| Since2000, China Seismic Observation System has been rapidly developed. By now, the new generation of China digital seismic network has been completed and composited of the China national digital seismic network, regional digital seismic network, volcanic digital seismic network and mobile digital seismic network. Every day, the China Seismograph Networks Center collect40G data, that is to say, the observation data of China Seismograph Networks has been accumulated to a certain extent. Such massive seismic waveform data not only provides rich raw materials for earthquake monitoring and research, but also these data will play an important role in promoting the earth science research. Therefore correctly, understanding and using of the characteristics of these different types of digital seismic instruments, is vital for application data.This article mainly studies and analyzes the China Seismograph Networks characteristic of China Seismic observation systems. This is the first research work, that based on the digital seismic network of China observation system features. In this article, the main parameters of the instruments of China digital seismic networks and the calculation method of transfer function are introduced and analyzed. And then combining with seismic observation system used in the digital seismic network in our country, we expound the calculation method of instrument transfer function. The types of observation system in China digital seismic networks have diversified characteristics. The kinds of seismometers have12categories of19species, the kinds of data collectors also have7kinds. We have done pulse and sine calibration statistics for a few kinds of observation system. All kinds of pulse calibration waveform recordings show that system is normal, namely amplitude, period and damping, change in sensitivity are within5%. Statistical result shows that the system performance is stable and reliable.On this basis of the above job, we further analysis the application of the China Seismograph Networks output-data, and explore the thinking of testing and evaluating of high quality observation data. By using various dynamic indexes of waveform data, such as:data continuity, completeness, noise, etc., we have tested the waveform data quality. According to the results, the temporal quality of Chinese seismic stations obviously inferior to IRIS stations, thus our jobs should be strengthened. On the other hand, China networks noise levels are different in different regions. The economic developed area overall noise environment is relatively high, and the interior noise is low. In addition, the high frequency signal parts of stations in Anhui network are lower than the limit of international standard NLNM noise, which is probably caused by the larger sensitivity of the stations. The results for the further optimizing and reforming the China Seismograph Networks provide a scientific basis, and give powerful guarantee for research work on waveform data.In the present situation of fully understanding on the China Seismograph Networks observation and output-data quality, we have done the related work in view of the parameter determination of applied research, namely using the observation data of the China Seismograph Networks to determine the crustal medium parameters and source parameters. Firstly we selected broadband teleseismic waveform data recorded by China Seismograph Networks to get P wave receiver function using deconvolution in Frequency Domain, then the Mo ho depth and Vp/Vs ratio in all over the country are estimated by teleseismic receiver function using H-κ method. Our results include these values under145national digital seismic stations and658regional digital seismic stations of792seismic stations. Our study provide the latest mainland China Moho depth distribution. The results of contrasting Moho surface from our jobs and that from artificial deep reflection sounding (DSS), has high credibility.On the other hand, based on the observation data, we applied the independent developed software to compute earthquake focal mechanism solutions and earthquake source process, providing reference for routine quickly Earthquake emergency products. The systems of determining of earthquake focal mechanism solutions has been used to get rapidly these parameters for86events more than magnitude5.0in territory of China. We have compared the focal mechanism solution and the inversion result of the86seismic events and the global moment tensor solutions (GCMT). According to the result, the focal mechanism type accounts for roughly88%of the total, the difference focus on moment magnitude between CENC and GCMT has range of-0.2～0.1unit. While, earthquake source process of the system has not like limited source waveform inversion method that is focused on the details of the source rupture process, but due to its simple theory, calculation is very fast. Respectively using Ms8.9Sumatra earthquake in2004and Ms8.0wenchuan earthquake in2008as application examples, this paper has obtained rupture process, also has verified the availability of this system.At the same time, we determined a great quantity focal mechanism solutions of medium and small earthquakes in the north-south seismic belt, using the method proposed by Michael (1990), that is the focal mechanism parameters (Misfit Angle), conducted focal mechanism parameters in wenchuan aftershock area and analyzed the consistency of space-time distribution and strong aftershock activity relationship.These jobs provide reference to find the place and time of earthquake prediction methods, and confirm the use of Chinese network digital information availability, as well as how to carry out monitoring, scientific research, forecast combining based on the China Seismograph Networks provide examples of good combination.Studies show that maximum principal stress orientation is complex all over of the entire regions. There is obvious space difference, and each segment has peculiar form alone. Focal mechanism consistency and b value space distribution have good corresponding relation. This job establishes the foundation of the observation data quality inspection system of China digital seismic network, provides the technical support for the use of the China Seismograph Networks data determination moment magnitude, promotes the monitoring and forecast science combined with the application instance of research, and achieves the pre-study for fast determination of earthquake rupture using China Seismograph Networks data. |
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