Sismo literally means 'earthquake' or 'seismic tremor'. It's a powerful word used to describe the shaking of the earth.
In 'Ginza', J Balvin uses this word as a vivid metaphor for intense chemistry on the dance floor. He sings, "Tu cadera con la mía / Hacen un sismo" (Your hip with mine / Make an earthquake), painting a picture of their dancing being so energetic and connected that it's powerful enough to shake the ground.
J Balvin's "Ginza" is a straight-up party anthem that tells you exactly what it's about from the very first line. The whole song is an invitation to forget everything and just dance. He sets the scene in a club where "en esta disco todos somos iguales" [in this club we are all equal] and the only goal is to move. Balvin is completely focused on a woman on the dance floor, telling her to keep going because "para eso te traje" [that's what I brought you for]. It's not subtle at all, especially with the chorus telling her to "vamos a pegarnos como animales" [let's get together like animals].
What's really interesting is how the song pushes aside any idea of romance. Balvin sings that "el amor ahora es turismo" [love is now tourism], meaning it's something temporary you just visit for a little while. He's all about the physical connection right now, the "magnetismo" [magnetism] of two people dancing so hard their hips "hacen un sismo" [make an earthquake]. It's a song for the moment, for the feeling of the beat and the energy of the club, with no promises for tomorrow.