## Current Flow From Two Closely Spaced Electrodes

In practice, we will need to place the two current electrodes close to each other.
In doing so, however, the current distribution and equipotentials produced within a homogeneous
earth become more complicated than those shown previously.

Instead of the current flowing radially out from the current electrodes, it now flows along
curved paths connecting the two current electrodes.
Six current paths are shown (red lines). Between the surface of the earth and any current path we can compute
the total proportion of current encompassed.
The table below shows this proportion for the six paths shown above.
Current paths are labeled 1 through 6 starting with the top-most path and proceeding to the bottom-most
path.

Current Path | % of Total Current |

1 | 17 |

2 | 32 |

3 | 43 |

4 | 49 |

5 | 51 |

6 | 57 |

From these calculations and the graph of the current flow shown above, notice that almost 50% of the current
placed into the ground flows through rock
at depths shallower or equal to the current electrode spacing.