PubTalk 11/2005 — Shifting Shoals and Shattered Rocks

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Detailed Description

HOW MAN HAS CHANGED THE FLOOR OF SAN FRANCISCO BAY

by John Chin and Florence Wong, Geologists

 

  • San Francisco Bay is one of the world's finest natural harbors and a major center of maritime trade
  • All ships visiting bay ports are funneled through the central bay
  • Bedrock knobs that rise from the central bay floor have been repeatedly blasted to accommodate vessels of increasingly deeper draft
  • Sediment dredged from harbors and shipping channels has been disposed of on the bay floor
  • Since the early 1900s, the bay floor has been mined for sand and gravel
  • New tools are allowing scientists to create detailed views of the bay floor, revealing changes that man has made since the Gold Rush

Details

Image Dimensions: 320 x 240

Date Taken:

Length: 01:26:41

Location Taken: Menlo Park, CA, US

Transcript

Contact wmcesic@usgs.gov for transcript.