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Schlumberger Soundings in the Long Beach-Wilmington Area, County of Los Angeles, California

By Robert J. Bisdorf and David V. Fitterman

Open-File Report 2004-1053
thumbnail image of study area in LA
Version 1.0
Published 2004
Schlumberger DC resistivity soundings were made in the Long Beach-Wilmington area of Los Angeles County, California to map subsurface resistivity structure and to correlate areas of low resistivity with saltwater intrusion. A total of 78 soundings were made in a highly developed, urban area, making the selection of measurement sites challenging. Soundings were interpreted using automatic interpretation procedures to produce resistivity-depth functions. Cross sections were constructed from the layered-earth interpretations. The results are also displayed as resistivity depth slices. Resistivities of less than 4.5 ohm-m are interpreted as being caused by intrusion of seawater into pore spaces. The extent of this zone roughly parallels the coast. However, the tidal flow in the Dominguez Channel has a low resistivity zone associated with it that extends at least 3 kilometers further inland than in surrounding areas.

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OF 2004-1053 PDF file (3.5 MB) (This version of the report is accessible as defined in Section 508.)

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