引言美国地质调查局(USGS)正在通过提供有关潜在地震的震源、震级、发生率以及地震效应的资料,致力于减轻地震损失的工作。各级政府和私人部门都需要对灾害的性质、范围、严重程度以及灾害可能造成的损失所作出的评定。他们的决策对建筑、土地利用、灾害预防、震后恢复以及对地震预报的反应诸方面都 Introduction The United States Geological Survey (USGS) is working to mitigate earthquake damage by providing information on the sources, magnitude, occurrences and seismic effects of potential earthquakes. Governments at all levels and the private sector need to assess the nature, extent and severity of disasters and the potential damage they may cause. Their decision-making has implications for buildings, land use, disaster prevention, post-earthquake recovery, and response to earthquake prediction