leading wave First arriving wave of a tsunami. In some cases, the leading wave produces an initial depression or drop in water level, and in some cases an elevation or rise in water level.

local tsunami or near-field  A tsunami from a nearby source, generally less than 200 km away. A local tsunami is generated by a small earthquake, a landslide or a pyroclastic flow. Numerical Modeling: snapshots of the water surfaces 10 minutes after the initiation of the submarine landslide of the pyroclastic flow (on the South-East part of Monserrat Island)

low water The lowest water level reached during a tide cycle. The accepted popular term is low tide.