Combined characterisation of GOME and TOMS total ozone measurements from space using ground-based observations from the NDSC

Several years of total ozone measured from space by the ERS-2 GOME, the Earth Probe TOMS, and the ADEOS TOMS, are compared with high-quality ground-based observations associated with the Network for the Detection of Stratospheric Change (NDSC), over an extended latitude range and a variety of geophysical conditions. The comparisons with each spaceborne sensor are combined altogether for investigating their respective solar zenith angle (SZA) dependence, dispersion, and difference of sensitivity. The space- and ground-based data are found to agree within a few percent on average. However, the analysis highlights for both GOME and TOMS several sources of discrepancies: (i) a SZA dependence with TOMS beyond 80° SZA; (ii) a seasonal SZA dependence with GOME beyond 70° SZA; (iii) a difference of sensitivity with GOME at high latitudes; (iv) a difference of sensitivity to low ozone values between satellite and SAOZ sensors around the southern tropics; (v) a north/south difference of TOMS with the ground-based observations; and (vi) internal inconsistencies in GOME total ozone. © 2001 COSPAR. Published by Elsevier Science Ltd. All rights reserved.

The use of shallow seismic reflection technique in near surface exploration of urban sites: An evaluation in the city of SãO Paulo, Brazil

In order to evaluate the use of shallow seismic technique to delineate geological and geotechnical features up to 40 meters depth in noisy urban areas covered with asphalt pavement, five survey lines were conducted in the metropolitan area of São Paulo City. The data were acquired using a 24-bit, 24-channel seismograph, 30 and 100 Hz geophones and a sledgehammer-plate system as seismic source. Seismic reflection data were recorded using a CMP (common mid point) acquisition method. The processing routine consisted of: prestack band-pass filtering (90-250 Hz); automatic gain control (AGC); muting (digital zeroin) of dead/noisy traces, ground roll, air-wave and refracted-wave; CMP sorting; velocity analyses; normal move-out corrections; residual static corrections; f-k filtering; CMP stacking. The near surface is geologically characterized by unconsolidated fill materials and Quaternary sediments with organic material overlying Tertiary sediments with the water table 2 to 5 m below the surface. The basement is composed of granite and gneiss. Reflections were observed from 40 milliseconds to 65 ms two-way traveltime and were related to the silt clay layer and fine sand layer contact of the Tertiary sediments and to the weathered basement. The CMP seismic-reflection technique has been shown to be useful for mapping the sedimentary layers and the bedrock of the São Paulo sedimentary basin for the purposes of shallow investigations related to engineering problems. In spite of the strong cultural noise observed in these urban areas and problems with planting geophones we verified that, with the proper equipment, field parameters and particularly great care in data collection and processing, we can overcome the adverse field conditions and to image reflections from layers as shallow as 20 meters.

Birds of a eucalyptus woodlot in interior São Paulo.

Some 255 birds were recorded between 1982-2001 in and near a 2314-ha Horto of old eucalyptus plantations with native understory and a lake, near Rio Claro, in central São Paulo, Brazil. This is close to the 263 recorded in and around a ten-times smaller nearby 230-ha woodlot of semideciduous forest. Different species were 44, for a total of 307 in both areas. One hundred and fifty nonvagrant forest and border species were recorded in 1982-86, a number close to the 152 in the small native woodlot. With dry years and logging of plots in 1985-93, 21 of the 150 species were lost, 42 species decreased in numbers, 49 were stable, 19 increased (15 being border species), and 5 entered (one of dry forest and 4 of borders), so 129 species remained in 1996-2001 compared to 133 in the native woodlot. Open-area birds were 33, versus 50 in better-checked grassy swales in sugar cane near the natural woodlot, for a total of 53. Several species, like some border ones, did not enter the open but isolated and mowed interior lake area, or took years to do so. Water and marsh birds were 46 versus 40 in smaller creeks and ponds near the natural woodlot (total, 55) but many were migrants or infrequent visitors using distant areas, and perhaps should be counted as 0.1-0.9 local species rather than 1 species. Use of this more accurate method would reduce waterbird totals by 14 species in the Horto and by 11 around the native woodlot. I also recommend longer censusing at the edges in large woodlots or many edge species will be recorded only in small fragments of habitat. Several species increased and others decreased with occasional cat-tail and water-lily cleanups at the lake. A forested corridor between the Horto and natural woodlot is recommended, with old eucalyptus left to provide flowers for hummingbirds.

Specific depth cone resistivity measurements to determine soil engineering properties

The University of British Columbia (UBC) began performing piezocone penetration tests (CPTU) with electrical resistivity measurements (RCPTU) in 1989. Since then, RCPTU research at UBC has focused on obtaining geo-environmental parameters such as fluid resistivity and soil engineering properties such as porosity and degree of saturation from measurements of bulk soil electrical resistivity using the empirical relationship proposed by Archie (1942). Within this framework, the paper illustrates and discusses important design and calibration issues for resistivity modules such as the use of isolated circuitry to achieve linear calibrations over large ranges of resistivity. The suitability of RCPTU measurements for determination of geo-environmental and geotechnical parameters are assessed using typical ranges of soil and groundwater properties and methods of isolating individual factors for study are discussed. Illustrative examples of RCPTU research efforts including the environmental characterization of mine tailings, delineation of saline water intrusions in fresh water aquifers and the quality control of geotechnical ground densification are presented throughout the text. It is shown that groundwater temperature and hence ion mobility is not significantly altered by frictional heat generated during piezocone penetration and that ratio-based approaches to monitoring soil porosity can be used to eliminate the requirement for extensive groundwater sampling programs. Lastly, it is shown that RCPTU measurements above the water table can only be made using resistivity modules that are stable over a large range of resistivities and that such measurements are the most difficult to interpret because of grain surface conduction effects and generally unknown fluid resistivities.

Resistivity piezocone for geo-environmental site characterization: Two case histories from Brazil

This paper presents two case histories from Brazil where geophysical and resistivity piezocone tests were carried out to detect contamination. At the first one, the site investigation program was carried out to detect salt-water intrusions in a superficial sedimentary aquifer, at the Paranaguá harbor, in Paraná State. The second case history is a sanitary landfill from Bauru City, São Paulo State. In both sites, superficial geophysical tests were interpreted to detect and delineate the shape of contamination plume, helping to locate the resistivity piezocone tests. It was found that the interpretation of resistivity piezocone tests is straightforward to assess salt-water intrusion in sedimentary sands. For tropical soils, this technique presented some limitations since the groundwater table sometimes is deeper than the layer penetratable to the cone. Moreover, the genesis of those soils affects soil behavior and soil and water sampling is required to support interpretation.

Levantamento gravimétrico na região de Franca - SP e delfinópolis - MG, no reconhecimento e delimitação de feições estruturais (Zonas de Sutura)

This paper presents the results of a geophysical study carried out in northeastern São Paulo State and southwestern Minas Gerais State over an area 80 km wide and 97.5 km long in SE Brazil. The Bouguer anomaly map, and geological and structural data allowed to identify three different gravity domains - crustal blocks limited by major discontinuities -related to the structural pattern of the area. These discontinuities were interpreted as geosuture zones underlying the Paraná Basin sediments which have extensions in the Pre-cambrian Basement. The crustal discontinuities named Alterosa and Ribeirão Preto may be seen as A - type collision sutures in a triple junction arramgement. Two prominent linear anomalies are recognized in the Bouguer anomaly map, as well as the limit between the Brasilia and São Paulo crustal blocks or paleoplates. The Alterosa suture zone trends NW-SE while the Ribeirão Preto suture has a NE-SW direction. The Bouguer anomaly map provides subsidies and information on new concepts and theories leading to the refinement of tectonic models.

Classification of petroleum well drilling operations using Support Vector Machine (SVM)

During the petroleum well drilling operation many mechanical and hydraulic parameters are monitored by an instrumentation system installed in the rig called a mud-logging system. These sensors, distributed in the rig, monitor different operation parameters such as weight on the hook and drillstring rotation. These measurements are known as mud-logging records and allow the online following of all the drilling process with well monitoring purposes. However, in most of the cases, these data are stored without taking advantage of all their potential. On the other hand, to make use of the mud-logging data, an analysis and interpretationt is required. That is not an easy task because of the large volume of information involved. This paper presents a Support Vector Machine (SVM) used to automatically classify the drilling operation stages through the analysis of some mud-logging parameters. In order to validate the results of SVM technique, it was compared to a classification elaborated by a Petroleum Engineering expert. © 2006 IEEE.

Emprego da sondagem elétrica vertical com o método da eletroresistividade no estudo do lixão de Macapá-Ap

Vertical electrical soundings using eletroresistivity method were carried out in the public waste landfill in Macapá - AP, having as a goal to investigate the geoelectrical and hidrogeologic characteristics of the ground. The results of geophysics interpretation allowed obtaining a model of five geoelectrical layers until the depth of 14,6 m. This model is correlated to a sedimentary sequence of clay-silt-sandy with laterite. The main flow of the water table, also determined, is concordant to the topographical gradient.

Variação temporal da resistividade elétrica em contaminação por gasolina

The definition of models and base parameters for application of investigation tools in environment with high complexity are a basic premise to any sciences. The geophysics is a science with solid theoretical base and applications in diversified areas of the sciences geological, astronomical, meteorological, among many others. Its application in environmental studies is relatively recent and needs further research. To understand the behavior of resident contaminants in a dynamic and complex environment as the geological, it requests studies in scale laboratorial, under control of factors seasonality variable. This work simulates a leak of gasoline in soil, under conditions and in laboratory scale, with the objective of monitoring the temporary behavior of the hydrocarbon under the optics of variation of the parameter physical electric resistivity. The results indicate increase of the resistivity in recent periods the contamination, followed for stability in the values and finally fall and return tendency to the natural conditions.

Classification of petroleum well drilling operations with a hybrid particle swarm/ant colony algorithm

This paper describes an investigation of the hybrid PSO/ACO algorithm to classify automatically the well drilling operation stages. The method feasibility is demonstrated by its application to real mud-logging dataset. The results are compared with bio-inspired methods, and rule induction and decision tree algorithms for data mining. © 2009 Springer Berlin Heidelberg.

Infuěncia do relevo na produtividade e custos do harvester

Among the several variables that influence timber harvesting is the slope, which influences the productivity of forest machines. In this experiment the harvester was evaluated technically and economically while cutting and processing eucalyptus activity on different slope classes. The technical analysis included a study of time and movements by the method of continuous time; productivity was determined by the volume in cubic meters of wood processing. The economic analysis included the parameters of operational cost, production cost and energy consumption. The analysis of the data showed that productivity decreased according to the increase of the percent slope inclination, resulting in an effective work hour productivity increase from 18.72 to 39.71 m 3sc, with a mean of operating cost of US$ 78.78 per work hour.

An intelligent system to detect drilling problems through drilled cuttings return analysis

Cuttings return analysis is an important tool to detect and prevent problems during the petroleum well drilling process. Several measurements and tools have been developed for drilling problems detection, including mud logging, PWD and downhole torque information. Cuttings flow meters were developed in the past to provide information regarding cuttings return at the shale shakers. Their use, however, significantly impact the operation including rig space issues, interferences in geological analysis besides, additional personel required. This article proposes a non intrusive system to analyze the cuttings concentration at the shale shakers, which can indicate problems during drilling process, such as landslide, the collapse of the well borehole walls. Cuttings images are acquired by a high definition camera installed above the shakers and sent to a computer coupled with a data analysis system which aims the quantification and closure of a cuttings material balance in the well surface system domain. No additional people at the rigsite are required to operate the system. Modern Artificial intelligence techniques are used for pattern recognition and data analysis. Techniques include the Optimum-Path Forest (OPF), Artificial Neural Network using Multilayer Perceptrons (ANN-MLP), Support Vector Machines (SVM) and a Bayesian Classifier (BC). Field test results conducted on offshore floating vessels are presented. Results show the robustness of the proposed system, which can be also integrated with other data to improve the efficiency of drilling problems detection. Copyright 2010, IADC/SPE Drilling Conference and Exhibition.

The Brazilian Seismographic Integrated Systems (BRASIS): Infrastructure and data management

In geophysics and seismology, raw data need to be processed to generate useful information that can be turned into knowledge by researchers. The number of sensors that are acquiring raw data is increasing rapidly. Without good data management systems, more time can be spent in querying and preparing datasets for analyses than in acquiring raw data. Also, a lot of good quality data acquired at great effort can be lost forever if they are not correctly stored. Local and international cooperation will probably be reduced, and a lot of data will never become scientific knowledge. For this reason, the Seismological Laboratory of the Institute of Astronomy, Geophysics and Atmospheric Sciences at the University of São Paulo (IAG-USP) has concentrated fully on its data management system. This report describes the efforts of the IAG-USP to set up a seismology data management system to facilitate local and international cooperation. © 2011 by the Istituto Nazionale di Geofisica e Vulcanologia. All rights reserved.

Monitoramento temporal da pluma de contaminação no aterro de resíduos urbanos de Rio Claro (SP) por meio do método geofísico da eletrorresistividade

Several factors have contributed to the increase the world production of urban solid waste, resulting in difficulties to the correct management and the final environmentally appropriate disposal, in addition to causing serious socio-economic, environmental, and public health troubles. The soil and groundwater contamination by leachate in waste disposal sites is almost always present, leveraging the emergence and/or adaptation of methodologies for environmental assessment of these areas. The geophysical methods, especially the electrical resistivity method, are fast, reliable and low-cost alternative for this purpose. This paper reports the methodology adopted for the temporal monitoring of the plume of contamination of controlled landfill in the municipality of Rio Claro (SP). Electrical resistivity data were obtained in 1999 and 2008, by the resistivity method, using the techniques of vertical electrical sounding and electrical profile. In both years, similar tests were carried out in the same locations within the disposal area. The results indicated that the plume of contamination has resistivity values less than or equal to 50 ohm.m and moves guided by 2 flows: the main, to the southeast, and the secondary, to the west. Relatively to the first series of tests in 1999, the plume of contamination was higher and deeper in 2008, contrary to what was expected for a landfill deactivated for at least 10 years.

Polarização induzida aplicada no estudo de ocorrencia de cobre localizada a nordeste de Caçapava do Sul (RS)

Mineral research works are fundamentals for recognition and incorporation of new reserves. This paper present an integrated analysis of geologic and metallogenetics data, with results gotten from the application of the Induced Polarization geophysical method, in an copper ore occurrence, inserted in Camaquã sedimentary basin, situated in northeast of Caçapava do Sul city (RS). In area ocurr arkosean arenites average coarse, the intensely silicified and recrystallized, pertaining to Passo da Promessa Formation. The presence of azurita and malachite in breakings and high porosity zones of the host rock characterizes the mineral occurrence in surface, located in the crossing two fault families. The inversion models indicate the predominance of high chargeability in vulcanics tuff, rock of high porosity in relation to the andesites and metaconglomerates gifts in the area. The strong structural control of the mineral occurrence associated the high chargeability in volcanic tuff is indications of the hydrothermal fluid access by means of faults, until rocks with great porosity, where it occurred disseminations of copper sulfides in depth and carbonates in surface.