Computers have had a major effect on the efficiency and effectiveness of geophysical site investigations - and as a result acceptance is increasing too.
TEN years ago a geophysical contractor would write down every number from a site survey by hand. Back in the office they would type the survey results into a primitive computer, which might undertake some simple mathematical manipulation, and perhaps produce some kind of output plot that only an expert could begin to comprehend.
By about seven years ago digital data acquisition had become usable, which meant more information could be acquired and transferred directly to PC, cutting down time. Preliminary reports could now be delivered in days rather than weeks.
But according to Angus Jack of STS a more significant change has come in the last few years as computing power has escalated while its cost has plummeted. A contractor can now easily afford to make many data manipulations. This gives the ability to consider a wider variety of possibilities in the data set and potentially increases the thoroughness of the interpretation.
The increased speed also means clients are expecting results and interpretation on site at the end of a day's survey. Contractors are beginning to be able to deliver this, which makes integrating geophysical and intrusive investigations a much more viable and realistic proposition for clients.
Working is now undoubtedly more efficient and more effective with reduced costs. Up to a point these changes have led to a increase in acceptance, although 'there is still a need to educate those who are sceptical', says Jacks. 'People still may not trust geophysics because of a bad experience where they have been let down as a contractor has failed to deliver.'
Even this area can be improved by computing power which allows forward modelling. Provided you are supplied with sensible parameters on the likely conditions beforehand, it is now possible to run a model of anticipated conditions and check that a particular technique is going to be effective, and even how to use the equipment to get the best available information from the site.
This makes engineering geophysics much less of a black art and clients with limited experience are now much less at the mercy of the contractor. As forward modelling becomes the industry practice, so the situations where unscrupulous or simply inexperienced contractors oversell the capabilities of a geophysical technique should be cut down further.