The news reports magnitude. What damages your property is intensity. Here is the difference, in plain words, and why it changes how you read a fault distance.
An earthquake happens and two numbers appear. A magnitude, like 6.7. And later, a list of intensities by town: Intensity VI here, Intensity IV there.
People treat these as the same measurement reported twice. They are not. Understanding the difference changes how you read the fault distance on a hazard report.
Magnitude measures the energy released at the source. One earthquake has one magnitude. It does not change depending on where you are standing.
It is calculated from instrument readings, and it is a logarithmic scale, which means each step up is a large jump in energy, not a small one. A magnitude 7 releases far more energy than a magnitude 6.
Magnitude is a fact about the event. It is not a fact about your address.
Intensity measures the effect of the shaking at a particular place. One earthquake produces many different intensities, one for each location.
In the Philippines, PHIVOLCS uses the PHIVOLCS Earthquake Intensity Scale (PEIS), running from I to X. It is described in words and observed effects: what people felt, what moved, what cracked, what fell. Intensity is assigned by observation, not by instrument alone.
The same magnitude 6.5 earthquake can produce strong shaking in one town and be barely noticed two provinces away.
Three things, mainly:
That third point is why soil matters, and why liquefaction is a separate hazard layer. See what liquefaction is.
A hazard report tells you the distance from your point to the nearest mapped active fault. People read that number as a verdict: close is bad, far is safe.
That is not what it means.
So the fault distance is a design input for a licensed structural engineer, not a pass or fail for the property. The post on checking whether a property is in a fault zone covers how to use it properly.
Not distance. Structure.
Most Philippine earthquake deaths come from buildings failing, not from the ground opening. A well-built house near a fault is safer than a badly built house far from one. That is the argument in most Philippine homes are not built for a big quake.
A hazard screening reports the distance from your point to the nearest mapped active fault and an estimate of liquefaction susceptibility. It does not predict earthquakes, assign an expected intensity, or assess a building. PHIVOLCS is the authority on faults and intensity, and only a licensed structural engineer can tell you how a specific house will behave.
CheckHazard does not replace a professional geotechnical or engineering survey.