How to interpret an earthquake record

Earth Pulse helps a curious reader understand what a reported magnitude, depth, location, shaking product, or other earthquake record may mean without turning a limited observation into a broader claim. For a selected event, it looks for one useful public question that the available material can answer within clear boundaries.

A story explains selected evidence in the record; it does not independently investigate the earthquake. Earth Pulse is not a substitute for a seismologist, an emergency service, or the official source behind the data.

The system separates finding suitable material from writing about it. Each stage narrows what the final explanation is allowed to say.

1. Observation The system reads a named public source and preserves its reported values, product type, and update time.
2. Context Only relevant scientific context or bounded comparisons are attached. Context can explain meaning, but it cannot prove an event-specific cause.
3. Selection The available material must support one useful public question and an approved type of story. Selecting a topic is not itself a scientific finding.
4. Validation Structured rules record what each source supports, what it cannot establish, and whether two products depend on the same underlying evidence.
5. Explanation An AI language model drafts plain-language prose from that prepared material. Separate sentence-level checks reject claims that exceed it.
6. Publication A story becomes public only when automated evidence checks pass and its source record is current. Material source changes can trigger re-evaluation or removal.

A source-backed record is a value or statement that can be traced to a named source and version. This means SOLAST can show where a claim came from; it does not mean that every value is exact, final, or independent of other products.

Published event record

Reported event time, location, magnitude, depth, status, and other fields tied to an identified source record.

Observation or analytical product

Recorded ground motion, public felt reports, mapped shaking, or wave-based products, each kept with its own method and limits.

Official interpretation

An interpretation explicitly published by the source, such as a sequence relationship or regional event context. It remains attributed to that source.

Scientific context or comparison

Established background knowledge or a bounded calculation that helps explain scale and setting without becoming proof about the event's cause.

Different parts of an earthquake record answer different questions. A clean number, point, or line on a map can look more certain — and more complete — than the underlying measurement or estimate really is.

The explanation may connect a record with established science, but scientific context constrains what can be said; it does not independently confirm an event-specific cause.

Earth Pulse does not try to make an uncertain record sound definitive. The same limits attached to the prepared evidence must remain visible in the published explanation.

• Values and conclusions remain attributed to their source or product.
• Words such as reported, estimated, calculated, may, and approximately are preserved when they matter.
• Precision is not added beyond what the source supports.
• Products that share underlying inputs are not described as independent confirmation.
• Missing evidence and the important question that remains unresolved are stated rather than filled with a guess.

Automated evidence checks test whether every sentence remains within the prepared record and its limits. They do not independently verify the earthquake, constitute scientific peer review, or certify an explanation of its cause.

Most earthquakes will not receive an Earth Pulse story. Publishing nothing is the correct result when the available material cannot support one useful explanation without guessing or overstating certainty.

• No approved public question is sufficiently supported by the available products.
• Required information is missing, conflicting, or has changed materially.
• The uncertainty cannot be communicated clearly in a short explanation.
• The draft does not pass the automated evidence checks.

Missing prose does not mean that an event is unimportant. The Story Atlas is a curated educational collection, not a complete seismic catalog, and must not be used to compare earthquake frequency, danger, or regional activity.

Story families use named public sources appropriate to the question they answer. The labels below describe the evidentiary role behind each family, not a claim that every earthquake can support every question. A calculated product, a public report, and general scientific context are not treated as interchangeable forms of proof.

• Official event contextUSGS event pages, detail records, and official event products.
• Underground scaleUSGS event geometry and bounded source-specific scale comparisons.
• Earthquake sequenceExplicit relationships published in USGS event products; no sequence is inferred from timing alone.
• Historical neighborhoodBounded searches of the USGS Comprehensive Earthquake Catalog.
• Reported and calculated shakingDid You Feel It? reports and ShakeMap estimates, kept distinct.
• Depth and surface shakingUSGS event depth together with separately identified public-report or ShakeMap evidence.
• Shallow start and weak shakingUSGS event geometry and bounded surface-shaking observations with their uncertainty retained.
• Deep-focus earthquakeUSGS event geometry and source-backed regional context; the reported depth is not treated as exact.
• Triple-junction settingUSGS location data and published scientific plate-boundary datasets used only for broad setting.
• Ocean-ridge settingUSGS location data and published scientific plate-boundary datasets, without claiming an exact fault.
• Plate-boundary settingUSGS event records and the broad global boundary geometry described by Bird (2003).
• Local earthquake concentrationBounded USGS catalog results showing events close in time and place, without assigning a sequence type.
• Rock movementPublished USGS moment-tensor or focal-mechanism products, including their ambiguity and method limits.

Core event material is attributed to the USGS Earthquake Hazards Program, and each story links to its original USGS event record. An AI language model drafts the prose; SOLAST controls the evidence selection, boundaries, automated checks, and publication rules. The model itself is not treated as a source.

Earthquake records can be revised after publication. If a required source value changes materially, the related story can be re-evaluated or hidden rather than silently presented as current.

Unknown remains unknown. Earth Pulse does not infer an exact fault, complete rupture shape, reason the earthquake happened at that moment, future activity, local damage, or danger unless an appropriate source explicitly establishes the narrower claim. A short explanation also cannot represent every scientific interpretation of an event.

Earth Pulse is not a warning, forecast, damage estimate, hazard assessment, or safety service. For current official information and emergency guidance, use the relevant geological survey, warning center, and local authorities. See the full legal notice and disclaimer.