When an earthquake appears on a live map, the first number most people look at is its magnitude. That number is useful, but it is not a complete description of what people on the ground will experience. Two earthquakes with a similar magnitude can produce very different levels of shaking because depth, distance, geology, rupture direction and the vulnerability of buildings all change the outcome. Quake Pulse lets you compare those dimensions across the live database, including the recent events M 5.9 — southern East Pacific Rise and M 5.2 — 78 km SSW of Nikolski, Alaska. Understanding those differences is the first step toward reading earthquake data without turning a single metric into a headline.
Magnitude measures size, not local damage
Magnitude is designed to describe the size of an earthquake at its source. Modern catalogues commonly use moment magnitude for larger events because it relates to the physical size of the rupture and the amount of slip. The scale is logarithmic: a one-unit increase represents a large jump in recorded ground motion and an even larger increase in released energy. That does not mean every magnitude 6 earthquake causes the same consequences. A remote offshore event can be barely noticed by people, while a smaller shallow event directly beneath a dense city may be disruptive. The USGS Earthquake Hazards Program explains the distinction between earthquake parameters and their effects in detail.
Depth changes how seismic energy reaches the surface
The hypocentral depth tells us how far below the surface the rupture began. Shallow earthquakes often generate stronger local shaking because seismic waves have less distance in which to spread and lose energy before reaching buildings. Deeper earthquakes can be felt over a much wider area, yet the shaking directly above them may be less intense than for a shallower event of comparable magnitude. This is why a depth value should always be read next to magnitude. On the Quake Pulse live map, the point is only the surface location; the event page adds depth so the three-dimensional geometry is not hidden behind a flat dot.
Distance matters, but the nearest place is not the whole story
Shaking generally decreases with distance from the rupture, but real earthquakes are not perfect point sources. Large ruptures can extend for tens or hundreds of kilometres, and seismic energy may be radiated more strongly in some directions. A city farther from the epicentre can therefore experience significant motion while another place at a similar distance feels less. The location text attached to an event is a convenient geographic reference rather than a full impact map. For stronger earthquakes, products such as ShakeMap combine instrumental observations and models to estimate the spatial distribution of shaking. A useful background introduction is the Wikipedia article on earthquakes, which links the basic vocabulary of focus, epicentre, waves and faults.
Local geology can amplify or reshape shaking
Bedrock, sediment, reclaimed land and sedimentary basins do not respond to seismic waves in the same way. Soft sediments can amplify certain frequencies and prolong shaking. Basins can trap seismic energy, while steep changes in geology may focus or scatter waves. This helps explain why neighbourhoods within the same metropolitan area can record different motions during one earthquake. It also means that a global event catalogue cannot replace local microzonation studies. Quake Pulse is designed to help users explore where and when events occurred; site-specific engineering decisions need detailed geological and geotechnical information that goes far beyond a global database.
Intensity describes effects at a place
Magnitude belongs to the earthquake; intensity belongs to a location. Intensity scales describe how strongly the ground shook and what effects were observed in a particular area. A single earthquake therefore has one reported magnitude but many possible intensity values across the affected region. Felt reports can add useful human context, although they are influenced by population distribution and participation. When Quake Pulse displays a “felt” count, it should be read as a reporting signal rather than a direct measurement of total exposure. This distinction is especially important when comparing a heavily populated city with a remote oceanic or mountain region.
Buildings turn ground motion into human consequences
The same ground motion can have very different consequences depending on building age, structural system, maintenance, construction quality and local codes. Flexible engineered structures may move substantially without collapsing, while brittle or poorly connected buildings can suffer severe damage under lower motions. Non-structural components also matter: ceilings, façades, shelves, pipes and equipment can create hazards even when the main structure remains stable. That is why earthquake risk is usually understood as a combination of hazard, exposure and vulnerability. Magnitude is part of the hazard picture, but it says nothing by itself about how many people or assets are in harm’s way.
How to read a Quake Pulse event page
Start with the time and location, then look at magnitude and depth together. Check whether the event has been reviewed or remains automatic, because early solutions can be revised as more stations contribute data. Compare the event with nearby recent activity rather than with a global average that may mix very different tectonic settings. If an event is important for safety, use official local authorities for protective instructions. Quake Pulse is an independent observatory and does not predict earthquakes. Its value is to place live observations into a consistent interface so that users can ask better questions about the data rather than overreacting to one number.
The practical takeaway
A magnitude value is a starting point, not a verdict. Depth, rupture geometry, distance, ground conditions and the built environment determine how seismic energy becomes experienced shaking and damage. When you see a new event, resist the temptation to compare it only by magnitude with a famous historical earthquake. Instead, read the full record, examine its location on the globe, consider the depth and wait for reviewed information when the event is significant. That habit makes live earthquake data more informative and less sensational, which is exactly the approach Quake Pulse is designed to support.