Where and How Blasts Are Monitored

A blasting seismograph is set up prior to a blast, usually by an employee of the company conducting blasting or by a third-party consultant. The seismograph is normally placed at the residential structure closest to a blast. Continuous monitoring stations might be used at quarries, mines and long-term projects.

Blasting seismographs begin recording at threshold levels of vibrations, which is referred to as the trigger level. This level is set low enough to detect the blast vibrations, but high enough that it will not accidentally record non-blast vibrations (such as nearby human activity). Once triggered, the data is recorded, stored in the seismograph and cannot be altered.

The International Society of Explosives Engineers (ISEE) Field Practice Guidelines for Blasting Seismographs, is the industry standard for the correct monitoring of blast vibrations.

Any recordings made by the seismograph are retrieved and evaluated to ensure that the vibrations were within appropriate limits.