PubTalk 1/2007 — The Hidden World of the Golden Gate

How tides, currents, and humans have created an array of sea-floor features

By Patrick Barnard, Marine Geologist, and Peter Dartnell, Physical Scientist

• A century of technical advances allow scientists to identify and visualize spectacular sea-bottom features
• Recent collaborative research outside the Golden Gate found that 100 million cubic yards of sediment disappeared in the past 50 years
• Swift, powerful tidal currents have scoured the Golden Gate down to bedrock and moved massive amounts of sediment
• Giant sand waves near the Golden Gate reach 30 feet in height and more than 700 feet in wavelength
• Why is the sediment in this area mostly from local sources, while farther out to sea are masses of sediment derived from erosion of the Sierra Nevada?