USGS（美国地质调查局）
定义
负责监测地震、运营国家地震信息中心和发布实时全球地震数据的主要美国政府机构。
示例
USGS每年定位约20,000次地震，或约每天55次。
相关术语
相关指南
里氏量表解释:历史、公式和局限性
Discover the history of the Richter scale, how Charles Richter created it in 1935, and why scientists now prefer the moment magnitude scale.
理解矩震级标度
The moment magnitude scale (Mw) is the modern gold standard for measuring earthquakes. Learn how it works and why it replaced the Richter scale.
修正梅卡利烈度等级:测量你感受到的
The Modified Mercalli Intensity scale rates earthquake effects from I (not felt) to XII (total destruction). Learn what each level means.
震中(epicenter) vs 震源(hypocenter):有什么区别?
The epicenter is on the surface; the hypocenter is underground. Learn how scientists locate both and why the distinction matters for safety.
地震频率:多久发生一次?
About 500,000 earthquakes occur yearly, but only 100 cause damage. Learn the frequency-magnitude relationship and why big quakes are rare.
2011年东北地震和海啸:完整分析
The 2011 M9.1 Tohoku earthquake triggered a devastating tsunami and nuclear disaster. A comprehensive analysis of one of history's worst earthquakes.
2010年海地地震:灾难和救援
The 2010 M7.0 Haiti earthquake killed over 200,000 people. Learn why the devastation was so extreme and the lessons for earthquake preparedness.
2023年土耳其-叙利亚地震:双重灾难
Two devastating earthquakes within hours killed over 50,000 in Turkey and Syria. The most destructive earthquake disaster of the 2020s.
地震后的搜索和救援如何进行
Search and rescue teams race against the 72-hour survival window. Learn how urban search and rescue operates after earthquake disasters.
最初72小时:应急响应时间表
The first 72 hours after an earthquake determine survival outcomes. Learn the emergency response timeline from initial shaking to organized relief.
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。