| Magnetotelluric sounding (MT) is the study of crust and upper mantle structure ageophysical detection method, the main working procedures including data collection,data processing and inversion interpretation of three parts. Among them, the dataacquisition quality determines the success of target task. Therefore, how to guaranteethe quality of data collection, which is the key and is the basis of the magnetotelluricsounding work, this article search a in good fortune gong-sichuan panzhihua-yunnan qiaojia old magnetotelluric sounding profiles, on the basis of detailed studiesof magnetotelluric sounding in the field noise analysis the influence of processing onthe inversion interpretation.First, how to effectively analysis and processing of magnetotelluric sounding inthe outdoor environment is the interference of noise, as far as possible, the reductionof noise interference of inversion error caused by the interpretation, effectivelyimprove the quality of the observed data of magnetotelluric sounding, this is the workof magnetotelluric sounding in the core of data acquisition and processing steps. Inthis paper, first of all, on the basis of access to many data, combined with the dataacquisition test, through the method of combining the theory with time, first in, first tothe field of natural electromagnetic field source type and natural characteristics of theamplitude of the electromagnetic field in detail, the noise existing in magnetotelluricsounding and distribution were analyzed.By means of numerical simulation method, then, in the theoretical model andnoise model after studied the effect of inversion, especially for thin layer of noise areanalyzed; For the sampling interval of magnetotelluric sounding intermediatefrequency point and the lowest frequency effect on the inversion interpretation, thethesis has carried on the detailed elaboration, think of a single encryption samplinginterval of MT resolution increases and there is no direct role, it will increase the costof work, reduce the working efficiency; While the lower the minimum observationfrequency determines the depth of exploration, but then continue to fall as thefrequency f, the level of noise interference are also increased sharply, and the lowerthe frequency, the measured data of the less layers, further restrictions on the quality of the magnetotelluric sounding dataThen, using the magnetotelluric deep reference measurement method, combiningwith the theoretical basis, the in field data acquisition processing, there is noise of themeasured data (such as: observation "blind area","distortion" of this curve and theoverall improvement of data quality, etc.), the observed data of magnetotelluricsounding has obvious effect, the improvement in the next, far reference applicationseveral technical problems in the MT, such as relevant conditions, the electric part inmagnetic noise and the application of the distance, far in the reference pole orientationand reference of the measured point data such as the improvement of the quality, etcare discussed in this paper.Search a at last, the paper in good fortune gong-sichuan panzhihua-yunnanqiaojia old magnetotelluric sounding data processing and interpretation, for example,in data collection and processing of using far reference technology, compare theregional geological and geophysical data, comprehensive geological interpretation ofthe section, thinks that the regional electrical structure have the features of horizontalpartitioning, regional fault zone, and generally of the geological unit block boundaries,synthesis of long period magnetotelluric sounding data, explain the structurecharacteristics of the southeast margin of qinghai-tibet plateau, think deep tectonicunits of high resistance body, often may be mainly area earthquake，Finally, detaileddescription of the qinghai-tibet plateau Cenozoic magmatic activity in thecharacteristics in the study area. |
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