Historically, sea floor mapping occurred with a more simple data collection method: soundings. Soundings are taken by dropping a weight with a pre-measured rope off the side of the boat and noting the measurement on the rope when the...

This map details the area around the Marshall Island seamounts. Seamounts are one of many features that are found in conjunction with abyssal plains.

Detailed website that was a companion to a 1995 traveling exhibit of the Smithsonian. Links to lesson plans and other educational materials are at the bottom of the page. Enter the exhibition to explore the world of the ocean.