A magnitude 7.7 earthquake hits Panama's Azuero Peninsula and sets off a tsunami alert

A magnitude 7.7 earthquake struck southern Panama on Friday afternoon, shaking buildings in Panama City and prompting a regional tsunami warning. The US Geological Survey placed the origin at 17:56:06 UTC, 12 km west-southwest of Pitaloza Arriba on the Azuero Peninsula, at 7.587 degrees north and 80.769 degrees west. The depth was 12.6 km. USGS reviewed the event as magnitude 7.7 on the moment magnitude scale.

Local time at the epicentre was 12:56 p.m. The New York Times, using Eastern time, put the same shock at 1:56 p.m. and noted strong aftershocks at 2:22 p.m. and 2:37 p.m. Early wire reports had carried a preliminary figure of 7.6. The reviewed USGS page is the figure that now stands.

USGS assigned the quake a PAGER red alert, its highest impact colour. The agency said extensive shaking impacts were probable and that the disaster was likely widespread. It estimated that about 4.6 million people experienced shaking from moderate, level V on the Modified Mercalli scale, to severe, level VIII. Landslide and liquefaction models both showed a significant area affected. Liquefaction exposure was marked as significant for population as well.

What residents and officials reported

In Panama City, northeast of the epicentre, buildings shook and people left offices and homes for the street. The capital region holds about 2 million people. Omar Smith of the National Civil Protection Service, SINAPROC, told Telemetro Reporta that damage was concentrated in the central provinces of Veraguas, Herrera and Los Santos. He said there were no reports of damage in the capital, which is lined with high-rises. That split matters. A shallow 7.7 under a rural peninsula can wreck masonry towns and still leave a distant skyline standing.

Rosendo Domínguez, 60, speaking to the Associated Press by phone from Herrera, said the shock knocked things over in the kitchen. He said everyone was outside and scared. Aftershocks continued to move the ground in the hour after the main event.

The National Weather Service issued a tsunami warning for the coasts of Panama, Colombia, Ecuador, Nicaragua and Guatemala. USGS pointed readers to tsunami.gov for alert updates. A warning is not the same as a confirmed wave. It means coastal authorities have a window in which to move people off beaches and low harbours until gauges clear the threat.

Why this fault matters

Panama sits on the Pacific Ring of Fire, the belt of subduction and transform faults that produces most of the world's large earthquakes. The Azuero Peninsula is not the canal. The waterway and its locks lie farther north, on the isthmus between the Caribbean and the Pacific. A shock centred near Pitaloza Arriba is closer to the southern coast and the farming provinces than to the Gatun locks. Any effect on canal operations would depend on later inspections of dams, power lines and approach channels, not on the epicentre itself.

Depth is the other number that sets the hazard. At 12.6 km the rupture is shallow. Shallow crustal and interface quakes put more energy into the surface than a deep slab event of the same magnitude. That is why a town 12 km from the origin can see severe shaking while a city more than 100 km away mainly sees swaying towers and broken crockery.

USGS also flagged aftershocks. A main shock of this size commonly produces further shocks above magnitude 5 in the following days, some of them strong enough to bring down walls already cracked. The two events recorded within about 40 minutes of the main shock fit that pattern. Residents who re-entered damaged houses on Friday afternoon were taking a risk the agency had already named.

What is still unknown

By Friday evening no national death toll had been published by SINAPROC in the accounts available from the capital. Smith had localised the damage geographically. He had not given a count of collapsed houses, blocked roads or injured people. That gap is the story's next number. Herrera and Los Santos are rural, with towns spread along the peninsula. A red PAGER does not fix a casualty figure. It says the exposure is large enough that a low count would be the surprise.

The practical sequence for the next day is straightforward. Gauges will confirm or cancel the tsunami warning. Provincial civil protection will count houses that cannot be slept in. The canal authority, if it follows its usual practice after a felt quake, will say whether transits were paused for inspection. Until those three statements exist, the verified facts are the origin, the depth, the red alert, the 4.6 million people inside the shaking footprint, and a warning still open on five coasts.