地震变得越来越强是真的吗?

The Myth: Earthquakes Are Getting Stronger

Related to but distinct from the "earthquakes are becoming more frequent" myth is the claim that individual earthquakes are becoming more powerful — that climate change, nuclear testing, or some other human or environmental force is intensifying the maximum magnitude of earthquakes. This myth surfaces particularly after major events, when commentators sometimes suggest the extreme magnitude reflects an escalating planetary crisis. The physics of 矩震级衡量地震规模的现代标准（Mw），基于地震矩——即断层面积、平均滑动量与岩石刚度的乘积。对任何规模的地震都能给出准确结果。 and the geological record provide a clear answer, though some nuances deserve careful treatment.

How Earthquake Magnitude Is Measured

Modern earthquake magnitude is measured primarily through the 矩震级衡量地震规模的现代标准（Mw），基于地震矩——即断层面积、平均滑动量与岩石刚度的乘积。对任何规模的地震都能给出准确结果。 scale (Mw), which was developed in the 1970s to overcome limitations of Charles Richter's original 里氏震级查尔斯·里克特于1935年提出的最初对数震级标度，用于测量地方性地震的震级。如今已在很大程度上被矩震级取代，但媒体报道中仍常被提及。 and is now the standard for large earthquakes. The moment magnitude is derived from the 地震矩衡量地震释放总能量的指标，由断层面积、平均位移量与岩石的剪切模量相乘计算得出，是矩震级的计算基础。 — the product of the shear modulus of the rock, the area of the fault that ruptured, and the average slip across that area. It is a measure of the total energy radiated as seismic waves.

The moment magnitude scale is logarithmic: each unit increase represents about 32 times more energy. A M9.0 earthquake like the 2011 Tohoku event releases approximately 32 times more energy than a M8.0 event, and about 1,000 times more energy than a M7.0 event. The largest earthquakes ever recorded (estimated M9.4-9.6 for the 1960 Valdivia, Chile, earthquake) are bounded by the maximum fault dimensions physically possible on Earth.

What Determines Maximum Earthquake Magnitude

The maximum possible earthquake magnitude on any given fault system is determined by the physical dimensions of the fault. Fault rupture cannot exceed the length of the fault segment, the width (depth extent) of the seismogenic zone, and the amount of accumulated slip. For the largest subduction zones — like the Cascadia Subduction Zone, the Japan Trench, or the South American subduction zone — rupture lengths of 1,000+ km are possible, enabling M9+ events. For strike-slip faults like the San Andreas, the geometry limits maximum magnitude to approximately M8.0-8.5. These limits are set by geology and physics, not by time period.

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 describes the frequency-magnitude distribution of earthquakes in any region: for each unit of magnitude increase, frequency decreases by roughly a factor of 10. The slope of this relationship (the b-value) and the maximum magnitude are properties of the fault system determined by geology. They do not change on human timescales in response to climate, nuclear testing, or any other human activity.

The Historical Record vs. Instrumental Period

The 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。 that provides consistent global monitoring of earthquakes only achieved modern global coverage in the 1960s-1970s. Before this period, earthquake catalogs become increasingly incomplete as you go further back in time. This creates an observational artifact: the largest recorded earthquakes in the modern era (1960 Chile M9.5, 1964 Alaska M9.2, 2004 Indian Ocean M9.2, 2011 Japan M9.0) could create the impression that the most extreme events are recent phenomena.

But this apparent concentration of extreme events in the modern era largely reflects improved detection and recording. [[Paleoseismology]] — the study of prehistoric earthquakes from geological evidence — reveals that M8-9+ events have occurred repeatedly throughout geological history on the same fault systems we observe today. Japanese historical records document major tsunamis and earthquakes consistent with M9-class Tohoku-type events going back many centuries. The sediment record of the Cascadia Subduction Zone shows complete M9 ruptures occurring roughly every 200-500 years for thousands of years.

Why the Modern Instrumental Period Looks Extreme

The four M9.0+ events since 1960 (Chile 1960, Alaska 1964, Indian Ocean 2004, Tohoku 2011) might suggest a modern clustering of extreme events. Seismologists have examined this question carefully. The global rate of M9+ events in the instrumental era (approximately 1 per 20 years) is broadly consistent with geological estimates of recurrence intervals, though the clustering of large events in a 60-year window is on the high side of expected variability. This is within the expected natural randomness of a Poisson process with rare events — four events in 60 years is unusual but not statistically implausible given a 20-year mean recurrence.

Climate Change and Earthquake Magnitude

A common contemporary version of the myth is that climate change is making earthquakes stronger. There is no credible mechanism by which atmospheric warming could increase the maximum magnitude of tectonic earthquakes, and no evidence that it does. Tectonic earthquake magnitude is determined by fault geometry and accumulated strain, not by surface conditions.

However, there are legitimate research questions about climate-earthquake interactions at much smaller scales and longer timescales. Deglaciation — the melting of major ice sheets — changes the load on the crust and can affect seismicity rates over centuries to millennia as the crust rebounds (isostatic rebound). Some researchers have hypothesized that accelerated glacial melting could affect seismicity in formerly glaciated regions (Scandinavia, Iceland, Alaska) over coming decades to centuries, though the magnitudes involved are far smaller than the scale of effects implied by popular claims.

The Role of 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。 Improvements

The same monitoring improvements that make it appear more earthquakes are occurring (as discussed in the "earthquakes more frequent" guide) also affect the apparent record for large events. Better 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 means that earthquakes that would have been assigned lower magnitudes due to incomplete waveform data in the 1960s might be assessed at higher magnitudes today. Some upward revisions of historical earthquake magnitudes are the result of reanalysis using modern methods, not actual stronger shaking.

The Sumatra 2004 earthquake was initially reported as M9.0, then revised upward to M9.2-9.3 as more data became available and more complete waveform analysis was applied. This reflects improved methodology, not escalating seismicity.

What Is Genuinely Changing

While tectonic earthquake maximum magnitude is not changing, the consequences of earthquakes of a given magnitude are changing — upward. Growing population in coastal and seismically active zones, increasing urbanization in regions with inadequate 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, aging infrastructure, and global supply chain interdependencies mean that a M7.8 earthquake in 2026 affects far more people and causes far greater economic disruption than a comparable event in 1926. This is a genuine and serious trend, but it reflects human vulnerability, not geological escalation.

The appropriate response is investing in 抗震加固对既有建筑进行强化以提高其抗震能力的工程措施，常见方法包括增设钢支撑、加固基础以及将结构与基础用螺栓连接。 programs, updating building codes in rapidly urbanizing developing nations, improving 地震预警（EEW）一种在强震到达前探测地震并向人员和系统发送警报的系统，可提供数秒至数十秒的预警时间，足以采取自我保护行动。 infrastructure, and building institutional capacity for post-earthquake response — not alarm about inherently increasing earthquake power. The earth's geology is not conspiring against us; we are making choices about where and how we build that determine how consequential each earthquake becomes.