Abstract: A method for deriving seismic information from over a relatively large expanse of land to determine relevant strike, dip, velocity and related information. The method consists of the utilization of a plurality of strike, dip, velocity (SDV) cross patterned source-receiver arrays disposed at spaced known locations over a selected terrain, thereafter to derive localized and offset seismic data relative to selected pairs or groups of the SDV cross patterns with further signal processing to smooth and integrate strike, dip and velocity information over a specific substratum. The method utilizes information as derived from each SDV cross pattern, as well as offset seismic signal information derived from source/receiver combinations spanning two selected SDV cross patterns.

Abstract: A borehole logging device for obtaining shear wave velocities in formations adjacent the borehole, a device which utilizes a closely controlled, relatively low frequency torsional shear wave. The system includes an elongated housing for suspension within the borehole, said housing including a shear wave source for generating shear waves directly within the borehole wall, and including two spaced, variable reluctance torsional detectors which are also placed in direct contact with the borehole wall. The torsional detectors are, of course, at known spacing from the source such that cross-correlative procsssing of the detector output signals will enable a very accurate phase difference indicative of the shear wave velocity in the formation.

Abstract: A method for boring a hole so that its axis is substantially parallel to the axis of a previously bored hole for positioning an acoustical transmitter and receiver against the hole of the hole being bored so that their position on the wall lies on a horizontal plane through the axis of the bore hole being bored. Then transmitting an acoustical frequency acoustical signal into the wall of the hole. The reflected signal is then received from the adjacent wall along with other unwanted additional reflections. The phase shift is then determined between the transmitted and received signal and the changes in the distance between the wall of the bore hole is then determined.

Abstract: A method and apparatus for shear wave logging which utilizes relatively high frequency sweep control transmission and subsequent correlation of received signals in order to define travel times of horizontally polarized shear and/or torsional wave energy. The apparatus includes specific sonde structure for effecting firm contact of transmitting and receiving elements with the borehole wall.

Abstract: A method for deriving seismic information of more generalized nature over a relatively large and previously unexplored expanse of land to determine relevant strike, dip, velocity and related information. The method consists of the placing of a plurality of seismic sources and receivers in respective lines arranged in a cross pattern, each line being generally at right angles each to the other, and thereafter exciting the sources and recording the received energy for further processing to derive the strike, dip and velocity information for selected strata by using travel times of signal return.

Abstract: A combination of fixed geometry of vibrating masses on a baseplate coupled to the ground, the masses being at a fixed angle to each other and of relatively variable phase, can be controlled to produce both compressional and shear waves simultaneously in a seismic exploration system.

Abstract: A method for deriving seismic information through the simultaneous operation of a plurality of vibrational seismic energy source systems such that the information produced by each source system may be separated from the combined recorded information.

Abstract: A method for deriving seismic information from over a relatively large expanse of land to determine relevant strike, dip, velocity and related information. The method consists of the utilization of a plurality of strike, dip, velocity (SDV) cross patterned source-receiver arrays disposed at spaced known locations over a selected terrain, thereafter to derive localized and offset seismic data relative to selected pairs of groups of the SDV cross patterns with further signal processing to smooth and integrate strike, dip and velocity information over a specific substratum. The method utilizes information as derived from each SDV cross pattern, as well as offset seismic signal information derived from source/receiver combinations spanning two selected SDV cross patterns.

Abstract: A shear wave vibrator is constructed having a frame with first and second oppositely facing plenum chambers secured to the frame and each having an outer periphery. A skirt is attached to each of the outer peripheries. A fan is attached to the frame with conduits supplying a volume of air under pressure to each of the plenum chambers. A modulation apparatus is mounted in each of the first and second plenum chambers to cause a variation in air pressure in each of the plenum chambers in accordance with a predetermined signal in a manner to cause the air pressure in one chamber to decrease at the same instant the air pressure in the oppositely facing chamber is increasing and vice versa. The entire apparatus is mounted between opposite walls of a trench.

Abstract: Apparatus for controlling the lateral position of a marine seismic cable relative to water current which is effective through utilization of one or more cable paravanes having a thrust adjustable hydrofoil and/or stabilizer elements. The hydrofoil is constructed as a pivotally supportable frame having an elastomeric skin which is supported on the sides of the hydrofoil by movable support members, and a servo-controlled reversible motor is controlled to reciprocate the opposite side support members relative to the hydrofoil longitudinal center line. One or more hydrofoils may then be controlled as to angle of attack and camber from the towing ship by means of acoustic energy transmission and reception at the paravane.

Abstract: A system for maintaining a continuous log of activity in and around an underground mine wherein seismic energy in the area is continually monitored, processed and classified into meaningful relative data indications; and which system further includes selectively deployable seismic energy monitoring equipment providing more specific data in the event of mine catastrophy. This system utilizes permanently disposed seismic energy detectors and/or emergency detectors placed in accordance with the particular exigency, and detected seismic energy return is continually processed to maintain a data log indicative of general type and location of mine activity, with particular capability for isolation of unusual seismic events by comparison with statistical data constraints of predetermined character.