U.S. flag An official website of the United States government.
				Here's how you know we're official. **Official websites use .gov** A **.gov** website belongs to an official government organization in the United States.
 **Secure websites use HTTPS** A small lock or **https://** means you’ve safely connected to a .gov website. Share sensitive information only on official, secure websites.


Toggle navigation Toggle search National Ocean Service National Oceanic and Atmospheric Administration
 Search
					Search National Ocean Service


Home
				Ocean Facts

				Topics
					Explore All Topics 
                        Arctic 
                        Careers 
                        Economy 
                        Ecosystems 
                        Geodesy 
                        Hazards 
                        International
                        Navigation 
                        Observations 
                        Ocean 
                        Recreation 
                         Sea Level Rise 
                        Story Maps 
                        Tools
                
                			Education

				
				News
				Podcasts
				Video
				Images
				About Us


1. Home
2. Facts
3. How does backscatter help us understand the sea floor?

**How does backscatter help us understand the sea floor?**  **Intensity of sound** reflected off the sea floor indicates the bottom type. It appears that your browser doesn't support HTML5 video.
						Here's a direct link to
							the video instead.
  VIDEO: How does backscatter help us understand the sea floor? Here's an overview in under two minutes. Transcript  Backscatter is the reflection of a signal (such as sound waves or light) back in the direction from where it originated. Backscatter is commonly used in medical ultrasounds to understand characteristics of the human body, but in the world of hydrography and marine science, backscatter from soundwaves helps us understand characteristics of the sea floor. **Blue Carbon** *A backscatter mosaic, which records the strength of the sonar return from the ocean floor, is overlaid on a nautical chart.*
 NOAA ships equipped with multibeam echo sounders use beams of sound to map the ocean floor. These sonar systems collect two types of 3D data: sea floor depth and backscatter. The sea floor depth, or bathymetry, is computed by measuring the time it takes for the sound to leave the sonar, hit the sea floor, and return to the sonar. Backscatter is computed by measuring the amount of sound that is reflected by the sea floor and received by the sonar. Different bottom types “scatter” sound energy differently, telling scientists about their relative hardness and roughness. Harder bottom types (like rock) reflect more sound than softer bottom types (like mud), and smoother bottom types (like pavement) reflect more sound than bumpier bottom types (like coral reef). Combining bathymetry and backscatter data collected by multibeam echo sounders allows scientists to create very detailed 3D maps of the sea floor and the habitats present there. The information is used for multiple purposes, including marine ecosystem protection, coastal hazard preparedness, and navigation safety.  Video Transcript Backscatter—measure of sound that is reflected by the sea floor and received by the sonar. A stronger return signal indicates a hard bottom such as coral or rocks. A weaker return signal indicates a soft bottom such as mud. Scientists use this information to create detailed 3D maps of the sea floor and the habitats present on the bottom of the ocean with the goal of improving navigation safety and marine ecosystem protection.
 **Did you know?** *A 3D map of the ocean floor can tell scientists and resource managers important details, such as the distribution and health of a coral reef ecosystem or which areas certain species of fish prefer for spawning. This helps us better conserve and protect our ocean and all the creatures that live there.*  More **Information** Office of Coast Survey   Get **Social** Social
  **Last updated:** 10/04/23 **Author:** NOAA How to cite this article Contact Us


Feedback Provide Feedback
							Contact Us
							Report an error
 Social Instagram Logo/a>


*Science. Service.Stewardship.*
 About NOS About Us
							NOS Program Offices
							Media Inquiries
							Website Acknowledgements
                            Site Index
							Disclaimer
 More Resources Freedom of Information Act
							Accessibility
							Information Quality
							Privacy Policy
							NOS For Employees
							USA.gov
 Department of Commerce
									National Oceanic and Atmospheric Administration (NOAA)
									National Ocean Service