shallow low angle borehole extends through rock layers no liner is required if however the shallow low angle boreholes extend through loose soil or through wet conditions a liner may be required fig2 b shows an elevational view of creating the shallow low angle boreholes of an embodiment in which the entry and exit points connect and also shows a surface anomaly traversed in particular in fig2 b the horizontal borehole 32 or at least a pilot hole thereof has already been drilled in this case the horizontal drilling equipment 20 is shown pulling sensor cable 34 through the horizontal borehole although not specifically required given the proportions of the sensor cable 34 and the borehole 32 this pull back may include use of a reamer 36 which increases the diameter of the hole as well as a swivel couple 38 which allows the sensor cable 34 to remain untwisted in spite of the twisting of the drill string 24 as can be appreciated from the drawing of fig2 b permanently or semi permanently installing the sensor cable 34 under a surface anomaly in this case a river 40 drastically increases the repeatability and practicality of repeated seismic surveys although fig2 b shows the sensor cable entering the borehole directly in the preferred embodiments the sensor cable is within a lining for example metal or plastic tubing thus the sensor cables may eventually be removed leaving.