2017 Valparaíso earthquake
earthquake in Chile
The Valparaíso earthquake of April 2017 was a strong earthquake that shook the cities of Valparaíso and Santiago on Monday, April 24, 2017, at 18:38 local time (21:38 UTC). Its epicenter was located off the coast of the Valparaíso Region and had a magnitude of 6.9 Mw. On the scale of Mercalli, the earthquake reached an intensity of VII (Very Strong).
Before this seismic event there was an unusual increase in seismic activity (seismic swarm) that began on Saturday, April 22 and before the event of magnitude 6.9 more than 180 foreshocks had been recorded, the strongest being that of magnitude 6.0 that occurred in the dawn of the April 22, 2017.
Subsequent to this event, more than 1000 aftershocks have been recorded, including several earthquakes of magnitude greater than 5.0 and two earthquakes of magnitude 5.8 and 6.0 on Moment magnitude scale that occurred on Friday, April 28, 2017, at 12:30 and 13:05 local time respectively.
Modified Mercalli intensities for some localities
The earthquake was widely felt throughout the central zone of Chile and in at least two provinces of Argentina.
Intensities of the earthquake on the scale of Mercalli in Chile according to ONEMI.
Intensities of the earthquake on the scale of Mercalli in Argentina according to INPRES.
Foreshock
The first foreshock quake was recorded at 19:46 (local time) and 22:49 (UTC) on April 22, and had a magnitude of 4.8 Mw, with epicenter 32 km west of Valparaíso and 28.1 km deep.
Aftershock
After the earthquake more than 1000 aftershocks were registered, the largest one had a magnitude of 6.0 Mw, with an epicenter 14 kilometers south of Valparaíso and 25.9 kilometers deep.
Tectonic summary
The April 24, 2017, M6.9 earthquake west of Valparaiso, Chile, occurred as the result of thrust faulting on or near the subduction zone interface between the Nazca and Pacific plates. At the latitude of this event, the Nazca plate is moving towards the east-northeast at a velocity of 74 mm/year with respect to South America, and begins its subduction beneath the continent at the Peru–Chile Trench, 80 km to the west of the April 24 earthquake.
The public source identifies “2017 Valparaíso earthquake” as earthquake in Chile. This brief keeps that definition visible, then builds a research path around Valparaíso, earthquake and Chile.
Why this record matters
A short description can identify a subject without explaining its stakes. For “2017 Valparaíso earthquake”, the useful work is to connect “earthquake in Chile” to the records capable of establishing context and consequence.
The citation trail is more important than the brevity of the summary: it shows where individual claims can be examined in context. The source revision retrieved here is dated Sep 17, 2026. The linked authority identifier is Q30911842. Authority coordinates are -33.038, -72.062. 1 of 1 selected statements include explicit references; 0 carry qualifiers and 0 use preferred rank. The first chronological checks are 2017 and 1000.
Overview language is designed for orientation and should not be treated as a substitute for the evidence cited beneath it. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Use the entry as an orientation point, then follow its citations and revision history. Names, dates and institutional relationships should be checked against the original record.
- Subject orientation
- Search vocabulary
- Locating named sources
The closest primary source, responsible institution and strongest cited specialist reference.
Three-step research path
- Establish the record: confirm the title “2017 Valparaíso earthquake”, its source revision and the description used here.
- Expand the search: follow 2017 Valparaíso earthquake primary sources, 2017 Valparaíso earthquake archive and Valparaíso research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “2017 Valparaíso earthquake”?
- What terminology or title could unlock a more precise catalogue search?
- Which institution is responsible for the underlying evidence?
Search terms from this dossier
This entry incorporates text from “2017 Valparaíso earthquake” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.