn and Uranus; and the water ice I--->II phase transformation, whmh not only applies directly to process deep in the interiors of Ganymede and Callisto, but holds implications fox deep terrestrial earthquakes as well. Rheology of NH_-HzO Ices to T=130 K. The NH 3 proportion of condensed volatiles on icy moons, taken as a bulk average, may be as high as 0.15 of the H20 mass fraction (1). Natural refinement, especially through extraction of partial melts, can increase this fraction to that of the pure ammonia dihydrate (NH3-2H20) composition, about 0.29. We have carried out in the laboratory mechanical tests on samples of ammonia-water mixtures in the compositional range 0 to 29 wt. % NI-I3, at temperatures from above the peritectic melting temperature (176 K) to as low as 130 K, at confining pressures of 50 and 100 MPa and at strain rates from 3.5 × 10-_ to 3.5 × 10-7 s-1 (Fig. ). Our ability to deform at strain rates of 3.5 × 10 -7 s -1, and thus induce ductile flow at T<145 K without brittle failure, is the result of a recent hardware change that improved our low strain rate limit by an order of magnitude.

We report the results of exploratory measurements on the plastic yield strength of fully dense methane hydrate + quartz sand aggregates, and CO 2 hydrate + quartz sand aggregates, at conditions relevant to hydrate-bearing environments on Earth. We compare these results to those measured previously on pure end-member gas hydrates (sI methane hydrate, sI CO 2 hydrate, and sII methane-ethane hydrate) as well as to pure water ice and to ice + sand aggregate mixtures. All gas hydrates we have tested to date are exceptionally strong relative to ice, and hence may serve to increase the strength and cohesion of hydrate-bearing sediments significantly more than previously predicted. Lastly, we use cryogenic scanning electron microscopy (SEM) imaging techniques to examine the phase distribution, grain morphology, grain contacts, and textural evolution within the samples.

Earth&#39;s deepest earthquakes occur as a population in subducting or previously subducted lithosphere at depths ranging from about 325 to 690 km. This depth interval closely brackets the mantle transition zone, characterized by rapid seismic velocity increases resulting from the transformation of upper mantle minerals to higher‐pressure phases. Deep earthquakes thus provide the primary direct evidence for subduction of the lithosphere to these depths and allow us to investigate the deep thermal, thermodynamic, and mechanical ferment inside slabs. Numerical simulations of reaction rates show that the olivine → spinel transformation should be kinetically hindered in old, cold slabs descending into the transition zone. Thus wedge‐shaped zones of metastable peridotite probably persist to depths of more than 600 km. Laboratory deformation experiments on some metastable minerals display a shear instability called transformational faulting. This instability involves sudden failure by loc...

We review recent results concerning the theology of the lithosphere with special attention to the following topics: 1) the flexure of the oceanic lithosphere, 2) deformation of the continental lithosphere resulting from vertical surface loads and forces applied at plate margins, 3) the theological stratification of the continents, 4) strain localization and shear zone development, and 5) sCrain-induced crystallographic preferred orientations and anisotropies in body-wave velocities. We conclude with a section citing the 1983-1986 rock mechanics literature by category. CHARACTERIZATION OF FAULTED SURFACES AND DE-FORMED GOUGES..BI'o•n and •½holz [1983, 1984, 1985], Chester and Logan [1986], DarieN a•d Pollard [1986], De•9 et al. [1986], Hua•9 et al. [1985], W•lace a•d • S•TU ST•ZSS •ZSSU•Z•ZSTS W•T• •Z•, •T-TL• L•THOSPH•R•. MeGapr [1980], Zobac• a•d A•der-C•T•CL•ST•C D•rOgU•T•ON. A•derso• et al. [1983], Bitgel et al. [1985], Ble•%sop a•d R•tter [1986], WAite a•d WAite [1983].

Eclogitization of the basaltic and gabbroic layer in the oceanic crust involves a volume reduction of 10%-15%. One consequence of the negative volume change is the formation of a paired stress fi eld as a result of strain compatibility across the reaction front. Here we use waveform analysis of a tiny seismic cluster in the lower crust of the downgoing Pacifi c plate and reveal new evidence in favor of this mechanism: tensional earthquakes lying 1 km above compressional earthquakes, and earthquakes with highly similar waveforms lying on welldefi ned planes with complementary rupture areas. The tensional stress is interpreted to be caused by the dimensional mismatch between crust transformed to eclogite and underlying untransformed crust, and the earthquakes are probably facilitated by reactivation of fossil faults extant in the subducting plate. These observations provide seismic evidence for the role of volume change-related stresses and, possibly, fl uid-related embrittlement as viable processes for nucleating earthquakes in downgoing oceanic lithosphere.

Numerical models used in weather and climate prediction take into account a comprehensive set of atmospheric processes (i.e., phenomena) such as the resolved and unresolved fluid dynamics, radiative transfer, cloud and aerosol life cycles, and mass or energy exchanges with the Earth's surface. In order to identify model deficiencies and improve predictive skills, it is important to obtain processlevel understanding of the interactions between different processes. Conditional sampling and budget analysis are powerful tools for process-oriented model evaluation, but they often require tedious ad hoc coding and large amounts of instantaneous model output, resulting in inefficient use of human and computing resources. This paper presents an online diagnostic tool that addresses this challenge by monitoring model variables in a generic manner as they evolve within the time integration cycle. The tool is convenient to use. It allows users to select sampling conditions and specify monitored variables at run time. Both the evolving values of the model variables and their increments caused by different atmospheric processes can be monitored and archived. Online calculation of vertical integrals is also supported. Multiple sampling conditions can be monitored in a single simulation in combination with unconditional sampling. The paper explains in detail the design and implementation of the tool in the Energy Exascale Earth System Model (E3SM) version 1. The usage is demonstrated through three examples: a global budget analysis of dust aerosol mass concentration, a composite analysis of sea salt emission and its dependency on surface wind speed, and a conditionally sampled relative humidity budget. The tool is expected to be easily portable to closely related atmospheric models that use the same or similar data structures and time integration methods.

This study assesses the relative importance of time integration error in present-day climate simulations conducted with the atmosphere component of the Energy Exascale Earth System Model version 1 (EAMv1) at 1 • horizontal resolution. We show that a factor-of-6 reduction of time step size in all major parts of the model leads to significant changes in the long-term mean climate. Examples of changes in 10-year mean zonal averages include the following: H. Wan et al.: Time step sensitivities in EAMv1

The dominantly plutonic Canadian Coast Belt is flanked on the northwest by a Late Jurassic-Early Cretaceous intra-or back-arc basin. In the south it contains strata of the same age deposited in an accretionary fore-arc complex, east of a coeval arc. This distribution is ascribed to pre-mid-Cretaceous sinistral movement of part of the Jurassic-Cretaceous North American plate margin arc to a position west of the accretionary fore-arc complex.

created wetlands posed any problems for migratory waterfowl and was instrumental to this research by providing insight into farm operations. The authors also thank those that contributed time and effort in completing this study. Steve Moran contributed funding for water quality analyses. Dr. Dan Snow conducted the analyses of antibiotics in water and sediment samples. Brenda Berlowski and Heather Gutzman analyzed all samples for bacterial pathogens and assisted with sample collections. Jeff Runge monitored water quality during the summer and fall of 2000. Christina Lydick, Jeff Runge, Steve Lydick, Jeanette O'Neal, and John Meisner assisted with several aspects of the field work. Beth Goldowitz assisted with the logistics behind invertebrate diversity sampling and analysis. Jeff Drahota performed the waterfowl brood surveys. Dr. David Marx provided technical support on statistical analyses and performed the proc mixed analysis in SAS ®. Dr. James Rosowski provided technical support to identify algae. Andy Bishop helped construct site map figures. John Cochnar, Christina Lydick, Brenda Berlowski, Dan Martin, Craig Giggleman, and Dr. Dan Snow reviewed report drafts. Larry Gamble reviewed the report draft and coordinated project funding and sample submission.

One of the characteristics of petroleum industry in developing countries is incessant flare of gases with its attendant socio-ecological impacts. Gas flaring has not only contributed to poor environmental quality and pollution but play remarkable role in micro-climate modification. The aim of this study was to examine the effects of gas flaring on air quality of Ologbo flow station, Edo state. Data was collected for air within defined distances from the flaring point in accordance with standard procedure. A 4 km distance from the flare facility was buffered. Sampling sites 1, 2, and 3 are within the vicinity of the flare facility, while the control point (Evbuarhue) is located 30 km from the fence of the flare facility. Air Quality measurements were done for carbon monoxide (CO), nitrogen dioxide (NO2), methane CH4 and ammonia (NH3) using toxic gas monitors meter; toxic EEX 79 IICT3-T4 and CE89/336/EEC. The Ambient Air Quality and humidity were analyzed in situ using the standards a...

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Ricardo Sánchez-Murillo (1), Germain Esquivel-Hernández (1), Leonardo Corrales-Salazar (1), Laura Castro-Chacón (2), Ana María Durán-Quesada (3), Manuel Guerrero-Hernández (4), Valeria Delgado (5), Javier Barberena (5), Katia Montenegro-Rayo (5), Heyddy Calderón (6), Carlos Chevez (7), Tania Peña-Paz (8), Saúl García-Santos (8), Pedro Ortiz-Roque (9), Yaneth Alvarado-Callejas (10), Laura Benegas (10), Arturo Hernández-Antonio (11), Marcela Matamoros-Ortega (12), Lucía Ortega (13), and Stefan Terzer-Wassmuth (13)

Coffee-flux is a platform where collaborative research on coffee agroforestry is promoted: data are being shared between collaborators and positive interactions are enhanced. The philosophy is to concentrate several investigations on one specific site and for several years, to share a useful common experimental database, to develop modelling and to publish results in highly-ranked scientific journals. Applied research is also highly encouraged (e.g. C-Neutral certification, NAMA, Agronomy, etc.). Coffee-Flux benefits from infrastructure, easy access from CATIE and very good security, ready to welcome complementary scientific investigations and collaborations. The project is wide open to complementary projects, scientists and of course to students. The core data base is for sharing. The aim of Coffee-Flux is to assess carbon, nutrients, water and sediment Ecosystem Services (ES) at the scale of a coffee agroforestry watershed. Observation, experimentation, modelling and remote-sensin...

Prediction of ice mass flow and associated dynamics is pivotal at a time of climate change. Ice flow is dominantly accommodated by the motion of crystal defects -the dislocations. In the specific case of ice, their observation is not always accessible by means of the classical tools such as X-ray diffraction or transmission electron microscopy (TEM). Part of the dislocation population, the geometrically necessary dislocations (GNDs) can nevertheless be constrained using crystal orientation measurements via electron backscattering diffraction (EBSD) associated with appropriate analyses based on the Nye (1950) approach. The present study uses the Weighted Burgers Vectors, a reduced formulation of the Nye theory that enables the characterization of GNDs. Applied to ice, this method documents, for the first time, the presence of dislocations with non-basal [c] or < c+a > Burgers vectors. These [c] or < c+a > dislocations represent up to 35% of the GNDs observed in laboratory-deformed ice samples. Our findings offer a more complex and comprehensive picture of the key plasticity processes responsible for polycrystalline ice creep and provide better constraints on the constitutive mechanical laws implemented in ice sheet flow models used to predict the response of Earth ice masses to climate change.

Existing automated methods for the determination of ammonia in natural waters suffer from serious 'salt error' in estuaries because of changes in pH, ionic strength and optical properties with salinity. A modified automated indophenol blue method is described which minimizes the 'salt error' to less than 8% over the entire salinity of estuaries.

Monitoring drought in real-time using minimal field data is a challenge for ecosystem management and conservation. Most methods require extensive data collection and in-situ calibration and accuracy is difficult to evaluate. Here, we demonstrated how the space-borne canopy "thermal stress", defined as surface-air temperature difference, provides a reliable surrogate for drought-induced water stress in vegetation. Using physics-based relationships that accommodate uncertainties, we showed how changes in canopy water flux from ground-based measurements relate to both the surface energy balance and remotely-sensed thermal stress. Field measurements of evapotranspiration in the southeastern and northwestern US verify this approach based on sensitivity of evapotranspiration to thermal stress in a large range of atmospheric and climate conditions. We found that a 1 °C change in the thermal stress is comparable to 1-1.2 mm day -1 of evapotranspiration, depending on site and climate conditions. We quantified temporal and spatial sensitivity of evapotranspiration to the thermal stress and showed that it has the strongest relationship with evapotranspiration during warm and dry seasons, when monitoring drought is essential. Using only air and surface temperatures, we predicted the inter-annual anomaly in thermal stress across the contiguous United States over the course of 15 years and compared it with conventional drought indices. Among drought metrics that were considered in this study, the thermal stress had the highest correlation values. Our sensitivity results demonstrated that the thermal stress is a particularly strong indicator of water-use in warm seasons and regions. This simple metric can be used at varying time-scales to monitor surface evapotranspiration and drought in large spatial extents in near real-time.

In this report we review 239 records of 86 species and one hybrid recently assessed by the California Bird Records Committee (hereafter the Committee or CBRC). Of these records, 160 were accepted, yielding an acceptance rate (68%) consistent with the most recent reports (Roberson 1993, Patten and. This rate, however, is lower than in earlier reports, primarily for two reasons. First, in the recent reports, we have voted on a substantial number of historical records that have been published but not reviewed, and a higher percentage of these records has been rejected. Second, the Committee has become more conservative recently. For this report, records dating from 1956 to 1991 were reviewed, the majority being from the summer of 1990 through the spring of 1991. This report adds no species to the California list, which stands at 586 species. This "inactivity" is temporaw, as the acceptance of the Alder Flycatcher (Empidonax alnorum) will be reported in the 17th report and that of Great Frigatebird (Fregata minor) and Fork-tailed Flycatcher (Tyrannus savanna) in the 18th. Other potential additions to the state list under review are the Dark-rumped Petrel (Pterodroma phaeopygia), Manx Shearwate, r (Puffinus), and Black-tailed Gull (Larus crassirostris). The Band-rumped Storm-Petrel (Oceanodroma castro), on the state list by means of a single sight record, is being reconsidered. Outstanding decisions included in this report are the acceptance of California's second record of Stejneger's Petrel (Pterodroma 1ongirostris) and the rejection of prospective first state records of Townsend's Sheareeater (Puffin us a u ricu la r/s), the Band-tailed (Larus belcheri), Iceland (L. glaucoides) and Swallow-tailed Gulls (Creagrus furcatus), and the Oriental Turtle-Dove (Streptopelia orientalis). All records reviewed by the CBRC are archived at the Western Foundation of Vertebrate Zoology, 439 Calle San Pablo, Camarillo, CA 93010. All CALIFORNIA BIRD RECORDS forms of documentation (written descriptions, photographs, recordings, videotapes, etc.) are housed at the foundation, where they are organized taxonomically and by CBRC record number. All are available for public review. The CBRC solicits information on all occurrences in California of species on its Review List (see Roberson 1993) and requests that documentation be sent to Michael A.

The areal exposure of continental shelves during glacial sea level lowering enhanced the transfer of erodible reactive organic matter to the open ocean. Sea level fall also activated submarine canyons thereby allowing large rivers to deposit their particulate load, via gravity flows, directly in the deep-sea. Here, we analyze the effects of shelf erosion and particulate matter re-routing to the open ocean during interglacial to glacial transitions, using a coupled model of the marine phosphorus, organic carbon and oxygen cycles. The results indicate that shelf erosion and submarine canyon formation may significantly lower deep-sea oxygen levels, by up to 25%, during sea level low stands, mainly due to the supply of new material from the shelves, and to a lesser extent due to particulate organic matter bypassing the coastal zone. Our simulations imply that deep-sea oxygen levels can drop significantly if eroded shelf material is deposited to the seafloor. Thus the glacial ocean's oxygen content could have been significantly lower than during interglacial stages. Primary production, organic carbon burial and dissolved phosphorus inventories are all affected by the erosion and rerouting mechanisms. However, re-routing of the continental and eroded shelf material to the deep-sea has the effect of decoupling deep-sea oxygen demand from primary productivity in the open ocean. P burial is also not affected showing a disconnection between the biogeochemical cycles in the water column and the P burial record.

Peatlands are wetlands that provide important ecosystem services including carbon sequestration and water storage that respond to hydrological, biological, and biogeochemical processes. These processes are strongly influenced by the complex pore structure of peat soils. We explore the literature on peat pore structure and the implications for hydrological, biogeochemical, and microbial processes in peat, highlighting the gaps in our current knowledge and a path to move forward. Peat is an elastic and multi-porous structured organic soil. Surficial (near-surface) peats are typically dominated by large interconnected macropores that rapidly transmit water and solutes when saturated, but these large pores drain rapidly with a reduction in pore-water pressure, and disproportionally decrease the bulk effective hydraulic conductivity, thus water fluxes that drive ecohydrological functions. The more advanced state of decomposition of older (deeper) peat, with a greater abundance of small pores, restricts the loss of moisture at similar soil water pressures and is associated with higher unsaturated hydraulic conductivities. As evaporation and precipitation occur, peat soils shrink and swell, respectively, changing the hydrological connectivity that maintain physiological processes at the peat surface. Due to the disproportionate change in pore structure and associated hydraulic properties with state of decomposition, transport processes are limited at depth, creating a zone of enhanced transport in the less decomposed peat near the surface. At the micro-scale, rapid equilibration of solutes and water occurs between the mobile and immobile pores due to diffusion, resulting in pore regions with similar chemical concentrations that are not affected by advective fluxes. These immobile regions may be the primary sites for microbial biogeochemical processes in peat. Mass transfer limitations may therefore largely regulate belowground microbial turnover and, hence, biogeochemical cycling. For peat, the development of a comprehensive theory that links the hydrological, biological, and biogeochemical processes will require a concerted interdisciplinary effort. To that end, we have highlighted four primary areas to focus our collective research: 1) understanding the combined and interrelated effects of parent material, decomposition, and nutrient status on peat pore connectivity, macropore development and collapse, and solute transport, 2) determining the influence of changing pore structure due to freeze-thaw or dewatering on the hydrology and biogeochemistry, 3) better elucidating the non-equilibrium transport processes in peat, and 4) exploring the implications of peat's pore structure on microbiological and biogeochemical processes.

A novel methodology for predicting upward diffusive fluxes of dissolved methane in gassy marine sediments is pcesented, The predicted fluxes are derived from a set of theoretical simulation data generated using a diagenetlc reaction-transport model. The model calculates the upward methane flux for a given free gas depth (FGD) below the sedoor and a given in situ gas solubility, which together define the methane concentration gradient. Fluxes can thus be extracted from a nomogram of FGD and solubility parameter space. Because, in general, microorganisms anaerobically oxidize all dissolved methane before it can escape the &men4 the estimated fluxes are equivalent to the amount of methane trapped by this subsurface microbial barrier. A test of the approach using measured methane fluxes from Aarhus Bay, Denmark, reveals a statistically significant correlation between the observed and predicted fluxes. rhe predicted fluxes further show a low sensitivity toward enhanced sediment mixing by faunal activity, a* well as the deposition flux and reactivity of Organic matter. Therefore, only a iimited amount of data at strategic coring sites is required to constrain the major physical and geochemical forcings for a particular study area in order to extraplate fluxes at a regional scale. Because the FGD can be mapped over large areas of the seafloor from shipboard seismic survey, the new approach r e p resents a means to estimate regional methane flux budgets for g m y sediments in a cost-efficient manner. @ 2w 'he Geological Society of America. For permission to copy, contact Copyright Permissions, GSA, or

We present a one-dimensional reactive transport model to estimate benthic fluxes of dissolved inorganic carbon (DIC) and alkalinity (A T ) from coastal marine sediments. The model incorporates the transport processes of sediment accumulation, molecular diffusion, bioturbation and bioirrigation, while the reactions included are the redox path-BGD

Deep-focus earthquakes, located in very high-pressure conditions 300 to 700 km below the Earth's surface within sinking slabs of relatively cold oceanic lithosphere, are mysterious phenomena. The largest recorded deep-focus earthquake (M W 7.9) in the Izu-Bonin slab struck on 30 May 2015 beneath the Ogasawara (Bonin) Islands, isolated from prior seismicity by over 100 km in depth, and followed by only a few small aftershocks. Globally, this is the deepest (680 km centroid depth) event with M W ≥ 7.8 in the seismological record. Seismicity indicates along-strike contortion of the Izu-Bonin slab, with horizontal flattening near a depth of 550 km in the Izu region and rapid steepening to near-vertical toward the south above the location of the 2015 event. This event was exceptionally well-recorded by seismic stations around the world, allowing detailed constraints to be placed on the source process. Analyses of a large global data set of P, SH and pP seismic phases using short-period back-projection, subevent directivity, and broadband finite-fault inversion indicate that the mainshock ruptured a shallowlydipping fault plane with patchy slip that spread over a distance of ~40 km with a multistage expansion rate (~5+ km/s down-dip initially, ~3 km/s up-dip later). During the 17 s total rupture duration the radiated energy was ~3.3 x 10 16 J and the stress drop was ~38 MPa. The radiation efficiency is moderate (0.34), intermediate to that of the 1994 Bolivia and 2013 Sea of Okhotsk M W 8.3 deep earthquakes, indicating that source processes of very large deep earthquakes sample a wide range of behavior from dissipative, more viscous failure to very brittle failure. The isolated occurrence of the event, much deeper than the apparently thermally-bounded distribution of Bonin-slab seismicity above 600 km depth, suggests that localized stress concentration associated with the pronounced deformation of the Izu-Bonin slab and proximity to the 660-km phase transition likely played a dominant role in generating this major earthquake.

Finite-source rupture models for the great 11 March 2011 off the Pacific coast of Tohoku (M w 9.0) Earthquake obtained by inversions of seismic waves and geodetic observations are used to reconstruct deep-water tsunami recordings from DART buoys near Japan. One model is from least-squares inversion of teleseismic P waves, and another from iterative least-squares search-based joint inversion of teleseismic P waves, short-arc Rayleigh wave relative source time functions, and high-rate GPS observations from northern Honshu. These rupture model inversions impose similar kinematic constraints on the rupture growth, and both have concentrations of slip of up to 42 m up-dip from the hypocenter, with substantial slip extending to the trench. Tsunami surface elevations were computed using the model NEOWAVE, which includes a vertical momentum equation and a non-hydrostatic pressure term in the nonlinear shallow-water equations to account for the time-history of seafloor deformation and propagation of weakly dispersive tsunami waves. Kinematic seafloor deformations were computed using the Okada solutions for the rupture models. Good matches to the tsunami arrival times and waveforms are achieved for the DART recordings for models with slip extending all the way to the trench, whereas shifting fault slip toward the coast degrades the predictions.

Understanding how tectonics, climate and lithology interact to control fluvial erosion is complicated because these factors are spatially-variable and they may not be well-represented by mean values. We address these complications using eight new and 54 published 10 Be catchment-wide fluvial erosion rates from the south-central Andes. We assess how tectonics, climate, lithology, and topography control erosion through bivariate and multivariate Bayesian regression analysis. We first compare catchment-wide mean values of independent variables compared to other summary statistics and find that metrics that capture extreme values (e.g., 90th percentile) and spatial variability (e.g., 90th minus 10th percentile) produce stronger correlations. This suggests that catchment-wide means may oversimplify the roles of tectonics, climate, and lithology in influencing erosion rates. We find that the overall variability of erosion rates in the south-central Andes is best explained by a combination of lithologic resistance and spatial variability in both vegetation (using the normalized difference vegetation index, NDVI) and topography (using specific stream power). Despite poor bivariate correlations, both lithologic resistance and spatial variability of specific stream power are significant regressors in our multivariate modeling. Lithology influences the relationship (i.e., linearity) between topography and erosion rates. Spatial variability of NDVI produces the strongest correlation with erosion rates of any of the variables we consider. Hence, spatial variability of NDVI both accounts for potential non-uniform vegetation responses to climate and also incorporates the role of both humid climates (high 90th percentile) and large bare regions (low 10th percentile) within a single catchment.

Tropical peatlands are a major, but understudied, biophysical feedback factor on the atmospheric greenhouse effect. The largest expanses of tropical peatlands are located in lowland areas of Southeast Asia and the Amazon basin. The Loreto Region of Amazonian Peru contains ~63,000 km 2 of peatlands. However, little is known about the biogeochemistry of these peatlands, and in particular, the cycling of carbon dioxide (CO 2 ) and methane (CH 4 ), and their responses to hydrometeorological forcings. To address these knowledge gaps, we established an eddy covariance (EC) flux tower in a natural palm (Mauritia flexuosa L.f.) swamp peatland near Iquitos, Peru. Here, we report ecosystem-scale CO 2 and CH 4 flux observations for this Amazonian palm swamp peatland over a two-year period in relation to hydrometeorological forcings. Seasonal and short-term variations in hydrometeorological forcing had a strong effect on CO 2 and CH 4 fluxes. High air temperature and vapor pressure deficit (VPD) exerted an important limitation on photosynthesis during the dry season, while latent heat flux appeared to be insensitive to these climate drivers. Evidence from light-response analyses and flux partitioning support that photosynthetic activity was downregulated during dry conditions, while ecosystem respiration (RE) was either inhibited or enhanced depending on water table position. The cumulative net ecosystem CO 2 exchange indicated that the peatland was a significant CO 2 sink ranging from -465 (-279 to -651) g C m -2 y -1 in 2018 to -462 (-277 to -647) g C m -2 y -1 in 2019. The forest was a CH 4 source of 22 (20 to 24) g C m -2 y -1 , similar in magnitude to other tropical peatlands and larger than boreal and arctic peatlands. Thus, the annual carbon budget of this Amazonian palm swamp peatland appears to be a major carbon sink under current hydrometeorological conditions. , representing an important biophysical feedback on Earth's radiative forcing . Furthermore, when they are disturbed, and especially when drained for agriculture, they can become a major CO 2 source . It is important, therefore, to understand the role that intact tropical peatlands play in terms of their net biogeochemical forcing on

Crustal Structure Convener:*Ayako Nakanishi(Institute for Frontier Research on Earth Evolution, Japan Agency for MarineEarth Science and Technology), Chair:Ayako Nakanishi(Institute for Frontier Research on Earth Evolution, Japan Agency for Marine-Earth Science and Technology) Wed. Apr 30, 2014 2:15 PM 4:00 PM 315 (3F) The aim of this session is to cover seismological and geophysical studies on the Earth&#39;s crust. Contribution on seismological and geophysical structure of the crust, processes that develop in the crust which include earthquakes, volcanoes and geological descriptions of the crust are welcomed. We also welcome theoretical and methodological studies that will serve as basics in such explorations.

The cross section and decay angular distributions for the coherent φ-meson photoproduction on the deuteron have been measured for the first time up to a squared four-momentum transfer t = (p γp φ ) 2 = -2 GeV 2 /c 2 , using the CLAS detector at the Thomas Jefferson National Accelerator Facility. The cross sections are compared with predictions from a rescattering model. In a framework of vector meson dominance, the data are consistent with the total φ-N cross section σ φN at about 10 mb. If vector meson dominance is violated, a larger σ φN is possible by introducing a larger t slope for the φN → φN process than that for the γ N → φN process. The decay angular distributions of the φ are consistent with helicity conservation.

The spin structure functions g1 for the proton and the deuteron have been measured over a wide kinematic range in x and Q 2 using 1.6 and 5.7 GeV longitudinally polarized electrons incident upon polarized NH3 and ND3 targets at Jefferson Lab. Scattered electrons were detected in the CEBAF Large Acceptance Spectrometer, for 0.05 < Q 2 < 5 GeV 2 and W < 3 GeV. The first moments of g1 for the proton and deuteron are presented -both have a negative slope at low Q 2 , as predicted by the extended Gerasimov-Drell-Hearn sum rule. The first extraction of the generalized forward spin polarizability of the proton γ p 0 is also reported. This quantity shows strong Q 2 dependence at low Q 2 . Our analysis of the Q 2 evolution of the first moment of g1 shows agreement in leading order with Heavy Baryon Chiral Perturbation Theory. However, a significant discrepancy is observed between the γ p 0 data and Chiral Perturbation calculations for γ p 0 , even at the lowest Q 2 .

Beam-helicity asymmetries for the two-pion-photoproduction reaction γp → pπ + π -have been studied for the first time in the resonance region for center-of-mass energies between 1.35 GeV and 2.30 GeV. The experiment was performed at Jefferson Lab with the CEBAF Large Acceptance Spectrometer using circularly polarized tagged photons incident on an unpolarized hydrogen target. Beam-helicity-dependent angular distributions of the final-state particles were measured. The large cross-section asymmetries exhibit strong sensitivity to the kinematics and dynamics of the reaction. The data are compared with the results of various phenomenological model calculations, and show that these models currently do not provide an adequate description for the behavior of this new observable.

continuous support of my master's study and research, for his patience, motivation and immense knowledge. His invaluable guidance helped me in all the time of research and writing of this thesis. Besides my advisor, I would like to thank the rest of my thesis committee Dr. Neil S. Grigg and Dr. Michael J. Ronayne. My sincere thanks also go to all of the kind people I met in Colorado, who supported me through my studies. Last but not least, I would like to thank my beloved family, my parents Salwa El-Banna and Salah El-Kurdi, my brother Wael and my two sisters Sarah and Raghda for supporting me throughout my life; for their understanding & endless love.

Secondary ion mass spectrometry and electron microprobe studies demonstrated that melt inclusions in magnesian olivine bear evidence of the composition and formation conditions of the primary melts and their mixing products, including the initial water contents of the mantle melts. This information is partially or completely obliterated in the compositions of rocks and glasses by later processes of mixing, contamination, degassing, and crystal fractionation. The typical oceanic basalt of the Mid-Atlantic Ridge is shown to have formed through the mixing of primary melts that were derived by the critical melting of a mantle column, more than 50 km thick. The melting began in the presence of garnet and proceeded in an open system which could retain no more than 2-3 wt % melt. The mixing of the primary melts took place both in magma chambers, simultaneously with crystallization and, probably, during melt transport through the mantle. The initial concentrations of H 2 O in the mantle magmas of suprasubduction zones were as high as 2-3 wt %, which is significantly higher than was estimated previously. No correlation was found between the concentrations of H 2 O in the primary MORB magmas and those of elements with a similar incompatibility degree (La, Ce, K). This fact may indicate the continuous interaction of the melts with H 2 O-bearing CO 2 -rich fluid.

The Earth has made about 800 rotations around itself since I started my Master's in Informatics. It is inestimable for me how much I have been growing in terms of scientific maturity from then on. First of all, I would like to thank my family and my dear girlfriend Marcelle Olivier for all the support they provided me with along that time. Without their comprehension and encouragement, the work reported in this thesis would not be possible. I am also grateful to my English teacher Sarah for her pleasant dedication in the improvement of my English. In the context of UFES, the first person for whom I owe this opportunity and would like to express my gratitude is prof. Rosane Caruso. She has been the first person who believed me as a student and applicant for scientific initiation. Furthermore, her passion for Logics has inspired plenty of students at UFES/DI, and me in particular. Thanks a lot, Rô! The next person who I am indebted to is prof. José Gonçalves Pereira Filho. He is responsible for over my two first years of scientific initiation. Although our discussions were unfortunately always with time to end due to his uncountable number of important duties, they were always funny, fruitful and inspiring. He dedicated his time on the task of making me a technical writer. Zé Gonçalves is also an admirable person due to his belief in and fight for making Brazil, in general, and Espírito Santo, in particular, a nice place in terms of higher education. But among many other good things, the most important one that comes to my mind when I think of Zé Gonçalves, is that in the most difficult situations I was in, he was there for me. Thank you very much for all, Zé! Now it is time to put prof. Giancarlo Guizzardi in the story. Since Giancarlo came to UFES in 2006 my vision of research and Computer Science has been greatly expanded. The very first lecture I took from him was for me such a breakthrough that sometimes I find myself grateful to life for putting me in the right place at the right time. Since then Giancarlo has been for me a kind of "best partner", to cite an expression brought by Renata Guizzardi. This partnership means for me somewhat I see in reading Ancient Philosophy, like in the ancient initiation of young students in Philosophy. If I would have to choose one aspect of Giancarlo's guidance which has been the most fundamental for me, I would say that it is the very balance between rationality and passion in seeking the truth. For three years he has been encouraging me in doing research with scientific impartiality, but also with a pre-socratic-like enthusiasm. Gian, I have no words to express my gratitude for all that you have been teaching me, even implicitly. Thank you for reading every page of this thesis; but above all, thank you for showing me the way to become an ontologist. I would also like to thank prof. Berilhes Garcia for being gently open for a number of coffee breaks which the subject of discussion somehow insisted to fall into Philosophy of Science. I'm lucky as well to have had the opportunity to do this Master's course besides Veruska Zamborlini, Raphael Santos and Felipe Frechiani. Either in technical discussions or in coffee breaks and happy hours, they have been essential parts of my master's trajectory. Veruska has been a great research colleague, who contributed significantly to the work reported on this thesis. Raphael and Felipe in turn, besides our good discussions about research, are mostly my "programming partners", always there for sharing nice programming tips. Finally, I would like to thank my classmates from the graduation in Computer Science at UFES; my colleagues André Costa and Luiz Rodrigo from the TeleCardio project; William Hisatugu for being a very nice lab colleague; and also all professors from whom I took lectures at UFES/DI.

The limited availability of high-resolution continuous archives, insufficient chronological control, and complex hydro-climatic forcing mechanisms lead to many uncertainties in palaeo-hydrological reconstructions for the Western Mediterranean. In this study we present a newly recovered 19.63 m long core from Lake Sidi Ali in the North African Middle Atlas, a transition zone of Atlantic, Western Mediterranean and Saharan air mass trajectories. With a multi-proxy approach based on magnetic susceptibility, carbonate and total organic C content, core-scanning and quantitative XRF, stable isotopes of ostracod shells, charcoal counts, Cedrus pollen abundance, and a first set of diatom data, we reconstruct Western Mediterranean hydro-climatic variability, seasonality and forcing mechanisms during the last 12,000 yr. A robust chronological model based on AMS 14 C dated pollen concentrates supports our highresolution multi-proxy study. Long-term trends reveal low lake levels at the end of the Younger Dryas, during the mid-Holocene interval 6.6 to 5.4 cal ka BP, and during the last 3000 years. In contrast, lake levels are mostly high during the Early and Mid-Holocene. The record also shows sub-millennial-to centennial-scale decreases in Western Mediterranean winter rain at 11.4,

Metabolic and thermoregulatory variables of six rodent species inhabiting a desert environment were compared with those of six species inhabiting mesic environments. The results of such a comparison show that species originating in deserts are more efficient in conserving energy and presumably water when compared with those species originating in mesic habitats. Reduced resting metabolic rates (RMR) which characterize desert species are an important adaptation. However, the ability to inhabit mesic or very cold environments by such species is achieved through different morphological, physiological or behavioural adaptations, and not by an increase in RMR values. Nonshivering thermogenesis (NST) seems to be an important physiological adaptation in such desert rodents. The relatively high values of NST capacity found in desert species seem to compensate for their low RMR values.

Two ways of aerosols spreading analysis in atmosphere are presented. The first one is based on the one-level barotropic models. This case includes the simple tests of the numerical simulations spreading of a clouds of contaminants in free atmosphere. The solutions for this example was obtained using the non-divergent equation of the quasi-solenoidal or quasi-geostrophic models in the barotropic approaches. The considered equation is a nonlinear differential equation of Monge-Ampere (MA) type used for determining a streamfunction field when the geopotential field is known. It is obtained by transforming the governing equations and assuming that the divergence of wind field is equal to zero. The nonlinear balance equation is a part of the general system equations describing quasi-solenoidal or quasi-geostrophic models. The second way of the analysis is based on the COAMPS (Coupled Ocean/Atmosphere Mesoscale Prediction System) non-hydrostatic numerical weather prediction model develope...

The beta lactamase gene blaCTX-M, responsible of the resistance to cephalosporins, has been detected in microbes from hospitals to open waters. We studied the seasonality and stability of blaCTX-M in Lake Maggiore over 3 years and the role of potential inputs of allochthonous bacteria and/or antibiotic pollution in promoting its occurrence. blaCTX-M was mainly present from January to July in the pelagic microbial community and the gene occurrence was significantly related to low water temperature. To evaluate its temporal stability in the bacterial community over a short period, we measured blaCTX-M daily over the course of 6 days. The gene was below the limit of quantification except for one sampling when its abundance peaked, suggesting a point contamination. The bacterial community of the lake in which blaCTX-M was detected suggests that at least two distinct bacterial populations contained the gene. The occurrence of known blaCTX-M containing genera and the occurrence of the gene, however, did not overlap. Furthermore, the experimental addition of cefotaxime to lake water incubations did not promote abundance of the gene. These data imply that blaCTX-M was present in the environmental microbial community. Increases of gene abundances were likely caused by environmental parameters other than antibiotic contamination.

Collisions of spacecraft in orbit with Space Debris (SD) or Micro-Meteoroids (MM) lead to payload degradation, anomalies or failures in spacecraft operation or even to loss of a whole mission. Existing flux models and impact risk assessment tools, like MASTER or ORDEM, PIRAT, ESABASE2 and BUMPER II are used to analyze the mission risk concerning this hazard potential. The validation of the flux models so far is partly based on SD and MM impact data from in-situ impact detectors, e.g. DEBIE, GORID, capture cells and on the analyses of retrieved hardware from space, e.g. LDEF, HST or EURECA. However the knowledge on the small objects populations (millimeter down to micron sized) in space is rather limited and needs to be enhanced for reliable models. As a contribution Deto soft-ware validation in terms of data acquisition, a new type of impact detector is currently under development at DLR. The Solar Generator based Space Debris Impact Detector (SOLID) makes use of spacecraft solar pa...

We exploit the advanced Interferometric Synthetic Aperture Radar (InSAR) technique referred to as the Small BAseline Subset (SBAS) algorithm to analyze the creeping section of the San Andreas Fault in Central California. Various geodetic creep rate measurements along the Central San Andreas Fault (CSAF) have been made since 1969 including creepmeters, alignment arrays, geodolite, and GPS. They show that horizontal surface displacements increase from a few mm/yr at either end to a maximum of up to ~34 mm/yr in the central portion. They also indicate some discrepancies in rate estimates, with the range being as high as 10 mm/yr at some places along the fault. This variation is thought to be a result of the different geodetic techniques used and of measurements being made at variable distances from the fault. An interferometric stack of 12 interferograms for the period 1992-2001 shows the spatial variation of creep that occurs within a narrow (&lt;2 km) zone close to the fault trace. T...

The hydrogeologic influence of the Elkhorn fault in South Park, Colorado, USA, is examined through hydrologic data supplemented by electrical resistivity tomography and self-potential measurements. Water-level data indicate that groundwater flow is impeded by the fault on the spatial scale of tens of meters, but the lack of outcrop prevents interpretation of why the fault creates this hydrologic heterogeneity. By supplementing hydrologic and geologic data with geoelectrical measurements, further hydrogeologic interpretation is possible. Resistivity profiles and self-potential data are consistent with the interpretation of increased fracturing within 70m of the fault. Further interpretation of the fault zone includes the possibility of a vertical groundwater flow component in a fractured and relatively high permeability damage zone and one or more relatively low permeability fault cores resulting in a conduit-barrier behavior of the fault zone at the meter to tens-of-meters scale. Calculated hydraulic heads from the self-potential data reveal additional complexity in permeability structure, including a steeper hydraulic gradient immediately west of the interpreted fault trace than suggested by the well data alone.

In this study we present a list of invasive/potential invasive alien species in the East and South European Network for Invasive Alien Species (ESENIAS) countries with marine borders. The species were classified according to the existing literature and experts’ judgment, as established, casual, invasive and expected. Finally, factsheets were compiled for ten species of high importance based on their expanding/invading character. Of the 160 species comprising the list, 149 were already present in the ESENIAS countries, while eleven were invasive species either present in the Mediterranean or in other European Seas, likely to be recorded in the ESENIAS countries. The majority of the species were of Red Sea/IndoPacific origin (97 species; 60.6%). Italy, Turkey and Greece were the countries with the highest representation of species (159, 152 and 139 species respectively), due to their extended coastline and the number of scholars working on marine invasive species. The highest number o...

Wetlands cover a small portion of the world, but have disproportionate influence on global carbon (C) sequestration, carbon dioxide and methane emissions, and aquatic C fluxes. However, the underlying biogeochemical processes that affect wetland C pools and fluxes are complex and dynamic, making measurements of wetland C challenging. Over decades of research, many observational, experimental, and analytical approaches have been developed to understand and quantify pools and fluxes of wetland C. Sampling approaches range in their representation of wetland C from short to long timeframes and local to landscape spatial scales. This review summarizes common and cutting-edge methodological approaches for quantifying wetland C pools and fluxes. We first define each of the major C pools and fluxes and provide rationale for their importance to wetland C dynamics. For each approach, we clarify what component of wetland C is measured and its spatial and temporal representativeness and constraints. We describe practical considerations for each approach, such as where and when an approach is typically used, who can conduct the measurements (expertise, training requirements), and how approaches are conducted, including considerations on equipment complexity and costs. Finally, we review key covariates and ancillary measurements that enhance the interpretation of findings and facilitate model development. The protocols that we describe to measure soil, water, vegetation, and gases are also relevant for related disciplines such as ecology. Improved quality and consistency of data collection and reporting across studies will help reduce global uncertainties and develop management strategies to use wetlands as nature-based climate solutions.