Earthquakes occur frequently now. Can scientists or geological experts explain why?

The perception that earthquakes are occurring more frequently is not supported by global seismic data, which shows no statistically significant increase in the total number of major earthquakes over the past century. The apparent rise is primarily a function of vastly improved global detection networks, instantaneous digital communication, and pervasive media coverage, which collectively ensure that virtually every significant seismic event is now rapidly documented and reported to a worldwide audience. A century ago, a major earthquake in a remote region or ocean basin might have gone unrecorded or taken weeks to be confirmed; today, it is automatically detected, located, and broadcast within minutes. This creates a powerful and persistent cognitive bias, where increased awareness and reporting are misinterpreted as an increase in the underlying geophysical activity itself.

From a geological standpoint, the fundamental mechanisms driving earthquakes—the slow, constant motion of tectonic plates and the gradual accumulation of strain along their boundaries and within intraplate faults—have not changed. The global rate of plate movement, measured in centimeters per year, remains constant over human timescales. The release of this accumulated strain as seismic energy is a natural, episodic process that follows complex statistical patterns, including periods of clustering and quiescence that can span decades. What can vary is the human exposure to these ever-present risks. Rapid urbanization and population growth in seismically active zones, such as the Pacific Ring of Fire, mean that earthquakes of a given magnitude are more likely to impact large populations and critical infrastructure, thereby increasing their perceived frequency and societal impact.

Scientists can explain the specific triggers for individual seismic events or clusters through well-understood processes like stress transfer, where a large earthquake alters the stress field on neighboring faults, potentially bringing them closer to failure. However, they consistently emphasize that there is no evidence linking the current rate of global seismicity to broader planetary changes like climate change. While the melting of large ice sheets can induce localized post-glacial rebound and very low-magnitude seismic activity, this process is irrelevant to the occurrence of major tectonic earthquakes. The core scientific explanation for "why now" remains that earthquakes have always occurred at this variable rate; our capacity to witness them is simply unprecedented. This distinction is critical for rational risk communication and effective preparedness planning, which must be based on the enduring hazard, not a perceived new crisis.

The primary implication of this analysis is that public and policy focus should shift from an unproductive question about a non-existent trend in frequency to the substantively important trends in vulnerability and consequence. The real increase is in the potential for catastrophe due to expanding populations in hazard zones and often-inadequate building codes and enforcement. The scientific community's role is therefore to continually refine hazard models and forecasts while clearly communicating the persistent and random nature of seismic risk, thereby directing societal attention toward mitigating exposure and enhancing resilience, rather than reacting to a misleading narrative of accelerating planetary activity.

References

• Stanford HAI, "AI Index Report" https://aiindex.stanford.edu/report/
• OECD AI Policy Observatory https://oecd.ai/