主震
定义
地震序列中最大的地震，决定了整个事件的震级。之前有时有前震，之后必定有余震。
示例
M7.8主震于2023年2月6日当地时间凌晨4:17发生。
相关术语
相关指南
余震解释:为什么地震会成群出现?
Aftershocks can continue for months or years after a major earthquake. Learn what causes them, how they're predicted, and when they'll stop.
前震:能预测主震吗?
Foreshocks occur before some major earthquakes, but can they be used for prediction? Learn the science behind foreshocks and their limitations.
地震群:小地震不停止时
Earthquake swarms produce hundreds of small tremors without a clear mainshock. Learn what causes them and whether they signal bigger events.
尼泊尔和喜马拉雅碰撞带
The India-Eurasia collision builds the Himalayas and creates major earthquake risk for Nepal, Bangladesh, and northern India.
相关案例研究
2023年土耳其-叙利亚地震:造成59,000人死亡的双重主震
The deadliest earthquake disaster of the 2020s, notable for its unprecedented double mainshock sequence and the subsequent criminal prosecution of contractors for building code violations.
2016年熊本地震:改写地震灾害规则的双重主震
The earthquake doublet that overturned the assumption that the first large shock is always the mainshock, forcing Japan to revise its public messaging and early warning protocols.
2011年基督城地震:6.2级余震如何摧毁市中心
One of the few cases where an aftershock was more devastating than its mainshock, with a M6.2 at just 5 km depth producing 2.2g ground acceleration that obliterated Christchurch's city center.
1960年瓦尔迪维亚地震:有记录以来最强大的地震(M9.5)
The most powerful earthquake ever instrumentally recorded, releasing energy equivalent to 25% of all global seismic energy over a century and generating a tsunami that crossed the entire Pacific Ocean.
常见问题解答
震中是地表上位于震源（地震破裂开始处）正上方的点。通常以经纬度坐标报告。最强的震动通常发生在震中附近，但当地土壤条件和断层几何形态可能使最大损害区域发生偏移。
地震仪（地震计）是检测和记录地震波引起的地面运动的仪器。现代宽频带地震仪可以检测到比原子宽度还小的运动。全球地震仪网络使科学家能够在几分钟内确定地震的位置和震级。
P波（纵波）是通过岩石传播最快的压缩波，最先到达地震台站。S波（横波）到达较晚但引起更大的地面震动。P波可以通过固体、液体和气体传播；S波只能通过固体传播。两者之间的时间差有助于确定地震的距离。
震源是地球内部地震破裂开始的点。它由经度、纬度和深度来描述。震源与其正上方地表之间的垂直距离即为地震深度，这对地表感受到的震动强度有很大影响。
地震学是研究地震和地震波在地球内部传播的科学学科。它包括地震检测、定位和特征描述、地球内部结构、地震危险性评估和地震工程。地震学家利用全球地震仪网络的数据来研究这些现象。