Monday morning started off with a bang for residents of the Central Valley when a loud, as yet unidentified, series of booms rattled windows about 30 minutes after midnight. Many did not hear it, but enough people did to cause a firestorm of comment on social media such as Facebook and Twitter.
The strange sound was prolonged – many described it as lasting for five minutes or so. Perhaps the only one making no comments were scientists and government authorities, who were reticent about commenting or speculating. A few things it wasn’t: Volcanologists discounted a volcanic eruption; nor was it a supersonic aircraft, because the powerful radar at Juan Santamaría International Airport outside of San José picked up no planes at the time, not even subsonic ones.
Also, there were no climatological phenomena or strange weather conditions. By nightfall Monday, the speculation was still going along briskly with the major vote going to fireworks at the festival at Zapote, in San José. But many said it sounded like no fireworks they had ever heard. Mario Sánchez, spokesman for the National Meteorological Institute, discounted a storm because the only thing that would sound like the noise described would be a storm accompanied by lightning – and early Monday morning was clear with a full moon.
The sound reverberated in Coronado, Heredia, Desamparados, Escazú, Cartago, San Ramón, Turrialba and as far south as Pérez Zeledón near the Panama border.
Rafael Arias, advisor to the San José Municipality, confessed to being puzzled. Yes, he told the daily La Nación, there were fireworks that closed out the fiestas, and they might have been heard as far away as Desamparados – but not in San Joaquín de Flores. Although other citizens might be celebrating with fireworks, they certainly would not be heard that far away, he added.
The owner of fireworks firm Cavica, Carlos Villavicencio, thinks it could have been his company’s work in the night. “Yes, we closed out the festival with about 150 bombetas [exploding aerial bombs].” But he still couldn’t explain how they could have been heard in Turrialba.
The director of the School of Physics at the University of Costa Rica, Rodrigo Carboni, scoffed that only a volcanic eruption could be heard that far away. But Fabio Antonio Chávez, a Zapote resident, was not convinced the fireworks didn’t cause the uproar.
He told La Nación, “They set off my car alarm. They were very strong. ... I’ve never seen anything like them in the 10 years I’ve lived here.”