Natural Hazards

Hybrid seismic surveying is the appropriate surveying method to apply for information about slope instabilities, notably about the depth of the sliding surface and for mapping the internal structures in the subsurface favouring karst dissolution and sink holes.

Examples

Example 1: Determination of the cubature of a moving mass

A house on the bank of a hydroelectric dam lake had to be jacked up twice because of the creeping mass movement:
Natural Hazards Example 1 - Situation Map

Detailed mapping the nature of the bedding beneath the moving mass and its effect on the nature of the sliding surface:
Natural Hazards Example 1 - Seismic Profile

Example 2: Major sinkhole collapse with complete destruction of a 3-storey residential building

The sinkhole collapse resulted in cracks and crevices up to 15 cm wide in all rooms of a house which had then to be demolished:
Natural Hazards Example 2 - Situation Plan
Following the sink hole collapse a hybrid seismic survey was carried out with 7 lines totalling 3’100 m. The seismic line pictured below runs across the sink hole site. A well was drilled prior to the seismic survey.

Seismic mapping of the subsurface structures after filling the dolina with gravel:
Natural Hazards Example 2 - Seismic ProfileMore insights are gained by the pictorial evolution history provided by the interpretation of the results of the hybrid seismic data processing.
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Environment and natural hazards references (63)