Coastal & Marine Geology InfoBank

Home FACS Activities Atlas Geology School Related Sites More

USGS CMG InfoBank: Seawalls

Skip navigational links
Loading
Dictionaries: Our Mapping Systems   The USGS and Science Education   USGS Fact Sheets   Topics   Keywords   Data Dictionary   Metadata Dictionary   Computer Terminology   Digital Formats  
InfoBank Terms: Activity ID   activity overview   crew   digital data   formal metadata   lines   metadata   NGDC   port stops   project/theme   region   ship   stations   time   virtual globe   year  
Data Types: bathymetry   biological   geochemical   gravity   ground penetrating radar   imaging   LIDAR   logs   magnetics   metering equipment   navigation   samples   seismic   total station   definitions disclaimer  
Data Formats: ARC coverage   E00   FGDC metadata   gridded/image   imaging   material   scattered/swath   Shapefile   vector/polygon  
Comment: 15:30 - 16:26 (00:56)
Source: Annenberg/CPB Resources - Earth Revealed 24, Waves, Beaches and Coasts
Keywords: "J. Lawford Anderson", seawall, beach, erosion, coastline, "geologic hazard", sand, sediment, cliff

Our transcription: Those who are opposed, maintain that in the long run seawalls do more harm than good because they represent a threat to the beach itself.
Coastal erosion is a natural process, and as we begin to put houses on the edges of coastlines, I mean, we're concerned about losing some of those homes, and so you want to slow the erosion.
Well, you're trying to slow something that's quite natural.
When you do that, you upset the balance of things.
Seawalls to limit erosion are also cutting sand supply.
So putting in a seawall will, for a short period of time, lessen the amount of erosion, but what the result is that sediment is no longer there to be taken to the beaches.
The beaches receive part of their sand supply from cliff sides.
And as you slow down the erosion of cliff sides, then the beaches are losing a source, an important source of their sediments.

Geology School Keywords
Skip footer navigational links

Coastal and Marine Science Centers:  Pacific   St. Petersburg   Woods Hole  
InfoBank   Coastal and Marine Geology Program   Geologic Information   Ask-A-Geologist   USGS Disclaimer  


Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo USA.gov logo U.S. Department of the Interior | U.S. Geological Survey
URL: http://walrus.wr.usgs.gov/infobank/programs/html/school/moviepage/22.01.16.html
Page Contact Information: InfoBank staff
Page Last Modified: Thu Oct 31 04:27:55 PDT 2013  (chd)