Surtseyan eruptions are the "wet" equivalent of ground-based Strombolian eruptions, but because they take place in water they are much more explosive. As water is heated by lava, it flashes into steam and expands violently, fragmenting the magma it contacts into fine-grained ash.
Surtseyan eruptions share similarities with ground-based Strombolian eruptions but are distinguished by their aquatic environment, leading to increased explosiveness. As water is heated by lava, it swiftly converts into steam and expands violently, shattering the magma it interacts with into fine-grained ash.