Announcements
NORCAL celebrates 25th Anniversary in 2008
The year 2008 marks our 25th year of providing geophysical services. We are very proud of this milestone and we are even more eager for the next 25 years. During this time there have been monumental changes in the geophysical industry. These changes included the introduction of personal computers for data processing, instrumentation moving from analog to the digital age, significant improvement in computer software for both modeling and data presentation, and new methodologies that provide increased subsurface resolution. Consequently, geophysics is more routinely used with a higher level of confidence to stand alone or supplement other phases of an investigation. During the past 25 years we have seen the introduction of borehole televiewers for oriented 3D imaging of borehole walls, computer controlled switching for multi-electrode electrical resistivity profiling systems, analysis of seismic surface waves for the determination of shear wave velocities, 3D methods for seismic, electrical and ground penetrating radar, and increased accuracy of global positioning systems to name a few. Presently we are on the verge of wireless transmission of geophysical data. In the midst of all these technological advances, NORCAL has managed to stay at the fore front of new technology while at the same time providing “down to earth” answers and solutions for our clients.
NORCAL started in 1983 as a one office facility complete with an Apple IIe computer, an electronic typewriter, and a small storage space for equipment. In that office Ken Blom and Bill Black wore several hats while performing all of the duties required to run a business including data processing, report writing, graphics, accounting and clerical tasks. In 1984 we purchased our first seismograph and electrical resistivity system. By this time we had expanded to two separate offices and purchased our second computer complete with a dot-matix printer. By 1985 we were the proud owners of a new ground penetrating radar system and had hired our first employee. During 1985 to 1988 we further enhanced our geophysical equipment suite with a magnetometer, an electromagnetic conductivity EM-31 system and two more employees. In 1988 we moved to bigger and better office spaces with significantly larger warehouse space and added an office manager to our staff. For the next few years our work load increased significantly requiring the hiring of two additional geophysicists as well as the acquisition of more seismic and ground penetrating radar equipment. This was accompanied by constant upgrades in computer hardware and software. In 1994 NORCAL expanded its capabilities to include borehole logging and imaging instrumentation and by the hiring of Bill Henrich to manage this new department. Over the next few years our ever challenging projects required an increased usage of all terrain vehicles, electrical resistivity profiling, specialized seismic sources, and more sophisticated borehole logging equipment. Consequently our suite of field equipment increased even more. A noteable milestone occurred in 2004 when we designed and built a 6500 square foot building tailored to our office and warehouse needs. Presently we can offer a lengthy resume of experience, the best geophysical crew in the business, a full suite of field equipment, the latest in computer processing software, and the desire to get even better. Our sincere thanks to all of our clients that have put trust in our services. The next 25 years will be a great journey!
Recent Notable Projects
During the past year we have performed a variety of investigations that had unique objectives, were conducted in unusual conditions, or required demanding logistics to accomplish our goals. A few of these notable projects are as follows:
Borehole televiewer 3D imaging for a proposed southern California water tunnel in a hole 2500 feet deep. This project required the transporting of equipment and personnel by helicopter to the logging site. The logging took over 12 continuous hours.
Ground penetrating radar survey on the Northslope of Alaska to determine gravel thickness along 30 miles of road and along a airport runway. The temperatures at the time of the field survey with a wind chill factor was minus 55 degrees F.
Seismic refraction survey was performed at a proposed pump storage facility. This facility is located in a very remote area that required the backpacking of the seismic equipment to the job site. Typically 1 to 3 hours of hiking was required each day in addition to the data acquisition activities.
Vibration monitoring at a construction site in Sacramento, CA to monitor and archive ground vibration levels for future reference.. The survey requires 6 instruments operating 24 hours per day, 7 days per week for 20 months to date. The data are automatically telemetered to our office and the structural engineer office at predetermined times each day to monitor and archive ground vibration levels for future reference.
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Very high resolution electrical resistivity and seismic refraction profiling to determine the thickness of engineered cap that covers radio-active waste and the depth to the underlying bedrock at the Idaho National Laboratory. This required the use of non-invasive method to characterize the subsurface conditions so that the hazardous waste was not encountered during excavation activities.
Magnetometer survey to search for a murder weapon that was reportedly discarded 20-years earlier by a death-row inmate. We determined the search area based on hand-drawn maps by the inmate. Based on our findings and activities by the defense attorney the gun was found and turned over to the Court. This was recently reported in the LA Times.