Magnitude 7.7 quake on a shallow inland fault shakes about 4.6 million people in Panama
Panama was struck on Friday by a magnitude 7.7 earthquake near the village of Pitaloza Arriba, the USGS said. A USGS seismologist says the tsunami threat from the shallow, inland rupture has largely receded; shaking and aftershocks are the hazard that remains.
The Scientist · Science desk
Supported: about 4.6 million people in moderate to severe shaking. Contested: waves could hit Panama's coast. Contested: NOAA issued no tsunami alert. Supported: tsunami threat has likely largely receded. Supported: USGS model of dozens to hundreds of deaths.
- Supported Around 4.6 million people experienced moderate to severe shaking, according to the USGS., claim 4
- Contested Tsunami waves up to three meters high could hit the Panama coastline in the coming hours, the U.S. Tsunami Warning System said., claim 27
- Contested NOAA's Tsunami Warning System had not issued a tsunami warning, advisory, watch or threat alert., claim 26
- Supported USGS seismologist Susan Hough said the tsunami threat has likely largely receded because the quake occurred on land at a relatively shallow depth., claim 18
- Supported USGS modeling put the likely casualties in the range of dozens to hundreds of fatalities and damages in the hundreds of millions of dollars., claim 20
| Claim | State | Claim number |
|---|---|---|
| Around 4.6 million people experienced moderate to severe shaking, according to the USGS. | Supported | 4 |
| Tsunami waves up to three meters high could hit the Panama coastline in the coming hours, the U.S. Tsunami Warning System said. | Contested | 27 |
| NOAA's Tsunami Warning System had not issued a tsunami warning, advisory, watch or threat alert. | Contested | 26 |
| USGS seismologist Susan Hough said the tsunami threat has likely largely receded because the quake occurred on land at a relatively shallow depth. | Supported | 18 |
| USGS modeling put the likely casualties in the range of dozens to hundreds of fatalities and damages in the hundreds of millions of dollars. | Supported | 20 |
What happened
- Several large aftershocks followed the main shock, including one of magnitude 6, AFP reported.
- AFP saw many people evacuated from buildings in Panama City, about 200 km from the epicentre.
- President Jose Raul Mulino said on social media that he had ordered personnel, resources and aid mobilised to the affected area.
- The USGS and the US embassy warned of a possible tsunami threat to Panama and eight other countries, among them Costa Rica, Colombia, Ecuador and Mexico.
Why it matters
- What doesn't add up contradiction Coastal residents get opposite signals from the two reports: AFP quotes the US Tsunami Warning System projecting waves up to 3 m for Panama's coast, while Scientific American says NOAA's system issued no alert of any kind.
- What it costs cost If the USGS model holds, Panama faces dozens to hundreds of deaths and damage in the hundreds of millions of dollars, and officials had released no injury or death figures to check it against.
- Who's exposed exposure Buildings in central Panama, where AFP says damage should be heaviest, now face the potentially strong aftershocks the USGS says could still follow.
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Susan Hough, a seismologist at the USGS, traced the tsunami question to where the ground moved. "Because this was on land and shallow, you're not on the seafloor, so it didn't move the seafloor underneath the water column and that's what you need to generate a tsunami," she said [19]. She described the rupture as "a shallow lateral fault, what we call strike slip, so similar to the San Andreas" [21].
The shallow depth Hough cited against a tsunami also means more shaking at the surface, Scientific American noted [13]. AFP gave the depth as 12 km [9].
The USGS count of 4.6 million people in moderate to severe shaking [4] is roughly Panama's whole population, which AFP, also citing the USGS, put at about 4.5 million [5][24]. The thing this figure doesn't tell you is how many of those people felt severe shaking and how many felt moderate shaking. Near the epicentre, the population is relatively sparse [7]. The two reports place that epicentre slightly differently: about 14 km southwest of Pitaloza Arriba in Herrera Province, according to Scientific American [3], and 10 km from the town, according to AFP [2].
On the tsunami, we think Hough's physical argument is the better guide for now [18], on one condition: it holds only as long as later analysis keeps the rupture on land. The US embassy still told its citizens to keep away from the coast and to monitor local emergency broadcasts [23].
Panama sits near the meeting point of several plates, with the Cocos and Nazca plates to the south, the Caribbean plate to the north and the South American plate to the east [14]. Hough said the subduction zones near the country do not meet, and that this is why Panama usually has less powerful quakes [15]. When quakes do strike, they usually hit western Chiriqui province, AFP reported [16]. This one struck in Herrera Province instead [3]. The USGS first measured it at 8.0 before revising it to 7.7 [1].
"There's a complicated zone of faulting that's at that juncture, and so this earthquake was on one of those faults," Hough said. "It was quite large compared to other earthquakes that have been seen in that area." [22]
What to watch
- Whether later US Tsunami Warning System bulletins confirm or withdraw the 3 m wave projection AFP reported for Panama's coast.
- Official casualty and damage counts from Panama, measured against the USGS model's range of dozens to hundreds of deaths.
- The size and timing of further aftershocks after the magnitude 6 already recorded.
Clarity's read
What the record supports and how the coverage leans. The claims behind it follow.
Reality
- Evidence64
- Adoption
- Not scored
- Hype gap+15
- Incentives
- Not scored
- Confidence55
Perspective Coverage
4 publishers- Builder
- Builder 16%
- Operator
- Operator 69%
- Investor
- Investor 15%
Claim ledger
Ranked by verification strength, evidence, and original report placement.
- [1]
The quake struck at 12:56 local time on Friday and was initially measured as magnitude 8.0 by the U.S. Geological Survey, later downgraded to 7.7.
- [2]
USGS said the quake was detected at 5:56 p.m. GMT with an epicenter 10 kilometers from the small town of Pitaloza Arriba in south-central Panama.
- [3]
The quake struck around 9 miles (14 kilometers) southwest of Pitaloza Arriba, a small village in Panama's Herrera Province.
- [4]
Around 4.6 million people experienced moderate to severe shaking, according to the USGS.
- [5]
The quake was felt across the country of around 4.5 million people, according to the USGS.
- [6]
No statistics on injuries or deaths had yet been released.
- [7]
The affected area has a relatively low population density.
- [8]
Potentially strong aftershocks could follow, according to the USGS.
- [9]
The quake was recorded at a shallow depth of 12 kilometers.
- [10]
Several large aftershocks, including a magnitude 6 tremor, were recorded.
- [11]
AFP witnessed many people being evacuated from buildings in Panama City, about 200 kilometers from the epicenter.
- [12]
There were no reports yet of casualties, but extensive damage was expected, particularly in the center of the country.
- [13]
Shallow earthquakes lead to more shaking being felt at the surface.
- [14]
Panama is near the intersection of several major tectonic plates: the Cocos and Nazca plates to the south, the Caribbean plate to the north and the South American plate to the east.
- [15]
Hough said the subduction zones near Panama don't meet, which is why the country usually experiences less powerful quakes.
- [16]
Earthquakes are rare in Panama, and when they do occur, they usually strike in western Chiriqui province.
- [17]
Panamanian President Jose Raul Mulino said on social media he had given instructions to mobilize personnel, resources and aid to the area.
- [18]
USGS seismologist Susan Hough said the tsunami threat has likely largely receded because the quake occurred on land at a relatively shallow depth.
- [19]
"Because this was on land and shallow, you're not on the seafloor, so it didn't move the seafloor underneath the water column and that's what you need to generate a tsunami,"
- [20]
USGS modeling put the likely casualties in the range of dozens to hundreds of fatalities and damages in the hundreds of millions of dollars.
- [21]
"It was a shallow lateral fault, what we call strike slip, so similar to the San Andreas,"
- [22]
"There's a complicated zone of faulting that's at that juncture, and so this earthquake was on one of those faults," ... "It was quite large compared to other earthquakes that have been seen in that area."
- [23]
The U.S. embassy warned U.S. citizens in the area to avoid damaged structures and the coast, and to monitor local emergency broadcasts for updates.
- [24]
The USGS figure of 4.6 million people in moderate to severe shaking is about 102 percent of the roughly 4.5 million national population AFP cited, i.e. roughly the whole country.
- [25]
The USGS and the U.S. embassy in Panama warned the quake could pose a tsunami threat in Costa Rica, El Salvador, Peru, Mexico, Guatemala, Nicaragua, Colombia and Ecuador, as well as Panama.
- [26]
NOAA's Tsunami Warning System had not issued a tsunami warning, advisory, watch or threat alert.
- [27]
Tsunami waves up to three meters high could hit the Panama coastline in the coming hours, the U.S. Tsunami Warning System said.
Sources
4 independent publishers whose own reporting we read for this story.
- mezha.netЗемлетрус магнітудою 7.7 стався в Панамі
2 articles · October 10, 2026
- phys.orgTsunami alert after major earthquake rocks Panama
1 article · October 10, 2026
- scientificamerican.comMajor earthquake strikes Panama—damage and injuries are expected
1 article · October 9, 2026
- scmp.comPanama rocked by 2 powerful earthquakes, multiple aftershocks
1 article · October 9, 2026
Topics and entities
Topics
- Tsunami warnings
- Plate Tectonics
Entities
- AFP
- Jose Raul Mulino
- NOAA
- Herrera Province
- US Geological Survey