# USGS Earthquake Monitor - Magnitude & Location Revisions

Track USGS earthquake magnitude, location and review-status revisions with stable event IDs, source timestamps and saved comparisons.

Canonical product page: https://mayd-it.com/data-tools/actors/usgs-earthquake-revision-monitor/

## Example input

```json
{
  "feeds": [
    "4.5_week"
  ],
  "maxResults": 5,
  "itemsPerQuery": 3
}
```

## Choose this tool

Infrastructure analysts reviewing revisions to observed seismic events. USGS event IDs distinguish magnitude and location revisions from new events.

Useful output columns: `eventId`, `magnitude`, `place`, `eventAt`, `updatedAt`, `longitude`.

## Practical workflow

Choose a USGS summary window. Keep a named baseline and compare stable event IDs on later runs. Review magnitude, coordinates and review-status revisions in your infrastructure workflow. Do not use this as an emergency alert system.

## Check the fit

USGS summary feeds only: significant_month, significant_week, 4.5_week, 2.5_day and all_day. No earthquake predictions, tsunami warning service or facility damage inference. Source revisions and event timestamps are kept separate from observation time.

## Real output sample

One selected row from a 2026-10-18 run. One saved row with selected scalar fields. Nested structures remain available in full Actor output.

Run: EfsqgzanTrXjgEAuM. Summary status: ok. Incomplete: false.

Historical bounded output from the recorded run. Current source values may differ.

```json
{
  "recordId": "us6000u35l",
  "title": "M 4.5 - Kermadec Islands, New Zealand",
  "eventId": "us6000u35l",
  "magnitude": 4.5,
  "place": "Kermadec Islands, New Zealand",
  "eventAt": "2026-10-18T12:42:22.533Z",
  "updatedAt": "2026-10-18T12:59:51.040Z",
  "longitude": -177.3838,
  "latitude": -30.1265,
  "depthKm": 10,
  "reviewStatus": "reviewed",
  "url": "https://earthquake.usgs.gov/earthquakes/eventpage/us6000u35l",
  "observedAt": "2026-10-18T15:33:13.414Z"
}
```


## Full guide

# USGS Earthquake Monitor - Magnitude & Location Revisions

<img src="https://apify-image-uploads-prod.s3.us-east-1.amazonaws.com/r4RVqhPKWACJsK9zp-actor-Dpbx3BiksngMqFG0X-h1j8hgMhxw-earthquake.png" alt="USGS Earthquake Monitor - Magnitude & Location Revisions icon" width="96" height="96">

**USGS event IDs distinguish magnitude and location revisions from new events.**

Track USGS earthquake magnitude, location and review-status revisions with stable event IDs, source timestamps and saved comparisons.

## Start in under a minute

1. Paste usgs feed names into the first input field, or use the included sample.
2. Keep the five-result limit for your first run and choose **Start**.
3. Open **Observations**, **Scope and diagnostics**, or the **Readable run report** in Output. Export CSV or JSON from the dataset.

```json
{
  "feeds": [
    "4.5_week"
  ],
  "maxResults": 5,
  "itemsPerQuery": 3
}
```

No source account, API key, paid proxy or extra subscription is required for these public endpoints. Source availability and rate limits still apply.

## Who this helps

Infrastructure analysts reviewing revisions to observed seismic events.

<!-- B19-REAL-SAMPLE -->
## A real output sample

Captured in a successful bounded Apify run; arrays and long text are shortened for readability. Values are snapshots, not live guarantees.

```json
{
  "recordId": "us6000u35l",
  "title": "M 4.5 - Kermadec Islands, New Zealand",
  "eventId": "us6000u35l",
  "magnitude": 4.5,
  "place": "Kermadec Islands, New Zealand",
  "eventAt": "2026-10-18T12:42:22.533Z",
  "updatedAt": "2026-10-18T12:59:51.040Z",
  "longitude": -177.3838,
  "latitude": -30.1265,
  "depthKm": 10,
  "reviewStatus": "reviewed",
  "url": "https://earthquake.usgs.gov/earthquakes/eventpage/us6000u35l",
  "observedAt": "2026-10-18T15:19:50.535Z",
  "comparisonStatus": "not_requested"
}
```

## What you receive

One row per unique confirmed observation. Every row includes a stable `recordId`, title, source URL and observation time.

| Field | Meaning |
|---|---|
| `eventId` | Source-reported event id; missing optional values remain null. |
| `magnitude` | Source-reported magnitude; missing optional values remain null. |
| `place` | Source-reported place; missing optional values remain null. |
| `eventAt` | Source-reported event at; missing optional values remain null. |
| `updatedAt` | Source-reported updated at; missing optional values remain null. |
| `longitude` | Source-reported longitude; missing optional values remain null. |
| `latitude` | Source-reported latitude; missing optional values remain null. |
| `depthKm` | Source-reported depth km; missing optional values remain null. |
| `reviewStatus` | Source-reported review status; missing optional values remain null. |
| `comparisonStatus` | not_requested, new, changed or unchanged |
| `changedFields` | Fields different from your last saved observation |
| `previous` | Previous saved source values when comparison is enabled |

## Saved comparisons

Enable **Compare with saved observations**, choose a snapshot name, and reuse the same input scope. The first run establishes history; it cannot report changes before that point. Enable **Save only new or changed observations** for later runs if you want a change-only export. An unchanged run can correctly save zero rows.

Only confirmed saved rows advance history. A bounded or failed run never establishes that a missing record was deleted. History is stored in a named key-value store in the running user's account. Use one writer per snapshot: do not overlap runs against the same snapshot. Change the snapshot name when starting a new independent workflow.

## Scope and limitations

USGS summary feeds only: significant_month, significant_week, 4.5_week, 2.5_day and all_day. No earthquake predictions, tsunami warning service or facility damage inference. Source revisions and event timestamps are kept separate from observation time.

At most ten input values and five hundred saved rows per run. Each input uses a bounded source response. Shared feeds are cached within the run; public documents may require a robots.txt request. Requests are paced. Responses are capped at 8 MiB and share the run deadline. No authentication bypass or code execution is performed. HTTP 429 stops further requests. Source failures appear in SUMMARY and the HTML report, never as paid data rows.

## Pricing

The configured base price is **$0.001 per saved observation**, plus **$0.00005 per start** at the default memory. Five observations cost $0.00505 at that base rate. Applicable plan discounts and the Store pricing panel govern actual charges. Set a maximum charge in Run options. Diagnostics, reports and unchanged skipped rows are not dataset result events.

## A practical workflow

Infrastructure analysts reviewing revisions to observed seismic events. USGS event IDs distinguish magnitude and location revisions from new events. Start with the included five-result sample, review source links, then save your own scope as an Actor task. Use a named snapshot for repeat runs and keep source metadata with downstream exports.

## Make it recurring

Save an Actor task with your inputs, then attach an Apify Schedule. For change detection, keep the same snapshot and avoid overlapping runs. Add an integration to deliver results to your own spreadsheet or workflow. No external delivery is enabled automatically.

## Frequently asked questions

**Why did a repeat run return zero rows?** With change-only mode enabled, unchanged records are skipped. Check SUMMARY to distinguish this from empty matches, limits, or an upstream error.

**Does a missing record mean it was deleted?** No. Searches cover a bounded source window; a record can move outside it. Missing records never become deletion claims.

**Can I export or integrate the data?** Yes. Use Apify dataset exports for CSV/JSON, or the Actor API and your own integrations. No external message or delivery is enabled by default.

## Examples

1. **USGS feed names: 4.5_week** — A bounded 4.5_week observation sample. Review source evidence and export rows or compare them in a later run.
2. **USGS feed names: 2.5_day** — A bounded 2.5_day observation sample. Review source evidence and export rows or compare them in a later run.
3. **USGS feed names: significant_month** — A bounded significant_month observation sample. Review source evidence and export rows or compare them in a later run.

## Source and support

[Official source documentation](https://earthquake.usgs.gov/earthquakes/feed/v1.0/geojson.php). This independent Mayd IT tool is not affiliated with the source platform. Open an Actor issue with the run ID and expected result, or contact bmay@mayd-it.com. Never include credentials.

## Workflow library and related tools

[Product guide](https://mayd-it.com/data-tools/actors/usgs-earthquake-revision-monitor/) · [Workflow and real output](https://mayd-it.com/data-tools/actors/usgs-earthquake-revision-monitor/workflow.md) · [All data tools](https://mayd-it.com/data-tools/) · [Use with AI](https://mayd-it.com/data-tools/ai/)
