Field Techniques

In these reminiscences from the Oral History project, eminent geophysicists remember what it was like to work in the field in the days before the technological revolution.
– Helen Isaac

Craig Ferris: In 1936 I had been at the University of Oklahoma for about three years and I was offered a job on a seismograph crew at 50 cents an hour. That doubled my salary. Back in those days, they called us placement engineers or jug hustlers. We had geophones that were maybe 4” in diameter and 10 or 12” in height. My job was to take a hand auger and bury those geophones. It was a very rewarding experience, $4 a day, no expenses, living in a boarding house.

In 1938 I was hired by the Mott-Smith Corporation to go to work on a gravity crew. At that time, Dr. Mott-Smith was assembling his gravity meters out at Rice University. They sent me out to the field to learn how to operate a gravity meter and they sent one of Dr. Mott-Smith’s students by the name of Sam Worden. Sam taught me all the finer points of reading the gravity meter. It turned out that Mr. Worden later developed his own gravity meter and became world famous. Sam Worden was able to take a fused quartz fibre and make a zero length spring out of it and whereas the Mott-Smith gravity meter that I first used weighed about 150 pounds, Sam Worden was able to reduce the size and weight and make a little portable meter that weighed just 5 or 6 pounds. The working gravity meter is temperature compensated and Sam Worden made that meter small enough to fit in a thermos bottle. The Lacoste-Romberg gravity meter would be connected up to the car battery and had a heating system that kept it at a constant temperature.

Norman Jones: I started in 1946 and compared to today’s seismic it was very primitive. We operated a 24 trace recording system, which was, I guess, at that time advanced because most of the other systems in use at that time were only 12 trace. We hand laid our own cables in those days. They were made out of simplex wire and they were hand taped with just ordinary electrical tape every 2 or 3 feet, just to keep them together. Our geophones were about the size of a quart oil tin. They were what we call oil damp and we had to change the oil in the winter and summer. When the weather cooled off we had to dilute the oil to about 50% kerosene 50% oil while in the summertime we just used straight oil. That was the damping mechanism - it was just the viscosity of the oil that stopped the geophone from resonating all the time. In those days we dug the geophones in, as they said. We used what they called a sharp shooter shovel, which is a very narrow, short handled narrow spade, sharply pointed. We dug the geophones in to stop the wind noise and so forth, and those phones were heavier than a quart oil can so you probably carried only three in each hand. Most of the time we were shooting what they called one mile correlation. In other words, you’d lay out your spread 12 traces either side of the shotpoint and shoot every mile.

Don Crane: Socony hired me as a geologist at $325 a month but wanted me to take some training as a geophysicist so they sent me off to a seismic field crew in Crossfield and I didn’t know one end of a seismic from another. So I went on the jug line as a helper and I learned how to lay geophones on the ground. There were two big geophones, weighing about 5 or 6 lb each and a big rope handle and you carried them around and put them down wherever the flags were and set them in properly. There were just two geophones per trace. Then after 2 or 3 months of that I became a shooter’s helper and learned how to stick caps into dynamite and put the dynamite in the ground. The holes were about 200 ft deep and we had 10 ft loading poles, so you’d link 20 of these loading poles together, one after another as the dynamite went down the holes. The cap fire was kept in one hand and you tried to keep it all from falling down the hole and sometimes you had to push very hard. So, anyway, you got the dynamite down there and we could get one shot.

We did have two young helpers who were blown up with improper linkage of the dynamite. It was a great lesson to everybody; the dynamite blew up right beside them and they were gone. We did not have any safety meetings in those days. People just said be careful and the shooter would say this is how you open the wooden box of dynamite, get up on a truck and throw it down on the ground as hard as you can and the box breaks and out comes the dynamite. He said it’s perfectly safe until you put a cap on. So that was a safety rule: don’t put the cap in.

We just wore runners and a cap, no hard hats. We wore mitts and needed special gloves to roll the cable up. There was a big power roller on the back of the truck and this long cable, a quarter mile, would be hooked on there and then you’d push a little button and this thing would roll up the cable and you had to guide it with your hand. You’d let it slide over your glove which had a steel face on it so you wouldn’t burn your hand. And often an arm would get caught in there if you weren’t careful so that was another safety lesson, don’t get your arm in there.

Later I became a Junior Observer and learned how to operate the truck inside. All the amplifiers and so on had tubes; we had to change now and then. We had a 24 trace capacity and the galvanometers were always going screwy and we had to get a little wrench out and get these galvos so that they would reflect the light on to the paper at the right spacing. We learned all these little tricks and how to plug in and how to fix a cable when somebody ran over it and broke it. There were a lot of wires in there and we had to take it apart and solder it and so on. Nowadays of course, they lay hundreds and hundreds, thousands sometimes, of geophones. We only had 2 per trace and 24 traces. Of course, the production was extremely slow in those days. You’d drill a hole in the ground, set the dynamite off, record it and it would come out on paper and the observer or the JO would look at this and say oh, there’s too much noise on one of the stations, replant the jug. So out come the shooters with their poles and they would have to put another load down the hole and that took a long time. Besides if we hit gravel or something the drills were very slow. They would shoot one hole maybe 3 times and the next hole twice. Our production was extremely low, 1 or 2 holes per day. Some days if the holes were good we’d get 5. And there was an awful lot of experimentation too on the records themselves. We had to shoot at different levels and use different augered powder sizes and so on.

Gerry Sykes: I went to work for Frontier Geophysical in May of 1951. I was out on a horseback crew and spent the summer up in the Burnt Timber area. It was very interesting since we soon learned that we should carry the instruments and the only thing we let the horses pack was the dynamite. We hand augered some of the holes. The horses weren’t really that good - some of them were kind of raunchy. I had friends in Keremeos who had horses they used for hunting, so I was well aware what a good horse was. Keremeos was kind of an interesting place. In those days they had a rodeo every Sunday on the Indian Reserve south of town. My friend Wendell Clifton and I used to come into town and try and lasso the girls on the main street.

The instruments were in wooden cases surrounded by foam but we were nervous about the horses so we carried the instruments by hand in aluminum cases with waterproof covers. The dynamite was too heavy to carry any other way than on the horses. Later in that crew we had a little tractor pulling a doghouse.

The instrument truck was a wheeled truck with a cab and was set up as a typical seismic truck of the era. We did the mile correlation - we drilled a hole on the corner of every section and shot it and we used short cables that were hand reeled out.

Andy Kennedy: The recorder would always give a blast on the horn before he was ready to shoot and that meant that wherever you were out there, you just stood still and didn’t move a muscle.

Occasionally, on a road that had a lot of traffic you would have to wait until all the traffic had cleared before you would shoot. So, many people have said, this is Joe Q Public now, I went by a seismic crew that was working today and I don’t know, you guys never work at all, every time I go by one there’s just guys standing around doing nothing. And I would answer and say, yes, they’re waiting for you to get the heck out of the way.

Bud St. Clair: Geotech designed and made their own instruments. They were the supplier to the U.S. government for all the instrumentation at the Bikini Atoll atom tests. They had a big lab in Virginia that did nothing but government research work and they did a lot of work for the government through the atom bomb testing and security work around bases. They used geophysics for security on bases and subsequently Teledyne had a lot of work with the U.S. Navy for the sensor rays that were laid in the Arctic by atomic submarines for the early warning. In one sense, it’s almost the way geophysics started. The army had a sort of a geophone that they used and they would time their artillery blasts and try through refraction and reflection to figure out how far their targets were away and whether they were coming close to their targets with artillery. So one of the early things in geophysics was really in the First World War.

Warner Loven: We just lived in tents and we had to dig the shotholes with a post hole auger and to lay the cables and geophones. It was all by hand and we hand moved the equipment, the instruments and batteries and stuff with a pack horse. We were probably lucky to get a hole a day and now they shoot three or four hundred. But this was all pretty intense labour and the bugs were fierce. The bugs, mosquitos, black flies, no-see-ums, deer flies, horse flies, everything that flew bit you.