Bathymetry is the study and mapping of the depth and floors of oceans, rivers or lakes. Much like a topographical map, which shows the depths and heights of land, bathymetrical maps show the shape and elevations of the water floors. The process for measuring the depths uses a multibeam echo sounder that sends out an array of sonar pulses and has the ability to measure a variety of angles as well as determine if the seafloor is made of hard or soft material. The sound pulses are sent from the bottom of a ship to the sea floor. The longer the time it takes to return to the ship, the deeper the water.
Bathymetry is a crucial element to understanding the workings of the marine environment. It is important in the nautical world, as the charts are used to effectively navigate waters. Without bathymetry, mariners wouldn’t know which waterways were impassible or dangerously shallow. Bathymetric maps also assist scientists in evaluating the effects of climate change on the environment, by alerting them to sea-level rise or impending beach erosion. Marine ecosystems are also monitored with the help of bathymetry, as scientists are able to assess the habitats for organisms.
Bathymetric data is also used by NOAA’s National Geophysical Data Center (NGDC) to create models of some United States coastal areas, so that they are able to better forecast tsunamis. Using bathymetry for these important models, the citizens of these coastal areas can be better informed and receive tsunami alerts in a timely manner for evacuation, making everyone safer.