If you were jolted awake around 1:40 a.m. this morning you felt one of the strongest quakes to hit the San José area this year. The shaking was sharp and close, and you should expect more of it through the day. The first quake hit at 1:37 a.m. with its epicenter in Vásquez de Coronado, roughly 15 kilometers (9 miles) northeast of downtown San José. A second, smaller quake followed within about three minutes. Both were shallow, which is why they hit so hard for their size.
There have been some discrepancies on how strong the first one was. The Observatorio Vulcanológico y Sismológico de Costa Rica (OVSICORI), put it at magnitude 5.0 at a depth of 11 kilometers (6.8 miles), about 8 kilometers (5 miles) from San Isidro de Coronado. The Red Sismológica Nacional revised its own reading upward to magnitude 5.4 at just 7 kilometers (4.3 miles) deep, placing the epicenter 11 kilometers (7 miles) north of Cascajal de Vásquez de Coronado. The United States Geological Survey logged magnitude 4.9 at 10 kilometers (6.2 miles).
Those gaps are normal in the first hours after a quake, and they will narrow as more data comes in. What all three agree on is the part that matters, it was shallow, and it was directly under a densely populated corner of the Central Valley. The second event registered at magnitude 4.5 on OVSICORI’s confirmed bulletin, with earlier readings listing it at 4.4. By 3:30 a.m., OVSICORI seismologist Marino Protti reported roughly 30 aftershocks.
Damage so far appears minimal as the Comisión Nacional de Emergencias said at 1:52 a.m. it had received no damage reports at all. It later confirmed a single 911 call reporting a damaged perimeter wall at a home in Vásquez de Coronado, plus a downed electrical pole in San Vicente de Moravia. Bomberos de Costa Rica and the Cruz Roja Costarricense both ruled out serious damage overnight.
Those in the area reported strong shaking in San Francisco de Dos Ríos, Tres Ríos, Moravia, Hatillo and parts of Alajuela. In Cariari de Pococí, on the Caribbean slope, people described it as mild. Expect aftershocks to keep coming as a sequence of 30 in under two hours is typical after a shallow magnitude 5, and smaller tremors can continue for days. Most will be too weak to feel. A few may be strong enough for you too feel.
As a precaution, walk through your home this morning before you assume everything is fine. Look at perimeter walls, masonry, and anywhere plaster meets a corner, because hairline cracks that appear after one quake can open further during aftershocks. Check that your water heater is still strapped and that gas connections are not leaking. A wall that shifted overnight is far easier to spot at 7 a.m. than it was at 1:40.
The Central Valley sits on top of an active fault and fold system, which is precisely why a moderate quake here produces harder shaking than a much larger one out at sea. That geology is not going to change, and neither is the answer to it. So, the useful response is not alarm but maintenance — knowing where your water shutoff is, keeping a flashlight somewhere you can find it in the dark, and checking the walls just to be sure all is in order.
