NEAR-BOTTOM STUDIES OF THE EAST PACIFIC RISE CREST AND TECTONICS OF THE MOUTH OF THE GULF OF CALIFORNIA,

Abstract

Bathymetric and magnetic measurements have been used to delineate the boundary between the North American and Pacific Plates in the vicinity of the mouth of the Gulf of California and indicate a spreading rate of 6 cm/yr. Magnetic anomalies, fracture zones and earthquake mechanisms indicate the validity of the rigid plate assumption for the interactions between the Pacific, American and Cocos plates. A survey with a near-bottom instrument over the East Pacific Rise crest shows lineated abyssal hills with no sediment cover at the rise crest itself. Magnetic field measurements made near the ocean floor show to a certain extent the history of the earth's magnetic field over the last 1.2 million years and show a reversal transition time of 1000 years and intensity fluctuations with periods ranging between 18000 and 50000 years. (Author)

Document Details

Document Type
Technical Report
Publication Date
Jul 01, 1970
Accession Number
AD0713165

Entities

People

  • Roger Lee Larson

Organizations

  • Scripps Institution of Oceanography

Tags

DTIC Thesaurus Topics

  • Boundaries
  • California
  • Earthquakes
  • East Pacific Rise
  • Intensity
  • Magnetic Anomalies
  • Magnetic Fields
  • Measurement
  • Seabed
  • Sediments
  • Tectonics
  • Transitions

Fields of Study

  • Geology

Readers

  • Oceanography.
  • Structural Dynamics.