When every other Princeton senior sat before a typewriter ready to compose their senior thesis, Larry Cathles stood in front of a big tub and poured in five pounds of silicone bouncing putty to simulate the effect of glacial rebound. Glaciers “a few hundred kilometers or so in diameter” support themselves by sinking into the mantle until they displace their own mass — like an ice cube in a glass of water, Cathles said. When the glacier melts, the surface of the earth rebounds. It was an unconventional senior thesis, and even today the unconventional continues to intrigue Cathles.
After obtaining an undergraduate degree in physics at Princeton, Cathles entered law school but decided at the end of one year that maybe geophysics “would be interesting.” After a graduate program and another “much more involved and mathematical” thesis on glacial rebound, Cathles “wanted to find out what the non-academic side of things was like.”
He began working for the Kennecott Copper Co., researching the formation of ore deposits and industrial processes used to mine them. It was here that he began looking into unconventional forms of energy.
At a time when Kennecott was going through a lot of purchasing and sales that Cathles was afraid would lead to “too much confusion for too long”, there was an opportunity to research black smokers at Pennsylvania State University. He took it and also participated in a program studying kuroko — massive sulfide deposits in Japan — which were “being formed on the sea floor and mined in Japan.”
About five years after joining Penn State, Cathles moved on again, this time to Chevron. In those days, Cathles recalled, “the oil companies all had the idea that they should be resource companies,” so they all developed mineral exploration components. From a management standpoint, however, the reality was much more difficult because investing money and seeing profit returns in minerals both occurred at a much slower pace than in oil. For a period of time, Chevron was “a very good place to do research,” but when the support began to erode, “it was clear that that era was ending,” Cathles said.
Around that time, Cathles received a phone call from Cornell asking, “are there any circumstances under which you might [consider] a position at Cornell?” He replied, “I can’t say there are no circumstances under which I might consider a position.” Cathles has now been a researcher and professor with Cornell for about 23 years. Though he started out in mineral research, his work at Chevron piqued his interest in hydrocarbons. Among other topics, Cathles has continued his study of unconventional fossil fuels.
Conventional fossil fuels are what is now being produced from “oil accumulations that are trapped under an anticline — an inverted bowl in the subsurface” of the Earth. The bowl is a relatively impermeable barrier that must be drilled through in order to pull up the oil.
Perhaps the biggest unconventional resource, according to Cathles, is in methane hydrates on the sea floor. Here, bacteria decay organic material, producing methane. When the methane gets near the surface in cold water, it forms a hydrate with water. Methane hydrates are an efficient trap for the gas — every cubic foot of methane hydrates holds 170 cubic feet of methane gas at standard temperature and pressure.
However abundant these unconventional resources are, they are still fossil fuels. If processed for conventional use, they will still release carbon emissions. This goes against the current push for renewable forms of energy that leave a smaller ecological footprint.
When confronted with this conflict, Cathles said, “we’ve got 6.5 billion people in the world, and over half of those are malnourished, and over half spend over half their income on food.” The world currently runs on really cheap energy, but if the cost of energy were to increase, “you’re going to drive a lot of people in the world to very desperate situations.”
Cathles’ most current research is on nanoparticles, which are “intriguing tracers because they move through the rock” as fluid would. Understanding fluid flow is at the heart of resource recovery and many environmental issues. A common way of extracting oil is injecting other fluids like water to “push the oil through the recovery well.” The use of nanoparticles as tracers can determine if the water flows through oil areas or if it goes straight into a recovery well. Nanoparticles could also potentially be used to manipulate the flow pattern of the fluids.
From an environmental standpoint, nanoparticles could be used to predict the flow of materials in a dangerous spill “well ahead of when the chemistry would arrive,” Cathles said. In a sense, nanoparticles are like “eyes underground,” but Cathles’ added “that’s a vision down the line” and that there’s still work to be done.
“As a planet,” Cathles said, “we’re very well endowed, but individual countries are not well-endowed with everything.” This doesn’t mean that a standard of living on par with what the Europeans enjoy isn’t feasible for everyone in the world. The work that Cathles advocates is in education, technology and making decisions that effectively exchange the wealth of resources available on Earth.