A magnitude 4.3 earthquake struck northeastern Oregon at 07:42 UTC on Nov. 10, which was 11:42 p.m. Pacific time on Nov. 9, with an epicenter 18 km southeast of the town of Joseph. The U.S. Geological Survey graded the event green on its impact-alert scale and recorded no tsunami. By the time the agency last updated its record late on Nov. 10, 123 people had filed accounts of the shaking.
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The magnitude comes from the University of Washington’s origin solution, which lists a local magnitude of 4.3, and the USGS’s own origin separately reads 4.3 on a body-wave scale. Two independent calculations landing on the same value is a small sign that the size of the quake is settled even while the felt-report tally keeps moving.
Joseph, Wallowa County, and the University of Washington origin
The USGS event page for uw714136981 places the epicenter 18 km southeast of Joseph, a small town in Wallowa County in the state’s far northeastern corner. The identifier starts with “uw,” the code for the University of Washington network that contributed the location and local magnitude, and the page carries a reviewed status, meaning the automatic first solution has since been checked by an analyst rather than left as a raw machine estimate.
Different versions of the record place the epicenter a kilometer or so apart, and the depth varies between solutions, so the safest reading is a shallow event beneath the mountain country east of Joseph. The USGS event web service returned a magnitude of 4.29, an instrumental intensity of about 4.2 from the ShakeMap and a green alert.
Felt reports rising from 66 to 123
The count of people who felt the quake was not a fixed number. A query of the USGS service made after the morning update on Nov. 10 returned 66 felt reports, while the full detail record, last revised at 02:31 UTC on Nov. 11, listed 123 responses to the agency’s felt-report system, known as DYFI. That is an almost twofold rise over a single day, which fits how the system works: people find the questionnaire after they wake up, after they read the news, or after a neighbor mentions the jolt.
Each of those responses is a short questionnaire about what the person noticed, such as whether objects rattled or whether the shaking woke them. The USGS explains on its DYFI scientific background page that answers are pooled by community, usually ZIP code, converted to numeric scores, weighted so that felt, rattling and damage questions count most, and fed into a formula that yields a Community Decimal Intensity. For this event that figure came out at 4.3.
The agency is explicit that the result describes a place and not a person. In its words, Community Decimal Intensities are not individual observations, and the unchecked raw responses behind them can differ from one household to the next because of local ground conditions and building construction.
Responses from people who felt nothing count as well. USGS notes that reports of no effect help fix the share of residents who noticed an earthquake and the line where felt shaking fades out, which is why the agency invites a reply even from someone in a nearby town who slept through it. In a sparsely populated part of Oregon, a few dozen extra replies can move a community’s intensity by a noticeable amount, and early maps cover only a handful of areas before the consensus settles.
Magnitude 4.3 versus shaking near intensity 4
Magnitude and intensity answer separate questions, and the USGS explainer on magnitude, energy release and shaking intensity keeps them apart: an earthquake has one magnitude, while intensity is the shaking at each location and depends mostly on distance from the fault rupture. The ShakeMap value of roughly 4 on the Modified Mercalli scale, which uses Roman numerals, is the modeled shaking near the epicenter, and the DYFI intensity of 4.3 is its human-reported counterpart.
The same page notes that each whole-number step in magnitude releases about 32 times more energy. A magnitude 4.3 event is therefore a modest release of energy by earthquake standards, large enough to be noticed across a valley and small enough that the agency’s alert level stayed at its lowest tier.
The record’s other flags are quiet. The alert field reads green, the tsunami flag is 0, and nothing in the USGS data for the event points to reported damage, which matches what a shallow magnitude 4.3 shock under mountain terrain is expected to produce: a sharp jolt and rattling at close range, then a rapid falloff in shaking with distance. Residents nearest Joseph would have felt the strongest motion, and the late-night origin time put most of them in bed when it arrived.
The tally of 123 is the open item in the record. The feed showed 66 reports on the morning of Nov. 10 and 123 by that evening, and USGS says more responses make an area’s assigned intensity more reliable, so the final felt count and the community intensity could still shift as late questionnaires arrive and as analysts revise the page.
This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.
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