A dual frequency ultrasonic and sonic actuator with constrained impact mass is presented. According to one aspect, displacement of the impact mass is constrained by cavity to which ultrasonic stress from the tip of a horn is applied. According to another aspect, the displacement of the impact mass is constrained by a spring attached to the tip of the horn. According to another aspect, the displacement of the impact mass is constrained by a flexure. The constrained impact mass converts the ultrasonic stress to lower frequency sonic stress that is coupled to a transmitting element for transmission through a surface. According to one aspect, the transmitting element is a longitudinal probe. According to another aspect, the transmitting element is a drill bit used to penetrate though the surface. According to another aspect, the transmitting element is a thumper used to transmit elastic waves though the surface.

The present disclosure belongs to the technical field of monitoring landslide mass geological disasters, and discloses a multi-state triggered system and method for remote automatic monitoring and early warning of a landslide mass. The multi-state triggered system for remote automatic monitoring and early warning of a landslide mass includes: a landslide mass monitoring module, a data preprocessing module, a communication module, a central control module, a displacement monitoring module, a stability evaluation module, an abnormality early warning module, a power supply module, a data storage module and a display update module. In the present disclosure, through the displacement monitoring module and the stability evaluation module, long-term automatic monitoring of the landslide mass can be realized, and the displacement change of the landslide mass can be grasped so as to evaluate the stability of the landslide mass.

The disclosure provides systems and methods to enhance pre-stack data for seismic data analysis by: sorting the reflection seismic data acquired from cross-spread gathers into sets of data sections; performing data enhancement on the sets of data sections to generate enhanced traces by: (i) applying forward normal-moveout (NMO) corrections such that arrival times of primary reflection events become more flat, (ii) estimating beamforming parameters including a nonlinear traveltime surface and a summation aperture, (iii) generating enhanced traces that combine contributions from original traces in the sets of data sections, and (iv) applying inverse NMO corrections to the enhanced traces such that temporal rearrangements due to the forward NMO corrections are undone.

An inline source can be used for a marine survey. For example, a marine survey vessel can tow source units in line. The source units can be actuated near-continuously to cause a respective signal emitted by each of the source units to be uncorrelated with signals emitted by other of the source units.

A method and apparatus for marine surveying. A system includes: a standard-volume source element; a large-volume source element comprising an airgun having a volume greater than 1200 cubic inches; and a long-offset survey streamer. A method includes: towing a standard-volume source element; and towing a large-volume source element; activating the large-volume source element at large shotpoint intervals; and activating the standard-volume source element at standard shotpoint intervals, wherein the large shotpoint intervals are at least twice as long as the standard shotpoint intervals. A method includes: obtaining geophysical data for a subterranean formation; and processing the geophysical data to produce an image of the subterranean formation. A method includes: obtaining a firing plan for a plurality of seismic sources, wherein: a first seismic source of the plurality comprises a large-volume source element, and a second seismic source of the plurality consists of standard-volume source elements.

The present disclosure discloses a seismic vibrator, a vibration device and a driving apparatus for the same. The seismic vibrator comprises: a base; a mounting plate; a first spring configured to connect the base and the mounting plate, so that the mounting plate reciprocates relative to the base; a coil fixed with the base; a magnet having one end fixed with the mounting plate, and the other end stretched into the coil; a magnetic steel fixed with the magnet, wherein a gap for accommodating the coil is provided between the magnetic steel and the magnet; and a counterweight fixed with the mounting plate. The vibration device comprises the above seismic vibrator and an adjustable base. Compared with the traditional electromagnetic controllable seismic vibrator, the structure of the seismic vibrator provided by the present disclosure is simpler.

A long offset land seismic survey spread includes a plurality of sensors within an area thereby defining a sensor receiver patch, a plurality of long offset sensor receivers outside of the receiver patch thereby surrounding the receiver patch and defining a sensor long offset area that is fee from sensor receivers that also defines a distance separating an external border of the sensor receiver patch and the long offset sensor receivers being a minimum offset distance that is a long offset distance.

A seismic data acquisition system is configured to collect seismic data. The system includes a marine source array configured to be attached to a fixed structure floating at the water surface and including vibratory source elements; and a controller configured to control the vibratory source elements so that a beam formed by the source array is steerable.

A subaqueous underground survey system using a reflection seismic survey method includes: multiple sound sources 1 for generating sound waves in the water; a controller 2 for controlling phases of the sound waves; a geophone 3 for receiving reflected waves of the sound waves; and an observation ship 4 equipped with the sound sources 1, wherein the controller 2 controls phases of the sound sources 1 so that the sound waves generated from the respective sound sources 1 have a phase difference at a water bottom surface B, thereby controlling generation of shear waves to propagate into the ground.

Systems and methods of near surface imaging and hazard detection with increased receiver spacing are provided. The system includes: a first string of one or more acoustic sources, a second string of one or more acoustic sources opposite the first string, a first one or more hydrophones mounted within a predetermined distance of the first string, and a second one or more hydrophones mounted within the predetermined distance of the second string. The first one or more hydrophones records an acoustic shot generated from the first string. The second one or more hydrophones records the acoustic shot and acoustic reflections corresponding to the acoustic shot. The system generates an image from the recorded acoustic shot and the acoustic reflections.