Data Management Of Seismic Array

With the establishment of China Science Detection Array observation systems, large-scale mobile seismic array observation projects have been carried out. One observation project named Dynamical Process of Active Block boundary belts and Strong Earthquake Predictiont, has installed about 300 sets of broad band seismic instrumentsin Sichuan and Yunnan. And other one array detection experiment project consists of about 250 sets of seismic instruments has been carrying out in the capital area. The instrument scale of the former observation project is equal to two times the present country seismic network. The original data output of one year observation is more than 4 TB. With large-scale mobile seismic array observation, gathering data quantity will unceasingly to inflate over time. The seismic array data transmission and collection, mass storage and highly effective management then become the most important question which array research faces. As representative projects, they have an unprecedented urgent request on the effective management and automatic processing for mobile digital seismic array data. The data acquired from mobile digital seismic instruments is stored in many scattered storage media. To further data storing together, processing and using, all the data should be archived in accordance with the requirements of a unified format. A unified format is convenient not only to data management, also to further research.Data management and processing of the current digital seismic network have been more mature, such as NetDC of IRIS, SeisComP in Europe and the China seismic network data management system. They have achieved seismic network data collection, storage and sharing, certain degree of automatic processing. Seismic array has unique characteristics of liquidity, data-intensive and data-relevance. It is necessary to ensure efficient management of many related parameters of array equipment. Ensuring easy to amend and change the observation data, pooling these data to data center, is also needed. The current data management solutions to seismic network can not fully meet the actual needs.As for data management of mobile seismic array, Antelop a much expensive software tools is used in the data centre of PASSCAL, and NetDC only inluding the capability of collecting and archiving is used by many data centres in Europe. SeisComP is developed for seismic network data management. There are many aspects that can not satisfy the actual needs for the array data management. However, in SeisComP the data communications, archiving and processing modules, are in common use for array management. Based on SeisComP some parts can be modified to adapt to the array processing requirements. In this thesis SeisComp software which can be used for mobile array data management and preprocessing has been introduced also with data archive characteristic. One kind of much efficient method, based on some SeisComP packages with integration of data format conversion and parameter modification, has been given in view of the characteristic of many amount instruments and elaborate parameter configuration and complex data process, which makes it possible the automatic data archive and efficient data management, meanwhile , much convenient for data information distribution and sharing. With the accumulation of seismic array data, data amount will be very great. All the data could not be stored in one big data centre. That is a good idea to combine some parts of the array into multiple virtual networks. Thus data are stored in various scattered virtual network data centers. Exchange between the scattered data center and sharing of data query will become the key issue. In the data management solution based on SeisComP, ArcLink can be used to achieve the exchange and release of seismic data. For enquiries and access to the data are operated interactively only on the same pages. The non-real-time or near real-time waveform data and related metadata archiving in the special data structure can be requested through ArcLink. SDS(Seiscomp Data Structure) which is used in SeisComP is supported by ArcLink. After requests whose operating status can be checked in real time are submitted, the data will be prepared for download. Communication connectivity is using TCP / IP protocol in ArcLink. Because the requested data should not be remained in RAM, much large requested data is allowed. The data product will not be cleaned until receives clean commands. When a network error occurrs, the data can be reloaded after a new connection. ArcLink has the routing capability, so users need not know which data server has requested data in advance. TCP connecting transmission time will not affect the request processing time, which is usually much faster than protocol based on CORBA.The exchange of earthquake data, information output and rapid release is of extreme importance to earthquake relief. Real-time exchange and sharing of various regional seismic network's speed results, are particularly conducive to rapid judgement of the earthquake occurrence. Improveing rapid assessment and effective emergency response capacity to devastating earthquakes and tsunami depend on the speed of seismic reports. Seismic observation information system should be developed base on the needs of rapid response to large earthquakes. When a felt tremors in the earthquake occurs, if system immediately gives automatically broadcast the earthquake message and assessment to possible impact of the earthquake, for some region in the distance from epicenter, earthquake warning given a few seconds before the strong earthquake will undoubtedly reduce earthquake damage.In China work and technology of quick report to rapid reunification of the big earthquake's magnitude are fruitful. In recent years promoted software EQIM, a network rapid report to major earthquakes and data sharing system, can quickly and efficiently unify magnitudes of earthquakes and provide relevant information. Other countries' seismic seismic networks also have carried out a lot of research work in the earthquake rapid report.The QuakeWatch Information Distribution System (QWIDS) implementation of the Earthquake Information Distribution System (EIDS) provides end-to-end support for reliable XML-based messaging. And EIDS is the messaging infrastructure used to synchronize summary earthquake products among USGS data centers. As for the other three major existing or planned distribution systems (QDDS, QuakeWatch, and ShakeCast), none of these systems addressed all the current needs for earthquake information distribution. In particular, firewalls are a growing problem for systems relying on socket-based connections. In QWIDS the messaging system uses a leading open-source version of the industry-standard Common Object Request Broker Architecture (CORBA), which can be better to solve the firewall problem. And message is exchanged through CORBA in a very short time, generally around in a few seconds.From the automatic rapid earthquake positioning result by SeisComp can be drawn the seismic events information. When a destructive earthquake occurs, the seismic event information can be distributed timely and alarm by QWIDS immediately. However, the assessment to accuracy of rapid earthquake positioning results and conditions set to alarm is complex and difficult, and coordination of alarm mechanism is complicated. There is a long way to go for doing a good job of earthquake alarm. And more in-depth and meticulous research needs to be done. This thesis gives a software technology framework for the earthquake quick report.