Earthquake Frequency
Over Time
Is global earthquake activity increasing, decreasing, or stable?
Annual counts fluctuate but show no dramatic upward or downward trend over the decade. The ±1 SD band illustrates that year-to-year variation is normal statistical noise, not a structural shift. Tectonic processes operate on geological timescales, so a decade is simply too short to reveal long-term change.
Breaking frequency down by magnitude class reveals something striking: the proportion of each category is remarkably consistent year after year. Moderate events (M4–5) dominate every year.
Magnitude
Distribution
What does the global distribution of earthquake severity look like?
The histogram confirms a heavy right-skew: the vast majority of earthquakes are light or moderate. But the energy panel tells a different story. A single M8.0 event releases roughly 1,000× the energy of an M6.0! Rare, high-magnitude events dominate total seismic energy output despite being barely visible in event-count charts.
Nepal produces M7+ events at a significantly higher rate than the global average. While Nepal accounts for a tiny fraction of total event counts, its outsized share of major quakes means its risk profile far exceeds what frequency alone would suggest.
Earthquake
Depth
Does depth determine severity? And where do shallow earthquakes strike?
Over two-thirds of all earthquakes are shallow (under 70 km) — the category most destructive at the surface, as seismic energy has less distance to dissipate before reaching populated areas. Deep earthquakes, while dramatic in isolation, rarely cause comparable surface damage.
Does depth predict magnitude?
It seems intuitive: deeper earthquakes experience greater pressure and may therefore rupture more violently. Testing this directly on M6.0+ events reveals a near-flat trendline. Depth is not a reliable predictor of magnitude. The most catastrophic events regularly occur at shallow depths, precisely because that is where stress accumulates fastest along active fault systems.
Spatial
Distribution
Where on Earth does seismic activity concentrate? And why?
Four maps, each answering a sharper question: from raw locations, to magnitude-weighted density, to regional hotspots, to the dominant driver of global seismic activity.
Key Question: What does the general global quake distribution look like?
From the above map, we can begin to see tectonic plates. By designing the map further around the density of earthquakes, these plates will become even clearer.
Key Question: Which regions of the world experience the highest concentration of earthquakes?
The density map makes the tectonic structure of the Earth immediately visible. Earthquake activity forms continuous bands aligning with major plate boundaries. The Pacific Ring of Fire dominates global seismic activity, forming an arc from South America through North America, Japan, Southeast Asia, and New Zealand. Secondary concentrations are also visible along mid-ocean ridges, particularly in the Atlantic.
The Ring of Fire encircles the Pacific Plate, producing approximately 90% of the world's earthquakes. Subduction zones exist along its length, where one plate dives beneath another, generate the stress conditions required for the largest ruptures.
Case Study:
Nepal
How does a small landlocked country punch so far above its weight seismically?
Nepal sits at the collision point of the Indian and Eurasian plates which is one of the most geologically active areas on Earth. The 2015 Gorkha earthquake made global headlines, but Nepal's seismic story extends far beyond a single event.
Epicentres cluster tightly along the Main Himalayan Thrust fault, directly beneath densely populated valleys including Kathmandu. Unlike coastal subduction zones where offshore earthquakes provide some buffer distance, Nepal's earthquakes originate immediately beneath its population centres.
Nepal's M7+ rate consistently exceeds the global average relative to its geographic footprint. The 2015 Gorkha sequence is immediately visible as a spike that temporarily distorted global earthquake statistics, confirming this is a structurally hazardous region, not a statistical anomaly.
Conclusions
What does a decade of global earthquake data actually tell us?
Frequency is stable
No statistically significant trend in annual earthquake counts from 2015–2025. Year-to-year variation reflects normal seismic noise, not a structural change in global tectonics.
Count ≠ Impact
Light and moderate events dominate the catalogue numerically, but major and great earthquakes account for the overwhelming majority of total seismic energy released.
Shallow = Dangerous
Over two-thirds of earthquakes are shallow (<70 km). Depth does not reliably predict magnitude. The most destructive events regularly occur closest to the surface.
Geography is destiny
Seismic hazard is geographically structured, not random. The Pacific Ring of Fire, Himalayan collision zone, and Mid-Atlantic Ridge account for the vast majority of global activity.
Nepal: small country, outsized risk
Nepal's position on the Main Himalayan Thrust produces M7+ events at rates far above the global average relative to its size. Its epicentres lie directly beneath its population centres acting as a compounding factor that transforms seismic hazard into severe humanitarian risk.