中文摘要：

介绍了美国中加州帕克菲尔德（Parkfield）地震预报实验场的建设、运行和试验场工作期间发生的2004年6级地震的情况。着重阐述了在实验场20多年的地震预测研究中遇到的一系列科学问题以及一些新的认识。这些科学认识包括：对活动构造破裂分段的研究是地震长期预测的基础;无震滑动是地震预测中的一大难点和障碍;地震复发模型具有的相当大的不确定性且在预测应用上有很大的局限性;地震前兆的复杂性、差异性及其对地震预测中常用原则——前兆异常重现性和相似性的挑战等。这些认识对地震预测研究与实验场建设有一定的启示意义。

英文摘要：

It describes the construction and operation of Parkfield earthquake prediction experiment in California,USA and circumstance about the 2004 M6.0 earthquake during the experiment.Focuses are given on a series of scientific problems and their new understandings in the 20 years of earthquake prediction research.These scientific understandings include the sub-ruptures of active geological structure,which is the base of long-term earthquake prediction,the aseismic slip,which is one of major difficulties and obstacles for earthquake prediction,earthquake recurrence models,which arouse considerable uncertainty and have significant limitation in forecasting application and the complexity and the differences of earthquake precursors which are challenges to principles usually used in earthquake prediction,such as reproducibility and similarity of precursor.These understandings have certain significance to earthquake prediction research and the construction of experiment.