Earthquake Geology & Paleoseismology

USGS and university geologists study the walls of a trench across a recently discovered strand of the Seattle fault.

Earthquake geology in the broad sense is the study of the history, effects, and mechanics of earthquakes within and on the Earth's crust. Most often, earthquake geology is synonymous with active tectonics, a term used to describe the study of tectonic movements that are expected to occur within a future time span of concern to society. Such definitions overlap considerably with other research topics on this site, such as Crustal Deformation, Seismology and Earth Structure, and Strong Motion and Site Response. Important aspects of earthquake geology include the study of tectonic landforms on the Earth's surface and folds and faults within its crust produced by many earthquakes over thousands to millions of years.

Paleoseismology is the study of the timing, location, and size of prehistoric earthquakes. Paleoseismology differs from other aspects of earthquake geology in its focuses on the almost instantaneous deformation of landforms and sediments during individual earthquakes. This focus permits study of the distribution of earthquakes in space and over time periods of hundreds to tens of thousands of years. Such paleoseismic histories help us understand other aspects of earthquake geology, such as regional patterns of tectonic deformation and the long-term behavior of specific faults. More importantly, knowledge of when, where, and how often, large earthquakes occur is crucial for characterizing the seismic hazard of a region.

地震地质学广义而言是历史长期的，效果的 , 有关地表内外的地震构造研究。 更多时候，地震地质学与活跃的地质构造学同义, 这一词语用来表述构造运动研究，也就是为社会所关心的，未来时间段里能够预料发生的地壳运动研究。

这样的定义与其它同一领域的课题研究定义重叠,例如地壳变形，地震学和地球结构 , 强运动和区域感应。 地震地质学的重要方面包括对地球表面的地形构造研究、地表折层研究、以及数千年到数百万年前由许多地震形成的地壳裂缝研究。

Paleoseismology（古地震学） 是对史前地震的时间测定，位置和大小的研究。 Paleoseismology（古地震学）与地震地质学的研究内容有所区别，主要集中在有关特殊地震导致的地形和沉积物的瞬间变形。这一焦点使得地震在分布上跨越空间和跨越数百甚至数万年的时间进行研究。paleoseismic（古地震学）的历史帮助我们了解地震地质学的其他方面,诸如结构变形的地域模式，特殊地震带的长期活动。 更重要的是,有关大地震发生的时间、地点、频率对描述一个地区地震危害的特点极为重要。