Natural hazard natural hazards and anthropic processes. For example, groundwater abstraction may trigger groundwater-related subsidence. Effective hazard analysis in any given area (e.g., for the purposes of disaster risk reduction) should ideally include an examination of all relevant hazards and their interactions. To be of most use for risk reduction, hazard analysis should be extended to risk assessment wherein the vulnerability of the built environment to each of the hazards is taken into account. This step is well developed for seismic risk, where the possible effect of future earthquakes on structures and infrastructure is assessed, as well as for risk from extreme
Seismic vibrator measured in pound-force. To transmit a maximum force to the ground and prevent the shaker from bumping, part of the weight of the vibrator is applied to the shaker. Seismic vibrator A seismic vibrator is a truck-mounted or buggy-mounted device that is capable of injecting low-frequency vibrations into the earth. It is one of a number of seismic sources used in reflection seismology. The ‘Vibroseis’ exploration technique (performed with vibrators) was developed by the Continental Oil Company (Conoco) during the 1950s and was a trademark until the company's patent lapsed. Today, seismic vibrators are used to perform about half of