地震变得更频繁吗?

The Myth: Earthquakes Are Becoming More Frequent

After any active period of seismicity — a run of large earthquakes around the Pacific 环太平洋火山带环绕太平洋的马蹄形地带，全球约90%的地震发生于此。该地带绵延40,000公里，包含452座火山。, a cluster of damaging events in weeks or months — media coverage inevitably raises the question: are earthquakes becoming more frequent? Social media amplifies this perception further, with crowdsourced reports and rapid news cycles making every significant earthquake globally visible within minutes of occurrence. The feeling that "there seem to be a lot of earthquakes lately" is real and understandable. But the scientific record tells a different story.

What the Earthquake Record Actually Shows

The USGS maintains comprehensive statistics on global earthquake frequency. For large earthquakes — magnitude 7.0 and above — the global average has been remarkably consistent at approximately 15-20 events per year over the period of modern seismic monitoring. For magnitude 8.0 and above, the average is about one per year. Year-to-year variation is substantial due to the random nature of earthquake occurrence, but there is no statistically significant long-term trend toward increasing frequency when examined over the full instrumental record.

The 全球地震台网（GSN）由150多个宽频带地震台站组成的全球网络，提供对全球地震活动的全面监测，由美国地质调查局、美国国家科学基金会及IRIS联合运营。, which became truly global and standardized in the 1960s, provides the most reliable comparison baseline. Analyzing this record using the 古登堡—里克特定律描述地震频率与震级之间关系的统计规律：震级每增加一个单位，地震发生频率约降为原来的十分之一。 relationship, seismologists find that the frequency-magnitude statistics have remained stable. There are active years and quiet years, but no systematic upward trend for large earthquakes.

The Detection Bias Problem

For smaller earthquakes, the picture is genuinely different — but not because they are more common. The number of recorded small earthquakes has increased enormously over the past several decades, but this reflects dramatic improvements in 地震观测网由若干地震台站协同组成、持续监测地震活动的系统。全球地震台网（GSN）拥有150多个台站，提供全球范围的观测覆盖。 coverage and sensitivity rather than actual increases in earthquake occurrence. In 1960, the global seismic network consisted of a few hundred stations, many of them old instruments with limited sensitivity. Today, thousands of high-quality broadband stations operate worldwide, supplemented by dense regional networks and even smartphone-based crowdsourced sensing.

More stations with better sensitivity detect smaller and more distant events. A magnitude 2.0 earthquake in a previously unmonitored region that would have been invisible in 1970 is now routinely recorded and catalogued. This creates an apparent increase in earthquake frequency that is entirely an artifact of improved monitoring. When analysts apply magnitude completeness thresholds — focusing only on events large enough to have been reliably detected throughout the historical record — the frequency trends flatten out.

Normal Statistical Clustering

Even when earthquake frequency is steady on average, the actual occurrence of earthquakes is not evenly distributed in time. Earthquakes cluster. A major earthquake increases stress on surrounding fault systems, triggering 余震在同一断层区域内、发生于主震之后的较小地震。余震序列可持续数周至数年，最大余震的震级通常比主震低1.0至1.2级。 sequences that can last years and occasionally produce M6+ events. When a major subduction zone ruptures, it may set off a sequence of large events on adjacent fault segments over a period of years to decades. The 2004 Indian Ocean earthquake was followed by the 2005 Nias earthquake, the 2007 Bengkulu earthquakes, and other large events on the Sunda subduction zone. This is seismically normal behavior, not an escalating trend.

Conversely, periods of relative global seismic quiet also occur and are equally unremarkable. The randomness inherent in earthquake processes means that clusters and gaps are expected features of any earthquake catalog, not signals of fundamental change.

Why It Feels Like More

Several cognitive and social factors make it seem like earthquakes are becoming more common even when they are not. Global news coverage of earthquakes has increased enormously since the advent of the internet and 24-hour news cycles. An earthquake that would have received a two-paragraph wire service notice in 1985 now generates hours of live television coverage, thousands of social media posts, and real-time data visualizations. The “你感觉到了吗？”（DYFI）美国地质调查局的一项计划，收集震后公众的烈度报告，形成基于公众参与的烈度分布图，任何感受到地震的人都可以提交报告。 system alone has sensitized millions of people to earthquakes they would previously have ignored.

Population growth in earthquake-prone regions also means more people are affected by earthquakes of a given 震级量化地震所释放总能量的单一数值。震级每增加一个整数单位，释放的能量约增加31.6倍。, generating more news coverage and more personal accounts. The 1906 San Francisco earthquake struck a city of 400,000; the same rupture today would affect a metropolitan population of 4.7 million. The earthquake itself would be identical in physical terms, but its human visibility would be vastly greater.

The Exception: Induced Seismicity

There is one genuine exception to the "no trend" finding: 诱发地震活动由水力压裂、废水回注、采矿或水库蓄水等人类活动引发的地震。大多数震级较小（低于4级），但部分曾超过5.5级。 — earthquakes caused by human activities such as wastewater injection from oil and gas operations. In Oklahoma, for example, earthquake rates jumped dramatically between 2009 and 2015, correlating closely with the expansion of wastewater disposal wells from hydraulic fracturing operations. This was a real increase in earthquake frequency in a specific region, caused by a specific human activity, and was documented by detailed analysis of seismic catalogs and injection well records. Oklahoma went from about 1-2 M3+ earthquakes per year historically to over 900 in 2015. Regulatory interventions reducing injection volumes subsequently decreased earthquake rates.

This is localized industrial seismicity, not evidence of a global trend, but it represents a genuine documented increase in earthquake frequency that serves as a reminder that the "no trend" conclusion applies to tectonic earthquakes, not all seismicity.

What Seismologists Actually Monitor

Rather than tracking frequency trends, seismologists focus on understanding fault systems well enough to estimate the probability of future large events on specific faults. The 概率地震危险性分析（PSHA）一种量化地震危险性的方法，综合考虑所有可能的地震震源、震级及地震动水平，以超过特定震动水平的概率来表示结果。 (probabilistic seismic hazard analysis) framework integrates fault geometry, 滑动速率断层沿线位移的平均速率，通常以每年若干毫米衡量。滑动速率越高，通常意味着地震发生频率和危险性越高。 estimates, recurrence interval data from 古地震学通过断层探槽、隆起阶地和海啸沉积物等地质证据研究史前地震的学科，将地震记录延伸至数千年前。, and 古登堡—里克特定律描述地震频率与震级之间关系的统计规律：震级每增加一个单位，地震发生频率约降为原来的十分之一。 statistics to produce probabilistic forecasts. These forecasts are the scientific foundation for 抗震建筑规范为确保建筑物达到最低地震安全水平而制定的一套法律要求，涉及建筑的设计与施工，通常在重大地震暴露出新的薄弱环节后进行修订。 requirements, 地震危险性图显示在特定时间段内地震震动超过指定水平之概率的地图，供工程师、规划者和保险公司用于评估地震风险。 products, and long-term risk planning — and they rely on the stationarity of seismicity rates, not on detecting trends.

The Bottom Line

Earthquakes are not becoming more frequent in any meaningful scientific sense for the earthquakes that matter most — large magnitude events driven by tectonic forces. The perception of increasing frequency is a product of better detection, greater media coverage, and growing population in hazard zones. Understanding this should provide neither false reassurance (the hazard remains real and serious) nor unnecessary alarm. The scientifically appropriate response is continued investment in monitoring infrastructure, seismic hazard research, and 抗震设计旨在使结构物能够承受地震作用力的设计实践。现代抗震设计致力于防止倒塌、保护生命，同时在大地震中允许出现一定程度的结构损伤。 standards rather than anxiety about an apparent trend that does not exist.