Geophysical Service Incorporated (often abbreviated GSI) was founded by John Clarence Karcher and Eugene McDermott in 1930 for the purpose of using refraction and reflection seismology to explore for petroleum deposits. It became one of the most successful seismic exploration contractors in the industry for many years. On December 6, 1941, the company was purchased by McDermott, Cecil Howard Green, Erik Jonsson, and H.B. Peacock. During World War II, the company produced submarine detection devices. In 1951, the company was renamed Texas Instruments (TI) with GSI as a division. GSI was later sold by TI, repurchased, and finally sold again to Halliburton in 1988. Halliburton then sold its geophysical business to Western Geophysical in 1994. Western Geophysical was sold to Baker Hughes in 1998 and became part of WesternGeco in 2000. 1930 is a common year starting on Wednesday. ... Reflection seismology is a branch of seismology that uses reflected seismic waves to produce images of the Earths subsurface. ... Nodding donkey pumping an oil well near Sarnia, Ontario, 2001 Petroleum (from Latin petrus – rock and oleum – oil), mineral oil, or crude oil, sometimes colloquially called black gold, is a thick, dark brown or greenish flammable liquid, which exists in the upper strata of some areas of the Earths... December 6 is the 340th day (341st on leap years) of the year in the Gregorian calendar. ... 1941 was a common year starting on Wednesday (link will take you to calendar). ... Cecil Howard Green (August 6, 1900 – April 11, 2003) was a geophysicist who trained at the University of British Columbia and the Massachusetts Institute of Technology, and a founder of the company Texas Instruments. ... Mushroom cloud from the nuclear explosion over Nagasaki rising 18 km into the air. ... Texas Instruments (NYSE: TXN), better known in the electronics industry as TI, is a company based in Dallas, Texas, renowned for developing and commercializing semiconductor and computer technology. ... For information on the early 20th century explorer of the same name, see Richard Halliburton Halliburton Energy Services (NYSE: HAL) is a multinational corporation based in Houston, Texas, in the United States and the worlds second-largest oilfield services company behind Schlumberger Limited. ... 1988 is a leap year starting on a Friday of the Gregorian calendar. ... 1994 was a common year starting on Saturday of the Gregorian calendar, and was designated the International year of the Family. ... Baker Hughes (NYSE: BHI) is the worlds third-largest oil-services company behind Schlumberger and Halliburton . ... 1998 is a common year starting on Thursday of the Gregorian calendar, and was designated the International Year of the Ocean. ... WesternGeco, a joint venture of Schlumberger Limited and Baker Hughes, is the worlds largest seismic contracting company. ... 2000 is a leap year starting on Saturday of the Gregorian calendar. ...

See also

• List of oilfield service companies