Modified baseplate for sandy soil

A method for seismic surveying, comprising:

• connecting a coupler to a base plate associated with a seismic source, wherein the coupler has at least one downwardly projecting wall;
• positioning a seismic source over a ground surface having unconsolidated soil;
• contacting the ground with the base plate and coupler;
• preventing soil under the base plate from shift from beneath the base plate using the at least one wall;
• removing the coupler from the base plate;
• moving the seismic source to a ground that has consolidated soil;
• and
• contacting the ground with only the base plate.

An apparatus generating seismic signals in an earth formation, comprising:

• a seismic source;
• a base plate driven by the seismic source, the base plate having an upper surface engaging the seismic source, a lower surface configured to contact a soil surface, and a perimeter;
• and
• at least one contact member projecting from the lower surface, the at least one contact member having a planar bottom surface with a surface area less than a surface area of the base plate lower surface.

A method for generating seismic signal, comprising:

• positioning a seismic source over a ground surface having unconsolidated soil;
• driving a base plate using the seismic source, the base plate having an upper surface engaging the seismic source, a lower surface configured to contact a soil surface, and a perimeter;
• and
• contacting a soil surface using only at least one contact member projecting from the lower surface, the at least one contact member having a bottom surface with a surface area less than a surface of the base plate lower surface;
• removing the at least one contact member from the base plate;
• moving the seismic source to a ground that has consolidated soil;
• and
• contacting the ground with only the base plate.

An apparatus for seismic surveying, comprising:

• a hydraulically actuated seismic source that includes a reaction mass;
• a base plate acted on by the reaction mass when driven by the seismic source to generate a pulse having an amplitude sustained over a predefined time period in a downward vertical direction, the base plate having a bottom surface physically contacting a surface of the ground;
• and
• a coupler connectable to the bottom surface of the base plate, the coupler projecting downward from the base plate and configured to contain soil under the base plate, wherein the coupler includes at least one downwardly projecting wall that is formed along a perimeter of the coupler and arranged to prevent soil underneath the base plate from shifting to a location adjacent to the base plate,
• wherein a bottom surface of the base plate physically contacts and transmits force to the earth.