IF a big enough chunk falls off the island at one time. Sure, landslides above and below water cause tsunami waves, and the other bad thing would be a crack letting seawater into the magma to build up steam as in Krakatoa. I read somewhere it would take billions of tons for the hypothesized mega tsunami, which seemed like it would be most of an island. As of yesterday it wasn't too bad.
IF a big enough chunk falls off the island at one time. Sure, landslides above and below water cause tsunami waves, and the other bad thing would be a crack letting seawater into the magma to build up steam as in Krakatoa. I read somewhere it would take billions of tons for the hypothesized mega tsunami, which seemed like it would be most of an island. As of yesterday it wasn't too bad.